[PATCH 00/20] drm: Add Support for Passive RGB to VGA bridges

[PATCH 00/20] drm: Add Support for Passive RGB to VGA bridges

[Maxime Ripard]

Hi,

This serie is about adding support for the RGB to VGA bridge found in
the A13-Olinuxino and the CHIP VGA adapter.

Both these boards rely on an entirely passive bridge made out of
resitor ladders that do not require any initialisation. The only thing
needed is to get the timings from the screen if available (and if not,
fall back on XGA standards), set up the display pipeline to output on
the RGB bus with the proper timings, and you're done.

This serie also fixes a bunch of bugs uncovered when trying to
increase the resolution, and hence the pixel clock, of our
pipeline. It also fixes a few bugs in the DRM driver itself that went
unnoticed before.

Let me know what you think,
Maxime

Maxime Ripard (20):
  clk: fixed-factor: Pass clk rates change to the parent
  clk: multiplier: Prevent the multiplier from under / over flowing
  clk: sunxi: tcon-ch1: Do not return a negative error in get_parent
  clk: sunxi: display: Add per-clock flags
  drm/sun4i: request exact rates to our parents
  drm/sun4i: allow dclk to modify its parent rate
  drm/sun4i: rgb: Validate the clock rate
  drm/sun4i: rgb: panel is an error pointer
  drm/sun4i: defer only if we didn't find our panel
  drm/sun4i: remove simplefb at probe
  drm/sun4i: Convert to connector register helpers
  drm/sun4i: Add bridge support
  drm/bridge: Add RGB to VGA bridge support
  ARM: sun5i: a13: Add LCD pins
  ARM: sun5i: Move display blocks to A13
  ARM: sun5i: a13-olinuxino: Enable VGA bridge
  ARM: multi_v7: Enable sun4i DRM driver
  ARM: multi_v7: enable VGA bridge
  ARM: sunxi: Enable sun4i DRM driver
  ARM: sunxi: Enable VGA bridge

 .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
 arch/arm/boot/dts/sun5i-a13-olinuxino.dts          |  34 ++++
 arch/arm/boot/dts/sun5i-a13.dtsi                   | 122 ++++++++++++++
 arch/arm/boot/dts/sun5i-r8.dtsi                    | 120 +------------
 arch/arm/configs/multi_v7_defconfig                |   2 +
 arch/arm/configs/sunxi_defconfig                   |   3 +
 drivers/clk/clk-fixed-factor.c                     |   3 +-
 drivers/clk/clk-multiplier.c                       |  20 ++-
 drivers/clk/sunxi/clk-sun4i-display.c              |   5 +-
 drivers/clk/sunxi/clk-sun4i-tcon-ch1.c             |   3 -
 drivers/gpu/drm/bridge/Kconfig                     |   6 +
 drivers/gpu/drm/bridge/Makefile                    |   1 +
 drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
 drivers/gpu/drm/sun4i/sun4i_dotclock.c             |  31 +++-
 drivers/gpu/drm/sun4i/sun4i_drv.c                  |  54 +++---
 drivers/gpu/drm/sun4i/sun4i_rgb.c                  |  70 ++++++--
 drivers/gpu/drm/sun4i/sun4i_tcon.c                 |  59 +++++--
 drivers/gpu/drm/sun4i/sun4i_tcon.h                 |   1 +
 18 files changed, 578 insertions(+), 182 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
 create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c

-- 
2.8.2

[PATCH 00/20] drm: Add Support for Passive RGB to VGA bridges

[Maxime Ripard]

Hi,

This serie is about adding support for the RGB to VGA bridge found in
the A13-Olinuxino and the CHIP VGA adapter.

Both these boards rely on an entirely passive bridge made out of
resitor ladders that do not require any initialisation. The only thing
needed is to get the timings from the screen if available (and if not,
fall back on XGA standards), set up the display pipeline to output on
the RGB bus with the proper timings, and you're done.

This serie also fixes a bunch of bugs uncovered when trying to
increase the resolution, and hence the pixel clock, of our
pipeline. It also fixes a few bugs in the DRM driver itself that went
unnoticed before.

Let me know what you think,
Maxime

Maxime Ripard (20):
  clk: fixed-factor: Pass clk rates change to the parent
  clk: multiplier: Prevent the multiplier from under / over flowing
  clk: sunxi: tcon-ch1: Do not return a negative error in get_parent
  clk: sunxi: display: Add per-clock flags
  drm/sun4i: request exact rates to our parents
  drm/sun4i: allow dclk to modify its parent rate
  drm/sun4i: rgb: Validate the clock rate
  drm/sun4i: rgb: panel is an error pointer
  drm/sun4i: defer only if we didn't find our panel
  drm/sun4i: remove simplefb at probe
  drm/sun4i: Convert to connector register helpers
  drm/sun4i: Add bridge support
  drm/bridge: Add RGB to VGA bridge support
  ARM: sun5i: a13: Add LCD pins
  ARM: sun5i: Move display blocks to A13
  ARM: sun5i: a13-olinuxino: Enable VGA bridge
  ARM: multi_v7: Enable sun4i DRM driver
  ARM: multi_v7: enable VGA bridge
  ARM: sunxi: Enable sun4i DRM driver
  ARM: sunxi: Enable VGA bridge

 .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
 arch/arm/boot/dts/sun5i-a13-olinuxino.dts          |  34 ++++
 arch/arm/boot/dts/sun5i-a13.dtsi                   | 122 ++++++++++++++
 arch/arm/boot/dts/sun5i-r8.dtsi                    | 120 +------------
 arch/arm/configs/multi_v7_defconfig                |   2 +
 arch/arm/configs/sunxi_defconfig                   |   3 +
 drivers/clk/clk-fixed-factor.c                     |   3 +-
 drivers/clk/clk-multiplier.c                       |  20 ++-
 drivers/clk/sunxi/clk-sun4i-display.c              |   5 +-
 drivers/clk/sunxi/clk-sun4i-tcon-ch1.c             |   3 -
 drivers/gpu/drm/bridge/Kconfig                     |   6 +
 drivers/gpu/drm/bridge/Makefile                    |   1 +
 drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
 drivers/gpu/drm/sun4i/sun4i_dotclock.c             |  31 +++-
 drivers/gpu/drm/sun4i/sun4i_drv.c                  |  54 +++---
 drivers/gpu/drm/sun4i/sun4i_rgb.c                  |  70 ++++++--
 drivers/gpu/drm/sun4i/sun4i_tcon.c                 |  59 +++++--
 drivers/gpu/drm/sun4i/sun4i_tcon.h                 |   1 +
 18 files changed, 578 insertions(+), 182 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
 create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c

-- 
2.8.2

[PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Maxime Ripard]

A fixed factor clock, if it needs to change its rate, by definition do not
have any choice but to modify its parent rate.

Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/clk-fixed-factor.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index 75cd6c792cb8..3363abd9b4ae 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
 	of_property_read_string(node, "clock-output-names", &clk_name);
 	parent_name = of_clk_get_parent_name(node, 0);
 
-	clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
+	clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
+					CLK_SET_RATE_PARENT,
 					mult, div);
 	if (!IS_ERR(clk))
 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
-- 
2.8.2

[PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Maxime Ripard]

A fixed factor clock, if it needs to change its rate, by definition do not
have any choice but to modify its parent rate.

Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/clk-fixed-factor.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index 75cd6c792cb8..3363abd9b4ae 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
 	of_property_read_string(node, "clock-output-names", &clk_name);
 	parent_name = of_clk_get_parent_name(node, 0);
 
-	clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
+	clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
+					CLK_SET_RATE_PARENT,
 					mult, div);
 	if (!IS_ERR(clk))
 		of_clk_add_provider(node, of_clk_src_simple_get, clk);
-- 
2.8.2

[PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Maxime Ripard]

In the current multiplier base clock implementation, if the
CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
multiplier computed remains within the boundaries of our clock.

This means that if the clock we want to reach is below the parent rate,
or if the multiplier is above the maximum that we can reach, we will end up
with a completely bogus one that the clock cannot achieve.

Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 drivers/clk/clk-multiplier.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-multiplier.c b/drivers/clk/clk-multiplier.c
index 9e449c7b751c..dc037c957acd 100644
--- a/drivers/clk/clk-multiplier.c
+++ b/drivers/clk/clk-multiplier.c
@@ -52,14 +52,28 @@ static unsigned long __bestmult(struct clk_hw *hw, unsigned long rate,
 				unsigned long *best_parent_rate,
 				u8 width, unsigned long flags)
 {
+	struct clk_multiplier *mult = to_clk_multiplier(hw);
 	unsigned long orig_parent_rate = *best_parent_rate;
 	unsigned long parent_rate, current_rate, best_rate = ~0;
 	unsigned int i, bestmult = 0;
+	unsigned int maxmult = (1 << width) - 1;
+
+	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
+		bestmult = rate / orig_parent_rate;
+
+		/* Make sure we don't end up with a 0 multiplier */
+		if ((bestmult == 0) &&
+		    !(mult->flags & CLK_MULTIPLIER_ZERO_BYPASS))
+			bestmult = 1;
 
-	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT))
-		return rate / *best_parent_rate;
+		/* Make sure we don't overflow the multiplier */
+		if (bestmult > maxmult)
+			bestmult = maxmult;
+
+		return bestmult;
+	}
 
-	for (i = 1; i < ((1 << width) - 1); i++) {
+	for (i = 1; i < maxmult; i++) {
 		if (rate == orig_parent_rate * i) {
 			/*
 			 * This is the best case for us if we have a
-- 
2.8.2

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[PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Maxime Ripard]

In the current multiplier base clock implementation, if the
CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
multiplier computed remains within the boundaries of our clock.

This means that if the clock we want to reach is below the parent rate,
or if the multiplier is above the maximum that we can reach, we will end up
with a completely bogus one that the clock cannot achieve.

Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/clk-multiplier.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-multiplier.c b/drivers/clk/clk-multiplier.c
index 9e449c7b751c..dc037c957acd 100644
--- a/drivers/clk/clk-multiplier.c
+++ b/drivers/clk/clk-multiplier.c
@@ -52,14 +52,28 @@ static unsigned long __bestmult(struct clk_hw *hw, unsigned long rate,
 				unsigned long *best_parent_rate,
 				u8 width, unsigned long flags)
 {
+	struct clk_multiplier *mult = to_clk_multiplier(hw);
 	unsigned long orig_parent_rate = *best_parent_rate;
 	unsigned long parent_rate, current_rate, best_rate = ~0;
 	unsigned int i, bestmult = 0;
+	unsigned int maxmult = (1 << width) - 1;
+
+	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
+		bestmult = rate / orig_parent_rate;
+
+		/* Make sure we don't end up with a 0 multiplier */
+		if ((bestmult == 0) &&
+		    !(mult->flags & CLK_MULTIPLIER_ZERO_BYPASS))
+			bestmult = 1;
 
-	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT))
-		return rate / *best_parent_rate;
+		/* Make sure we don't overflow the multiplier */
+		if (bestmult > maxmult)
+			bestmult = maxmult;
+
+		return bestmult;
+	}
 
-	for (i = 1; i < ((1 << width) - 1); i++) {
+	for (i = 1; i < maxmult; i++) {
 		if (rate == orig_parent_rate * i) {
 			/*
 			 * This is the best case for us if we have a
-- 
2.8.2

[PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Maxime Ripard]

In the current multiplier base clock implementation, if the
CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
multiplier computed remains within the boundaries of our clock.

This means that if the clock we want to reach is below the parent rate,
or if the multiplier is above the maximum that we can reach, we will end up
with a completely bogus one that the clock cannot achieve.

Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/clk-multiplier.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-multiplier.c b/drivers/clk/clk-multiplier.c
index 9e449c7b751c..dc037c957acd 100644
--- a/drivers/clk/clk-multiplier.c
+++ b/drivers/clk/clk-multiplier.c
@@ -52,14 +52,28 @@ static unsigned long __bestmult(struct clk_hw *hw, unsigned long rate,
 				unsigned long *best_parent_rate,
 				u8 width, unsigned long flags)
 {
+	struct clk_multiplier *mult = to_clk_multiplier(hw);
 	unsigned long orig_parent_rate = *best_parent_rate;
 	unsigned long parent_rate, current_rate, best_rate = ~0;
 	unsigned int i, bestmult = 0;
+	unsigned int maxmult = (1 << width) - 1;
+
+	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
+		bestmult = rate / orig_parent_rate;
+
+		/* Make sure we don't end up with a 0 multiplier */
+		if ((bestmult == 0) &&
+		    !(mult->flags & CLK_MULTIPLIER_ZERO_BYPASS))
+			bestmult = 1;
 
-	if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT))
-		return rate / *best_parent_rate;
+		/* Make sure we don't overflow the multiplier */
+		if (bestmult > maxmult)
+			bestmult = maxmult;
+
+		return bestmult;
+	}
 
-	for (i = 1; i < ((1 << width) - 1); i++) {
+	for (i = 1; i < maxmult; i++) {
 		if (rate == orig_parent_rate * i) {
 			/*
 			 * This is the best case for us if we have a
-- 
2.8.2

[PATCH 03/20] clk: sunxi: tcon-ch1: Do not return a negative error in get_parent

[Maxime Ripard]

get_parent is supposed to return an unsigned 8 bit integer, so returning
-EINVAL is a bad idea.

Remove it.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/sunxi/clk-sun4i-tcon-ch1.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
index 98a4582de56a..248585238b1c 100644
--- a/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
+++ b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
@@ -85,9 +85,6 @@ static u8 tcon_ch1_get_parent(struct clk_hw *hw)
 	reg = readl(tclk->reg) >> TCON_CH1_SCLK2_MUX_SHIFT;
 	reg &= reg >> TCON_CH1_SCLK2_MUX_MASK;
 
-	if (reg >= num_parents)
-		return -EINVAL;
-
 	return reg;
 }
 
-- 
2.8.2

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[PATCH 03/20] clk: sunxi: tcon-ch1: Do not return a negative error in get_parent

[Maxime Ripard]

get_parent is supposed to return an unsigned 8 bit integer, so returning
-EINVAL is a bad idea.

Remove it.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/sunxi/clk-sun4i-tcon-ch1.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
index 98a4582de56a..248585238b1c 100644
--- a/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
+++ b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
@@ -85,9 +85,6 @@ static u8 tcon_ch1_get_parent(struct clk_hw *hw)
 	reg = readl(tclk->reg) >> TCON_CH1_SCLK2_MUX_SHIFT;
 	reg &= reg >> TCON_CH1_SCLK2_MUX_MASK;
 
-	if (reg >= num_parents)
-		return -EINVAL;
-
 	return reg;
 }
 
-- 
2.8.2

[PATCH 03/20] clk: sunxi: tcon-ch1: Do not return a negative error in get_parent

[Maxime Ripard]

get_parent is supposed to return an unsigned 8 bit integer, so returning
-EINVAL is a bad idea.

Remove it.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/sunxi/clk-sun4i-tcon-ch1.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
index 98a4582de56a..248585238b1c 100644
--- a/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
+++ b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
@@ -85,9 +85,6 @@ static u8 tcon_ch1_get_parent(struct clk_hw *hw)
 	reg = readl(tclk->reg) >> TCON_CH1_SCLK2_MUX_SHIFT;
 	reg &= reg >> TCON_CH1_SCLK2_MUX_MASK;
 
-	if (reg >= num_parents)
-		return -EINVAL;
-
 	return reg;
 }
 
-- 
2.8.2

[PATCH 04/20] clk: sunxi: display: Add per-clock flags

[Maxime Ripard]

The TCON channel 0 clock that is the parent clock of our pixel clock is
expected to change its rate depending on the resolution we want to output
in our display engine.

However, since it's only a mux, the only way it can do that is by changing
its parents rate.

Allow to give flags in our display clocks description, and add the
CLK_SET_RATE_PARENT flag for the TCON channel 0 flag.

Fixes: a3b4956ee6d9 ("clk: sunxi: display: Add per-clock flags")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/sunxi/clk-sun4i-display.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sunxi/clk-sun4i-display.c b/drivers/clk/sunxi/clk-sun4i-display.c
index 445a7498d6df..9780fac6d029 100644
--- a/drivers/clk/sunxi/clk-sun4i-display.c
+++ b/drivers/clk/sunxi/clk-sun4i-display.c
@@ -33,6 +33,8 @@ struct sun4i_a10_display_clk_data {
 
 	u8	width_div;
 	u8	width_mux;
+
+	u32	flags;
 };
 
 struct reset_data {
@@ -166,7 +168,7 @@ static void __init sun4i_a10_display_init(struct device_node *node,
 				     data->has_div ? &div->hw : NULL,
 				     data->has_div ? &clk_divider_ops : NULL,
 				     &gate->hw, &clk_gate_ops,
-				     0);
+				     data->flags);
 	if (IS_ERR(clk)) {
 		pr_err("%s: Couldn't register the clock\n", clk_name);
 		goto free_div;
@@ -232,6 +234,7 @@ static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initcon
 	.offset_rst	= 29,
 	.offset_mux	= 24,
 	.width_mux	= 2,
+	.flags		= CLK_SET_RATE_PARENT,
 };
 
 static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
-- 
2.8.2

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[PATCH 04/20] clk: sunxi: display: Add per-clock flags

[Maxime Ripard]

The TCON channel 0 clock that is the parent clock of our pixel clock is
expected to change its rate depending on the resolution we want to output
in our display engine.

However, since it's only a mux, the only way it can do that is by changing
its parents rate.

Allow to give flags in our display clocks description, and add the
CLK_SET_RATE_PARENT flag for the TCON channel 0 flag.

Fixes: a3b4956ee6d9 ("clk: sunxi: display: Add per-clock flags")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/sunxi/clk-sun4i-display.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sunxi/clk-sun4i-display.c b/drivers/clk/sunxi/clk-sun4i-display.c
index 445a7498d6df..9780fac6d029 100644
--- a/drivers/clk/sunxi/clk-sun4i-display.c
+++ b/drivers/clk/sunxi/clk-sun4i-display.c
@@ -33,6 +33,8 @@ struct sun4i_a10_display_clk_data {
 
 	u8	width_div;
 	u8	width_mux;
+
+	u32	flags;
 };
 
 struct reset_data {
@@ -166,7 +168,7 @@ static void __init sun4i_a10_display_init(struct device_node *node,
 				     data->has_div ? &div->hw : NULL,
 				     data->has_div ? &clk_divider_ops : NULL,
 				     &gate->hw, &clk_gate_ops,
-				     0);
+				     data->flags);
 	if (IS_ERR(clk)) {
 		pr_err("%s: Couldn't register the clock\n", clk_name);
 		goto free_div;
@@ -232,6 +234,7 @@ static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initcon
 	.offset_rst	= 29,
 	.offset_mux	= 24,
 	.width_mux	= 2,
+	.flags		= CLK_SET_RATE_PARENT,
 };
 
 static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
-- 
2.8.2

[PATCH 04/20] clk: sunxi: display: Add per-clock flags

[Maxime Ripard]

The TCON channel 0 clock that is the parent clock of our pixel clock is
expected to change its rate depending on the resolution we want to output
in our display engine.

However, since it's only a mux, the only way it can do that is by changing
its parents rate.

Allow to give flags in our display clocks description, and add the
CLK_SET_RATE_PARENT flag for the TCON channel 0 flag.

Fixes: a3b4956ee6d9 ("clk: sunxi: display: Add per-clock flags")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/clk/sunxi/clk-sun4i-display.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sunxi/clk-sun4i-display.c b/drivers/clk/sunxi/clk-sun4i-display.c
index 445a7498d6df..9780fac6d029 100644
--- a/drivers/clk/sunxi/clk-sun4i-display.c
+++ b/drivers/clk/sunxi/clk-sun4i-display.c
@@ -33,6 +33,8 @@ struct sun4i_a10_display_clk_data {
 
 	u8	width_div;
 	u8	width_mux;
+
+	u32	flags;
 };
 
 struct reset_data {
@@ -166,7 +168,7 @@ static void __init sun4i_a10_display_init(struct device_node *node,
 				     data->has_div ? &div->hw : NULL,
 				     data->has_div ? &clk_divider_ops : NULL,
 				     &gate->hw, &clk_gate_ops,
-				     0);
+				     data->flags);
 	if (IS_ERR(clk)) {
 		pr_err("%s: Couldn't register the clock\n", clk_name);
 		goto free_div;
@@ -232,6 +234,7 @@ static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initcon
 	.offset_rst	= 29,
 	.offset_mux	= 24,
 	.width_mux	= 2,
+	.flags		= CLK_SET_RATE_PARENT,
 };
 
 static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
-- 
2.8.2

[PATCH 05/20] drm/sun4i: request exact rates to our parents

[Maxime Ripard]

Our pixel clock currently only tries to deal with the current parent rate.

While that works when the resolution is the same than the one already
program, or when we can compute directly the rate from the current parent
rate, it cannot work in most situation when we want to change the
frequency, and we end up with an improper pixel clock rate, which obviously
doesn't work as expected.

Ask our parent for all the possible dividers if it can reach that
frequency, and return the best parent rate to the clock framework so that
we can use it.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_dotclock.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index 6c9c090a8006..1ddf6d7a7107 100644
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -72,14 +72,40 @@ static unsigned long sun4i_dclk_recalc_rate(struct clk_hw *hw,
 static long sun4i_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
 				  unsigned long *parent_rate)
 {
-	return *parent_rate / DIV_ROUND_CLOSEST(*parent_rate, rate);
+	unsigned long best_parent = 0;
+	u8 best_div = 1;
+	int i;
+
+	for (i = 6; i < 127; i++) {
+		unsigned long ideal = rate * i;
+		unsigned long rounded;
+
+		rounded = clk_hw_round_rate(clk_hw_get_parent(hw),
+					    ideal);
+
+		if (rounded == ideal) {
+			best_parent = rounded;
+			best_div = i;
+			goto out;
+		}
+
+		if ((rounded < ideal) && (rounded > best_parent)) {
+			best_parent = rounded;
+			best_div = i;
+		}
+	}
+
+out:
+	*parent_rate = best_parent;
+
+	return best_parent / best_div;
 }
 
 static int sun4i_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
 			       unsigned long parent_rate)
 {
 	struct sun4i_dclk *dclk = hw_to_dclk(hw);
-	int div = DIV_ROUND_CLOSEST(parent_rate, rate);
+	u8 div = parent_rate / rate;
 
 	return regmap_update_bits(dclk->regmap, SUN4I_TCON0_DCLK_REG,
 				  GENMASK(6, 0), div);
-- 
2.8.2

[PATCH 05/20] drm/sun4i: request exact rates to our parents

[Maxime Ripard]

Our pixel clock currently only tries to deal with the current parent rate.

While that works when the resolution is the same than the one already
program, or when we can compute directly the rate from the current parent
rate, it cannot work in most situation when we want to change the
frequency, and we end up with an improper pixel clock rate, which obviously
doesn't work as expected.

Ask our parent for all the possible dividers if it can reach that
frequency, and return the best parent rate to the clock framework so that
we can use it.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_dotclock.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index 6c9c090a8006..1ddf6d7a7107 100644
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -72,14 +72,40 @@ static unsigned long sun4i_dclk_recalc_rate(struct clk_hw *hw,
 static long sun4i_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
 				  unsigned long *parent_rate)
 {
-	return *parent_rate / DIV_ROUND_CLOSEST(*parent_rate, rate);
+	unsigned long best_parent = 0;
+	u8 best_div = 1;
+	int i;
+
+	for (i = 6; i < 127; i++) {
+		unsigned long ideal = rate * i;
+		unsigned long rounded;
+
+		rounded = clk_hw_round_rate(clk_hw_get_parent(hw),
+					    ideal);
+
+		if (rounded == ideal) {
+			best_parent = rounded;
+			best_div = i;
+			goto out;
+		}
+
+		if ((rounded < ideal) && (rounded > best_parent)) {
+			best_parent = rounded;
+			best_div = i;
+		}
+	}
+
+out:
+	*parent_rate = best_parent;
+
+	return best_parent / best_div;
 }
 
 static int sun4i_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
 			       unsigned long parent_rate)
 {
 	struct sun4i_dclk *dclk = hw_to_dclk(hw);
-	int div = DIV_ROUND_CLOSEST(parent_rate, rate);
+	u8 div = parent_rate / rate;
 
 	return regmap_update_bits(dclk->regmap, SUN4I_TCON0_DCLK_REG,
 				  GENMASK(6, 0), div);
-- 
2.8.2

[PATCH 06/20] drm/sun4i: allow dclk to modify its parent rate

[Maxime Ripard]

The pixel clock being only a divider of its parent clock, depending on the
resolution, it's expected to change its parent rate. Add that flag so that
the clock framework knows it.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_dotclock.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index 1ddf6d7a7107..5b3463197c48 100644
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -170,6 +170,7 @@ int sun4i_dclk_create(struct device *dev, struct sun4i_tcon *tcon)
 	init.ops = &sun4i_dclk_ops;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_PARENT;
 
 	dclk->regmap = tcon->regs;
 	dclk->hw.init = &init;
-- 
2.8.2

[PATCH 06/20] drm/sun4i: allow dclk to modify its parent rate

[Maxime Ripard]

The pixel clock being only a divider of its parent clock, depending on the
resolution, it's expected to change its parent rate. Add that flag so that
the clock framework knows it.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_dotclock.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index 1ddf6d7a7107..5b3463197c48 100644
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -170,6 +170,7 @@ int sun4i_dclk_create(struct device *dev, struct sun4i_tcon *tcon)
 	init.ops = &sun4i_dclk_ops;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_PARENT;
 
 	dclk->regmap = tcon->regs;
 	dclk->hw.init = &init;
-- 
2.8.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 06/20] drm/sun4i: allow dclk to modify its parent rate

[Maxime Ripard]

The pixel clock being only a divider of its parent clock, depending on the
resolution, it's expected to change its parent rate. Add that flag so that
the clock framework knows it.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_dotclock.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
index 1ddf6d7a7107..5b3463197c48 100644
--- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
+++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
@@ -170,6 +170,7 @@ int sun4i_dclk_create(struct device *dev, struct sun4i_tcon *tcon)
 	init.ops = &sun4i_dclk_ops;
 	init.parent_names = &parent_name;
 	init.num_parents = 1;
+	init.flags = CLK_SET_RATE_PARENT;
 
 	dclk->regmap = tcon->regs;
 	dclk->hw.init = &init;
-- 
2.8.2

[PATCH 07/20] drm/sun4i: rgb: Validate the clock rate

[Maxime Ripard]

Our pixel clock cannot reach a high enough rate for some rather high while
common resolutions (like 1080p60).

Make sure we filter the resolutions we cannot reach in our mode_valid
function.

Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_rgb.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index ab6494818050..923f55039cb1 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -54,8 +54,13 @@ static int sun4i_rgb_get_modes(struct drm_connector *connector)
 static int sun4i_rgb_mode_valid(struct drm_connector *connector,
 				struct drm_display_mode *mode)
 {
+	struct sun4i_rgb *rgb = drm_connector_to_sun4i_rgb(connector);
+	struct sun4i_drv *drv = rgb->drv;
+	struct sun4i_tcon *tcon = drv->tcon;
 	u32 hsync = mode->hsync_end - mode->hsync_start;
 	u32 vsync = mode->vsync_end - mode->vsync_start;
+	unsigned long rate = mode->crtc_clock * 1000;
+	long rounded_rate;
 
 	DRM_DEBUG_DRIVER("Validating modes...\n");
 
@@ -87,6 +92,15 @@ static int sun4i_rgb_mode_valid(struct drm_connector *connector,
 
 	DRM_DEBUG_DRIVER("Vertical parameters OK\n");
 
+	rounded_rate = clk_round_rate(tcon->dclk, rate);
+	if (rounded_rate < rate)
+		return MODE_CLOCK_LOW;
+
+	if (rounded_rate > rate)
+		return MODE_CLOCK_HIGH;
+
+	DRM_DEBUG_DRIVER("Clock rate OK\n");
+
 	return MODE_OK;
 }
 
-- 
2.8.2

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH 07/20] drm/sun4i: rgb: Validate the clock rate

[Maxime Ripard]

Our pixel clock cannot reach a high enough rate for some rather high while
common resolutions (like 1080p60).

Make sure we filter the resolutions we cannot reach in our mode_valid
function.

Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_rgb.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index ab6494818050..923f55039cb1 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -54,8 +54,13 @@ static int sun4i_rgb_get_modes(struct drm_connector *connector)
 static int sun4i_rgb_mode_valid(struct drm_connector *connector,
 				struct drm_display_mode *mode)
 {
+	struct sun4i_rgb *rgb = drm_connector_to_sun4i_rgb(connector);
+	struct sun4i_drv *drv = rgb->drv;
+	struct sun4i_tcon *tcon = drv->tcon;
 	u32 hsync = mode->hsync_end - mode->hsync_start;
 	u32 vsync = mode->vsync_end - mode->vsync_start;
+	unsigned long rate = mode->crtc_clock * 1000;
+	long rounded_rate;
 
 	DRM_DEBUG_DRIVER("Validating modes...\n");
 
@@ -87,6 +92,15 @@ static int sun4i_rgb_mode_valid(struct drm_connector *connector,
 
 	DRM_DEBUG_DRIVER("Vertical parameters OK\n");
 
+	rounded_rate = clk_round_rate(tcon->dclk, rate);
+	if (rounded_rate < rate)
+		return MODE_CLOCK_LOW;
+
+	if (rounded_rate > rate)
+		return MODE_CLOCK_HIGH;
+
+	DRM_DEBUG_DRIVER("Clock rate OK\n");
+
 	return MODE_OK;
 }
 
-- 
2.8.2

[PATCH 07/20] drm/sun4i: rgb: Validate the clock rate

[Maxime Ripard]

Our pixel clock cannot reach a high enough rate for some rather high while
common resolutions (like 1080p60).

Make sure we filter the resolutions we cannot reach in our mode_valid
function.

Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_rgb.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index ab6494818050..923f55039cb1 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -54,8 +54,13 @@ static int sun4i_rgb_get_modes(struct drm_connector *connector)
 static int sun4i_rgb_mode_valid(struct drm_connector *connector,
 				struct drm_display_mode *mode)
 {
+	struct sun4i_rgb *rgb = drm_connector_to_sun4i_rgb(connector);
+	struct sun4i_drv *drv = rgb->drv;
+	struct sun4i_tcon *tcon = drv->tcon;
 	u32 hsync = mode->hsync_end - mode->hsync_start;
 	u32 vsync = mode->vsync_end - mode->vsync_start;
+	unsigned long rate = mode->crtc_clock * 1000;
+	long rounded_rate;
 
 	DRM_DEBUG_DRIVER("Validating modes...\n");
 
@@ -87,6 +92,15 @@ static int sun4i_rgb_mode_valid(struct drm_connector *connector,
 
 	DRM_DEBUG_DRIVER("Vertical parameters OK\n");
 
+	rounded_rate = clk_round_rate(tcon->dclk, rate);
+	if (rounded_rate < rate)
+		return MODE_CLOCK_LOW;
+
+	if (rounded_rate > rate)
+		return MODE_CLOCK_HIGH;
+
+	DRM_DEBUG_DRIVER("Clock rate OK\n");
+
 	return MODE_OK;
 }
 
-- 
2.8.2

[PATCH 08/20] drm/sun4i: rgb: panel is an error pointer

[Maxime Ripard]

In case of an error, our pointer to the drm_panel structure attached to our
encoder will hold an error pointer, not a NULL pointer.

Make sure we check the right thing.

Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_rgb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index 923f55039cb1..b46d2c15dc95 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -217,7 +217,7 @@ int sun4i_rgb_init(struct drm_device *drm)
 	int ret;
 
 	/* If we don't have a panel, there's no point in going on */
-	if (!tcon->panel)
+	if (IS_ERR(tcon->panel))
 		return -ENODEV;
 
 	rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
-- 
2.8.2

[PATCH 08/20] drm/sun4i: rgb: panel is an error pointer

[Maxime Ripard]

In case of an error, our pointer to the drm_panel structure attached to our
encoder will hold an error pointer, not a NULL pointer.

Make sure we check the right thing.

Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_rgb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index 923f55039cb1..b46d2c15dc95 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -217,7 +217,7 @@ int sun4i_rgb_init(struct drm_device *drm)
 	int ret;
 
 	/* If we don't have a panel, there's no point in going on */
-	if (!tcon->panel)
+	if (IS_ERR(tcon->panel))
 		return -ENODEV;
 
 	rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
-- 
2.8.2


_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 08/20] drm/sun4i: rgb: panel is an error pointer

[Maxime Ripard]

In case of an error, our pointer to the drm_panel structure attached to our
encoder will hold an error pointer, not a NULL pointer.

Make sure we check the right thing.

Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_rgb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index 923f55039cb1..b46d2c15dc95 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -217,7 +217,7 @@ int sun4i_rgb_init(struct drm_device *drm)
 	int ret;
 
 	/* If we don't have a panel, there's no point in going on */
-	if (!tcon->panel)
+	if (IS_ERR(tcon->panel))
 		return -ENODEV;
 
 	rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
-- 
2.8.2

[PATCH 09/20] drm/sun4i: defer only if we didn't find our panel

[Maxime Ripard]

Our code currently defers our probe on any error, even if we were not
expecting to have one at all.

Make sure we return -EPROBE_DEFER only when we were supposed to have a
panel, but it's not probed yet.

Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 9f19b0e08560..eed6a9e8d9a6 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -429,7 +429,7 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
 		return ERR_PTR(-EINVAL);
 	}
 
-	return of_drm_find_panel(remote);
+	return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
 }
 
 static int sun4i_tcon_bind(struct device *dev, struct device *master,
@@ -522,12 +522,13 @@ static int sun4i_tcon_probe(struct platform_device *pdev)
 	 * Defer the probe.
 	 */
 	panel = sun4i_tcon_find_panel(node);
-	if (IS_ERR(panel)) {
-		/*
-		 * If we don't have a panel endpoint, just go on
-		 */
-		if (PTR_ERR(panel) != -ENODEV)
-			return -EPROBE_DEFER;
+
+	/*
+	 * If we don't have a panel endpoint, just go on
+	 */
+	if (PTR_ERR(panel) == -EPROBE_DEFER) {
+		DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
+		return -EPROBE_DEFER;
 	}
 
 	return component_add(&pdev->dev, &sun4i_tcon_ops);
-- 
2.8.2

[PATCH 09/20] drm/sun4i: defer only if we didn't find our panel

[Maxime Ripard]

Our code currently defers our probe on any error, even if we were not
expecting to have one at all.

Make sure we return -EPROBE_DEFER only when we were supposed to have a
panel, but it's not probed yet.

Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 9f19b0e08560..eed6a9e8d9a6 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -429,7 +429,7 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
 		return ERR_PTR(-EINVAL);
 	}
 
-	return of_drm_find_panel(remote);
+	return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
 }
 
 static int sun4i_tcon_bind(struct device *dev, struct device *master,
@@ -522,12 +522,13 @@ static int sun4i_tcon_probe(struct platform_device *pdev)
 	 * Defer the probe.
 	 */
 	panel = sun4i_tcon_find_panel(node);
-	if (IS_ERR(panel)) {
-		/*
-		 * If we don't have a panel endpoint, just go on
-		 */
-		if (PTR_ERR(panel) != -ENODEV)
-			return -EPROBE_DEFER;
+
+	/*
+	 * If we don't have a panel endpoint, just go on
+	 */
+	if (PTR_ERR(panel) == -EPROBE_DEFER) {
+		DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
+		return -EPROBE_DEFER;
 	}
 
 	return component_add(&pdev->dev, &sun4i_tcon_ops);
-- 
2.8.2

[PATCH 10/20] drm/sun4i: remove simplefb at probe

[Maxime Ripard]

If simplefb was setup by our bootloader and enabled in the DT, we will have
a first framebuffer loaded in our system.

However, as soon as our DRM driver will load, it will reset the controller,
initialise it and, if the framebuffer emulation is enabled, register a
second framebuffer device.

This is obviously pretty bad, since the first framebuffer will be some kind
of a black hole, with memory still reserved that we can write to safely,
but not displayed anywhere.

Make sure we remove that framebuffer when we probe so we don't end up in
that situation.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_drv.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 76e922bb60e5..af62b24c39b1 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -125,6 +125,22 @@ static struct drm_driver sun4i_drv_driver = {
 	.disable_vblank		= sun4i_drv_disable_vblank,
 };
 
+static void sun4i_remove_framebuffers(void)
+{
+	struct apertures_struct *ap;
+
+	ap = alloc_apertures(1);
+	if (!ap)
+		return;
+
+	/* The framebuffer can be located anywhere in RAM */
+	ap->ranges[0].base = 0;
+	ap->ranges[0].size = ~0;
+
+	remove_conflicting_framebuffers(ap, "sun4i-drm-fb", false);
+	kfree(ap);
+}
+
 static int sun4i_drv_bind(struct device *dev)
 {
 	struct drm_device *drm;
@@ -172,6 +188,9 @@ static int sun4i_drv_bind(struct device *dev)
 	}
 	drm->irq_enabled = true;
 
+	/* Remove early framebuffers (ie. simplefb) */
+	sun4i_remove_framebuffers();
+
 	/* Create our framebuffer */
 	drv->fbdev = sun4i_framebuffer_init(drm);
 	if (IS_ERR(drv->fbdev)) {
-- 
2.8.2

[PATCH 10/20] drm/sun4i: remove simplefb at probe

[Maxime Ripard]

If simplefb was setup by our bootloader and enabled in the DT, we will have
a first framebuffer loaded in our system.

However, as soon as our DRM driver will load, it will reset the controller,
initialise it and, if the framebuffer emulation is enabled, register a
second framebuffer device.

This is obviously pretty bad, since the first framebuffer will be some kind
of a black hole, with memory still reserved that we can write to safely,
but not displayed anywhere.

Make sure we remove that framebuffer when we probe so we don't end up in
that situation.

Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_drv.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 76e922bb60e5..af62b24c39b1 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -125,6 +125,22 @@ static struct drm_driver sun4i_drv_driver = {
 	.disable_vblank		= sun4i_drv_disable_vblank,
 };
 
+static void sun4i_remove_framebuffers(void)
+{
+	struct apertures_struct *ap;
+
+	ap = alloc_apertures(1);
+	if (!ap)
+		return;
+
+	/* The framebuffer can be located anywhere in RAM */
+	ap->ranges[0].base = 0;
+	ap->ranges[0].size = ~0;
+
+	remove_conflicting_framebuffers(ap, "sun4i-drm-fb", false);
+	kfree(ap);
+}
+
 static int sun4i_drv_bind(struct device *dev)
 {
 	struct drm_device *drm;
@@ -172,6 +188,9 @@ static int sun4i_drv_bind(struct device *dev)
 	}
 	drm->irq_enabled = true;
 
+	/* Remove early framebuffers (ie. simplefb) */
+	sun4i_remove_framebuffers();
+
 	/* Create our framebuffer */
 	drv->fbdev = sun4i_framebuffer_init(drm);
 	if (IS_ERR(drv->fbdev)) {
-- 
2.8.2

[PATCH 11/20] drm/sun4i: Convert to connector register helpers

[Maxime Ripard]

Now that connector register helpers have been created, switch to them.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_drv.c | 31 ++-----------------------------
 1 file changed, 2 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index af62b24c39b1..257d2b4f3645 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -24,34 +24,6 @@
 #include "sun4i_layer.h"
 #include "sun4i_tcon.h"
 
-static int sun4i_drv_connector_plug_all(struct drm_device *drm)
-{
-	struct drm_connector *connector, *failed;
-	int ret;
-
-	mutex_lock(&drm->mode_config.mutex);
-	list_for_each_entry(connector, &drm->mode_config.connector_list, head) {
-		ret = drm_connector_register(connector);
-		if (ret) {
-			failed = connector;
-			goto err;
-		}
-	}
-	mutex_unlock(&drm->mode_config.mutex);
-	return 0;
-
-err:
-	list_for_each_entry(connector, &drm->mode_config.connector_list, head) {
-		if (failed == connector)
-			break;
-
-		drm_connector_unregister(connector);
-	}
-	mutex_unlock(&drm->mode_config.mutex);
-
-	return ret;
-}
-
 static int sun4i_drv_enable_vblank(struct drm_device *drm, unsigned int pipe)
 {
 	struct sun4i_drv *drv = drm->dev_private;
@@ -206,7 +178,7 @@ static int sun4i_drv_bind(struct device *dev)
 	if (ret)
 		goto free_drm;
 
-	ret = sun4i_drv_connector_plug_all(drm);
+	ret = drm_connector_register_all(drm);
 	if (ret)
 		goto unregister_drm;
 
@@ -223,6 +195,7 @@ static void sun4i_drv_unbind(struct device *dev)
 {
 	struct drm_device *drm = dev_get_drvdata(dev);
 
+	drm_connector_unregister_all(drm);
 	drm_dev_unregister(drm);
 	drm_kms_helper_poll_fini(drm);
 	sun4i_framebuffer_free(drm);
-- 
2.8.2

[PATCH 11/20] drm/sun4i: Convert to connector register helpers

[Maxime Ripard]

Now that connector register helpers have been created, switch to them.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_drv.c | 31 ++-----------------------------
 1 file changed, 2 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index af62b24c39b1..257d2b4f3645 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -24,34 +24,6 @@
 #include "sun4i_layer.h"
 #include "sun4i_tcon.h"
 
-static int sun4i_drv_connector_plug_all(struct drm_device *drm)
-{
-	struct drm_connector *connector, *failed;
-	int ret;
-
-	mutex_lock(&drm->mode_config.mutex);
-	list_for_each_entry(connector, &drm->mode_config.connector_list, head) {
-		ret = drm_connector_register(connector);
-		if (ret) {
-			failed = connector;
-			goto err;
-		}
-	}
-	mutex_unlock(&drm->mode_config.mutex);
-	return 0;
-
-err:
-	list_for_each_entry(connector, &drm->mode_config.connector_list, head) {
-		if (failed == connector)
-			break;
-
-		drm_connector_unregister(connector);
-	}
-	mutex_unlock(&drm->mode_config.mutex);
-
-	return ret;
-}
-
 static int sun4i_drv_enable_vblank(struct drm_device *drm, unsigned int pipe)
 {
 	struct sun4i_drv *drv = drm->dev_private;
@@ -206,7 +178,7 @@ static int sun4i_drv_bind(struct device *dev)
 	if (ret)
 		goto free_drm;
 
-	ret = sun4i_drv_connector_plug_all(drm);
+	ret = drm_connector_register_all(drm);
 	if (ret)
 		goto unregister_drm;
 
@@ -223,6 +195,7 @@ static void sun4i_drv_unbind(struct device *dev)
 {
 	struct drm_device *drm = dev_get_drvdata(dev);
 
+	drm_connector_unregister_all(drm);
 	drm_dev_unregister(drm);
 	drm_kms_helper_poll_fini(drm);
 	sun4i_framebuffer_free(drm);
-- 
2.8.2

[PATCH 12/20] drm/sun4i: Add bridge support

[Maxime Ripard]

Our RGB bus can be either connected to a bridge or a panel. While the panel
support was already there, the bridge was not.

Fix that.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_drv.c  |  4 +--
 drivers/gpu/drm/sun4i/sun4i_rgb.c  | 56 +++++++++++++++++++++++++++-----------
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 48 ++++++++++++++++++++++++++++----
 drivers/gpu/drm/sun4i/sun4i_tcon.h |  1 +
 4 files changed, 86 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 257d2b4f3645..1f9e00db747d 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -268,8 +268,8 @@ static int sun4i_drv_add_endpoints(struct device *dev,
 		}
 
 		/*
-		 * If the node is our TCON, the first port is used for our
-		 * panel, and will not be part of the
+		 * If the node is our TCON, the first port is used for
+		 * panel or bridges, and will not be part of the
 		 * component framework.
 		 */
 		if (sun4i_drv_node_is_tcon(node)) {
diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index b46d2c15dc95..c3c611b08269 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -161,7 +161,12 @@ static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
 
 	DRM_DEBUG_DRIVER("Enabling RGB output\n");
 
-	drm_panel_enable(tcon->panel);
+	if (!IS_ERR(tcon->panel))
+		drm_panel_enable(tcon->panel);
+
+	if (!IS_ERR(tcon->bridge))
+		drm_bridge_enable(tcon->bridge);
+
 	sun4i_tcon_channel_enable(tcon, 0);
 }
 
@@ -174,7 +179,12 @@ static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
 	DRM_DEBUG_DRIVER("Disabling RGB output\n");
 
 	sun4i_tcon_channel_disable(tcon, 0);
-	drm_panel_disable(tcon->panel);
+
+	if (!IS_ERR(tcon->bridge))
+		drm_bridge_disable(tcon->bridge);
+
+	if (!IS_ERR(tcon->panel))
+		drm_panel_disable(tcon->panel);
 }
 
 static void sun4i_rgb_encoder_mode_set(struct drm_encoder *encoder,
@@ -216,10 +226,6 @@ int sun4i_rgb_init(struct drm_device *drm)
 	struct sun4i_rgb *rgb;
 	int ret;
 
-	/* If we don't have a panel, there's no point in going on */
-	if (IS_ERR(tcon->panel))
-		return -ENODEV;
-
 	rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
 	if (!rgb)
 		return -ENOMEM;
@@ -240,19 +246,37 @@ int sun4i_rgb_init(struct drm_device *drm)
 	/* The RGB encoder can only work with the TCON channel 0 */
 	rgb->encoder.possible_crtcs = BIT(0);
 
-	drm_connector_helper_add(&rgb->connector,
-				 &sun4i_rgb_con_helper_funcs);
-	ret = drm_connector_init(drm, &rgb->connector,
-				 &sun4i_rgb_con_funcs,
-				 DRM_MODE_CONNECTOR_Unknown);
-	if (ret) {
-		dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
-		goto err_cleanup_connector;
+	if (!IS_ERR(tcon->panel)) {
+		drm_connector_helper_add(&rgb->connector,
+					 &sun4i_rgb_con_helper_funcs);
+		ret = drm_connector_init(drm, &rgb->connector,
+					 &sun4i_rgb_con_funcs,
+					 DRM_MODE_CONNECTOR_Unknown);
+		if (ret) {
+			dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
+			goto err_cleanup_connector;
+		}
+
+		drm_mode_connector_attach_encoder(&rgb->connector,
+						  &rgb->encoder);
+
+		ret = drm_panel_attach(tcon->panel, &rgb->connector);
+		if (ret) {
+			dev_err(drm->dev, "Couldn't attach our panel\n");
+			goto err_cleanup_connector;
+		}
 	}
 
-	drm_mode_connector_attach_encoder(&rgb->connector, &rgb->encoder);
+	if (!IS_ERR(tcon->bridge)) {
+		rgb->encoder.bridge = tcon->bridge;
+		tcon->bridge->encoder = &rgb->encoder;
 
-	drm_panel_attach(tcon->panel, &rgb->connector);
+		ret = drm_bridge_attach(drm, tcon->bridge);
+		if (ret) {
+			dev_err(drm->dev, "Couldn't attach our bridge\n");
+			goto err_cleanup_connector;
+		}
+	}
 
 	return 0;
 
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index eed6a9e8d9a6..4618d98913b4 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -432,6 +432,40 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
 	return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
 }
 
+static struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node)
+{
+	struct device_node *port, *remote, *child;
+	struct device_node *end_node = NULL;
+
+	/* Inputs are listed first, then outputs */
+	port = of_graph_get_port_by_id(node, 1);
+
+	/*
+	 * Our first output is the RGB interface where the panel will
+	 * be connected.
+	 */
+	for_each_child_of_node(port, child) {
+		u32 reg;
+
+		of_property_read_u32(child, "reg", &reg);
+		if (reg == 0)
+			end_node = child;
+	}
+
+	if (!end_node) {
+		DRM_DEBUG_DRIVER("Missing bridge endpoint\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	remote = of_graph_get_remote_port_parent(end_node);
+	if (!remote) {
+		DRM_DEBUG_DRIVER("Enable to parse remote node\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	return of_drm_find_bridge(remote) ?: ERR_PTR(-EPROBE_DEFER);
+}
+
 static int sun4i_tcon_bind(struct device *dev, struct device *master,
 			   void *data)
 {
@@ -485,8 +519,9 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 	}
 
 	tcon->panel = sun4i_tcon_find_panel(dev->of_node);
-	if (IS_ERR(tcon->panel)) {
-		dev_info(dev, "No panel found... RGB output disabled\n");
+	tcon->bridge = sun4i_tcon_find_bridge(dev->of_node);
+	if (IS_ERR(tcon->panel) && IS_ERR(tcon->bridge)) {
+		dev_info(dev, "No panel or bridge found... RGB output disabled\n");
 		return 0;
 	}
 
@@ -515,19 +550,22 @@ static struct component_ops sun4i_tcon_ops = {
 static int sun4i_tcon_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
+	struct drm_bridge *bridge;
 	struct drm_panel *panel;
 
 	/*
-	 * The panel is not ready.
+	 * Neither the bridge or the panel is ready.
 	 * Defer the probe.
 	 */
 	panel = sun4i_tcon_find_panel(node);
+	bridge = sun4i_tcon_find_bridge(node);
 
 	/*
 	 * If we don't have a panel endpoint, just go on
 	 */
-	if (PTR_ERR(panel) == -EPROBE_DEFER) {
-		DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
+	if ((PTR_ERR(panel) == -EPROBE_DEFER) &&
+	    (PTR_ERR(bridge) == -EPROBE_DEFER)) {
+		DRM_DEBUG_DRIVER("Still waiting for our panel/bridge. Deferring...\n");
 		return -EPROBE_DEFER;
 	}
 
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index 0e0b11db401b..31069027d7fb 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -162,6 +162,7 @@ struct sun4i_tcon {
 	/* Platform adjustments */
 	bool				has_mux;
 
+	struct drm_bridge		*bridge;
 	struct drm_panel		*panel;
 };
 
-- 
2.8.2

[PATCH 12/20] drm/sun4i: Add bridge support

[Maxime Ripard]

Our RGB bus can be either connected to a bridge or a panel. While the panel
support was already there, the bridge was not.

Fix that.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_drv.c  |  4 +--
 drivers/gpu/drm/sun4i/sun4i_rgb.c  | 56 +++++++++++++++++++++++++++-----------
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 48 ++++++++++++++++++++++++++++----
 drivers/gpu/drm/sun4i/sun4i_tcon.h |  1 +
 4 files changed, 86 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
index 257d2b4f3645..1f9e00db747d 100644
--- a/drivers/gpu/drm/sun4i/sun4i_drv.c
+++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
@@ -268,8 +268,8 @@ static int sun4i_drv_add_endpoints(struct device *dev,
 		}
 
 		/*
-		 * If the node is our TCON, the first port is used for our
-		 * panel, and will not be part of the
+		 * If the node is our TCON, the first port is used for
+		 * panel or bridges, and will not be part of the
 		 * component framework.
 		 */
 		if (sun4i_drv_node_is_tcon(node)) {
diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
index b46d2c15dc95..c3c611b08269 100644
--- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
+++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
@@ -161,7 +161,12 @@ static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
 
 	DRM_DEBUG_DRIVER("Enabling RGB output\n");
 
-	drm_panel_enable(tcon->panel);
+	if (!IS_ERR(tcon->panel))
+		drm_panel_enable(tcon->panel);
+
+	if (!IS_ERR(tcon->bridge))
+		drm_bridge_enable(tcon->bridge);
+
 	sun4i_tcon_channel_enable(tcon, 0);
 }
 
@@ -174,7 +179,12 @@ static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
 	DRM_DEBUG_DRIVER("Disabling RGB output\n");
 
 	sun4i_tcon_channel_disable(tcon, 0);
-	drm_panel_disable(tcon->panel);
+
+	if (!IS_ERR(tcon->bridge))
+		drm_bridge_disable(tcon->bridge);
+
+	if (!IS_ERR(tcon->panel))
+		drm_panel_disable(tcon->panel);
 }
 
 static void sun4i_rgb_encoder_mode_set(struct drm_encoder *encoder,
@@ -216,10 +226,6 @@ int sun4i_rgb_init(struct drm_device *drm)
 	struct sun4i_rgb *rgb;
 	int ret;
 
-	/* If we don't have a panel, there's no point in going on */
-	if (IS_ERR(tcon->panel))
-		return -ENODEV;
-
 	rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
 	if (!rgb)
 		return -ENOMEM;
@@ -240,19 +246,37 @@ int sun4i_rgb_init(struct drm_device *drm)
 	/* The RGB encoder can only work with the TCON channel 0 */
 	rgb->encoder.possible_crtcs = BIT(0);
 
-	drm_connector_helper_add(&rgb->connector,
-				 &sun4i_rgb_con_helper_funcs);
-	ret = drm_connector_init(drm, &rgb->connector,
-				 &sun4i_rgb_con_funcs,
-				 DRM_MODE_CONNECTOR_Unknown);
-	if (ret) {
-		dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
-		goto err_cleanup_connector;
+	if (!IS_ERR(tcon->panel)) {
+		drm_connector_helper_add(&rgb->connector,
+					 &sun4i_rgb_con_helper_funcs);
+		ret = drm_connector_init(drm, &rgb->connector,
+					 &sun4i_rgb_con_funcs,
+					 DRM_MODE_CONNECTOR_Unknown);
+		if (ret) {
+			dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
+			goto err_cleanup_connector;
+		}
+
+		drm_mode_connector_attach_encoder(&rgb->connector,
+						  &rgb->encoder);
+
+		ret = drm_panel_attach(tcon->panel, &rgb->connector);
+		if (ret) {
+			dev_err(drm->dev, "Couldn't attach our panel\n");
+			goto err_cleanup_connector;
+		}
 	}
 
-	drm_mode_connector_attach_encoder(&rgb->connector, &rgb->encoder);
+	if (!IS_ERR(tcon->bridge)) {
+		rgb->encoder.bridge = tcon->bridge;
+		tcon->bridge->encoder = &rgb->encoder;
 
-	drm_panel_attach(tcon->panel, &rgb->connector);
+		ret = drm_bridge_attach(drm, tcon->bridge);
+		if (ret) {
+			dev_err(drm->dev, "Couldn't attach our bridge\n");
+			goto err_cleanup_connector;
+		}
+	}
 
 	return 0;
 
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index eed6a9e8d9a6..4618d98913b4 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -432,6 +432,40 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
 	return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
 }
 
+static struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node)
+{
+	struct device_node *port, *remote, *child;
+	struct device_node *end_node = NULL;
+
+	/* Inputs are listed first, then outputs */
+	port = of_graph_get_port_by_id(node, 1);
+
+	/*
+	 * Our first output is the RGB interface where the panel will
+	 * be connected.
+	 */
+	for_each_child_of_node(port, child) {
+		u32 reg;
+
+		of_property_read_u32(child, "reg", &reg);
+		if (reg == 0)
+			end_node = child;
+	}
+
+	if (!end_node) {
+		DRM_DEBUG_DRIVER("Missing bridge endpoint\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	remote = of_graph_get_remote_port_parent(end_node);
+	if (!remote) {
+		DRM_DEBUG_DRIVER("Enable to parse remote node\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	return of_drm_find_bridge(remote) ?: ERR_PTR(-EPROBE_DEFER);
+}
+
 static int sun4i_tcon_bind(struct device *dev, struct device *master,
 			   void *data)
 {
@@ -485,8 +519,9 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
 	}
 
 	tcon->panel = sun4i_tcon_find_panel(dev->of_node);
-	if (IS_ERR(tcon->panel)) {
-		dev_info(dev, "No panel found... RGB output disabled\n");
+	tcon->bridge = sun4i_tcon_find_bridge(dev->of_node);
+	if (IS_ERR(tcon->panel) && IS_ERR(tcon->bridge)) {
+		dev_info(dev, "No panel or bridge found... RGB output disabled\n");
 		return 0;
 	}
 
@@ -515,19 +550,22 @@ static struct component_ops sun4i_tcon_ops = {
 static int sun4i_tcon_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
+	struct drm_bridge *bridge;
 	struct drm_panel *panel;
 
 	/*
-	 * The panel is not ready.
+	 * Neither the bridge or the panel is ready.
 	 * Defer the probe.
 	 */
 	panel = sun4i_tcon_find_panel(node);
+	bridge = sun4i_tcon_find_bridge(node);
 
 	/*
 	 * If we don't have a panel endpoint, just go on
 	 */
-	if (PTR_ERR(panel) == -EPROBE_DEFER) {
-		DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
+	if ((PTR_ERR(panel) == -EPROBE_DEFER) &&
+	    (PTR_ERR(bridge) == -EPROBE_DEFER)) {
+		DRM_DEBUG_DRIVER("Still waiting for our panel/bridge. Deferring...\n");
 		return -EPROBE_DEFER;
 	}
 
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index 0e0b11db401b..31069027d7fb 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -162,6 +162,7 @@ struct sun4i_tcon {
 	/* Platform adjustments */
 	bool				has_mux;
 
+	struct drm_bridge		*bridge;
 	struct drm_panel		*panel;
 };
 
-- 
2.8.2

[PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Maxime Ripard]

Some boards have an entirely passive RGB to VGA bridge, based on either
DACs or resistor ladders.

Those might or might not have an i2c bus routed to the VGA connector in
order to access the screen EDIDs.

Add a bridge that doesn't do anything but expose the modes available on the
screen, either based on the EDIDs if available, or based on the XGA
standards.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
 drivers/gpu/drm/bridge/Kconfig                     |   6 +
 drivers/gpu/drm/bridge/Makefile                    |   1 +
 drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
 4 files changed, 233 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
 create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c

diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
new file mode 100644
index 000000000000..757f04de97f3
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
@@ -0,0 +1,40 @@
+Passive RGB to VGA bridge
+-------------------------
+
+This binding is aimed for entirely passive RGB to VGA bridges that do not
+require any configuration.
+
+Required properties:
+
+- compatible: Should be "dumb-vga-bridge"
+
+Optional properties:
+
+- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
+
+Required nodes:
+
+This device has one video port. Its connection is modelled using the OF
+graph bindings specified in Documentation/devicetree/bindings/graph.txt. This
+connection is meant to be the RGB input bus.
+
+
+Example
+-------
+
+bridge {
+        compatible = "dumb-vga-bridge";
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        port@0 {
+                reg = <0>;
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                vga_input: endpoint@0 {
+                        reg = <0>;
+                        remote-endpoint = <&tcon0_out_vga>;
+               };
+        };
+};
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 8f7423f18da5..cf279956cbec 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -17,6 +17,12 @@ config DRM_ANALOGIX_ANX78XX
 	  the HDMI output of an application processor to MyDP
 	  or DisplayPort.
 
+config DRM_DUMB_VGA
+	tristate "Dumb RGB to VGA Bridge support"
+	select DRM_KMS_HELPER
+	help
+	  Support for passive RGB to VGA bridges
+
 config DRM_DW_HDMI
 	tristate
 	select DRM_KMS_HELPER
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 96b13b30e6ab..63f21120e8f8 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -1,6 +1,7 @@
 ccflags-y := -Iinclude/drm
 
 obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
+obj-$(CONFIG_DRM_DUMB_VGA) += dumb-vga.o
 obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
diff --git a/drivers/gpu/drm/bridge/dumb-vga.c b/drivers/gpu/drm/bridge/dumb-vga.c
new file mode 100644
index 000000000000..2864fa535bf8
--- /dev/null
+++ b/drivers/gpu/drm/bridge/dumb-vga.c
@@ -0,0 +1,186 @@
+
+#include <linux/module.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+
+struct dumb_vga {
+	struct drm_bridge	bridge;
+	struct drm_connector	connector;
+
+	struct i2c_adapter	*ddc;
+};
+
+static inline struct dumb_vga *
+drm_bridge_to_dumb_vga(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct dumb_vga, bridge);
+}
+
+static inline struct dumb_vga *
+drm_connector_to_dumb_vga(struct drm_connector *connector)
+{
+	return container_of(connector, struct dumb_vga, connector);
+}
+
+static int dumb_vga_get_modes(struct drm_connector *connector)
+{
+	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
+	struct edid *edid;
+	int ret;
+
+	if (!vga->ddc)
+		goto fallback;
+
+	edid = drm_get_edid(connector, vga->ddc);
+	if (!edid) {
+		DRM_INFO("EDID readout failed, falling back to standard modes\n");
+		goto fallback;
+	}
+
+	drm_mode_connector_update_edid_property(connector, edid);
+	return drm_add_edid_modes(connector, edid);
+
+fallback:
+	/*
+	 * In case we cannot retrieve the EDIDs (broken or missing i2c
+	 * bus), fallback on the XGA standards
+	 */
+	ret = drm_add_modes_noedid(connector, 1920, 1200);
+
+	/* And prefer a mode pretty much anyone can handle */
+	drm_set_preferred_mode(connector, 1024, 768);
+
+	return ret;
+}
+
+static struct drm_encoder *
+dumb_vga_best_encoder(struct drm_connector *connector)
+{
+	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
+
+	return vga->bridge.encoder;
+}
+
+static struct drm_connector_helper_funcs dumb_vga_con_helper_funcs = {
+	.get_modes	= dumb_vga_get_modes,
+	.best_encoder	= dumb_vga_best_encoder,
+};
+
+static enum drm_connector_status
+dumb_vga_connector_detect(struct drm_connector *connector, bool force)
+{
+	return connector_status_connected;
+}
+
+static void
+dumb_vga_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_cleanup(connector);
+}
+
+static struct drm_connector_funcs dumb_vga_con_funcs = {
+	.dpms			= drm_atomic_helper_connector_dpms,
+	.detect			= dumb_vga_connector_detect,
+	.fill_modes		= drm_helper_probe_single_connector_modes,
+	.destroy		= dumb_vga_connector_destroy,
+	.reset			= drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
+};
+
+static int dumb_vga_attach(struct drm_bridge *bridge)
+{
+	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
+	int ret;
+
+	if (!bridge->encoder) {
+		DRM_ERROR("Missing encoder\n");
+		return -ENODEV;
+	}
+
+	drm_connector_helper_add(&vga->connector,
+				 &dumb_vga_con_helper_funcs);
+	ret = drm_connector_init(bridge->dev, &vga->connector,
+				 &dumb_vga_con_funcs, DRM_MODE_CONNECTOR_VGA);
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector\n");
+		return ret;
+	}
+
+	drm_mode_connector_attach_encoder(&vga->connector,
+					  bridge->encoder);
+
+	return 0;
+}
+
+static void dumb_vga_nop(struct drm_bridge *bridge) {};
+
+static struct drm_bridge_funcs dumb_vga_bridge_funcs = {
+	.attach		= dumb_vga_attach,
+	.enable		= dumb_vga_nop,
+	.disable	= dumb_vga_nop,
+	.pre_enable	= dumb_vga_nop,
+	.post_disable	= dumb_vga_nop,
+};
+
+static int dumb_vga_probe(struct platform_device *pdev)
+{
+	struct dumb_vga *vga;
+	struct device_node *ddc;
+
+	vga = devm_kzalloc(&pdev->dev, sizeof(*vga), GFP_KERNEL);
+	if (!vga)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, vga);
+
+	ddc = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
+	if (ddc) {
+		vga->ddc = of_find_i2c_adapter_by_node(ddc);
+		of_node_put(ddc);
+
+		if (!vga->ddc) {
+			dev_err(&pdev->dev, "Couldn't retrieve i2c bus\n");
+			return -EPROBE_DEFER;
+		}
+	} else {
+		dev_info(&pdev->dev,
+			 "No i2c bus specified... Disabling EDID readout\n");
+	}
+
+	vga->bridge.funcs = &dumb_vga_bridge_funcs;
+	vga->bridge.of_node = pdev->dev.of_node;
+
+	return drm_bridge_add(&vga->bridge);
+}
+
+static int dumb_vga_remove(struct platform_device *pdev)
+{
+	struct dumb_vga *vga = platform_get_drvdata(pdev);
+
+	drm_bridge_remove(&vga->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id dumb_vga_match[] = {
+	{ .compatible = "dumb-vga-bridge" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dumb_vga_match);
+
+struct platform_driver dumb_vga_driver = {
+	.probe	= dumb_vga_probe,
+	.remove	= dumb_vga_remove,
+	.driver		= {
+		.name		= "dumb-vga-bridge",
+		.of_match_table	= dumb_vga_match,
+	},
+};
+module_platform_driver(dumb_vga_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Dumb RGB to VGA bridge driver");
+MODULE_LICENSE("GPL");
-- 
2.8.2

[PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Maxime Ripard]

Some boards have an entirely passive RGB to VGA bridge, based on either
DACs or resistor ladders.

Those might or might not have an i2c bus routed to the VGA connector in
order to access the screen EDIDs.

Add a bridge that doesn't do anything but expose the modes available on the
screen, either based on the EDIDs if available, or based on the XGA
standards.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
 drivers/gpu/drm/bridge/Kconfig                     |   6 +
 drivers/gpu/drm/bridge/Makefile                    |   1 +
 drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
 4 files changed, 233 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
 create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c

diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
new file mode 100644
index 000000000000..757f04de97f3
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
@@ -0,0 +1,40 @@
+Passive RGB to VGA bridge
+-------------------------
+
+This binding is aimed for entirely passive RGB to VGA bridges that do not
+require any configuration.
+
+Required properties:
+
+- compatible: Should be "dumb-vga-bridge"
+
+Optional properties:
+
+- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
+
+Required nodes:
+
+This device has one video port. Its connection is modelled using the OF
+graph bindings specified in Documentation/devicetree/bindings/graph.txt. This
+connection is meant to be the RGB input bus.
+
+
+Example
+-------
+
+bridge {
+        compatible = "dumb-vga-bridge";
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        port at 0 {
+                reg = <0>;
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                vga_input: endpoint at 0 {
+                        reg = <0>;
+                        remote-endpoint = <&tcon0_out_vga>;
+               };
+        };
+};
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 8f7423f18da5..cf279956cbec 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -17,6 +17,12 @@ config DRM_ANALOGIX_ANX78XX
 	  the HDMI output of an application processor to MyDP
 	  or DisplayPort.
 
+config DRM_DUMB_VGA
+	tristate "Dumb RGB to VGA Bridge support"
+	select DRM_KMS_HELPER
+	help
+	  Support for passive RGB to VGA bridges
+
 config DRM_DW_HDMI
 	tristate
 	select DRM_KMS_HELPER
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 96b13b30e6ab..63f21120e8f8 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -1,6 +1,7 @@
 ccflags-y := -Iinclude/drm
 
 obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
+obj-$(CONFIG_DRM_DUMB_VGA) += dumb-vga.o
 obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
diff --git a/drivers/gpu/drm/bridge/dumb-vga.c b/drivers/gpu/drm/bridge/dumb-vga.c
new file mode 100644
index 000000000000..2864fa535bf8
--- /dev/null
+++ b/drivers/gpu/drm/bridge/dumb-vga.c
@@ -0,0 +1,186 @@
+
+#include <linux/module.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+
+struct dumb_vga {
+	struct drm_bridge	bridge;
+	struct drm_connector	connector;
+
+	struct i2c_adapter	*ddc;
+};
+
+static inline struct dumb_vga *
+drm_bridge_to_dumb_vga(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct dumb_vga, bridge);
+}
+
+static inline struct dumb_vga *
+drm_connector_to_dumb_vga(struct drm_connector *connector)
+{
+	return container_of(connector, struct dumb_vga, connector);
+}
+
+static int dumb_vga_get_modes(struct drm_connector *connector)
+{
+	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
+	struct edid *edid;
+	int ret;
+
+	if (!vga->ddc)
+		goto fallback;
+
+	edid = drm_get_edid(connector, vga->ddc);
+	if (!edid) {
+		DRM_INFO("EDID readout failed, falling back to standard modes\n");
+		goto fallback;
+	}
+
+	drm_mode_connector_update_edid_property(connector, edid);
+	return drm_add_edid_modes(connector, edid);
+
+fallback:
+	/*
+	 * In case we cannot retrieve the EDIDs (broken or missing i2c
+	 * bus), fallback on the XGA standards
+	 */
+	ret = drm_add_modes_noedid(connector, 1920, 1200);
+
+	/* And prefer a mode pretty much anyone can handle */
+	drm_set_preferred_mode(connector, 1024, 768);
+
+	return ret;
+}
+
+static struct drm_encoder *
+dumb_vga_best_encoder(struct drm_connector *connector)
+{
+	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
+
+	return vga->bridge.encoder;
+}
+
+static struct drm_connector_helper_funcs dumb_vga_con_helper_funcs = {
+	.get_modes	= dumb_vga_get_modes,
+	.best_encoder	= dumb_vga_best_encoder,
+};
+
+static enum drm_connector_status
+dumb_vga_connector_detect(struct drm_connector *connector, bool force)
+{
+	return connector_status_connected;
+}
+
+static void
+dumb_vga_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_cleanup(connector);
+}
+
+static struct drm_connector_funcs dumb_vga_con_funcs = {
+	.dpms			= drm_atomic_helper_connector_dpms,
+	.detect			= dumb_vga_connector_detect,
+	.fill_modes		= drm_helper_probe_single_connector_modes,
+	.destroy		= dumb_vga_connector_destroy,
+	.reset			= drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
+};
+
+static int dumb_vga_attach(struct drm_bridge *bridge)
+{
+	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
+	int ret;
+
+	if (!bridge->encoder) {
+		DRM_ERROR("Missing encoder\n");
+		return -ENODEV;
+	}
+
+	drm_connector_helper_add(&vga->connector,
+				 &dumb_vga_con_helper_funcs);
+	ret = drm_connector_init(bridge->dev, &vga->connector,
+				 &dumb_vga_con_funcs, DRM_MODE_CONNECTOR_VGA);
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector\n");
+		return ret;
+	}
+
+	drm_mode_connector_attach_encoder(&vga->connector,
+					  bridge->encoder);
+
+	return 0;
+}
+
+static void dumb_vga_nop(struct drm_bridge *bridge) {};
+
+static struct drm_bridge_funcs dumb_vga_bridge_funcs = {
+	.attach		= dumb_vga_attach,
+	.enable		= dumb_vga_nop,
+	.disable	= dumb_vga_nop,
+	.pre_enable	= dumb_vga_nop,
+	.post_disable	= dumb_vga_nop,
+};
+
+static int dumb_vga_probe(struct platform_device *pdev)
+{
+	struct dumb_vga *vga;
+	struct device_node *ddc;
+
+	vga = devm_kzalloc(&pdev->dev, sizeof(*vga), GFP_KERNEL);
+	if (!vga)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, vga);
+
+	ddc = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
+	if (ddc) {
+		vga->ddc = of_find_i2c_adapter_by_node(ddc);
+		of_node_put(ddc);
+
+		if (!vga->ddc) {
+			dev_err(&pdev->dev, "Couldn't retrieve i2c bus\n");
+			return -EPROBE_DEFER;
+		}
+	} else {
+		dev_info(&pdev->dev,
+			 "No i2c bus specified... Disabling EDID readout\n");
+	}
+
+	vga->bridge.funcs = &dumb_vga_bridge_funcs;
+	vga->bridge.of_node = pdev->dev.of_node;
+
+	return drm_bridge_add(&vga->bridge);
+}
+
+static int dumb_vga_remove(struct platform_device *pdev)
+{
+	struct dumb_vga *vga = platform_get_drvdata(pdev);
+
+	drm_bridge_remove(&vga->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id dumb_vga_match[] = {
+	{ .compatible = "dumb-vga-bridge" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dumb_vga_match);
+
+struct platform_driver dumb_vga_driver = {
+	.probe	= dumb_vga_probe,
+	.remove	= dumb_vga_remove,
+	.driver		= {
+		.name		= "dumb-vga-bridge",
+		.of_match_table	= dumb_vga_match,
+	},
+};
+module_platform_driver(dumb_vga_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Dumb RGB to VGA bridge driver");
+MODULE_LICENSE("GPL");
-- 
2.8.2

[PATCH 14/20] ARM: sun5i: a13: Add LCD pins

[Maxime Ripard]

The RGB bus can be used in several configurations, one of which being the
RGB666.

Add a pinctrl group for that case.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/boot/dts/sun5i-a13.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
index 263d46dbc7e6..79b5d513c142 100644
--- a/arch/arm/boot/dts/sun5i-a13.dtsi
+++ b/arch/arm/boot/dts/sun5i-a13.dtsi
@@ -237,6 +237,16 @@
 &pio {
 	compatible = "allwinner,sun5i-a13-pinctrl";
 
+	lcd_rgb666_pins: lcd_rgb666@0 {
+		allwinner,pins = "PD2", "PD3", "PD4", "PD5", "PD6", "PD7",
+				 "PD10", "PD11", "PD12", "PD13", "PD14", "PD15",
+				 "PD18", "PD19", "PD20", "PD21", "PD22", "PD23",
+				 "PD24", "PD25", "PD26", "PD27";
+		allwinner,function = "lcd0";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
+
 	uart1_pins_a: uart1@0 {
 		allwinner,pins = "PE10", "PE11";
 		allwinner,function = "uart1";
-- 
2.8.2

[PATCH 14/20] ARM: sun5i: a13: Add LCD pins

[Maxime Ripard]

The RGB bus can be used in several configurations, one of which being the
RGB666.

Add a pinctrl group for that case.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/boot/dts/sun5i-a13.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
index 263d46dbc7e6..79b5d513c142 100644
--- a/arch/arm/boot/dts/sun5i-a13.dtsi
+++ b/arch/arm/boot/dts/sun5i-a13.dtsi
@@ -237,6 +237,16 @@
 &pio {
 	compatible = "allwinner,sun5i-a13-pinctrl";
 
+	lcd_rgb666_pins: lcd_rgb666 at 0 {
+		allwinner,pins = "PD2", "PD3", "PD4", "PD5", "PD6", "PD7",
+				 "PD10", "PD11", "PD12", "PD13", "PD14", "PD15",
+				 "PD18", "PD19", "PD20", "PD21", "PD22", "PD23",
+				 "PD24", "PD25", "PD26", "PD27";
+		allwinner,function = "lcd0";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
+
 	uart1_pins_a: uart1 at 0 {
 		allwinner,pins = "PE10", "PE11";
 		allwinner,function = "uart1";
-- 
2.8.2

[PATCH 15/20] ARM: sun5i: Move display blocks to A13

[Maxime Ripard]

Most of the display engine is shared between the R8 and the A13. Move the
common parts to the Á13 DTSI.

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 arch/arm/boot/dts/sun5i-a13.dtsi | 112 ++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/sun5i-r8.dtsi  | 120 ++-------------------------------------
 2 files changed, 117 insertions(+), 115 deletions(-)

diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
index 79b5d513c142..e012890e0cf2 100644
--- a/arch/arm/boot/dts/sun5i-a13.dtsi
+++ b/arch/arm/boot/dts/sun5i-a13.dtsi
@@ -207,7 +207,50 @@
 		};
 	};
 
+	display-engine {
+		compatible = "allwinner,sun5i-a13-display-engine";
+		allwinner,pipelines = <&fe0>;
+	};
+
 	soc@01c00000 {
+		tcon0: lcd-controller@01c0c000 {
+			compatible = "allwinner,sun5i-a13-tcon";
+			reg = <0x01c0c000 0x1000>;
+			interrupts = <44>;
+			resets = <&tcon_ch0_clk 1>;
+			reset-names = "lcd";
+			clocks = <&ahb_gates 36>,
+				 <&tcon_ch0_clk>,
+				 <&tcon_ch1_clk>;
+			clock-names = "ahb",
+				      "tcon-ch0",
+				      "tcon-ch1";
+			clock-output-names = "tcon-pixel-clock";
+			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				tcon0_in: port@0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+
+					tcon0_in_be0: endpoint@0 {
+						reg = <0>;
+						remote-endpoint = <&be0_out_tcon0>;
+					};
+				};
+
+				tcon0_out: port@1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+				};
+			};
+		};
+
 		pwm: pwm@01c20e00 {
 			compatible = "allwinner,sun5i-a13-pwm";
 			reg = <0x01c20e00 0xc>;
@@ -215,6 +258,75 @@
 			#pwm-cells = <3>;
 			status = "disabled";
 		};
+
+		fe0: display-frontend@01e00000 {
+			compatible = "allwinner,sun5i-a13-display-frontend";
+			reg = <0x01e00000 0x20000>;
+			interrupts = <47>;
+			clocks = <&ahb_gates 46>, <&de_fe_clk>,
+				 <&dram_gates 25>;
+			clock-names = "ahb", "mod",
+				      "ram";
+			resets = <&de_fe_clk>;
+			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				fe0_out: port@1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+
+					fe0_out_be0: endpoint@0 {
+						reg = <0>;
+						remote-endpoint = <&be0_in_fe0>;
+					};
+				};
+			};
+		};
+
+		be0: display-backend@01e60000 {
+			compatible = "allwinner,sun5i-a13-display-backend";
+			reg = <0x01e60000 0x10000>;
+			clocks = <&ahb_gates 44>, <&de_be_clk>,
+				 <&dram_gates 26>;
+			clock-names = "ahb", "mod",
+				      "ram";
+			resets = <&de_be_clk>;
+			status = "disabled";
+
+			assigned-clocks = <&de_be_clk>;
+			assigned-clock-rates = <300000000>;
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				be0_in: port@0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+
+					be0_in_fe0: endpoint@0 {
+						reg = <0>;
+						remote-endpoint = <&fe0_out_be0>;
+					};
+				};
+
+				be0_out: port@1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+
+					be0_out_tcon0: endpoint@0 {
+						reg = <0>;
+						remote-endpoint = <&tcon0_in_be0>;
+					};
+				};
+			};
+		};
 	};
 };
 
diff --git a/arch/arm/boot/dts/sun5i-r8.dtsi b/arch/arm/boot/dts/sun5i-r8.dtsi
index c04cf690b858..8b058f53b7dc 100644
--- a/arch/arm/boot/dts/sun5i-r8.dtsi
+++ b/arch/arm/boot/dts/sun5i-r8.dtsi
@@ -76,122 +76,12 @@
 				};
 			};
 		};
-
-		tcon0: lcd-controller@01c0c000 {
-			compatible = "allwinner,sun5i-a13-tcon";
-			reg = <0x01c0c000 0x1000>;
-			interrupts = <44>;
-			resets = <&tcon_ch0_clk 1>;
-			reset-names = "lcd";
-			clocks = <&ahb_gates 36>,
-				 <&tcon_ch0_clk>,
-				 <&tcon_ch1_clk>;
-			clock-names = "ahb",
-				      "tcon-ch0",
-				      "tcon-ch1";
-			clock-output-names = "tcon-pixel-clock";
-			status = "disabled";
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				tcon0_in: port@0 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <0>;
-
-					tcon0_in_be0: endpoint@0 {
-						reg = <0>;
-						remote-endpoint = <&be0_out_tcon0>;
-					};
-				};
-
-				tcon0_out: port@1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					tcon0_out_tve0: endpoint@1 {
-						reg = <1>;
-						remote-endpoint = <&tve0_in_tcon0>;
-					};
-				};
-			};
-		};
-
-		fe0: display-frontend@01e00000 {
-			compatible = "allwinner,sun5i-a13-display-frontend";
-			reg = <0x01e00000 0x20000>;
-			interrupts = <47>;
-			clocks = <&ahb_gates 46>, <&de_fe_clk>,
-				 <&dram_gates 25>;
-			clock-names = "ahb", "mod",
-				      "ram";
-			resets = <&de_fe_clk>;
-			status = "disabled";
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				fe0_out: port@1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					fe0_out_be0: endpoint@0 {
-						reg = <0>;
-						remote-endpoint = <&be0_in_fe0>;
-					};
-				};
-			};
-		};
-
-		be0: display-backend@01e60000 {
-			compatible = "allwinner,sun5i-a13-display-backend";
-			reg = <0x01e60000 0x10000>;
-			clocks = <&ahb_gates 44>, <&de_be_clk>,
-				 <&dram_gates 26>;
-			clock-names = "ahb", "mod",
-				      "ram";
-			resets = <&de_be_clk>;
-			status = "disabled";
-
-			assigned-clocks = <&de_be_clk>;
-			assigned-clock-rates = <300000000>;
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				be0_in: port@0 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <0>;
-
-					be0_in_fe0: endpoint@0 {
-						reg = <0>;
-						remote-endpoint = <&fe0_out_be0>;
-					};
-				};
-
-				be0_out: port@1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					be0_out_tcon0: endpoint@0 {
-						reg = <0>;
-						remote-endpoint = <&tcon0_in_be0>;
-					};
-				};
-			};
-		};
 	};
+};
 
-	display-engine {
-		compatible = "allwinner,sun5i-a13-display-engine";
-		allwinner,pipelines = <&fe0>;
+&tcon0_out {
+	tcon0_out_tve0: endpoint@1 {
+		reg = <1>;
+		remote-endpoint = <&tve0_in_tcon0>;
 	};
 };
-- 
2.8.2

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[PATCH 15/20] ARM: sun5i: Move display blocks to A13

[Maxime Ripard]

Most of the display engine is shared between the R8 and the A13. Move the
common parts to the Á13 DTSI.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/boot/dts/sun5i-a13.dtsi | 112 ++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/sun5i-r8.dtsi  | 120 ++-------------------------------------
 2 files changed, 117 insertions(+), 115 deletions(-)

diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
index 79b5d513c142..e012890e0cf2 100644
--- a/arch/arm/boot/dts/sun5i-a13.dtsi
+++ b/arch/arm/boot/dts/sun5i-a13.dtsi
@@ -207,7 +207,50 @@
 		};
 	};
 
+	display-engine {
+		compatible = "allwinner,sun5i-a13-display-engine";
+		allwinner,pipelines = <&fe0>;
+	};
+
 	soc@01c00000 {
+		tcon0: lcd-controller@01c0c000 {
+			compatible = "allwinner,sun5i-a13-tcon";
+			reg = <0x01c0c000 0x1000>;
+			interrupts = <44>;
+			resets = <&tcon_ch0_clk 1>;
+			reset-names = "lcd";
+			clocks = <&ahb_gates 36>,
+				 <&tcon_ch0_clk>,
+				 <&tcon_ch1_clk>;
+			clock-names = "ahb",
+				      "tcon-ch0",
+				      "tcon-ch1";
+			clock-output-names = "tcon-pixel-clock";
+			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				tcon0_in: port@0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+
+					tcon0_in_be0: endpoint@0 {
+						reg = <0>;
+						remote-endpoint = <&be0_out_tcon0>;
+					};
+				};
+
+				tcon0_out: port@1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+				};
+			};
+		};
+
 		pwm: pwm@01c20e00 {
 			compatible = "allwinner,sun5i-a13-pwm";
 			reg = <0x01c20e00 0xc>;
@@ -215,6 +258,75 @@
 			#pwm-cells = <3>;
 			status = "disabled";
 		};
+
+		fe0: display-frontend@01e00000 {
+			compatible = "allwinner,sun5i-a13-display-frontend";
+			reg = <0x01e00000 0x20000>;
+			interrupts = <47>;
+			clocks = <&ahb_gates 46>, <&de_fe_clk>,
+				 <&dram_gates 25>;
+			clock-names = "ahb", "mod",
+				      "ram";
+			resets = <&de_fe_clk>;
+			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				fe0_out: port@1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+
+					fe0_out_be0: endpoint@0 {
+						reg = <0>;
+						remote-endpoint = <&be0_in_fe0>;
+					};
+				};
+			};
+		};
+
+		be0: display-backend@01e60000 {
+			compatible = "allwinner,sun5i-a13-display-backend";
+			reg = <0x01e60000 0x10000>;
+			clocks = <&ahb_gates 44>, <&de_be_clk>,
+				 <&dram_gates 26>;
+			clock-names = "ahb", "mod",
+				      "ram";
+			resets = <&de_be_clk>;
+			status = "disabled";
+
+			assigned-clocks = <&de_be_clk>;
+			assigned-clock-rates = <300000000>;
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				be0_in: port@0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+
+					be0_in_fe0: endpoint@0 {
+						reg = <0>;
+						remote-endpoint = <&fe0_out_be0>;
+					};
+				};
+
+				be0_out: port@1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+
+					be0_out_tcon0: endpoint@0 {
+						reg = <0>;
+						remote-endpoint = <&tcon0_in_be0>;
+					};
+				};
+			};
+		};
 	};
 };
 
diff --git a/arch/arm/boot/dts/sun5i-r8.dtsi b/arch/arm/boot/dts/sun5i-r8.dtsi
index c04cf690b858..8b058f53b7dc 100644
--- a/arch/arm/boot/dts/sun5i-r8.dtsi
+++ b/arch/arm/boot/dts/sun5i-r8.dtsi
@@ -76,122 +76,12 @@
 				};
 			};
 		};
-
-		tcon0: lcd-controller@01c0c000 {
-			compatible = "allwinner,sun5i-a13-tcon";
-			reg = <0x01c0c000 0x1000>;
-			interrupts = <44>;
-			resets = <&tcon_ch0_clk 1>;
-			reset-names = "lcd";
-			clocks = <&ahb_gates 36>,
-				 <&tcon_ch0_clk>,
-				 <&tcon_ch1_clk>;
-			clock-names = "ahb",
-				      "tcon-ch0",
-				      "tcon-ch1";
-			clock-output-names = "tcon-pixel-clock";
-			status = "disabled";
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				tcon0_in: port@0 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <0>;
-
-					tcon0_in_be0: endpoint@0 {
-						reg = <0>;
-						remote-endpoint = <&be0_out_tcon0>;
-					};
-				};
-
-				tcon0_out: port@1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					tcon0_out_tve0: endpoint@1 {
-						reg = <1>;
-						remote-endpoint = <&tve0_in_tcon0>;
-					};
-				};
-			};
-		};
-
-		fe0: display-frontend@01e00000 {
-			compatible = "allwinner,sun5i-a13-display-frontend";
-			reg = <0x01e00000 0x20000>;
-			interrupts = <47>;
-			clocks = <&ahb_gates 46>, <&de_fe_clk>,
-				 <&dram_gates 25>;
-			clock-names = "ahb", "mod",
-				      "ram";
-			resets = <&de_fe_clk>;
-			status = "disabled";
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				fe0_out: port@1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					fe0_out_be0: endpoint@0 {
-						reg = <0>;
-						remote-endpoint = <&be0_in_fe0>;
-					};
-				};
-			};
-		};
-
-		be0: display-backend@01e60000 {
-			compatible = "allwinner,sun5i-a13-display-backend";
-			reg = <0x01e60000 0x10000>;
-			clocks = <&ahb_gates 44>, <&de_be_clk>,
-				 <&dram_gates 26>;
-			clock-names = "ahb", "mod",
-				      "ram";
-			resets = <&de_be_clk>;
-			status = "disabled";
-
-			assigned-clocks = <&de_be_clk>;
-			assigned-clock-rates = <300000000>;
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				be0_in: port@0 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <0>;
-
-					be0_in_fe0: endpoint@0 {
-						reg = <0>;
-						remote-endpoint = <&fe0_out_be0>;
-					};
-				};
-
-				be0_out: port@1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					be0_out_tcon0: endpoint@0 {
-						reg = <0>;
-						remote-endpoint = <&tcon0_in_be0>;
-					};
-				};
-			};
-		};
 	};
+};
 
-	display-engine {
-		compatible = "allwinner,sun5i-a13-display-engine";
-		allwinner,pipelines = <&fe0>;
+&tcon0_out {
+	tcon0_out_tve0: endpoint@1 {
+		reg = <1>;
+		remote-endpoint = <&tve0_in_tcon0>;
 	};
 };
-- 
2.8.2

[PATCH 15/20] ARM: sun5i: Move display blocks to A13

[Maxime Ripard]

Most of the display engine is shared between the R8 and the A13. Move the
common parts to the ?13 DTSI.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/boot/dts/sun5i-a13.dtsi | 112 ++++++++++++++++++++++++++++++++++++
 arch/arm/boot/dts/sun5i-r8.dtsi  | 120 ++-------------------------------------
 2 files changed, 117 insertions(+), 115 deletions(-)

diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
index 79b5d513c142..e012890e0cf2 100644
--- a/arch/arm/boot/dts/sun5i-a13.dtsi
+++ b/arch/arm/boot/dts/sun5i-a13.dtsi
@@ -207,7 +207,50 @@
 		};
 	};
 
+	display-engine {
+		compatible = "allwinner,sun5i-a13-display-engine";
+		allwinner,pipelines = <&fe0>;
+	};
+
 	soc at 01c00000 {
+		tcon0: lcd-controller at 01c0c000 {
+			compatible = "allwinner,sun5i-a13-tcon";
+			reg = <0x01c0c000 0x1000>;
+			interrupts = <44>;
+			resets = <&tcon_ch0_clk 1>;
+			reset-names = "lcd";
+			clocks = <&ahb_gates 36>,
+				 <&tcon_ch0_clk>,
+				 <&tcon_ch1_clk>;
+			clock-names = "ahb",
+				      "tcon-ch0",
+				      "tcon-ch1";
+			clock-output-names = "tcon-pixel-clock";
+			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				tcon0_in: port at 0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+
+					tcon0_in_be0: endpoint at 0 {
+						reg = <0>;
+						remote-endpoint = <&be0_out_tcon0>;
+					};
+				};
+
+				tcon0_out: port at 1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+				};
+			};
+		};
+
 		pwm: pwm at 01c20e00 {
 			compatible = "allwinner,sun5i-a13-pwm";
 			reg = <0x01c20e00 0xc>;
@@ -215,6 +258,75 @@
 			#pwm-cells = <3>;
 			status = "disabled";
 		};
+
+		fe0: display-frontend at 01e00000 {
+			compatible = "allwinner,sun5i-a13-display-frontend";
+			reg = <0x01e00000 0x20000>;
+			interrupts = <47>;
+			clocks = <&ahb_gates 46>, <&de_fe_clk>,
+				 <&dram_gates 25>;
+			clock-names = "ahb", "mod",
+				      "ram";
+			resets = <&de_fe_clk>;
+			status = "disabled";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				fe0_out: port at 1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+
+					fe0_out_be0: endpoint at 0 {
+						reg = <0>;
+						remote-endpoint = <&be0_in_fe0>;
+					};
+				};
+			};
+		};
+
+		be0: display-backend at 01e60000 {
+			compatible = "allwinner,sun5i-a13-display-backend";
+			reg = <0x01e60000 0x10000>;
+			clocks = <&ahb_gates 44>, <&de_be_clk>,
+				 <&dram_gates 26>;
+			clock-names = "ahb", "mod",
+				      "ram";
+			resets = <&de_be_clk>;
+			status = "disabled";
+
+			assigned-clocks = <&de_be_clk>;
+			assigned-clock-rates = <300000000>;
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				be0_in: port at 0 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <0>;
+
+					be0_in_fe0: endpoint at 0 {
+						reg = <0>;
+						remote-endpoint = <&fe0_out_be0>;
+					};
+				};
+
+				be0_out: port at 1 {
+					#address-cells = <1>;
+					#size-cells = <0>;
+					reg = <1>;
+
+					be0_out_tcon0: endpoint at 0 {
+						reg = <0>;
+						remote-endpoint = <&tcon0_in_be0>;
+					};
+				};
+			};
+		};
 	};
 };
 
diff --git a/arch/arm/boot/dts/sun5i-r8.dtsi b/arch/arm/boot/dts/sun5i-r8.dtsi
index c04cf690b858..8b058f53b7dc 100644
--- a/arch/arm/boot/dts/sun5i-r8.dtsi
+++ b/arch/arm/boot/dts/sun5i-r8.dtsi
@@ -76,122 +76,12 @@
 				};
 			};
 		};
-
-		tcon0: lcd-controller at 01c0c000 {
-			compatible = "allwinner,sun5i-a13-tcon";
-			reg = <0x01c0c000 0x1000>;
-			interrupts = <44>;
-			resets = <&tcon_ch0_clk 1>;
-			reset-names = "lcd";
-			clocks = <&ahb_gates 36>,
-				 <&tcon_ch0_clk>,
-				 <&tcon_ch1_clk>;
-			clock-names = "ahb",
-				      "tcon-ch0",
-				      "tcon-ch1";
-			clock-output-names = "tcon-pixel-clock";
-			status = "disabled";
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				tcon0_in: port at 0 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <0>;
-
-					tcon0_in_be0: endpoint at 0 {
-						reg = <0>;
-						remote-endpoint = <&be0_out_tcon0>;
-					};
-				};
-
-				tcon0_out: port at 1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					tcon0_out_tve0: endpoint at 1 {
-						reg = <1>;
-						remote-endpoint = <&tve0_in_tcon0>;
-					};
-				};
-			};
-		};
-
-		fe0: display-frontend at 01e00000 {
-			compatible = "allwinner,sun5i-a13-display-frontend";
-			reg = <0x01e00000 0x20000>;
-			interrupts = <47>;
-			clocks = <&ahb_gates 46>, <&de_fe_clk>,
-				 <&dram_gates 25>;
-			clock-names = "ahb", "mod",
-				      "ram";
-			resets = <&de_fe_clk>;
-			status = "disabled";
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				fe0_out: port at 1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					fe0_out_be0: endpoint at 0 {
-						reg = <0>;
-						remote-endpoint = <&be0_in_fe0>;
-					};
-				};
-			};
-		};
-
-		be0: display-backend at 01e60000 {
-			compatible = "allwinner,sun5i-a13-display-backend";
-			reg = <0x01e60000 0x10000>;
-			clocks = <&ahb_gates 44>, <&de_be_clk>,
-				 <&dram_gates 26>;
-			clock-names = "ahb", "mod",
-				      "ram";
-			resets = <&de_be_clk>;
-			status = "disabled";
-
-			assigned-clocks = <&de_be_clk>;
-			assigned-clock-rates = <300000000>;
-
-			ports {
-				#address-cells = <1>;
-				#size-cells = <0>;
-
-				be0_in: port at 0 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <0>;
-
-					be0_in_fe0: endpoint at 0 {
-						reg = <0>;
-						remote-endpoint = <&fe0_out_be0>;
-					};
-				};
-
-				be0_out: port at 1 {
-					#address-cells = <1>;
-					#size-cells = <0>;
-					reg = <1>;
-
-					be0_out_tcon0: endpoint at 0 {
-						reg = <0>;
-						remote-endpoint = <&tcon0_in_be0>;
-					};
-				};
-			};
-		};
 	};
+};
 
-	display-engine {
-		compatible = "allwinner,sun5i-a13-display-engine";
-		allwinner,pipelines = <&fe0>;
+&tcon0_out {
+	tcon0_out_tve0: endpoint at 1 {
+		reg = <1>;
+		remote-endpoint = <&tve0_in_tcon0>;
 	};
 };
-- 
2.8.2

[PATCH 16/20] ARM: sun5i: a13-olinuxino: Enable VGA bridge

[Maxime Ripard]

Now that we have support for the VGA bridges using our DRM driver, enable
the display engine for the Olimex A13-Olinuxino.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/boot/dts/sun5i-a13-olinuxino.dts | 34 +++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/arch/arm/boot/dts/sun5i-a13-olinuxino.dts b/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
index b3c234c65ea1..b3298d231258 100644
--- a/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
+++ b/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
@@ -72,6 +72,27 @@
 			default-state = "on";
 		};
 	};
+
+	bridge {
+		compatible = "dumb-vga-bridge";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		port@0 {
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			vga_input: endpoint@0 {
+				reg = <0>;
+				remote-endpoint = <&tcon0_out_vga>;
+			};
+		};
+	};
+};
+
+&be0 {
+	status = "okay";
 };
 
 &ehci0 {
@@ -211,6 +232,19 @@
 	status = "okay";
 };
 
+&tcon0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&lcd_rgb666_pins>;
+	status = "okay";
+};
+
+&tcon0_out {
+	tcon0_out_vga: endpoint@0 {
+		reg = <0>;
+		remote-endpoint = <&vga_input>;
+	};
+};
+
 &uart1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart1_pins_b>;
-- 
2.8.2

[PATCH 16/20] ARM: sun5i: a13-olinuxino: Enable VGA bridge

[Maxime Ripard]

Now that we have support for the VGA bridges using our DRM driver, enable
the display engine for the Olimex A13-Olinuxino.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/boot/dts/sun5i-a13-olinuxino.dts | 34 +++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/arch/arm/boot/dts/sun5i-a13-olinuxino.dts b/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
index b3c234c65ea1..b3298d231258 100644
--- a/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
+++ b/arch/arm/boot/dts/sun5i-a13-olinuxino.dts
@@ -72,6 +72,27 @@
 			default-state = "on";
 		};
 	};
+
+	bridge {
+		compatible = "dumb-vga-bridge";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		port at 0 {
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			vga_input: endpoint at 0 {
+				reg = <0>;
+				remote-endpoint = <&tcon0_out_vga>;
+			};
+		};
+	};
+};
+
+&be0 {
+	status = "okay";
 };
 
 &ehci0 {
@@ -211,6 +232,19 @@
 	status = "okay";
 };
 
+&tcon0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&lcd_rgb666_pins>;
+	status = "okay";
+};
+
+&tcon0_out {
+	tcon0_out_vga: endpoint at 0 {
+		reg = <0>;
+		remote-endpoint = <&vga_input>;
+	};
+};
+
 &uart1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&uart1_pins_b>;
-- 
2.8.2

[PATCH 17/20] ARM: multi_v7: Enable sun4i DRM driver

[Maxime Ripard]

Enable the new DRM driver in the multi_v7 defconfig

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index f7e0d49b515a..80591f3e867e 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -552,6 +552,7 @@ CONFIG_DRM_ATMEL_HLCDC=m
 CONFIG_DRM_RCAR_DU=m
 CONFIG_DRM_RCAR_HDMI=y
 CONFIG_DRM_RCAR_LVDS=y
+CONFIG_DRM_SUN4I=m
 CONFIG_DRM_TEGRA=y
 CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0=m
 CONFIG_DRM_PANEL_SIMPLE=y
-- 
2.8.2

[PATCH 17/20] ARM: multi_v7: Enable sun4i DRM driver

[Maxime Ripard]

Enable the new DRM driver in the multi_v7 defconfig

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index f7e0d49b515a..80591f3e867e 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -552,6 +552,7 @@ CONFIG_DRM_ATMEL_HLCDC=m
 CONFIG_DRM_RCAR_DU=m
 CONFIG_DRM_RCAR_HDMI=y
 CONFIG_DRM_RCAR_LVDS=y
+CONFIG_DRM_SUN4I=m
 CONFIG_DRM_TEGRA=y
 CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0=m
 CONFIG_DRM_PANEL_SIMPLE=y
-- 
2.8.2

[PATCH 18/20] ARM: multi_v7: enable VGA bridge

[Maxime Ripard]

Enable the RGB to VGA bridge driver in the defconfig

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 80591f3e867e..5987688dea81 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -536,6 +536,7 @@ CONFIG_DRM=y
 CONFIG_DRM_I2C_ADV7511=m
 # CONFIG_DRM_I2C_CH7006 is not set
 # CONFIG_DRM_I2C_SIL164 is not set
+CONFIG_DRM_DUMB_VGA=m
 CONFIG_DRM_NXP_PTN3460=m
 CONFIG_DRM_PARADE_PS8622=m
 CONFIG_DRM_NOUVEAU=m
-- 
2.8.2

[PATCH 18/20] ARM: multi_v7: enable VGA bridge

[Maxime Ripard]

Enable the RGB to VGA bridge driver in the defconfig

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 80591f3e867e..5987688dea81 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -536,6 +536,7 @@ CONFIG_DRM=y
 CONFIG_DRM_I2C_ADV7511=m
 # CONFIG_DRM_I2C_CH7006 is not set
 # CONFIG_DRM_I2C_SIL164 is not set
+CONFIG_DRM_DUMB_VGA=m
 CONFIG_DRM_NXP_PTN3460=m
 CONFIG_DRM_PARADE_PS8622=m
 CONFIG_DRM_NOUVEAU=m
-- 
2.8.2

[PATCH 19/20] ARM: sunxi: Enable sun4i DRM driver

[Maxime Ripard]

Enable the new DRM driver in the sunxi default configuration

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 arch/arm/configs/sunxi_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/sunxi_defconfig b/arch/arm/configs/sunxi_defconfig
index e20ae3925e36..6a1447cf8feb 100644
--- a/arch/arm/configs/sunxi_defconfig
+++ b/arch/arm/configs/sunxi_defconfig
@@ -97,6 +97,8 @@ CONFIG_MEDIA_SUPPORT=y
 CONFIG_MEDIA_RC_SUPPORT=y
 CONFIG_RC_DEVICES=y
 CONFIG_IR_SUNXI=y
+CONFIG_DRM=y
+CONFIG_DRM_SUN4I=y
 CONFIG_FB=y
 CONFIG_FB_SIMPLE=y
 CONFIG_FRAMEBUFFER_CONSOLE=y
-- 
2.8.2

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[PATCH 19/20] ARM: sunxi: Enable sun4i DRM driver

[Maxime Ripard]

Enable the new DRM driver in the sunxi default configuration

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/configs/sunxi_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/sunxi_defconfig b/arch/arm/configs/sunxi_defconfig
index e20ae3925e36..6a1447cf8feb 100644
--- a/arch/arm/configs/sunxi_defconfig
+++ b/arch/arm/configs/sunxi_defconfig
@@ -97,6 +97,8 @@ CONFIG_MEDIA_SUPPORT=y
 CONFIG_MEDIA_RC_SUPPORT=y
 CONFIG_RC_DEVICES=y
 CONFIG_IR_SUNXI=y
+CONFIG_DRM=y
+CONFIG_DRM_SUN4I=y
 CONFIG_FB=y
 CONFIG_FB_SIMPLE=y
 CONFIG_FRAMEBUFFER_CONSOLE=y
-- 
2.8.2

[PATCH 19/20] ARM: sunxi: Enable sun4i DRM driver

[Maxime Ripard]

Enable the new DRM driver in the sunxi default configuration

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/configs/sunxi_defconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/configs/sunxi_defconfig b/arch/arm/configs/sunxi_defconfig
index e20ae3925e36..6a1447cf8feb 100644
--- a/arch/arm/configs/sunxi_defconfig
+++ b/arch/arm/configs/sunxi_defconfig
@@ -97,6 +97,8 @@ CONFIG_MEDIA_SUPPORT=y
 CONFIG_MEDIA_RC_SUPPORT=y
 CONFIG_RC_DEVICES=y
 CONFIG_IR_SUNXI=y
+CONFIG_DRM=y
+CONFIG_DRM_SUN4I=y
 CONFIG_FB=y
 CONFIG_FB_SIMPLE=y
 CONFIG_FRAMEBUFFER_CONSOLE=y
-- 
2.8.2

[PATCH 20/20] ARM: sunxi: Enable VGA bridge

[Maxime Ripard]

Enable the VGA bridge used on the A13-Olinuxino in the sunxi defconfig

Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
 arch/arm/configs/sunxi_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/sunxi_defconfig b/arch/arm/configs/sunxi_defconfig
index 6a1447cf8feb..3676cc2db2eb 100644
--- a/arch/arm/configs/sunxi_defconfig
+++ b/arch/arm/configs/sunxi_defconfig
@@ -98,6 +98,7 @@ CONFIG_MEDIA_RC_SUPPORT=y
 CONFIG_RC_DEVICES=y
 CONFIG_IR_SUNXI=y
 CONFIG_DRM=y
+CONFIG_DRM_DUMB_VGA=y
 CONFIG_DRM_SUN4I=y
 CONFIG_FB=y
 CONFIG_FB_SIMPLE=y
-- 
2.8.2

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[PATCH 20/20] ARM: sunxi: Enable VGA bridge

[Maxime Ripard]

Enable the VGA bridge used on the A13-Olinuxino in the sunxi defconfig

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/configs/sunxi_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/sunxi_defconfig b/arch/arm/configs/sunxi_defconfig
index 6a1447cf8feb..3676cc2db2eb 100644
--- a/arch/arm/configs/sunxi_defconfig
+++ b/arch/arm/configs/sunxi_defconfig
@@ -98,6 +98,7 @@ CONFIG_MEDIA_RC_SUPPORT=y
 CONFIG_RC_DEVICES=y
 CONFIG_IR_SUNXI=y
 CONFIG_DRM=y
+CONFIG_DRM_DUMB_VGA=y
 CONFIG_DRM_SUN4I=y
 CONFIG_FB=y
 CONFIG_FB_SIMPLE=y
-- 
2.8.2

[PATCH 20/20] ARM: sunxi: Enable VGA bridge

[Maxime Ripard]

Enable the VGA bridge used on the A13-Olinuxino in the sunxi defconfig

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 arch/arm/configs/sunxi_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/sunxi_defconfig b/arch/arm/configs/sunxi_defconfig
index 6a1447cf8feb..3676cc2db2eb 100644
--- a/arch/arm/configs/sunxi_defconfig
+++ b/arch/arm/configs/sunxi_defconfig
@@ -98,6 +98,7 @@ CONFIG_MEDIA_RC_SUPPORT=y
 CONFIG_RC_DEVICES=y
 CONFIG_IR_SUNXI=y
 CONFIG_DRM=y
+CONFIG_DRM_DUMB_VGA=y
 CONFIG_DRM_SUN4I=y
 CONFIG_FB=y
 CONFIG_FB_SIMPLE=y
-- 
2.8.2

Re: [PATCH 12/20] drm/sun4i: Add bridge support

[Daniel Vetter]

On Mon, May 16, 2016 at 2:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Our RGB bus can be either connected to a bridge or a panel. While the panel
> support was already there, the bridge was not.
>
> Fix that.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

For bridge support the only thing you need is to set
drm_encoder->bridge. Why do you need to hand-roll your own bridge
support? That pretty muchmeans you'll do it slightly differently (e.g.
you don't bother with a lot of the calls), which will make sharing
bridge drivers ever so harder. And also reviewing code, since using
shared code but slightly differently is really confusing.
-Daniel

> ---
>  drivers/gpu/drm/sun4i/sun4i_drv.c  |  4 +--
>  drivers/gpu/drm/sun4i/sun4i_rgb.c  | 56 +++++++++++++++++++++++++++-----------
>  drivers/gpu/drm/sun4i/sun4i_tcon.c | 48 ++++++++++++++++++++++++++++----
>  drivers/gpu/drm/sun4i/sun4i_tcon.h |  1 +
>  4 files changed, 86 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
> index 257d2b4f3645..1f9e00db747d 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_drv.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
> @@ -268,8 +268,8 @@ static int sun4i_drv_add_endpoints(struct device *dev,
>                 }
>
>                 /*
> -                * If the node is our TCON, the first port is used for our
> -                * panel, and will not be part of the
> +                * If the node is our TCON, the first port is used for
> +                * panel or bridges, and will not be part of the
>                  * component framework.
>                  */
>                 if (sun4i_drv_node_is_tcon(node)) {
> diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> index b46d2c15dc95..c3c611b08269 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> @@ -161,7 +161,12 @@ static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
>
>         DRM_DEBUG_DRIVER("Enabling RGB output\n");
>
> -       drm_panel_enable(tcon->panel);
> +       if (!IS_ERR(tcon->panel))
> +               drm_panel_enable(tcon->panel);
> +
> +       if (!IS_ERR(tcon->bridge))
> +               drm_bridge_enable(tcon->bridge);
> +
>         sun4i_tcon_channel_enable(tcon, 0);
>  }
>
> @@ -174,7 +179,12 @@ static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
>         DRM_DEBUG_DRIVER("Disabling RGB output\n");
>
>         sun4i_tcon_channel_disable(tcon, 0);
> -       drm_panel_disable(tcon->panel);
> +
> +       if (!IS_ERR(tcon->bridge))
> +               drm_bridge_disable(tcon->bridge);
> +
> +       if (!IS_ERR(tcon->panel))
> +               drm_panel_disable(tcon->panel);
>  }
>
>  static void sun4i_rgb_encoder_mode_set(struct drm_encoder *encoder,
> @@ -216,10 +226,6 @@ int sun4i_rgb_init(struct drm_device *drm)
>         struct sun4i_rgb *rgb;
>         int ret;
>
> -       /* If we don't have a panel, there's no point in going on */
> -       if (IS_ERR(tcon->panel))
> -               return -ENODEV;
> -
>         rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
>         if (!rgb)
>                 return -ENOMEM;
> @@ -240,19 +246,37 @@ int sun4i_rgb_init(struct drm_device *drm)
>         /* The RGB encoder can only work with the TCON channel 0 */
>         rgb->encoder.possible_crtcs = BIT(0);
>
> -       drm_connector_helper_add(&rgb->connector,
> -                                &sun4i_rgb_con_helper_funcs);
> -       ret = drm_connector_init(drm, &rgb->connector,
> -                                &sun4i_rgb_con_funcs,
> -                                DRM_MODE_CONNECTOR_Unknown);
> -       if (ret) {
> -               dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
> -               goto err_cleanup_connector;
> +       if (!IS_ERR(tcon->panel)) {
> +               drm_connector_helper_add(&rgb->connector,
> +                                        &sun4i_rgb_con_helper_funcs);
> +               ret = drm_connector_init(drm, &rgb->connector,
> +                                        &sun4i_rgb_con_funcs,
> +                                        DRM_MODE_CONNECTOR_Unknown);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
> +                       goto err_cleanup_connector;
> +               }
> +
> +               drm_mode_connector_attach_encoder(&rgb->connector,
> +                                                 &rgb->encoder);
> +
> +               ret = drm_panel_attach(tcon->panel, &rgb->connector);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't attach our panel\n");
> +                       goto err_cleanup_connector;
> +               }
>         }
>
> -       drm_mode_connector_attach_encoder(&rgb->connector, &rgb->encoder);
> +       if (!IS_ERR(tcon->bridge)) {
> +               rgb->encoder.bridge = tcon->bridge;
> +               tcon->bridge->encoder = &rgb->encoder;
>
> -       drm_panel_attach(tcon->panel, &rgb->connector);
> +               ret = drm_bridge_attach(drm, tcon->bridge);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't attach our bridge\n");
> +                       goto err_cleanup_connector;
> +               }
> +       }
>
>         return 0;
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index eed6a9e8d9a6..4618d98913b4 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -432,6 +432,40 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
>         return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
>  }
>
> +static struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node)
> +{
> +       struct device_node *port, *remote, *child;
> +       struct device_node *end_node = NULL;
> +
> +       /* Inputs are listed first, then outputs */
> +       port = of_graph_get_port_by_id(node, 1);
> +
> +       /*
> +        * Our first output is the RGB interface where the panel will
> +        * be connected.
> +        */
> +       for_each_child_of_node(port, child) {
> +               u32 reg;
> +
> +               of_property_read_u32(child, "reg", &reg);
> +               if (reg == 0)
> +                       end_node = child;
> +       }
> +
> +       if (!end_node) {
> +               DRM_DEBUG_DRIVER("Missing bridge endpoint\n");
> +               return ERR_PTR(-ENODEV);
> +       }
> +
> +       remote = of_graph_get_remote_port_parent(end_node);
> +       if (!remote) {
> +               DRM_DEBUG_DRIVER("Enable to parse remote node\n");
> +               return ERR_PTR(-EINVAL);
> +       }
> +
> +       return of_drm_find_bridge(remote) ?: ERR_PTR(-EPROBE_DEFER);
> +}
> +
>  static int sun4i_tcon_bind(struct device *dev, struct device *master,
>                            void *data)
>  {
> @@ -485,8 +519,9 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
>         }
>
>         tcon->panel = sun4i_tcon_find_panel(dev->of_node);
> -       if (IS_ERR(tcon->panel)) {
> -               dev_info(dev, "No panel found... RGB output disabled\n");
> +       tcon->bridge = sun4i_tcon_find_bridge(dev->of_node);
> +       if (IS_ERR(tcon->panel) && IS_ERR(tcon->bridge)) {
> +               dev_info(dev, "No panel or bridge found... RGB output disabled\n");
>                 return 0;
>         }
>
> @@ -515,19 +550,22 @@ static struct component_ops sun4i_tcon_ops = {
>  static int sun4i_tcon_probe(struct platform_device *pdev)
>  {
>         struct device_node *node = pdev->dev.of_node;
> +       struct drm_bridge *bridge;
>         struct drm_panel *panel;
>
>         /*
> -        * The panel is not ready.
> +        * Neither the bridge or the panel is ready.
>          * Defer the probe.
>          */
>         panel = sun4i_tcon_find_panel(node);
> +       bridge = sun4i_tcon_find_bridge(node);
>
>         /*
>          * If we don't have a panel endpoint, just go on
>          */
> -       if (PTR_ERR(panel) == -EPROBE_DEFER) {
> -               DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
> +       if ((PTR_ERR(panel) == -EPROBE_DEFER) &&
> +           (PTR_ERR(bridge) == -EPROBE_DEFER)) {
> +               DRM_DEBUG_DRIVER("Still waiting for our panel/bridge. Deferring...\n");
>                 return -EPROBE_DEFER;
>         }
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
> index 0e0b11db401b..31069027d7fb 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
> @@ -162,6 +162,7 @@ struct sun4i_tcon {
>         /* Platform adjustments */
>         bool                            has_mux;
>
> +       struct drm_bridge               *bridge;
>         struct drm_panel                *panel;
>  };
>
> --
> 2.8.2
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

[PATCH 12/20] drm/sun4i: Add bridge support

[Daniel Vetter]

On Mon, May 16, 2016 at 2:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Our RGB bus can be either connected to a bridge or a panel. While the panel
> support was already there, the bridge was not.
>
> Fix that.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

For bridge support the only thing you need is to set
drm_encoder->bridge. Why do you need to hand-roll your own bridge
support? That pretty muchmeans you'll do it slightly differently (e.g.
you don't bother with a lot of the calls), which will make sharing
bridge drivers ever so harder. And also reviewing code, since using
shared code but slightly differently is really confusing.
-Daniel

> ---
>  drivers/gpu/drm/sun4i/sun4i_drv.c  |  4 +--
>  drivers/gpu/drm/sun4i/sun4i_rgb.c  | 56 +++++++++++++++++++++++++++-----------
>  drivers/gpu/drm/sun4i/sun4i_tcon.c | 48 ++++++++++++++++++++++++++++----
>  drivers/gpu/drm/sun4i/sun4i_tcon.h |  1 +
>  4 files changed, 86 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c
> index 257d2b4f3645..1f9e00db747d 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_drv.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_drv.c
> @@ -268,8 +268,8 @@ static int sun4i_drv_add_endpoints(struct device *dev,
>                 }
>
>                 /*
> -                * If the node is our TCON, the first port is used for our
> -                * panel, and will not be part of the
> +                * If the node is our TCON, the first port is used for
> +                * panel or bridges, and will not be part of the
>                  * component framework.
>                  */
>                 if (sun4i_drv_node_is_tcon(node)) {
> diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> index b46d2c15dc95..c3c611b08269 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> @@ -161,7 +161,12 @@ static void sun4i_rgb_encoder_enable(struct drm_encoder *encoder)
>
>         DRM_DEBUG_DRIVER("Enabling RGB output\n");
>
> -       drm_panel_enable(tcon->panel);
> +       if (!IS_ERR(tcon->panel))
> +               drm_panel_enable(tcon->panel);
> +
> +       if (!IS_ERR(tcon->bridge))
> +               drm_bridge_enable(tcon->bridge);
> +
>         sun4i_tcon_channel_enable(tcon, 0);
>  }
>
> @@ -174,7 +179,12 @@ static void sun4i_rgb_encoder_disable(struct drm_encoder *encoder)
>         DRM_DEBUG_DRIVER("Disabling RGB output\n");
>
>         sun4i_tcon_channel_disable(tcon, 0);
> -       drm_panel_disable(tcon->panel);
> +
> +       if (!IS_ERR(tcon->bridge))
> +               drm_bridge_disable(tcon->bridge);
> +
> +       if (!IS_ERR(tcon->panel))
> +               drm_panel_disable(tcon->panel);
>  }
>
>  static void sun4i_rgb_encoder_mode_set(struct drm_encoder *encoder,
> @@ -216,10 +226,6 @@ int sun4i_rgb_init(struct drm_device *drm)
>         struct sun4i_rgb *rgb;
>         int ret;
>
> -       /* If we don't have a panel, there's no point in going on */
> -       if (IS_ERR(tcon->panel))
> -               return -ENODEV;
> -
>         rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
>         if (!rgb)
>                 return -ENOMEM;
> @@ -240,19 +246,37 @@ int sun4i_rgb_init(struct drm_device *drm)
>         /* The RGB encoder can only work with the TCON channel 0 */
>         rgb->encoder.possible_crtcs = BIT(0);
>
> -       drm_connector_helper_add(&rgb->connector,
> -                                &sun4i_rgb_con_helper_funcs);
> -       ret = drm_connector_init(drm, &rgb->connector,
> -                                &sun4i_rgb_con_funcs,
> -                                DRM_MODE_CONNECTOR_Unknown);
> -       if (ret) {
> -               dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
> -               goto err_cleanup_connector;
> +       if (!IS_ERR(tcon->panel)) {
> +               drm_connector_helper_add(&rgb->connector,
> +                                        &sun4i_rgb_con_helper_funcs);
> +               ret = drm_connector_init(drm, &rgb->connector,
> +                                        &sun4i_rgb_con_funcs,
> +                                        DRM_MODE_CONNECTOR_Unknown);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't initialise the rgb connector\n");
> +                       goto err_cleanup_connector;
> +               }
> +
> +               drm_mode_connector_attach_encoder(&rgb->connector,
> +                                                 &rgb->encoder);
> +
> +               ret = drm_panel_attach(tcon->panel, &rgb->connector);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't attach our panel\n");
> +                       goto err_cleanup_connector;
> +               }
>         }
>
> -       drm_mode_connector_attach_encoder(&rgb->connector, &rgb->encoder);
> +       if (!IS_ERR(tcon->bridge)) {
> +               rgb->encoder.bridge = tcon->bridge;
> +               tcon->bridge->encoder = &rgb->encoder;
>
> -       drm_panel_attach(tcon->panel, &rgb->connector);
> +               ret = drm_bridge_attach(drm, tcon->bridge);
> +               if (ret) {
> +                       dev_err(drm->dev, "Couldn't attach our bridge\n");
> +                       goto err_cleanup_connector;
> +               }
> +       }
>
>         return 0;
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index eed6a9e8d9a6..4618d98913b4 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -432,6 +432,40 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
>         return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
>  }
>
> +static struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node)
> +{
> +       struct device_node *port, *remote, *child;
> +       struct device_node *end_node = NULL;
> +
> +       /* Inputs are listed first, then outputs */
> +       port = of_graph_get_port_by_id(node, 1);
> +
> +       /*
> +        * Our first output is the RGB interface where the panel will
> +        * be connected.
> +        */
> +       for_each_child_of_node(port, child) {
> +               u32 reg;
> +
> +               of_property_read_u32(child, "reg", &reg);
> +               if (reg == 0)
> +                       end_node = child;
> +       }
> +
> +       if (!end_node) {
> +               DRM_DEBUG_DRIVER("Missing bridge endpoint\n");
> +               return ERR_PTR(-ENODEV);
> +       }
> +
> +       remote = of_graph_get_remote_port_parent(end_node);
> +       if (!remote) {
> +               DRM_DEBUG_DRIVER("Enable to parse remote node\n");
> +               return ERR_PTR(-EINVAL);
> +       }
> +
> +       return of_drm_find_bridge(remote) ?: ERR_PTR(-EPROBE_DEFER);
> +}
> +
>  static int sun4i_tcon_bind(struct device *dev, struct device *master,
>                            void *data)
>  {
> @@ -485,8 +519,9 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master,
>         }
>
>         tcon->panel = sun4i_tcon_find_panel(dev->of_node);
> -       if (IS_ERR(tcon->panel)) {
> -               dev_info(dev, "No panel found... RGB output disabled\n");
> +       tcon->bridge = sun4i_tcon_find_bridge(dev->of_node);
> +       if (IS_ERR(tcon->panel) && IS_ERR(tcon->bridge)) {
> +               dev_info(dev, "No panel or bridge found... RGB output disabled\n");
>                 return 0;
>         }
>
> @@ -515,19 +550,22 @@ static struct component_ops sun4i_tcon_ops = {
>  static int sun4i_tcon_probe(struct platform_device *pdev)
>  {
>         struct device_node *node = pdev->dev.of_node;
> +       struct drm_bridge *bridge;
>         struct drm_panel *panel;
>
>         /*
> -        * The panel is not ready.
> +        * Neither the bridge or the panel is ready.
>          * Defer the probe.
>          */
>         panel = sun4i_tcon_find_panel(node);
> +       bridge = sun4i_tcon_find_bridge(node);
>
>         /*
>          * If we don't have a panel endpoint, just go on
>          */
> -       if (PTR_ERR(panel) == -EPROBE_DEFER) {
> -               DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
> +       if ((PTR_ERR(panel) == -EPROBE_DEFER) &&
> +           (PTR_ERR(bridge) == -EPROBE_DEFER)) {
> +               DRM_DEBUG_DRIVER("Still waiting for our panel/bridge. Deferring...\n");
>                 return -EPROBE_DEFER;
>         }
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
> index 0e0b11db401b..31069027d7fb 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
> @@ -162,6 +162,7 @@ struct sun4i_tcon {
>         /* Platform adjustments */
>         bool                            has_mux;
>
> +       struct drm_bridge               *bridge;
>         struct drm_panel                *panel;
>  };
>
> --
> 2.8.2
>
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Laurent Pinchart]

Hi Maxime,

Thank you for the patch.

On Monday 16 May 2016 14:47:13 Maxime Ripard wrote:
> Some boards have an entirely passive RGB to VGA bridge, based on either
> DACs or resistor ladders.
> 
> Those might or might not have an i2c bus routed to the VGA connector in
> order to access the screen EDIDs.
> 
> Add a bridge that doesn't do anything but expose the modes available on the
> screen, either based on the EDIDs if available, or based on the XGA
> standards.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
>  drivers/gpu/drm/bridge/Kconfig                     |   6 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 ++++++++++++++++++
>  4 files changed, 233 insertions(+)
>  create mode 100644
> Documentation/devicetree/bindings/display/bridge/dumb-vga.txt create mode
> 100644 drivers/gpu/drm/bridge/dumb-vga.c
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt new file
> mode 100644
> index 000000000000..757f04de97f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> @@ -0,0 +1,40 @@
> +Passive RGB to VGA bridge
> +-------------------------
> +
> +This binding is aimed for entirely passive RGB to VGA bridges that do not
> +require any configuration.
> +
> +Required properties:
> +
> +- compatible: Should be "dumb-vga-bridge"
> +
> +Optional properties:
> +
> +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
> +
> +Required nodes:
> +
> +This device has one video port. Its connection is modelled using the OF
> +graph bindings specified in Documentation/devicetree/bindings/graph.txt.
> This +connection is meant to be the RGB input bus.

Should the bridge have two ports, one input port connected to a display engine 
and one output port connected to a VGA connector ?

> +
> +
> +Example
> +-------
> +
> +bridge {
> +        compatible = "dumb-vga-bridge";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        port@0 {
> +                reg = <0>;
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                vga_input: endpoint@0 {
> +                        reg = <0>;
> +                        remote-endpoint = <&tcon0_out_vga>;
> +               };
> +        };
> +};
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 8f7423f18da5..cf279956cbec 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -17,6 +17,12 @@ config DRM_ANALOGIX_ANX78XX
>  	  the HDMI output of an application processor to MyDP
>  	  or DisplayPort.
> 
> +config DRM_DUMB_VGA
> +	tristate "Dumb RGB to VGA Bridge support"
> +	select DRM_KMS_HELPER
> +	help
> +	  Support for passive RGB to VGA bridges
> +
>  config DRM_DW_HDMI
>  	tristate
>  	select DRM_KMS_HELPER
> diff --git a/drivers/gpu/drm/bridge/Makefile
> b/drivers/gpu/drm/bridge/Makefile index 96b13b30e6ab..63f21120e8f8 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,6 +1,7 @@
>  ccflags-y := -Iinclude/drm
> 
>  obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
> +obj-$(CONFIG_DRM_DUMB_VGA) += dumb-vga.o
>  obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>  obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
>  obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
> diff --git a/drivers/gpu/drm/bridge/dumb-vga.c
> b/drivers/gpu/drm/bridge/dumb-vga.c new file mode 100644
> index 000000000000..2864fa535bf8
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/dumb-vga.c
> @@ -0,0 +1,186 @@
> +
> +#include <linux/module.h>
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +
> +struct dumb_vga {
> +	struct drm_bridge	bridge;
> +	struct drm_connector	connector;
> +
> +	struct i2c_adapter	*ddc;
> +};
> +
> +static inline struct dumb_vga *
> +drm_bridge_to_dumb_vga(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct dumb_vga, bridge);
> +}
> +
> +static inline struct dumb_vga *
> +drm_connector_to_dumb_vga(struct drm_connector *connector)
> +{
> +	return container_of(connector, struct dumb_vga, connector);
> +}
> +
> +static int dumb_vga_get_modes(struct drm_connector *connector)
> +{
> +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> +	struct edid *edid;
> +	int ret;
> +
> +	if (!vga->ddc)
> +		goto fallback;
> +
> +	edid = drm_get_edid(connector, vga->ddc);
> +	if (!edid) {
> +		DRM_INFO("EDID readout failed, falling back to standard modes\n");
> +		goto fallback;
> +	}
> +
> +	drm_mode_connector_update_edid_property(connector, edid);
> +	return drm_add_edid_modes(connector, edid);
> +
> +fallback:
> +	/*
> +	 * In case we cannot retrieve the EDIDs (broken or missing i2c
> +	 * bus), fallback on the XGA standards
> +	 */
> +	ret = drm_add_modes_noedid(connector, 1920, 1200);

The DRM core adds modes up to 1024x768 in 
drm_helper_probe_single_connector_modes(). I wonder if it really makes sense 
to override that in drivers, compared to increasing the maximum resolution in 
the core. What we can reasonable expect from a VGA monitor doesn't really 
depend on which display engine it is connected to.

> +	/* And prefer a mode pretty much anyone can handle */
> +	drm_set_preferred_mode(connector, 1024, 768);
> +
> +	return ret;
> +}
> +
> +static struct drm_encoder *
> +dumb_vga_best_encoder(struct drm_connector *connector)
> +{
> +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> +
> +	return vga->bridge.encoder;
> +}
> +
> +static struct drm_connector_helper_funcs dumb_vga_con_helper_funcs = {
> +	.get_modes	= dumb_vga_get_modes,
> +	.best_encoder	= dumb_vga_best_encoder,
> +};
> +
> +static enum drm_connector_status
> +dumb_vga_connector_detect(struct drm_connector *connector, bool force)
> +{
> +	return connector_status_connected;

Shouldn't that be connector_status_unknown if you have no information about 
the connection status ?

Would it make sense to add an optional GPIO-based connection detection to this 
driver ?

> +}
> +
> +static void
> +dumb_vga_connector_destroy(struct drm_connector *connector)
> +{
> +	drm_connector_cleanup(connector);
> +}
> +
> +static struct drm_connector_funcs dumb_vga_con_funcs = {
> +	.dpms			= drm_atomic_helper_connector_dpms,
> +	.detect			= dumb_vga_connector_detect,
> +	.fill_modes		= drm_helper_probe_single_connector_modes,
> +	.destroy		= dumb_vga_connector_destroy,
> +	.reset			= drm_atomic_helper_connector_reset,
> +	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static int dumb_vga_attach(struct drm_bridge *bridge)
> +{
> +	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
> +	int ret;
> +
> +	if (!bridge->encoder) {
> +		DRM_ERROR("Missing encoder\n");
> +		return -ENODEV;
> +	}
> +
> +	drm_connector_helper_add(&vga->connector,
> +				 &dumb_vga_con_helper_funcs);
> +	ret = drm_connector_init(bridge->dev, &vga->connector,
> +				 &dumb_vga_con_funcs, DRM_MODE_CONNECTOR_VGA);
> +	if (ret) {
> +		DRM_ERROR("Failed to initialize connector\n");
> +		return ret;
> +	}
> +
> +	drm_mode_connector_attach_encoder(&vga->connector,
> +					  bridge->encoder);
> +
> +	return 0;
> +}
> +
> +static void dumb_vga_nop(struct drm_bridge *bridge) {};
> +
> +static struct drm_bridge_funcs dumb_vga_bridge_funcs = {
> +	.attach		= dumb_vga_attach,
> +	.enable		= dumb_vga_nop,
> +	.disable	= dumb_vga_nop,
> +	.pre_enable	= dumb_vga_nop,
> +	.post_disable	= dumb_vga_nop,
> +};
> +
> +static int dumb_vga_probe(struct platform_device *pdev)
> +{
> +	struct dumb_vga *vga;
> +	struct device_node *ddc;
> +
> +	vga = devm_kzalloc(&pdev->dev, sizeof(*vga), GFP_KERNEL);
> +	if (!vga)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, vga);
> +
> +	ddc = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
> +	if (ddc) {
> +		vga->ddc = of_find_i2c_adapter_by_node(ddc);

You're leaking the reference to the I2C adapter.

Also, shouldn't you use of_get_i2c_adapter_by_node() ? Otherwise you won't 
take a reference to the adapter module.

> +		of_node_put(ddc);
> +
> +		if (!vga->ddc) {
> +			dev_err(&pdev->dev, "Couldn't retrieve i2c bus\n");
> +			return -EPROBE_DEFER;
> +		}
> +	} else {
> +		dev_info(&pdev->dev,
> +			 "No i2c bus specified... Disabling EDID readout\n");
> +	}
> +
> +	vga->bridge.funcs = &dumb_vga_bridge_funcs;
> +	vga->bridge.of_node = pdev->dev.of_node;
> +
> +	return drm_bridge_add(&vga->bridge);
> +}
> +
> +static int dumb_vga_remove(struct platform_device *pdev)
> +{
> +	struct dumb_vga *vga = platform_get_drvdata(pdev);
> +
> +	drm_bridge_remove(&vga->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id dumb_vga_match[] = {
> +	{ .compatible = "dumb-vga-bridge" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, dumb_vga_match);
> +
> +struct platform_driver dumb_vga_driver = {
> +	.probe	= dumb_vga_probe,
> +	.remove	= dumb_vga_remove,
> +	.driver		= {
> +		.name		= "dumb-vga-bridge",
> +		.of_match_table	= dumb_vga_match,
> +	},
> +};
> +module_platform_driver(dumb_vga_driver);
> +
> +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
> +MODULE_DESCRIPTION("Dumb RGB to VGA bridge driver");
> +MODULE_LICENSE("GPL");

-- 
Regards,

Laurent Pinchart

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Laurent Pinchart]

Hi Maxime,

Thank you for the patch.

On Monday 16 May 2016 14:47:13 Maxime Ripard wrote:
> Some boards have an entirely passive RGB to VGA bridge, based on either
> DACs or resistor ladders.
> 
> Those might or might not have an i2c bus routed to the VGA connector in
> order to access the screen EDIDs.
> 
> Add a bridge that doesn't do anything but expose the modes available on the
> screen, either based on the EDIDs if available, or based on the XGA
> standards.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
>  drivers/gpu/drm/bridge/Kconfig                     |   6 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 ++++++++++++++++++
>  4 files changed, 233 insertions(+)
>  create mode 100644
> Documentation/devicetree/bindings/display/bridge/dumb-vga.txt create mode
> 100644 drivers/gpu/drm/bridge/dumb-vga.c
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt new file
> mode 100644
> index 000000000000..757f04de97f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> @@ -0,0 +1,40 @@
> +Passive RGB to VGA bridge
> +-------------------------
> +
> +This binding is aimed for entirely passive RGB to VGA bridges that do not
> +require any configuration.
> +
> +Required properties:
> +
> +- compatible: Should be "dumb-vga-bridge"
> +
> +Optional properties:
> +
> +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
> +
> +Required nodes:
> +
> +This device has one video port. Its connection is modelled using the OF
> +graph bindings specified in Documentation/devicetree/bindings/graph.txt.
> This +connection is meant to be the RGB input bus.

Should the bridge have two ports, one input port connected to a display engine 
and one output port connected to a VGA connector ?

> +
> +
> +Example
> +-------
> +
> +bridge {
> +        compatible = "dumb-vga-bridge";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        port@0 {
> +                reg = <0>;
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                vga_input: endpoint@0 {
> +                        reg = <0>;
> +                        remote-endpoint = <&tcon0_out_vga>;
> +               };
> +        };
> +};
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 8f7423f18da5..cf279956cbec 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -17,6 +17,12 @@ config DRM_ANALOGIX_ANX78XX
>  	  the HDMI output of an application processor to MyDP
>  	  or DisplayPort.
> 
> +config DRM_DUMB_VGA
> +	tristate "Dumb RGB to VGA Bridge support"
> +	select DRM_KMS_HELPER
> +	help
> +	  Support for passive RGB to VGA bridges
> +
>  config DRM_DW_HDMI
>  	tristate
>  	select DRM_KMS_HELPER
> diff --git a/drivers/gpu/drm/bridge/Makefile
> b/drivers/gpu/drm/bridge/Makefile index 96b13b30e6ab..63f21120e8f8 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,6 +1,7 @@
>  ccflags-y := -Iinclude/drm
> 
>  obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
> +obj-$(CONFIG_DRM_DUMB_VGA) += dumb-vga.o
>  obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>  obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
>  obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
> diff --git a/drivers/gpu/drm/bridge/dumb-vga.c
> b/drivers/gpu/drm/bridge/dumb-vga.c new file mode 100644
> index 000000000000..2864fa535bf8
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/dumb-vga.c
> @@ -0,0 +1,186 @@
> +
> +#include <linux/module.h>
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +
> +struct dumb_vga {
> +	struct drm_bridge	bridge;
> +	struct drm_connector	connector;
> +
> +	struct i2c_adapter	*ddc;
> +};
> +
> +static inline struct dumb_vga *
> +drm_bridge_to_dumb_vga(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct dumb_vga, bridge);
> +}
> +
> +static inline struct dumb_vga *
> +drm_connector_to_dumb_vga(struct drm_connector *connector)
> +{
> +	return container_of(connector, struct dumb_vga, connector);
> +}
> +
> +static int dumb_vga_get_modes(struct drm_connector *connector)
> +{
> +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> +	struct edid *edid;
> +	int ret;
> +
> +	if (!vga->ddc)
> +		goto fallback;
> +
> +	edid = drm_get_edid(connector, vga->ddc);
> +	if (!edid) {
> +		DRM_INFO("EDID readout failed, falling back to standard modes\n");
> +		goto fallback;
> +	}
> +
> +	drm_mode_connector_update_edid_property(connector, edid);
> +	return drm_add_edid_modes(connector, edid);
> +
> +fallback:
> +	/*
> +	 * In case we cannot retrieve the EDIDs (broken or missing i2c
> +	 * bus), fallback on the XGA standards
> +	 */
> +	ret = drm_add_modes_noedid(connector, 1920, 1200);

The DRM core adds modes up to 1024x768 in 
drm_helper_probe_single_connector_modes(). I wonder if it really makes sense 
to override that in drivers, compared to increasing the maximum resolution in 
the core. What we can reasonable expect from a VGA monitor doesn't really 
depend on which display engine it is connected to.

> +	/* And prefer a mode pretty much anyone can handle */
> +	drm_set_preferred_mode(connector, 1024, 768);
> +
> +	return ret;
> +}
> +
> +static struct drm_encoder *
> +dumb_vga_best_encoder(struct drm_connector *connector)
> +{
> +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> +
> +	return vga->bridge.encoder;
> +}
> +
> +static struct drm_connector_helper_funcs dumb_vga_con_helper_funcs = {
> +	.get_modes	= dumb_vga_get_modes,
> +	.best_encoder	= dumb_vga_best_encoder,
> +};
> +
> +static enum drm_connector_status
> +dumb_vga_connector_detect(struct drm_connector *connector, bool force)
> +{
> +	return connector_status_connected;

Shouldn't that be connector_status_unknown if you have no information about 
the connection status ?

Would it make sense to add an optional GPIO-based connection detection to this 
driver ?

> +}
> +
> +static void
> +dumb_vga_connector_destroy(struct drm_connector *connector)
> +{
> +	drm_connector_cleanup(connector);
> +}
> +
> +static struct drm_connector_funcs dumb_vga_con_funcs = {
> +	.dpms			= drm_atomic_helper_connector_dpms,
> +	.detect			= dumb_vga_connector_detect,
> +	.fill_modes		= drm_helper_probe_single_connector_modes,
> +	.destroy		= dumb_vga_connector_destroy,
> +	.reset			= drm_atomic_helper_connector_reset,
> +	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static int dumb_vga_attach(struct drm_bridge *bridge)
> +{
> +	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
> +	int ret;
> +
> +	if (!bridge->encoder) {
> +		DRM_ERROR("Missing encoder\n");
> +		return -ENODEV;
> +	}
> +
> +	drm_connector_helper_add(&vga->connector,
> +				 &dumb_vga_con_helper_funcs);
> +	ret = drm_connector_init(bridge->dev, &vga->connector,
> +				 &dumb_vga_con_funcs, DRM_MODE_CONNECTOR_VGA);
> +	if (ret) {
> +		DRM_ERROR("Failed to initialize connector\n");
> +		return ret;
> +	}
> +
> +	drm_mode_connector_attach_encoder(&vga->connector,
> +					  bridge->encoder);
> +
> +	return 0;
> +}
> +
> +static void dumb_vga_nop(struct drm_bridge *bridge) {};
> +
> +static struct drm_bridge_funcs dumb_vga_bridge_funcs = {
> +	.attach		= dumb_vga_attach,
> +	.enable		= dumb_vga_nop,
> +	.disable	= dumb_vga_nop,
> +	.pre_enable	= dumb_vga_nop,
> +	.post_disable	= dumb_vga_nop,
> +};
> +
> +static int dumb_vga_probe(struct platform_device *pdev)
> +{
> +	struct dumb_vga *vga;
> +	struct device_node *ddc;
> +
> +	vga = devm_kzalloc(&pdev->dev, sizeof(*vga), GFP_KERNEL);
> +	if (!vga)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, vga);
> +
> +	ddc = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
> +	if (ddc) {
> +		vga->ddc = of_find_i2c_adapter_by_node(ddc);

You're leaking the reference to the I2C adapter.

Also, shouldn't you use of_get_i2c_adapter_by_node() ? Otherwise you won't 
take a reference to the adapter module.

> +		of_node_put(ddc);
> +
> +		if (!vga->ddc) {
> +			dev_err(&pdev->dev, "Couldn't retrieve i2c bus\n");
> +			return -EPROBE_DEFER;
> +		}
> +	} else {
> +		dev_info(&pdev->dev,
> +			 "No i2c bus specified... Disabling EDID readout\n");
> +	}
> +
> +	vga->bridge.funcs = &dumb_vga_bridge_funcs;
> +	vga->bridge.of_node = pdev->dev.of_node;
> +
> +	return drm_bridge_add(&vga->bridge);
> +}
> +
> +static int dumb_vga_remove(struct platform_device *pdev)
> +{
> +	struct dumb_vga *vga = platform_get_drvdata(pdev);
> +
> +	drm_bridge_remove(&vga->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id dumb_vga_match[] = {
> +	{ .compatible = "dumb-vga-bridge" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, dumb_vga_match);
> +
> +struct platform_driver dumb_vga_driver = {
> +	.probe	= dumb_vga_probe,
> +	.remove	= dumb_vga_remove,
> +	.driver		= {
> +		.name		= "dumb-vga-bridge",
> +		.of_match_table	= dumb_vga_match,
> +	},
> +};
> +module_platform_driver(dumb_vga_driver);
> +
> +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
> +MODULE_DESCRIPTION("Dumb RGB to VGA bridge driver");
> +MODULE_LICENSE("GPL");

-- 
Regards,

Laurent Pinchart

[PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Laurent Pinchart]

Hi Maxime,

Thank you for the patch.

On Monday 16 May 2016 14:47:13 Maxime Ripard wrote:
> Some boards have an entirely passive RGB to VGA bridge, based on either
> DACs or resistor ladders.
> 
> Those might or might not have an i2c bus routed to the VGA connector in
> order to access the screen EDIDs.
> 
> Add a bridge that doesn't do anything but expose the modes available on the
> screen, either based on the EDIDs if available, or based on the XGA
> standards.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
>  drivers/gpu/drm/bridge/Kconfig                     |   6 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 ++++++++++++++++++
>  4 files changed, 233 insertions(+)
>  create mode 100644
> Documentation/devicetree/bindings/display/bridge/dumb-vga.txt create mode
> 100644 drivers/gpu/drm/bridge/dumb-vga.c
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt new file
> mode 100644
> index 000000000000..757f04de97f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> @@ -0,0 +1,40 @@
> +Passive RGB to VGA bridge
> +-------------------------
> +
> +This binding is aimed for entirely passive RGB to VGA bridges that do not
> +require any configuration.
> +
> +Required properties:
> +
> +- compatible: Should be "dumb-vga-bridge"
> +
> +Optional properties:
> +
> +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
> +
> +Required nodes:
> +
> +This device has one video port. Its connection is modelled using the OF
> +graph bindings specified in Documentation/devicetree/bindings/graph.txt.
> This +connection is meant to be the RGB input bus.

Should the bridge have two ports, one input port connected to a display engine 
and one output port connected to a VGA connector ?

> +
> +
> +Example
> +-------
> +
> +bridge {
> +        compatible = "dumb-vga-bridge";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        port at 0 {
> +                reg = <0>;
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                vga_input: endpoint at 0 {
> +                        reg = <0>;
> +                        remote-endpoint = <&tcon0_out_vga>;
> +               };
> +        };
> +};
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 8f7423f18da5..cf279956cbec 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -17,6 +17,12 @@ config DRM_ANALOGIX_ANX78XX
>  	  the HDMI output of an application processor to MyDP
>  	  or DisplayPort.
> 
> +config DRM_DUMB_VGA
> +	tristate "Dumb RGB to VGA Bridge support"
> +	select DRM_KMS_HELPER
> +	help
> +	  Support for passive RGB to VGA bridges
> +
>  config DRM_DW_HDMI
>  	tristate
>  	select DRM_KMS_HELPER
> diff --git a/drivers/gpu/drm/bridge/Makefile
> b/drivers/gpu/drm/bridge/Makefile index 96b13b30e6ab..63f21120e8f8 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,6 +1,7 @@
>  ccflags-y := -Iinclude/drm
> 
>  obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
> +obj-$(CONFIG_DRM_DUMB_VGA) += dumb-vga.o
>  obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>  obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
>  obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
> diff --git a/drivers/gpu/drm/bridge/dumb-vga.c
> b/drivers/gpu/drm/bridge/dumb-vga.c new file mode 100644
> index 000000000000..2864fa535bf8
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/dumb-vga.c
> @@ -0,0 +1,186 @@
> +
> +#include <linux/module.h>
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +
> +struct dumb_vga {
> +	struct drm_bridge	bridge;
> +	struct drm_connector	connector;
> +
> +	struct i2c_adapter	*ddc;
> +};
> +
> +static inline struct dumb_vga *
> +drm_bridge_to_dumb_vga(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct dumb_vga, bridge);
> +}
> +
> +static inline struct dumb_vga *
> +drm_connector_to_dumb_vga(struct drm_connector *connector)
> +{
> +	return container_of(connector, struct dumb_vga, connector);
> +}
> +
> +static int dumb_vga_get_modes(struct drm_connector *connector)
> +{
> +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> +	struct edid *edid;
> +	int ret;
> +
> +	if (!vga->ddc)
> +		goto fallback;
> +
> +	edid = drm_get_edid(connector, vga->ddc);
> +	if (!edid) {
> +		DRM_INFO("EDID readout failed, falling back to standard modes\n");
> +		goto fallback;
> +	}
> +
> +	drm_mode_connector_update_edid_property(connector, edid);
> +	return drm_add_edid_modes(connector, edid);
> +
> +fallback:
> +	/*
> +	 * In case we cannot retrieve the EDIDs (broken or missing i2c
> +	 * bus), fallback on the XGA standards
> +	 */
> +	ret = drm_add_modes_noedid(connector, 1920, 1200);

The DRM core adds modes up to 1024x768 in 
drm_helper_probe_single_connector_modes(). I wonder if it really makes sense 
to override that in drivers, compared to increasing the maximum resolution in 
the core. What we can reasonable expect from a VGA monitor doesn't really 
depend on which display engine it is connected to.

> +	/* And prefer a mode pretty much anyone can handle */
> +	drm_set_preferred_mode(connector, 1024, 768);
> +
> +	return ret;
> +}
> +
> +static struct drm_encoder *
> +dumb_vga_best_encoder(struct drm_connector *connector)
> +{
> +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> +
> +	return vga->bridge.encoder;
> +}
> +
> +static struct drm_connector_helper_funcs dumb_vga_con_helper_funcs = {
> +	.get_modes	= dumb_vga_get_modes,
> +	.best_encoder	= dumb_vga_best_encoder,
> +};
> +
> +static enum drm_connector_status
> +dumb_vga_connector_detect(struct drm_connector *connector, bool force)
> +{
> +	return connector_status_connected;

Shouldn't that be connector_status_unknown if you have no information about 
the connection status ?

Would it make sense to add an optional GPIO-based connection detection to this 
driver ?

> +}
> +
> +static void
> +dumb_vga_connector_destroy(struct drm_connector *connector)
> +{
> +	drm_connector_cleanup(connector);
> +}
> +
> +static struct drm_connector_funcs dumb_vga_con_funcs = {
> +	.dpms			= drm_atomic_helper_connector_dpms,
> +	.detect			= dumb_vga_connector_detect,
> +	.fill_modes		= drm_helper_probe_single_connector_modes,
> +	.destroy		= dumb_vga_connector_destroy,
> +	.reset			= drm_atomic_helper_connector_reset,
> +	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static int dumb_vga_attach(struct drm_bridge *bridge)
> +{
> +	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
> +	int ret;
> +
> +	if (!bridge->encoder) {
> +		DRM_ERROR("Missing encoder\n");
> +		return -ENODEV;
> +	}
> +
> +	drm_connector_helper_add(&vga->connector,
> +				 &dumb_vga_con_helper_funcs);
> +	ret = drm_connector_init(bridge->dev, &vga->connector,
> +				 &dumb_vga_con_funcs, DRM_MODE_CONNECTOR_VGA);
> +	if (ret) {
> +		DRM_ERROR("Failed to initialize connector\n");
> +		return ret;
> +	}
> +
> +	drm_mode_connector_attach_encoder(&vga->connector,
> +					  bridge->encoder);
> +
> +	return 0;
> +}
> +
> +static void dumb_vga_nop(struct drm_bridge *bridge) {};
> +
> +static struct drm_bridge_funcs dumb_vga_bridge_funcs = {
> +	.attach		= dumb_vga_attach,
> +	.enable		= dumb_vga_nop,
> +	.disable	= dumb_vga_nop,
> +	.pre_enable	= dumb_vga_nop,
> +	.post_disable	= dumb_vga_nop,
> +};
> +
> +static int dumb_vga_probe(struct platform_device *pdev)
> +{
> +	struct dumb_vga *vga;
> +	struct device_node *ddc;
> +
> +	vga = devm_kzalloc(&pdev->dev, sizeof(*vga), GFP_KERNEL);
> +	if (!vga)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, vga);
> +
> +	ddc = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
> +	if (ddc) {
> +		vga->ddc = of_find_i2c_adapter_by_node(ddc);

You're leaking the reference to the I2C adapter.

Also, shouldn't you use of_get_i2c_adapter_by_node() ? Otherwise you won't 
take a reference to the adapter module.

> +		of_node_put(ddc);
> +
> +		if (!vga->ddc) {
> +			dev_err(&pdev->dev, "Couldn't retrieve i2c bus\n");
> +			return -EPROBE_DEFER;
> +		}
> +	} else {
> +		dev_info(&pdev->dev,
> +			 "No i2c bus specified... Disabling EDID readout\n");
> +	}
> +
> +	vga->bridge.funcs = &dumb_vga_bridge_funcs;
> +	vga->bridge.of_node = pdev->dev.of_node;
> +
> +	return drm_bridge_add(&vga->bridge);
> +}
> +
> +static int dumb_vga_remove(struct platform_device *pdev)
> +{
> +	struct dumb_vga *vga = platform_get_drvdata(pdev);
> +
> +	drm_bridge_remove(&vga->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id dumb_vga_match[] = {
> +	{ .compatible = "dumb-vga-bridge" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, dumb_vga_match);
> +
> +struct platform_driver dumb_vga_driver = {
> +	.probe	= dumb_vga_probe,
> +	.remove	= dumb_vga_remove,
> +	.driver		= {
> +		.name		= "dumb-vga-bridge",
> +		.of_match_table	= dumb_vga_match,
> +	},
> +};
> +module_platform_driver(dumb_vga_driver);
> +
> +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
> +MODULE_DESCRIPTION("Dumb RGB to VGA bridge driver");
> +MODULE_LICENSE("GPL");

-- 
Regards,

Laurent Pinchart

Re: [PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Rob Herring]

On Mon, May 16, 2016 at 7:47 AM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Some boards have an entirely passive RGB to VGA bridge, based on either
> DACs or resistor ladders.
>
> Those might or might not have an i2c bus routed to the VGA connector in
> order to access the screen EDIDs.
>
> Add a bridge that doesn't do anything but expose the modes available on the
> screen, either based on the EDIDs if available, or based on the XGA
> standards.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
>  drivers/gpu/drm/bridge/Kconfig                     |   6 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
>  4 files changed, 233 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
>  create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> new file mode 100644
> index 000000000000..757f04de97f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> @@ -0,0 +1,40 @@
> +Passive RGB to VGA bridge
> +-------------------------
> +
> +This binding is aimed for entirely passive RGB to VGA bridges that do not
> +require any configuration.

No reset or enable lines or regulators?

> +
> +Required properties:
> +
> +- compatible: Should be "dumb-vga-bridge"
> +
> +Optional properties:
> +
> +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor

The i2c bus is a property of the connector, not the bridge chip, so it
belongs in a VGA connector node (which we already have binding for).

I think for the really "dumb" (or transparent case), you should only
have a connector. For anything more complex, then you should have both
a DAC and connector node.

On the driver side, I think we could handle multiple connectors with a
single driver. Ideally, that would work with any DRM driver that has a
connector node.

> +
> +Required nodes:
> +
> +This device has one video port. Its connection is modelled using the OF
> +graph bindings specified in Documentation/devicetree/bindings/graph.txt. This
> +connection is meant to be the RGB input bus.
> +
> +
> +Example
> +-------
> +
> +bridge {
> +        compatible = "dumb-vga-bridge";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        port@0 {
> +                reg = <0>;
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                vga_input: endpoint@0 {
> +                        reg = <0>;
> +                        remote-endpoint = <&tcon0_out_vga>;
> +               };
> +        };
> +};
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Rob Herring]

On Mon, May 16, 2016 at 7:47 AM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Some boards have an entirely passive RGB to VGA bridge, based on either
> DACs or resistor ladders.
>
> Those might or might not have an i2c bus routed to the VGA connector in
> order to access the screen EDIDs.
>
> Add a bridge that doesn't do anything but expose the modes available on the
> screen, either based on the EDIDs if available, or based on the XGA
> standards.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
>  drivers/gpu/drm/bridge/Kconfig                     |   6 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
>  4 files changed, 233 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
>  create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> new file mode 100644
> index 000000000000..757f04de97f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> @@ -0,0 +1,40 @@
> +Passive RGB to VGA bridge
> +-------------------------
> +
> +This binding is aimed for entirely passive RGB to VGA bridges that do not
> +require any configuration.

No reset or enable lines or regulators?

> +
> +Required properties:
> +
> +- compatible: Should be "dumb-vga-bridge"
> +
> +Optional properties:
> +
> +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor

The i2c bus is a property of the connector, not the bridge chip, so it
belongs in a VGA connector node (which we already have binding for).

I think for the really "dumb" (or transparent case), you should only
have a connector. For anything more complex, then you should have both
a DAC and connector node.

On the driver side, I think we could handle multiple connectors with a
single driver. Ideally, that would work with any DRM driver that has a
connector node.

> +
> +Required nodes:
> +
> +This device has one video port. Its connection is modelled using the OF
> +graph bindings specified in Documentation/devicetree/bindings/graph.txt. This
> +connection is meant to be the RGB input bus.
> +
> +
> +Example
> +-------
> +
> +bridge {
> +        compatible = "dumb-vga-bridge";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        port@0 {
> +                reg = <0>;
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                vga_input: endpoint@0 {
> +                        reg = <0>;
> +                        remote-endpoint = <&tcon0_out_vga>;
> +               };
> +        };
> +};

[PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Rob Herring]

On Mon, May 16, 2016 at 7:47 AM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Some boards have an entirely passive RGB to VGA bridge, based on either
> DACs or resistor ladders.
>
> Those might or might not have an i2c bus routed to the VGA connector in
> order to access the screen EDIDs.
>
> Add a bridge that doesn't do anything but expose the modes available on the
> screen, either based on the EDIDs if available, or based on the XGA
> standards.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
>  drivers/gpu/drm/bridge/Kconfig                     |   6 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
>  4 files changed, 233 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
>  create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> new file mode 100644
> index 000000000000..757f04de97f3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> @@ -0,0 +1,40 @@
> +Passive RGB to VGA bridge
> +-------------------------
> +
> +This binding is aimed for entirely passive RGB to VGA bridges that do not
> +require any configuration.

No reset or enable lines or regulators?

> +
> +Required properties:
> +
> +- compatible: Should be "dumb-vga-bridge"
> +
> +Optional properties:
> +
> +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor

The i2c bus is a property of the connector, not the bridge chip, so it
belongs in a VGA connector node (which we already have binding for).

I think for the really "dumb" (or transparent case), you should only
have a connector. For anything more complex, then you should have both
a DAC and connector node.

On the driver side, I think we could handle multiple connectors with a
single driver. Ideally, that would work with any DRM driver that has a
connector node.

> +
> +Required nodes:
> +
> +This device has one video port. Its connection is modelled using the OF
> +graph bindings specified in Documentation/devicetree/bindings/graph.txt. This
> +connection is meant to be the RGB input bus.
> +
> +
> +Example
> +-------
> +
> +bridge {
> +        compatible = "dumb-vga-bridge";
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        port at 0 {
> +                reg = <0>;
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +
> +                vga_input: endpoint at 0 {
> +                        reg = <0>;
> +                        remote-endpoint = <&tcon0_out_vga>;
> +               };
> +        };
> +};

Re: [PATCH 19/20] ARM: sunxi: Enable sun4i DRM driver

[Chen-Yu Tsai]

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Enable the new DRM driver in the sunxi default configuration
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Acked-by: Chen-Yu Tsai <wens@csie.org>

[PATCH 19/20] ARM: sunxi: Enable sun4i DRM driver

[Chen-Yu Tsai]

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Enable the new DRM driver in the sunxi default configuration
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Acked-by: Chen-Yu Tsai <wens@csie.org>

Re: [PATCH 04/20] clk: sunxi: display: Add per-clock flags

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> The TCON channel 0 clock that is the parent clock of our pixel clock is
> expected to change its rate depending on the resolution we want to output
> in our display engine.
>
> However, since it's only a mux, the only way it can do that is by changing
> its parents rate.
>
> Allow to give flags in our display clocks description, and add the
> CLK_SET_RATE_PARENT flag for the TCON channel 0 flag.
>
> Fixes: a3b4956ee6d9 ("clk: sunxi: display: Add per-clock flags")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/clk/sunxi/clk-sun4i-display.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/sunxi/clk-sun4i-display.c b/drivers/clk/sunxi/clk-sun4i-display.c
> index 445a7498d6df..9780fac6d029 100644
> --- a/drivers/clk/sunxi/clk-sun4i-display.c
> +++ b/drivers/clk/sunxi/clk-sun4i-display.c
> @@ -33,6 +33,8 @@ struct sun4i_a10_display_clk_data {
>
>         u8      width_div;
>         u8      width_mux;
> +

Don't really need this separator, but I'm ok either way.

> +       u32     flags;
>  };
>
>  struct reset_data {
> @@ -166,7 +168,7 @@ static void __init sun4i_a10_display_init(struct device_node *node,
>                                      data->has_div ? &div->hw : NULL,
>                                      data->has_div ? &clk_divider_ops : NULL,
>                                      &gate->hw, &clk_gate_ops,
> -                                    0);
> +                                    data->flags);
>         if (IS_ERR(clk)) {
>                 pr_err("%s: Couldn't register the clock\n", clk_name);
>                 goto free_div;
> @@ -232,6 +234,7 @@ static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initcon
>         .offset_rst     = 29,
>         .offset_mux     = 24,
>         .width_mux      = 2,
> +       .flags          = CLK_SET_RATE_PARENT,
>  };
>
>  static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
> --
> 2.8.2
>

Acked-by: Chen-Yu Tsai <wens@csie.org>

[PATCH 04/20] clk: sunxi: display: Add per-clock flags

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> The TCON channel 0 clock that is the parent clock of our pixel clock is
> expected to change its rate depending on the resolution we want to output
> in our display engine.
>
> However, since it's only a mux, the only way it can do that is by changing
> its parents rate.
>
> Allow to give flags in our display clocks description, and add the
> CLK_SET_RATE_PARENT flag for the TCON channel 0 flag.
>
> Fixes: a3b4956ee6d9 ("clk: sunxi: display: Add per-clock flags")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/clk/sunxi/clk-sun4i-display.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/sunxi/clk-sun4i-display.c b/drivers/clk/sunxi/clk-sun4i-display.c
> index 445a7498d6df..9780fac6d029 100644
> --- a/drivers/clk/sunxi/clk-sun4i-display.c
> +++ b/drivers/clk/sunxi/clk-sun4i-display.c
> @@ -33,6 +33,8 @@ struct sun4i_a10_display_clk_data {
>
>         u8      width_div;
>         u8      width_mux;
> +

Don't really need this separator, but I'm ok either way.

> +       u32     flags;
>  };
>
>  struct reset_data {
> @@ -166,7 +168,7 @@ static void __init sun4i_a10_display_init(struct device_node *node,
>                                      data->has_div ? &div->hw : NULL,
>                                      data->has_div ? &clk_divider_ops : NULL,
>                                      &gate->hw, &clk_gate_ops,
> -                                    0);
> +                                    data->flags);
>         if (IS_ERR(clk)) {
>                 pr_err("%s: Couldn't register the clock\n", clk_name);
>                 goto free_div;
> @@ -232,6 +234,7 @@ static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initcon
>         .offset_rst     = 29,
>         .offset_mux     = 24,
>         .width_mux      = 2,
> +       .flags          = CLK_SET_RATE_PARENT,
>  };
>
>  static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
> --
> 2.8.2
>

Acked-by: Chen-Yu Tsai <wens@csie.org>

Re: [PATCH 03/20] clk: sunxi: tcon-ch1: Do not return a negative error in get_parent

[Chen-Yu Tsai]

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> get_parent is supposed to return an unsigned 8 bit integer, so returning
> -EINVAL is a bad idea.
>
> Remove it.
>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Acked-by: Chen-Yu Tsai <wens@csie.org>

[PATCH 03/20] clk: sunxi: tcon-ch1: Do not return a negative error in get_parent

[Chen-Yu Tsai]

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> get_parent is supposed to return an unsigned 8 bit integer, so returning
> -EINVAL is a bad idea.
>
> Remove it.
>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Acked-by: Chen-Yu Tsai <wens@csie.org>

Re: [PATCH 14/20] ARM: sun5i: a13: Add LCD pins

[Chen-Yu Tsai]

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> The RGB bus can be used in several configurations, one of which being the
> RGB666.
>
> Add a pinctrl group for that case.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Acked-by: Chen-Yu Tsai <wens@csie.org>

> ---
>  arch/arm/boot/dts/sun5i-a13.dtsi | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
> index 263d46dbc7e6..79b5d513c142 100644
> --- a/arch/arm/boot/dts/sun5i-a13.dtsi
> +++ b/arch/arm/boot/dts/sun5i-a13.dtsi
> @@ -237,6 +237,16 @@
>  &pio {
>         compatible = "allwinner,sun5i-a13-pinctrl";
>
> +       lcd_rgb666_pins: lcd_rgb666@0 {
> +               allwinner,pins = "PD2", "PD3", "PD4", "PD5", "PD6", "PD7",
> +                                "PD10", "PD11", "PD12", "PD13", "PD14", "PD15",
> +                                "PD18", "PD19", "PD20", "PD21", "PD22", "PD23",
> +                                "PD24", "PD25", "PD26", "PD27";
> +               allwinner,function = "lcd0";
> +               allwinner,drive = <SUN4I_PINCTRL_10_MA>;

Just a thought: would we ever need to increase the drive strength for very high
resolutions?

> +               allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
> +       };
> +
>         uart1_pins_a: uart1@0 {
>                 allwinner,pins = "PE10", "PE11";
>                 allwinner,function = "uart1";
> --
> 2.8.2
>

[PATCH 14/20] ARM: sun5i: a13: Add LCD pins

[Chen-Yu Tsai]

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> The RGB bus can be used in several configurations, one of which being the
> RGB666.
>
> Add a pinctrl group for that case.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Acked-by: Chen-Yu Tsai <wens@csie.org>

> ---
>  arch/arm/boot/dts/sun5i-a13.dtsi | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
> index 263d46dbc7e6..79b5d513c142 100644
> --- a/arch/arm/boot/dts/sun5i-a13.dtsi
> +++ b/arch/arm/boot/dts/sun5i-a13.dtsi
> @@ -237,6 +237,16 @@
>  &pio {
>         compatible = "allwinner,sun5i-a13-pinctrl";
>
> +       lcd_rgb666_pins: lcd_rgb666 at 0 {
> +               allwinner,pins = "PD2", "PD3", "PD4", "PD5", "PD6", "PD7",
> +                                "PD10", "PD11", "PD12", "PD13", "PD14", "PD15",
> +                                "PD18", "PD19", "PD20", "PD21", "PD22", "PD23",
> +                                "PD24", "PD25", "PD26", "PD27";
> +               allwinner,function = "lcd0";
> +               allwinner,drive = <SUN4I_PINCTRL_10_MA>;

Just a thought: would we ever need to increase the drive strength for very high
resolutions?

> +               allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
> +       };
> +
>         uart1_pins_a: uart1 at 0 {
>                 allwinner,pins = "PE10", "PE11";
>                 allwinner,function = "uart1";
> --
> 2.8.2
>

Re: [PATCH 06/20] drm/sun4i: allow dclk to modify its parent rate

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> The pixel clock being only a divider of its parent clock, depending on the
> resolution, it's expected to change its parent rate. Add that flag so that
> the clock framework knows it.

This should be squashed into the previous patch. Otherwise, the previous one
doesn't really fix things, and probably makes things worse as it assumes the
parent clock would be changed.

ChenYu

> Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/sun4i_dotclock.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
> index 1ddf6d7a7107..5b3463197c48 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
> @@ -170,6 +170,7 @@ int sun4i_dclk_create(struct device *dev, struct sun4i_tcon *tcon)
>         init.ops = &sun4i_dclk_ops;
>         init.parent_names = &parent_name;
>         init.num_parents = 1;
> +       init.flags = CLK_SET_RATE_PARENT;
>
>         dclk->regmap = tcon->regs;
>         dclk->hw.init = &init;
> --
> 2.8.2
>

[PATCH 06/20] drm/sun4i: allow dclk to modify its parent rate

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> The pixel clock being only a divider of its parent clock, depending on the
> resolution, it's expected to change its parent rate. Add that flag so that
> the clock framework knows it.

This should be squashed into the previous patch. Otherwise, the previous one
doesn't really fix things, and probably makes things worse as it assumes the
parent clock would be changed.

ChenYu

> Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/sun4i_dotclock.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_dotclock.c b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
> index 1ddf6d7a7107..5b3463197c48 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_dotclock.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_dotclock.c
> @@ -170,6 +170,7 @@ int sun4i_dclk_create(struct device *dev, struct sun4i_tcon *tcon)
>         init.ops = &sun4i_dclk_ops;
>         init.parent_names = &parent_name;
>         init.num_parents = 1;
> +       init.flags = CLK_SET_RATE_PARENT;
>
>         dclk->regmap = tcon->regs;
>         dclk->hw.init = &init;
> --
> 2.8.2
>

Re: [PATCH 17/20] ARM: multi_v7: Enable sun4i DRM driver

[Chen-Yu Tsai]

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Enable the new DRM driver in the multi_v7 defconfig
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Acked-by: Chen-Yu Tsai <wens@csie.org>

[PATCH 17/20] ARM: multi_v7: Enable sun4i DRM driver

[Chen-Yu Tsai]

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Enable the new DRM driver in the multi_v7 defconfig
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Acked-by: Chen-Yu Tsai <wens@csie.org>

Re: [PATCH 08/20] drm/sun4i: rgb: panel is an error pointer

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> In case of an error, our pointer to the drm_panel structure attached to our
> encoder will hold an error pointer, not a NULL pointer.
>
> Make sure we check the right thing.
>
> Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/sun4i_rgb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> index 923f55039cb1..b46d2c15dc95 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> @@ -217,7 +217,7 @@ int sun4i_rgb_init(struct drm_device *drm)
>         int ret;
>
>         /* If we don't have a panel, there's no point in going on */
> -       if (!tcon->panel)
> +       if (IS_ERR(tcon->panel))

Without the next patch, tcon->panel could be the result of of_drm_find_panel(),
which could be NULL.

Use IS_ERR_OR_NULL here, or reorder/squash the patches.

Regards
ChenYu

>                 return -ENODEV;
>
>         rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
> --
> 2.8.2
>

[PATCH 08/20] drm/sun4i: rgb: panel is an error pointer

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> In case of an error, our pointer to the drm_panel structure attached to our
> encoder will hold an error pointer, not a NULL pointer.
>
> Make sure we check the right thing.
>
> Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/sun4i_rgb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> index 923f55039cb1..b46d2c15dc95 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> @@ -217,7 +217,7 @@ int sun4i_rgb_init(struct drm_device *drm)
>         int ret;
>
>         /* If we don't have a panel, there's no point in going on */
> -       if (!tcon->panel)
> +       if (IS_ERR(tcon->panel))

Without the next patch, tcon->panel could be the result of of_drm_find_panel(),
which could be NULL.

Use IS_ERR_OR_NULL here, or reorder/squash the patches.

Regards
ChenYu

>                 return -ENODEV;
>
>         rgb = devm_kzalloc(drm->dev, sizeof(*rgb), GFP_KERNEL);
> --
> 2.8.2
>

Re: [PATCH 09/20] drm/sun4i: defer only if we didn't find our panel

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> wrote:
> Our code currently defers our probe on any error, even if we were not
> expecting to have one at all.
>
> Make sure we return -EPROBE_DEFER only when we were supposed to have a
> panel, but it's not probed yet.
>
> Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> ---
>  drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index 9f19b0e08560..eed6a9e8d9a6 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -429,7 +429,7 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
>                 return ERR_PTR(-EINVAL);
>         }
>
> -       return of_drm_find_panel(remote);
> +       return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);

There's also a typo in the DRM_DEBUG_DRIVER call a few lines up. Could you
fix it as well?

ChenYu

>  }
>
>  static int sun4i_tcon_bind(struct device *dev, struct device *master,
> @@ -522,12 +522,13 @@ static int sun4i_tcon_probe(struct platform_device *pdev)
>          * Defer the probe.
>          */
>         panel = sun4i_tcon_find_panel(node);
> -       if (IS_ERR(panel)) {
> -               /*
> -                * If we don't have a panel endpoint, just go on
> -                */
> -               if (PTR_ERR(panel) != -ENODEV)
> -                       return -EPROBE_DEFER;
> +
> +       /*
> +        * If we don't have a panel endpoint, just go on
> +        */
> +       if (PTR_ERR(panel) == -EPROBE_DEFER) {
> +               DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
> +               return -EPROBE_DEFER;
>         }
>
>         return component_add(&pdev->dev, &sun4i_tcon_ops);
> --
> 2.8.2
>
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Re: [PATCH 09/20] drm/sun4i: defer only if we didn't find our panel

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Our code currently defers our probe on any error, even if we were not
> expecting to have one at all.
>
> Make sure we return -EPROBE_DEFER only when we were supposed to have a
> panel, but it's not probed yet.
>
> Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index 9f19b0e08560..eed6a9e8d9a6 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -429,7 +429,7 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
>                 return ERR_PTR(-EINVAL);
>         }
>
> -       return of_drm_find_panel(remote);
> +       return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);

There's also a typo in the DRM_DEBUG_DRIVER call a few lines up. Could you
fix it as well?

ChenYu

>  }
>
>  static int sun4i_tcon_bind(struct device *dev, struct device *master,
> @@ -522,12 +522,13 @@ static int sun4i_tcon_probe(struct platform_device *pdev)
>          * Defer the probe.
>          */
>         panel = sun4i_tcon_find_panel(node);
> -       if (IS_ERR(panel)) {
> -               /*
> -                * If we don't have a panel endpoint, just go on
> -                */
> -               if (PTR_ERR(panel) != -ENODEV)
> -                       return -EPROBE_DEFER;
> +
> +       /*
> +        * If we don't have a panel endpoint, just go on
> +        */
> +       if (PTR_ERR(panel) == -EPROBE_DEFER) {
> +               DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
> +               return -EPROBE_DEFER;
>         }
>
>         return component_add(&pdev->dev, &sun4i_tcon_ops);
> --
> 2.8.2
>

[PATCH 09/20] drm/sun4i: defer only if we didn't find our panel

[Chen-Yu Tsai]

Hi,

On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Our code currently defers our probe on any error, even if we were not
> expecting to have one at all.
>
> Make sure we return -EPROBE_DEFER only when we were supposed to have a
> panel, but it's not probed yet.
>
> Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> index 9f19b0e08560..eed6a9e8d9a6 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> @@ -429,7 +429,7 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
>                 return ERR_PTR(-EINVAL);
>         }
>
> -       return of_drm_find_panel(remote);
> +       return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);

There's also a typo in the DRM_DEBUG_DRIVER call a few lines up. Could you
fix it as well?

ChenYu

>  }
>
>  static int sun4i_tcon_bind(struct device *dev, struct device *master,
> @@ -522,12 +522,13 @@ static int sun4i_tcon_probe(struct platform_device *pdev)
>          * Defer the probe.
>          */
>         panel = sun4i_tcon_find_panel(node);
> -       if (IS_ERR(panel)) {
> -               /*
> -                * If we don't have a panel endpoint, just go on
> -                */
> -               if (PTR_ERR(panel) != -ENODEV)
> -                       return -EPROBE_DEFER;
> +
> +       /*
> +        * If we don't have a panel endpoint, just go on
> +        */
> +       if (PTR_ERR(panel) == -EPROBE_DEFER) {
> +               DRM_DEBUG_DRIVER("Still waiting for our panel. Deferring...\n");
> +               return -EPROBE_DEFER;
>         }
>
>         return component_add(&pdev->dev, &sun4i_tcon_ops);
> --
> 2.8.2
>

Re: [PATCH 06/20] drm/sun4i: allow dclk to modify its parent rate

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 730 bytes --]

On Tue, May 17, 2016 at 01:18:44AM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > The pixel clock being only a divider of its parent clock, depending on the
> > resolution, it's expected to change its parent rate. Add that flag so that
> > the clock framework knows it.
> 
> This should be squashed into the previous patch. Otherwise, the previous one
> doesn't really fix things, and probably makes things worse as it assumes the
> parent clock would be changed.

Merged the two patches and applied, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 06/20] drm/sun4i: allow dclk to modify its parent rate

[Maxime Ripard]

On Tue, May 17, 2016 at 01:18:44AM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > The pixel clock being only a divider of its parent clock, depending on the
> > resolution, it's expected to change its parent rate. Add that flag so that
> > the clock framework knows it.
> 
> This should be squashed into the previous patch. Otherwise, the previous one
> doesn't really fix things, and probably makes things worse as it assumes the
> parent clock would be changed.

Merged the two patches and applied, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 08/20] drm/sun4i: rgb: panel is an error pointer

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 1405 bytes --]

On Tue, May 17, 2016 at 11:51:36AM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > In case of an error, our pointer to the drm_panel structure attached to our
> > encoder will hold an error pointer, not a NULL pointer.
> >
> > Make sure we check the right thing.
> >
> > Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/gpu/drm/sun4i/sun4i_rgb.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> > index 923f55039cb1..b46d2c15dc95 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> > @@ -217,7 +217,7 @@ int sun4i_rgb_init(struct drm_device *drm)
> >         int ret;
> >
> >         /* If we don't have a panel, there's no point in going on */
> > -       if (!tcon->panel)
> > +       if (IS_ERR(tcon->panel))
> 
> Without the next patch, tcon->panel could be the result of of_drm_find_panel(),
> which could be NULL.
> 
> Use IS_ERR_OR_NULL here, or reorder/squash the patches.

Switched the order, and applied both, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 08/20] drm/sun4i: rgb: panel is an error pointer

[Maxime Ripard]

On Tue, May 17, 2016 at 11:51:36AM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > In case of an error, our pointer to the drm_panel structure attached to our
> > encoder will hold an error pointer, not a NULL pointer.
> >
> > Make sure we check the right thing.
> >
> > Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/gpu/drm/sun4i/sun4i_rgb.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_rgb.c b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> > index 923f55039cb1..b46d2c15dc95 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_rgb.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_rgb.c
> > @@ -217,7 +217,7 @@ int sun4i_rgb_init(struct drm_device *drm)
> >         int ret;
> >
> >         /* If we don't have a panel, there's no point in going on */
> > -       if (!tcon->panel)
> > +       if (IS_ERR(tcon->panel))
> 
> Without the next patch, tcon->panel could be the result of of_drm_find_panel(),
> which could be NULL.
> 
> Use IS_ERR_OR_NULL here, or reorder/squash the patches.

Switched the order, and applied both, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 09/20] drm/sun4i: defer only if we didn't find our panel

[Maxime Ripard]

[-- Attachment #1.1: Type: text/plain, Size: 1407 bytes --]

On Tue, May 17, 2016 at 11:52:10AM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Our code currently defers our probe on any error, even if we were not
> > expecting to have one at all.
> >
> > Make sure we return -EPROBE_DEFER only when we were supposed to have a
> > panel, but it's not probed yet.
> >
> > Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 ++++++++-------
> >  1 file changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > index 9f19b0e08560..eed6a9e8d9a6 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > @@ -429,7 +429,7 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
> >                 return ERR_PTR(-EINVAL);
> >         }
> >
> > -       return of_drm_find_panel(remote);
> > +       return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
> 
> There's also a typo in the DRM_DEBUG_DRIVER call a few lines up. Could you
> fix it as well?

Done, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 09/20] drm/sun4i: defer only if we didn't find our panel

[Maxime Ripard]

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On Tue, May 17, 2016 at 11:52:10AM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Our code currently defers our probe on any error, even if we were not
> > expecting to have one at all.
> >
> > Make sure we return -EPROBE_DEFER only when we were supposed to have a
> > panel, but it's not probed yet.
> >
> > Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 ++++++++-------
> >  1 file changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > index 9f19b0e08560..eed6a9e8d9a6 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > @@ -429,7 +429,7 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
> >                 return ERR_PTR(-EINVAL);
> >         }
> >
> > -       return of_drm_find_panel(remote);
> > +       return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
> 
> There's also a typo in the DRM_DEBUG_DRIVER call a few lines up. Could you
> fix it as well?

Done, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 09/20] drm/sun4i: defer only if we didn't find our panel

[Maxime Ripard]

On Tue, May 17, 2016 at 11:52:10AM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Our code currently defers our probe on any error, even if we were not
> > expecting to have one at all.
> >
> > Make sure we return -EPROBE_DEFER only when we were supposed to have a
> > panel, but it's not probed yet.
> >
> > Fixes: 29e57fab97fc ("drm: sun4i: Add RGB output")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/gpu/drm/sun4i/sun4i_tcon.c | 15 ++++++++-------
> >  1 file changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > index 9f19b0e08560..eed6a9e8d9a6 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > @@ -429,7 +429,7 @@ static struct drm_panel *sun4i_tcon_find_panel(struct device_node *node)
> >                 return ERR_PTR(-EINVAL);
> >         }
> >
> > -       return of_drm_find_panel(remote);
> > +       return of_drm_find_panel(remote) ?: ERR_PTR(-EPROBE_DEFER);
> 
> There's also a typo in the DRM_DEBUG_DRIVER call a few lines up. Could you
> fix it as well?

Done, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 14/20] ARM: sun5i: a13: Add LCD pins

[Maxime Ripard]

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On Tue, May 17, 2016 at 01:13:01AM +0800, Chen-Yu Tsai wrote:
> >  arch/arm/boot/dts/sun5i-a13.dtsi | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
> > index 263d46dbc7e6..79b5d513c142 100644
> > --- a/arch/arm/boot/dts/sun5i-a13.dtsi
> > +++ b/arch/arm/boot/dts/sun5i-a13.dtsi
> > @@ -237,6 +237,16 @@
> >  &pio {
> >         compatible = "allwinner,sun5i-a13-pinctrl";
> >
> > +       lcd_rgb666_pins: lcd_rgb666@0 {
> > +               allwinner,pins = "PD2", "PD3", "PD4", "PD5", "PD6", "PD7",
> > +                                "PD10", "PD11", "PD12", "PD13", "PD14", "PD15",
> > +                                "PD18", "PD19", "PD20", "PD21", "PD22", "PD23",
> > +                                "PD24", "PD25", "PD26", "PD27";
> > +               allwinner,function = "lcd0";
> > +               allwinner,drive = <SUN4I_PINCTRL_10_MA>;
> 
> Just a thought: would we ever need to increase the drive strength for very high
> resolutions?

I don't think we need to, but we can always change that later.

Applied, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 14/20] ARM: sun5i: a13: Add LCD pins

[Maxime Ripard]

On Tue, May 17, 2016 at 01:13:01AM +0800, Chen-Yu Tsai wrote:
> >  arch/arm/boot/dts/sun5i-a13.dtsi | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
> > index 263d46dbc7e6..79b5d513c142 100644
> > --- a/arch/arm/boot/dts/sun5i-a13.dtsi
> > +++ b/arch/arm/boot/dts/sun5i-a13.dtsi
> > @@ -237,6 +237,16 @@
> >  &pio {
> >         compatible = "allwinner,sun5i-a13-pinctrl";
> >
> > +       lcd_rgb666_pins: lcd_rgb666 at 0 {
> > +               allwinner,pins = "PD2", "PD3", "PD4", "PD5", "PD6", "PD7",
> > +                                "PD10", "PD11", "PD12", "PD13", "PD14", "PD15",
> > +                                "PD18", "PD19", "PD20", "PD21", "PD22", "PD23",
> > +                                "PD24", "PD25", "PD26", "PD27";
> > +               allwinner,function = "lcd0";
> > +               allwinner,drive = <SUN4I_PINCTRL_10_MA>;
> 
> Just a thought: would we ever need to increase the drive strength for very high
> resolutions?

I don't think we need to, but we can always change that later.

Applied, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 12/20] drm/sun4i: Add bridge support

[Maxime Ripard]

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Hi Daniel,

On Mon, May 16, 2016 at 03:12:15PM +0200, Daniel Vetter wrote:
> On Mon, May 16, 2016 at 2:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Our RGB bus can be either connected to a bridge or a panel. While the panel
> > support was already there, the bridge was not.
> >
> > Fix that.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> For bridge support the only thing you need is to set
> drm_encoder->bridge. Why do you need to hand-roll your own bridge
> support? That pretty muchmeans you'll do it slightly differently (e.g.
> you don't bother with a lot of the calls), which will make sharing
> bridge drivers ever so harder. And also reviewing code, since using
> shared code but slightly differently is really confusing.

Because I overlooked it :)

I'll change that.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 12/20] drm/sun4i: Add bridge support

[Maxime Ripard]

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Hi Daniel,

On Mon, May 16, 2016 at 03:12:15PM +0200, Daniel Vetter wrote:
> On Mon, May 16, 2016 at 2:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Our RGB bus can be either connected to a bridge or a panel. While the panel
> > support was already there, the bridge was not.
> >
> > Fix that.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> For bridge support the only thing you need is to set
> drm_encoder->bridge. Why do you need to hand-roll your own bridge
> support? That pretty muchmeans you'll do it slightly differently (e.g.
> you don't bother with a lot of the calls), which will make sharing
> bridge drivers ever so harder. And also reviewing code, since using
> shared code but slightly differently is really confusing.

Because I overlooked it :)

I'll change that.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 12/20] drm/sun4i: Add bridge support

[Maxime Ripard]

Hi Daniel,

On Mon, May 16, 2016 at 03:12:15PM +0200, Daniel Vetter wrote:
> On Mon, May 16, 2016 at 2:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Our RGB bus can be either connected to a bridge or a panel. While the panel
> > support was already there, the bridge was not.
> >
> > Fix that.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> For bridge support the only thing you need is to set
> drm_encoder->bridge. Why do you need to hand-roll your own bridge
> support? That pretty muchmeans you'll do it slightly differently (e.g.
> you don't bother with a lot of the calls), which will make sharing
> bridge drivers ever so harder. And also reviewing code, since using
> shared code but slightly differently is really confusing.

Because I overlooked it :)

I'll change that.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Maxime Ripard]

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Hi Laurent,

On Mon, May 16, 2016 at 04:24:15PM +0300, Laurent Pinchart wrote:
> Hi Maxime,
> 
> Thank you for the patch.
> 
> On Monday 16 May 2016 14:47:13 Maxime Ripard wrote:
> > Some boards have an entirely passive RGB to VGA bridge, based on either
> > DACs or resistor ladders.
> > 
> > Those might or might not have an i2c bus routed to the VGA connector in
> > order to access the screen EDIDs.
> > 
> > Add a bridge that doesn't do anything but expose the modes available on the
> > screen, either based on the EDIDs if available, or based on the XGA
> > standards.
> > 
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
> >  drivers/gpu/drm/bridge/Kconfig                     |   6 +
> >  drivers/gpu/drm/bridge/Makefile                    |   1 +
> >  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 ++++++++++++++++++
> >  4 files changed, 233 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/display/bridge/dumb-vga.txt create mode
> > 100644 drivers/gpu/drm/bridge/dumb-vga.c
> > 
> > diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> > b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt new file
> > mode 100644
> > index 000000000000..757f04de97f3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> > @@ -0,0 +1,40 @@
> > +Passive RGB to VGA bridge
> > +-------------------------
> > +
> > +This binding is aimed for entirely passive RGB to VGA bridges that do not
> > +require any configuration.
> > +
> > +Required properties:
> > +
> > +- compatible: Should be "dumb-vga-bridge"
> > +
> > +Optional properties:
> > +
> > +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
> > +
> > +Required nodes:
> > +
> > +This device has one video port. Its connection is modelled using the OF
> > +graph bindings specified in Documentation/devicetree/bindings/graph.txt.
> > This +connection is meant to be the RGB input bus.
> 
> Should the bridge have two ports, one input port connected to a display engine 
> and one output port connected to a VGA connector ?

And a separate node for the VGA connector? As far as I can see, all
the other bridges are represented using a single node.

> +static int dumb_vga_get_modes(struct drm_connector *connector)
> > +{
> > +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> > +	struct edid *edid;
> > +	int ret;
> > +
> > +	if (!vga->ddc)
> > +		goto fallback;
> > +
> > +	edid = drm_get_edid(connector, vga->ddc);
> > +	if (!edid) {
> > +		DRM_INFO("EDID readout failed, falling back to standard modes\n");
> > +		goto fallback;
> > +	}
> > +
> > +	drm_mode_connector_update_edid_property(connector, edid);
> > +	return drm_add_edid_modes(connector, edid);
> > +
> > +fallback:
> > +	/*
> > +	 * In case we cannot retrieve the EDIDs (broken or missing i2c
> > +	 * bus), fallback on the XGA standards
> > +	 */
> > +	ret = drm_add_modes_noedid(connector, 1920, 1200);
> 
> The DRM core adds modes up to 1024x768 in 
> drm_helper_probe_single_connector_modes(). I wonder if it really makes sense 
> to override that in drivers, compared to increasing the maximum resolution in 
> the core. What we can reasonable expect from a VGA monitor doesn't really 
> depend on which display engine it is connected to.

Actually, I would expect it to come from the connectors. Nowadays, the
core add modes that might not even be relevant at all for a given
connector. Take TV as an example, there's not a single TV output that
can reach 1024x768, but actually rely on very different resolutions.

> 
> > +	/* And prefer a mode pretty much anyone can handle */
> > +	drm_set_preferred_mode(connector, 1024, 768);
> > +
> > +	return ret;
> > +}
> > +
> > +static struct drm_encoder *
> > +dumb_vga_best_encoder(struct drm_connector *connector)
> > +{
> > +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> > +
> > +	return vga->bridge.encoder;
> > +}
> > +
> > +static struct drm_connector_helper_funcs dumb_vga_con_helper_funcs = {
> > +	.get_modes	= dumb_vga_get_modes,
> > +	.best_encoder	= dumb_vga_best_encoder,
> > +};
> > +
> > +static enum drm_connector_status
> > +dumb_vga_connector_detect(struct drm_connector *connector, bool force)
> > +{
> > +	return connector_status_connected;
> 
> Shouldn't that be connector_status_unknown if you have no information about 
> the connection status ?

Probably :)

What are the side effects from such a change? Does it change anything
related to how the fbdev emulation and how the rest of the display
stack detects and enables the outputs whose status are unknown?

> Would it make sense to add an optional GPIO-based connection detection to this 
> driver ?

I asked for it in our prototypes, and apparently, doing VGA cable
detection is really non-trivial, so I don't really expect it to be
found in a lot of designs.

I looked at three different designs done by different vendors, and
none of them have it, so I don't really expect anyone to have it, nor
do I have any hardware to test the code with. However, if there's an
i2c bus, we can always try to probe for the edid, and see if we have
an error. If there's none, then we know something is connected. If
there's an error, we can return connector_status_unknown.

On a set of three samples, only one has that i2c bus, so it might be
just a marginal improvement, but still.


> > +}
> > +
> > +static void
> > +dumb_vga_connector_destroy(struct drm_connector *connector)
> > +{
> > +	drm_connector_cleanup(connector);
> > +}
> > +
> > +static struct drm_connector_funcs dumb_vga_con_funcs = {
> > +	.dpms			= drm_atomic_helper_connector_dpms,
> > +	.detect			= dumb_vga_connector_detect,
> > +	.fill_modes		= drm_helper_probe_single_connector_modes,
> > +	.destroy		= dumb_vga_connector_destroy,
> > +	.reset			= drm_atomic_helper_connector_reset,
> > +	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
> > +	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
> > +};
> > +
> > +static int dumb_vga_attach(struct drm_bridge *bridge)
> > +{
> > +	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
> > +	int ret;
> > +
> > +	if (!bridge->encoder) {
> > +		DRM_ERROR("Missing encoder\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	drm_connector_helper_add(&vga->connector,
> > +				 &dumb_vga_con_helper_funcs);
> > +	ret = drm_connector_init(bridge->dev, &vga->connector,
> > +				 &dumb_vga_con_funcs, DRM_MODE_CONNECTOR_VGA);
> > +	if (ret) {
> > +		DRM_ERROR("Failed to initialize connector\n");
> > +		return ret;
> > +	}
> > +
> > +	drm_mode_connector_attach_encoder(&vga->connector,
> > +					  bridge->encoder);
> > +
> > +	return 0;
> > +}
> > +
> > +static void dumb_vga_nop(struct drm_bridge *bridge) {};
> > +
> > +static struct drm_bridge_funcs dumb_vga_bridge_funcs = {
> > +	.attach		= dumb_vga_attach,
> > +	.enable		= dumb_vga_nop,
> > +	.disable	= dumb_vga_nop,
> > +	.pre_enable	= dumb_vga_nop,
> > +	.post_disable	= dumb_vga_nop,
> > +};
> > +
> > +static int dumb_vga_probe(struct platform_device *pdev)
> > +{
> > +	struct dumb_vga *vga;
> > +	struct device_node *ddc;
> > +
> > +	vga = devm_kzalloc(&pdev->dev, sizeof(*vga), GFP_KERNEL);
> > +	if (!vga)
> > +		return -ENOMEM;
> > +	platform_set_drvdata(pdev, vga);
> > +
> > +	ddc = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
> > +	if (ddc) {
> > +		vga->ddc = of_find_i2c_adapter_by_node(ddc);
> 
> You're leaking the reference to the I2C adapter.
> 
> Also, shouldn't you use of_get_i2c_adapter_by_node() ? Otherwise you won't 
> take a reference to the adapter module.

Indeed, I'll fix it.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Maxime Ripard]

Hi Laurent,

On Mon, May 16, 2016 at 04:24:15PM +0300, Laurent Pinchart wrote:
> Hi Maxime,
> 
> Thank you for the patch.
> 
> On Monday 16 May 2016 14:47:13 Maxime Ripard wrote:
> > Some boards have an entirely passive RGB to VGA bridge, based on either
> > DACs or resistor ladders.
> > 
> > Those might or might not have an i2c bus routed to the VGA connector in
> > order to access the screen EDIDs.
> > 
> > Add a bridge that doesn't do anything but expose the modes available on the
> > screen, either based on the EDIDs if available, or based on the XGA
> > standards.
> > 
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
> >  drivers/gpu/drm/bridge/Kconfig                     |   6 +
> >  drivers/gpu/drm/bridge/Makefile                    |   1 +
> >  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 ++++++++++++++++++
> >  4 files changed, 233 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/display/bridge/dumb-vga.txt create mode
> > 100644 drivers/gpu/drm/bridge/dumb-vga.c
> > 
> > diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> > b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt new file
> > mode 100644
> > index 000000000000..757f04de97f3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> > @@ -0,0 +1,40 @@
> > +Passive RGB to VGA bridge
> > +-------------------------
> > +
> > +This binding is aimed for entirely passive RGB to VGA bridges that do not
> > +require any configuration.
> > +
> > +Required properties:
> > +
> > +- compatible: Should be "dumb-vga-bridge"
> > +
> > +Optional properties:
> > +
> > +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
> > +
> > +Required nodes:
> > +
> > +This device has one video port. Its connection is modelled using the OF
> > +graph bindings specified in Documentation/devicetree/bindings/graph.txt.
> > This +connection is meant to be the RGB input bus.
> 
> Should the bridge have two ports, one input port connected to a display engine 
> and one output port connected to a VGA connector ?

And a separate node for the VGA connector? As far as I can see, all
the other bridges are represented using a single node.

> +static int dumb_vga_get_modes(struct drm_connector *connector)
> > +{
> > +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> > +	struct edid *edid;
> > +	int ret;
> > +
> > +	if (!vga->ddc)
> > +		goto fallback;
> > +
> > +	edid = drm_get_edid(connector, vga->ddc);
> > +	if (!edid) {
> > +		DRM_INFO("EDID readout failed, falling back to standard modes\n");
> > +		goto fallback;
> > +	}
> > +
> > +	drm_mode_connector_update_edid_property(connector, edid);
> > +	return drm_add_edid_modes(connector, edid);
> > +
> > +fallback:
> > +	/*
> > +	 * In case we cannot retrieve the EDIDs (broken or missing i2c
> > +	 * bus), fallback on the XGA standards
> > +	 */
> > +	ret = drm_add_modes_noedid(connector, 1920, 1200);
> 
> The DRM core adds modes up to 1024x768 in 
> drm_helper_probe_single_connector_modes(). I wonder if it really makes sense 
> to override that in drivers, compared to increasing the maximum resolution in 
> the core. What we can reasonable expect from a VGA monitor doesn't really 
> depend on which display engine it is connected to.

Actually, I would expect it to come from the connectors. Nowadays, the
core add modes that might not even be relevant at all for a given
connector. Take TV as an example, there's not a single TV output that
can reach 1024x768, but actually rely on very different resolutions.

> 
> > +	/* And prefer a mode pretty much anyone can handle */
> > +	drm_set_preferred_mode(connector, 1024, 768);
> > +
> > +	return ret;
> > +}
> > +
> > +static struct drm_encoder *
> > +dumb_vga_best_encoder(struct drm_connector *connector)
> > +{
> > +	struct dumb_vga *vga = drm_connector_to_dumb_vga(connector);
> > +
> > +	return vga->bridge.encoder;
> > +}
> > +
> > +static struct drm_connector_helper_funcs dumb_vga_con_helper_funcs = {
> > +	.get_modes	= dumb_vga_get_modes,
> > +	.best_encoder	= dumb_vga_best_encoder,
> > +};
> > +
> > +static enum drm_connector_status
> > +dumb_vga_connector_detect(struct drm_connector *connector, bool force)
> > +{
> > +	return connector_status_connected;
> 
> Shouldn't that be connector_status_unknown if you have no information about 
> the connection status ?

Probably :)

What are the side effects from such a change? Does it change anything
related to how the fbdev emulation and how the rest of the display
stack detects and enables the outputs whose status are unknown?

> Would it make sense to add an optional GPIO-based connection detection to this 
> driver ?

I asked for it in our prototypes, and apparently, doing VGA cable
detection is really non-trivial, so I don't really expect it to be
found in a lot of designs.

I looked at three different designs done by different vendors, and
none of them have it, so I don't really expect anyone to have it, nor
do I have any hardware to test the code with. However, if there's an
i2c bus, we can always try to probe for the edid, and see if we have
an error. If there's none, then we know something is connected. If
there's an error, we can return connector_status_unknown.

On a set of three samples, only one has that i2c bus, so it might be
just a marginal improvement, but still.


> > +}
> > +
> > +static void
> > +dumb_vga_connector_destroy(struct drm_connector *connector)
> > +{
> > +	drm_connector_cleanup(connector);
> > +}
> > +
> > +static struct drm_connector_funcs dumb_vga_con_funcs = {
> > +	.dpms			= drm_atomic_helper_connector_dpms,
> > +	.detect			= dumb_vga_connector_detect,
> > +	.fill_modes		= drm_helper_probe_single_connector_modes,
> > +	.destroy		= dumb_vga_connector_destroy,
> > +	.reset			= drm_atomic_helper_connector_reset,
> > +	.atomic_duplicate_state	= drm_atomic_helper_connector_duplicate_state,
> > +	.atomic_destroy_state	= drm_atomic_helper_connector_destroy_state,
> > +};
> > +
> > +static int dumb_vga_attach(struct drm_bridge *bridge)
> > +{
> > +	struct dumb_vga *vga = drm_bridge_to_dumb_vga(bridge);
> > +	int ret;
> > +
> > +	if (!bridge->encoder) {
> > +		DRM_ERROR("Missing encoder\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	drm_connector_helper_add(&vga->connector,
> > +				 &dumb_vga_con_helper_funcs);
> > +	ret = drm_connector_init(bridge->dev, &vga->connector,
> > +				 &dumb_vga_con_funcs, DRM_MODE_CONNECTOR_VGA);
> > +	if (ret) {
> > +		DRM_ERROR("Failed to initialize connector\n");
> > +		return ret;
> > +	}
> > +
> > +	drm_mode_connector_attach_encoder(&vga->connector,
> > +					  bridge->encoder);
> > +
> > +	return 0;
> > +}
> > +
> > +static void dumb_vga_nop(struct drm_bridge *bridge) {};
> > +
> > +static struct drm_bridge_funcs dumb_vga_bridge_funcs = {
> > +	.attach		= dumb_vga_attach,
> > +	.enable		= dumb_vga_nop,
> > +	.disable	= dumb_vga_nop,
> > +	.pre_enable	= dumb_vga_nop,
> > +	.post_disable	= dumb_vga_nop,
> > +};
> > +
> > +static int dumb_vga_probe(struct platform_device *pdev)
> > +{
> > +	struct dumb_vga *vga;
> > +	struct device_node *ddc;
> > +
> > +	vga = devm_kzalloc(&pdev->dev, sizeof(*vga), GFP_KERNEL);
> > +	if (!vga)
> > +		return -ENOMEM;
> > +	platform_set_drvdata(pdev, vga);
> > +
> > +	ddc = of_parse_phandle(pdev->dev.of_node, "ddc-i2c-bus", 0);
> > +	if (ddc) {
> > +		vga->ddc = of_find_i2c_adapter_by_node(ddc);
> 
> You're leaking the reference to the I2C adapter.
> 
> Also, shouldn't you use of_get_i2c_adapter_by_node() ? Otherwise you won't 
> take a reference to the adapter module.

Indeed, I'll fix it.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Russell King - ARM Linux]

On Thu, May 26, 2016 at 10:53:30AM +0200, Maxime Ripard wrote:
> Hi Laurent,
> 
> On Mon, May 16, 2016 at 04:24:15PM +0300, Laurent Pinchart wrote:
> > Hi Maxime,
> > 
> > Thank you for the patch.
> > 
> > On Monday 16 May 2016 14:47:13 Maxime Ripard wrote:
> > > +fallback:
> > > +	/*
> > > +	 * In case we cannot retrieve the EDIDs (broken or missing i2c
> > > +	 * bus), fallback on the XGA standards
> > > +	 */
> > > +	ret = drm_add_modes_noedid(connector, 1920, 1200);
> > 
> > The DRM core adds modes up to 1024x768 in 
> > drm_helper_probe_single_connector_modes(). I wonder if it really makes sense 
> > to override that in drivers, compared to increasing the maximum resolution in 
> > the core. What we can reasonable expect from a VGA monitor doesn't really 
> > depend on which display engine it is connected to.
> 
> Actually, I would expect it to come from the connectors. Nowadays, the
> core add modes that might not even be relevant at all for a given
> connector. Take TV as an example, there's not a single TV output that
> can reach 1024x768, but actually rely on very different resolutions.

There is the requirement to support 640x480 almost universally.

> > Would it make sense to add an optional GPIO-based connection detection to this 
> > driver ?
> 
> I asked for it in our prototypes, and apparently, doing VGA cable
> detection is really non-trivial, so I don't really expect it to be
> found in a lot of designs.

... and prone to problems.  Intel designs try to measure the termination
resistance to detect whether something is connected (they pulse the RGB
signals and measure the current.)  This mostly works fine, except if you
have some KVM boxes which can make this very unreliable.

I ended up replacing the bipolar transistors switching the RGB signals
in my KVM switch with FETs because of this problem.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

[PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Russell King - ARM Linux]

On Thu, May 26, 2016 at 10:53:30AM +0200, Maxime Ripard wrote:
> Hi Laurent,
> 
> On Mon, May 16, 2016 at 04:24:15PM +0300, Laurent Pinchart wrote:
> > Hi Maxime,
> > 
> > Thank you for the patch.
> > 
> > On Monday 16 May 2016 14:47:13 Maxime Ripard wrote:
> > > +fallback:
> > > +	/*
> > > +	 * In case we cannot retrieve the EDIDs (broken or missing i2c
> > > +	 * bus), fallback on the XGA standards
> > > +	 */
> > > +	ret = drm_add_modes_noedid(connector, 1920, 1200);
> > 
> > The DRM core adds modes up to 1024x768 in 
> > drm_helper_probe_single_connector_modes(). I wonder if it really makes sense 
> > to override that in drivers, compared to increasing the maximum resolution in 
> > the core. What we can reasonable expect from a VGA monitor doesn't really 
> > depend on which display engine it is connected to.
> 
> Actually, I would expect it to come from the connectors. Nowadays, the
> core add modes that might not even be relevant at all for a given
> connector. Take TV as an example, there's not a single TV output that
> can reach 1024x768, but actually rely on very different resolutions.

There is the requirement to support 640x480 almost universally.

> > Would it make sense to add an optional GPIO-based connection detection to this 
> > driver ?
> 
> I asked for it in our prototypes, and apparently, doing VGA cable
> detection is really non-trivial, so I don't really expect it to be
> found in a lot of designs.

... and prone to problems.  Intel designs try to measure the termination
resistance to detect whether something is connected (they pulse the RGB
signals and measure the current.)  This mostly works fine, except if you
have some KVM boxes which can make this very unreliable.

I ended up replacing the bipolar transistors switching the RGB signals
in my KVM switch with FETs because of this problem.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

Re: [PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 3189 bytes --]

Hi Rob,

On Mon, May 16, 2016 at 09:07:18AM -0500, Rob Herring wrote:
> On Mon, May 16, 2016 at 7:47 AM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Some boards have an entirely passive RGB to VGA bridge, based on either
> > DACs or resistor ladders.
> >
> > Those might or might not have an i2c bus routed to the VGA connector in
> > order to access the screen EDIDs.
> >
> > Add a bridge that doesn't do anything but expose the modes available on the
> > screen, either based on the EDIDs if available, or based on the XGA
> > standards.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
> >  drivers/gpu/drm/bridge/Kconfig                     |   6 +
> >  drivers/gpu/drm/bridge/Makefile                    |   1 +
> >  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
> >  4 files changed, 233 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> >  create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c
> >
> > diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> > new file mode 100644
> > index 000000000000..757f04de97f3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> > @@ -0,0 +1,40 @@
> > +Passive RGB to VGA bridge
> > +-------------------------
> > +
> > +This binding is aimed for entirely passive RGB to VGA bridges that do not
> > +require any configuration.
> 
> No reset or enable lines or regulators?

On the three designs I've seen:
  - One doesn't need any of these
  - One has a GPIO enable pin but with it's resistor not populated
  - One has a regulator controlled by a GPIO

So I guess in most cases, we don't need anything, but we still might
to cover all cases.

> > +
> > +Required properties:
> > +
> > +- compatible: Should be "dumb-vga-bridge"
> > +
> > +Optional properties:
> > +
> > +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
> 
> The i2c bus is a property of the connector, not the bridge chip, so it
> belongs in a VGA connector node (which we already have binding for).
> 
> I think for the really "dumb" (or transparent case), you should only
> have a connector. For anything more complex, then you should have both
> a DAC and connector node.

So, in essence, something like:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/r8a7794-alt.dts#n37
 
> On the driver side, I think we could handle multiple connectors with a
> single driver. Ideally, that would work with any DRM driver that has a
> connector node.

I'm not sure what you mean by that. I really think it should be a
separate driver in order to share the common code that so far the
current implementations put in some driver specific code (even though
it might be completely generic).

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 13/20] drm/bridge: Add RGB to VGA bridge support

[Maxime Ripard]

Hi Rob,

On Mon, May 16, 2016 at 09:07:18AM -0500, Rob Herring wrote:
> On Mon, May 16, 2016 at 7:47 AM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Some boards have an entirely passive RGB to VGA bridge, based on either
> > DACs or resistor ladders.
> >
> > Those might or might not have an i2c bus routed to the VGA connector in
> > order to access the screen EDIDs.
> >
> > Add a bridge that doesn't do anything but expose the modes available on the
> > screen, either based on the EDIDs if available, or based on the XGA
> > standards.
> >
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  .../bindings/display/bridge/dumb-vga.txt           |  40 +++++
> >  drivers/gpu/drm/bridge/Kconfig                     |   6 +
> >  drivers/gpu/drm/bridge/Makefile                    |   1 +
> >  drivers/gpu/drm/bridge/dumb-vga.c                  | 186 +++++++++++++++++++++
> >  4 files changed, 233 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> >  create mode 100644 drivers/gpu/drm/bridge/dumb-vga.c
> >
> > diff --git a/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> > new file mode 100644
> > index 000000000000..757f04de97f3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/bridge/dumb-vga.txt
> > @@ -0,0 +1,40 @@
> > +Passive RGB to VGA bridge
> > +-------------------------
> > +
> > +This binding is aimed for entirely passive RGB to VGA bridges that do not
> > +require any configuration.
> 
> No reset or enable lines or regulators?

On the three designs I've seen:
  - One doesn't need any of these
  - One has a GPIO enable pin but with it's resistor not populated
  - One has a regulator controlled by a GPIO

So I guess in most cases, we don't need anything, but we still might
to cover all cases.

> > +
> > +Required properties:
> > +
> > +- compatible: Should be "dumb-vga-bridge"
> > +
> > +Optional properties:
> > +
> > +- ddc-i2c-bus: phandle to the i2c bus used to communicate with the monitor
> 
> The i2c bus is a property of the connector, not the bridge chip, so it
> belongs in a VGA connector node (which we already have binding for).
> 
> I think for the really "dumb" (or transparent case), you should only
> have a connector. For anything more complex, then you should have both
> a DAC and connector node.

So, in essence, something like:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/arch/arm/boot/dts/r8a7794-alt.dts#n37
 
> On the driver side, I think we could handle multiple connectors with a
> single driver. Ideally, that would work with any DRM driver that has a
> connector node.

I'm not sure what you mean by that. I really think it should be a
separate driver in order to share the common code that so far the
current implementations put in some driver specific code (even though
it might be completely generic).

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 03/20] clk: sunxi: tcon-ch1: Do not return a negative error in get_parent

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 599 bytes --]

On Tue, May 17, 2016 at 12:05:18AM +0800, Chen-Yu Tsai wrote:
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > get_parent is supposed to return an unsigned 8 bit integer, so returning
> > -EINVAL is a bad idea.
> >
> > Remove it.
> >
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> Acked-by: Chen-Yu Tsai <wens@csie.org>

Applied,

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 03/20] clk: sunxi: tcon-ch1: Do not return a negative error in get_parent

[Maxime Ripard]

On Tue, May 17, 2016 at 12:05:18AM +0800, Chen-Yu Tsai wrote:
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > get_parent is supposed to return an unsigned 8 bit integer, so returning
> > -EINVAL is a bad idea.
> >
> > Remove it.
> >
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> Acked-by: Chen-Yu Tsai <wens@csie.org>

Applied,

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 04/20] clk: sunxi: display: Add per-clock flags

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 2494 bytes --]

On Mon, May 16, 2016 at 11:21:41PM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > The TCON channel 0 clock that is the parent clock of our pixel clock is
> > expected to change its rate depending on the resolution we want to output
> > in our display engine.
> >
> > However, since it's only a mux, the only way it can do that is by changing
> > its parents rate.
> >
> > Allow to give flags in our display clocks description, and add the
> > CLK_SET_RATE_PARENT flag for the TCON channel 0 flag.
> >
> > Fixes: a3b4956ee6d9 ("clk: sunxi: display: Add per-clock flags")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/clk/sunxi/clk-sun4i-display.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/clk/sunxi/clk-sun4i-display.c b/drivers/clk/sunxi/clk-sun4i-display.c
> > index 445a7498d6df..9780fac6d029 100644
> > --- a/drivers/clk/sunxi/clk-sun4i-display.c
> > +++ b/drivers/clk/sunxi/clk-sun4i-display.c
> > @@ -33,6 +33,8 @@ struct sun4i_a10_display_clk_data {
> >
> >         u8      width_div;
> >         u8      width_mux;
> > +
> 
> Don't really need this separator, but I'm ok either way.
> 
> > +       u32     flags;
> >  };
> >
> >  struct reset_data {
> > @@ -166,7 +168,7 @@ static void __init sun4i_a10_display_init(struct device_node *node,
> >                                      data->has_div ? &div->hw : NULL,
> >                                      data->has_div ? &clk_divider_ops : NULL,
> >                                      &gate->hw, &clk_gate_ops,
> > -                                    0);
> > +                                    data->flags);
> >         if (IS_ERR(clk)) {
> >                 pr_err("%s: Couldn't register the clock\n", clk_name);
> >                 goto free_div;
> > @@ -232,6 +234,7 @@ static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initcon
> >         .offset_rst     = 29,
> >         .offset_mux     = 24,
> >         .width_mux      = 2,
> > +       .flags          = CLK_SET_RATE_PARENT,
> >  };
> >
> >  static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
> > --
> > 2.8.2
> >
> 
> Acked-by: Chen-Yu Tsai <wens@csie.org>

Applied,

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 04/20] clk: sunxi: display: Add per-clock flags

[Maxime Ripard]

On Mon, May 16, 2016 at 11:21:41PM +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Mon, May 16, 2016 at 8:47 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > The TCON channel 0 clock that is the parent clock of our pixel clock is
> > expected to change its rate depending on the resolution we want to output
> > in our display engine.
> >
> > However, since it's only a mux, the only way it can do that is by changing
> > its parents rate.
> >
> > Allow to give flags in our display clocks description, and add the
> > CLK_SET_RATE_PARENT flag for the TCON channel 0 flag.
> >
> > Fixes: a3b4956ee6d9 ("clk: sunxi: display: Add per-clock flags")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/clk/sunxi/clk-sun4i-display.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/clk/sunxi/clk-sun4i-display.c b/drivers/clk/sunxi/clk-sun4i-display.c
> > index 445a7498d6df..9780fac6d029 100644
> > --- a/drivers/clk/sunxi/clk-sun4i-display.c
> > +++ b/drivers/clk/sunxi/clk-sun4i-display.c
> > @@ -33,6 +33,8 @@ struct sun4i_a10_display_clk_data {
> >
> >         u8      width_div;
> >         u8      width_mux;
> > +
> 
> Don't really need this separator, but I'm ok either way.
> 
> > +       u32     flags;
> >  };
> >
> >  struct reset_data {
> > @@ -166,7 +168,7 @@ static void __init sun4i_a10_display_init(struct device_node *node,
> >                                      data->has_div ? &div->hw : NULL,
> >                                      data->has_div ? &clk_divider_ops : NULL,
> >                                      &gate->hw, &clk_gate_ops,
> > -                                    0);
> > +                                    data->flags);
> >         if (IS_ERR(clk)) {
> >                 pr_err("%s: Couldn't register the clock\n", clk_name);
> >                 goto free_div;
> > @@ -232,6 +234,7 @@ static const struct sun4i_a10_display_clk_data sun4i_a10_tcon_ch0_data __initcon
> >         .offset_rst     = 29,
> >         .offset_mux     = 24,
> >         .width_mux      = 2,
> > +       .flags          = CLK_SET_RATE_PARENT,
> >  };
> >
> >  static void __init sun4i_a10_tcon_ch0_setup(struct device_node *node)
> > --
> > 2.8.2
> >
> 
> Acked-by: Chen-Yu Tsai <wens@csie.org>

Applied,

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Maxime Ripard]

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On Mon, May 16, 2016 at 02:47:01PM +0200, Maxime Ripard wrote:
> A fixed factor clock, if it needs to change its rate, by definition do not
> have any choice but to modify its parent rate.
> 
> Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Mike, Stephen, any comments on this one?

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Maxime Ripard]

On Mon, May 16, 2016 at 02:47:01PM +0200, Maxime Ripard wrote:
> A fixed factor clock, if it needs to change its rate, by definition do not
> have any choice but to modify its parent rate.
> 
> Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Mike, Stephen, any comments on this one?

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Maxime Ripard]

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Hi Mike, Stephen,

On Mon, May 16, 2016 at 02:47:02PM +0200, Maxime Ripard wrote:
> In the current multiplier base clock implementation, if the
> CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
> multiplier computed remains within the boundaries of our clock.
> 
> This means that if the clock we want to reach is below the parent rate,
> or if the multiplier is above the maximum that we can reach, we will end up
> with a completely bogus one that the clock cannot achieve.
> 
> Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Any comments?

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Maxime Ripard]

Hi Mike, Stephen,

On Mon, May 16, 2016 at 02:47:02PM +0200, Maxime Ripard wrote:
> In the current multiplier base clock implementation, if the
> CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
> multiplier computed remains within the boundaries of our clock.
> 
> This means that if the clock we want to reach is below the parent rate,
> or if the multiplier is above the maximum that we can reach, we will end up
> with a completely bogus one that the clock cannot achieve.
> 
> Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Any comments?

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Michael Turquette]

Quoting Maxime Ripard (2016-05-16 05:47:01)
> A fixed factor clock, if it needs to change its rate, by definition do not
> have any choice but to modify its parent rate.

Logically it makes sense to always propagate the rate-change request up
to the parent for a fixed-factor clock if we desire to change its rate.
However, I wonder if doing this for all users of fixed-factor-clock in
DT is safe? Some users may be counting on it not changing.

There are 397 instances of fixed-factor-clock in .dts[i] today, so this
change worries me a bit.

> 
> Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> 
> Signed-off-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
> ---
>  drivers/clk/clk-fixed-factor.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
> index 75cd6c792cb8..3363abd9b4ae 100644
> --- a/drivers/clk/clk-fixed-factor.c
> +++ b/drivers/clk/clk-fixed-factor.c
> @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
>         of_property_read_string(node, "clock-output-names", &clk_name);
>         parent_name = of_clk_get_parent_name(node, 0);
>  
> -       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> +       clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
> +                                       CLK_SET_RATE_PARENT,

An alternative would be to pass in the flags you want, somehow. For the
clock you are trying to fix, is it inside of the SoC or external? If it
is internal, and part of a larger clock controller driver, is this for
the legacy style allwinner clock drivers that put everything in DT? If
not, it would better to initialize it statically and shove this flag
into the struct clk_init_data storage.

Regards,
Mike

>                                         mult, div);
>         if (!IS_ERR(clk))
>                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
> -- 
> 2.8.2
> 
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Re: [PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Michael Turquette]

Quoting Maxime Ripard (2016-05-16 05:47:01)
> A fixed factor clock, if it needs to change its rate, by definition do not
> have any choice but to modify its parent rate.

Logically it makes sense to always propagate the rate-change request up
to the parent for a fixed-factor clock if we desire to change its rate.
However, I wonder if doing this for all users of fixed-factor-clock in
DT is safe? Some users may be counting on it not changing.

There are 397 instances of fixed-factor-clock in .dts[i] today, so this
change worries me a bit.

> =

> Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> =

> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/clk/clk-fixed-factor.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> =

> diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-facto=
r.c
> index 75cd6c792cb8..3363abd9b4ae 100644
> --- a/drivers/clk/clk-fixed-factor.c
> +++ b/drivers/clk/clk-fixed-factor.c
> @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_n=
ode *node)
>         of_property_read_string(node, "clock-output-names", &clk_name);
>         parent_name =3D of_clk_get_parent_name(node, 0);
>  =

> -       clk =3D clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> +       clk =3D clk_register_fixed_factor(NULL, clk_name, parent_name,
> +                                       CLK_SET_RATE_PARENT,

An alternative would be to pass in the flags you want, somehow. For the
clock you are trying to fix, is it inside of the SoC or external? If it
is internal, and part of a larger clock controller driver, is this for
the legacy style allwinner clock drivers that put everything in DT? If
not, it would better to initialize it statically and shove this flag
into the struct clk_init_data storage.

Regards,
Mike

>                                         mult, div);
>         if (!IS_ERR(clk))
>                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
> -- =

> 2.8.2
>=20

[PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Michael Turquette]

Quoting Maxime Ripard (2016-05-16 05:47:01)
> A fixed factor clock, if it needs to change its rate, by definition do not
> have any choice but to modify its parent rate.

Logically it makes sense to always propagate the rate-change request up
to the parent for a fixed-factor clock if we desire to change its rate.
However, I wonder if doing this for all users of fixed-factor-clock in
DT is safe? Some users may be counting on it not changing.

There are 397 instances of fixed-factor-clock in .dts[i] today, so this
change worries me a bit.

> 
> Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/clk/clk-fixed-factor.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
> index 75cd6c792cb8..3363abd9b4ae 100644
> --- a/drivers/clk/clk-fixed-factor.c
> +++ b/drivers/clk/clk-fixed-factor.c
> @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
>         of_property_read_string(node, "clock-output-names", &clk_name);
>         parent_name = of_clk_get_parent_name(node, 0);
>  
> -       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> +       clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
> +                                       CLK_SET_RATE_PARENT,

An alternative would be to pass in the flags you want, somehow. For the
clock you are trying to fix, is it inside of the SoC or external? If it
is internal, and part of a larger clock controller driver, is this for
the legacy style allwinner clock drivers that put everything in DT? If
not, it would better to initialize it statically and shove this flag
into the struct clk_init_data storage.

Regards,
Mike

>                                         mult, div);
>         if (!IS_ERR(clk))
>                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
> -- 
> 2.8.2
> 

Re: [PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Maxime Ripard]

[-- Attachment #1.1: Type: text/plain, Size: 2450 bytes --]

On Fri, Jun 17, 2016 at 04:05:33PM -0700, Michael Turquette wrote:
> Quoting Maxime Ripard (2016-05-16 05:47:01)
> > A fixed factor clock, if it needs to change its rate, by definition do not
> > have any choice but to modify its parent rate.
> 
> Logically it makes sense to always propagate the rate-change request up
> to the parent for a fixed-factor clock if we desire to change its rate.
> However, I wonder if doing this for all users of fixed-factor-clock in
> DT is safe? Some users may be counting on it not changing.
> 
> There are 397 instances of fixed-factor-clock in .dts[i] today, so this
> change worries me a bit.

Understood.

> 
> > 
> > Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> > 
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/clk/clk-fixed-factor.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
> > index 75cd6c792cb8..3363abd9b4ae 100644
> > --- a/drivers/clk/clk-fixed-factor.c
> > +++ b/drivers/clk/clk-fixed-factor.c
> > @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
> >         of_property_read_string(node, "clock-output-names", &clk_name);
> >         parent_name = of_clk_get_parent_name(node, 0);
> >  
> > -       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> > +       clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
> > +                                       CLK_SET_RATE_PARENT,
> 
> An alternative would be to pass in the flags you want, somehow. For the
> clock you are trying to fix, is it inside of the SoC or external? If it
> is internal, and part of a larger clock controller driver, is this for
> the legacy style allwinner clock drivers that put everything in DT?

It is :(

What we could do, is have an extra compatible for that clock (like
"allwinner,sun4i-a10-pll3-x2" in that case), and set the flag only for
that compatible.

Would that work for you?

> If not, it would better to initialize it statically and shove this
> flag into the struct clk_init_data storage.

Hopefully, yes, that should be addressed by the new framework, but I
need reviews to get it merged ;)

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 2450 bytes --]

On Fri, Jun 17, 2016 at 04:05:33PM -0700, Michael Turquette wrote:
> Quoting Maxime Ripard (2016-05-16 05:47:01)
> > A fixed factor clock, if it needs to change its rate, by definition do not
> > have any choice but to modify its parent rate.
> 
> Logically it makes sense to always propagate the rate-change request up
> to the parent for a fixed-factor clock if we desire to change its rate.
> However, I wonder if doing this for all users of fixed-factor-clock in
> DT is safe? Some users may be counting on it not changing.
> 
> There are 397 instances of fixed-factor-clock in .dts[i] today, so this
> change worries me a bit.

Understood.

> 
> > 
> > Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> > 
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/clk/clk-fixed-factor.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
> > index 75cd6c792cb8..3363abd9b4ae 100644
> > --- a/drivers/clk/clk-fixed-factor.c
> > +++ b/drivers/clk/clk-fixed-factor.c
> > @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
> >         of_property_read_string(node, "clock-output-names", &clk_name);
> >         parent_name = of_clk_get_parent_name(node, 0);
> >  
> > -       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> > +       clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
> > +                                       CLK_SET_RATE_PARENT,
> 
> An alternative would be to pass in the flags you want, somehow. For the
> clock you are trying to fix, is it inside of the SoC or external? If it
> is internal, and part of a larger clock controller driver, is this for
> the legacy style allwinner clock drivers that put everything in DT?

It is :(

What we could do, is have an extra compatible for that clock (like
"allwinner,sun4i-a10-pll3-x2" in that case), and set the flag only for
that compatible.

Would that work for you?

> If not, it would better to initialize it statically and shove this
> flag into the struct clk_init_data storage.

Hopefully, yes, that should be addressed by the new framework, but I
need reviews to get it merged ;)

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Maxime Ripard]

On Fri, Jun 17, 2016 at 04:05:33PM -0700, Michael Turquette wrote:
> Quoting Maxime Ripard (2016-05-16 05:47:01)
> > A fixed factor clock, if it needs to change its rate, by definition do not
> > have any choice but to modify its parent rate.
> 
> Logically it makes sense to always propagate the rate-change request up
> to the parent for a fixed-factor clock if we desire to change its rate.
> However, I wonder if doing this for all users of fixed-factor-clock in
> DT is safe? Some users may be counting on it not changing.
> 
> There are 397 instances of fixed-factor-clock in .dts[i] today, so this
> change worries me a bit.

Understood.

> 
> > 
> > Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> > 
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/clk/clk-fixed-factor.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
> > index 75cd6c792cb8..3363abd9b4ae 100644
> > --- a/drivers/clk/clk-fixed-factor.c
> > +++ b/drivers/clk/clk-fixed-factor.c
> > @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
> >         of_property_read_string(node, "clock-output-names", &clk_name);
> >         parent_name = of_clk_get_parent_name(node, 0);
> >  
> > -       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> > +       clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
> > +                                       CLK_SET_RATE_PARENT,
> 
> An alternative would be to pass in the flags you want, somehow. For the
> clock you are trying to fix, is it inside of the SoC or external? If it
> is internal, and part of a larger clock controller driver, is this for
> the legacy style allwinner clock drivers that put everything in DT?

It is :(

What we could do, is have an extra compatible for that clock (like
"allwinner,sun4i-a10-pll3-x2" in that case), and set the flag only for
that compatible.

Would that work for you?

> If not, it would better to initialize it statically and shove this
> flag into the struct clk_init_data storage.

Hopefully, yes, that should be addressed by the new framework, but I
need reviews to get it merged ;)

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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Re: [PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Michael Turquette]

Quoting Maxime Ripard (2016-06-20 01:54:58)
> On Fri, Jun 17, 2016 at 04:05:33PM -0700, Michael Turquette wrote:
> > Quoting Maxime Ripard (2016-05-16 05:47:01)
> > > A fixed factor clock, if it needs to change its rate, by definition do not
> > > have any choice but to modify its parent rate.
> > 
> > Logically it makes sense to always propagate the rate-change request up
> > to the parent for a fixed-factor clock if we desire to change its rate.
> > However, I wonder if doing this for all users of fixed-factor-clock in
> > DT is safe? Some users may be counting on it not changing.
> > 
> > There are 397 instances of fixed-factor-clock in .dts[i] today, so this
> > change worries me a bit.
> 
> Understood.
> 
> > 
> > > 
> > > Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> > > 
> > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > > ---
> > >  drivers/clk/clk-fixed-factor.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
> > > index 75cd6c792cb8..3363abd9b4ae 100644
> > > --- a/drivers/clk/clk-fixed-factor.c
> > > +++ b/drivers/clk/clk-fixed-factor.c
> > > @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
> > >         of_property_read_string(node, "clock-output-names", &clk_name);
> > >         parent_name = of_clk_get_parent_name(node, 0);
> > >  
> > > -       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> > > +       clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
> > > +                                       CLK_SET_RATE_PARENT,
> > 
> > An alternative would be to pass in the flags you want, somehow. For the
> > clock you are trying to fix, is it inside of the SoC or external? If it
> > is internal, and part of a larger clock controller driver, is this for
> > the legacy style allwinner clock drivers that put everything in DT?
> 
> It is :(
> 
> What we could do, is have an extra compatible for that clock (like
> "allwinner,sun4i-a10-pll3-x2" in that case), and set the flag only for
> that compatible.
> 
> Would that work for you

Yes, I think that is the best way forward.

> 
> > If not, it would better to initialize it statically and shove this
> > flag into the struct clk_init_data storage.
> 
> Hopefully, yes, that should be addressed by the new framework, but I
> need reviews to get it merged ;)

Will do!

Regards,
Mike

> 
> Thanks!
> Maxime
> 
> -- 
> Maxime Ripard, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com
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Re: [PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Michael Turquette]

Quoting Maxime Ripard (2016-06-20 01:54:58)
> On Fri, Jun 17, 2016 at 04:05:33PM -0700, Michael Turquette wrote:
> > Quoting Maxime Ripard (2016-05-16 05:47:01)
> > > A fixed factor clock, if it needs to change its rate, by definition d=
o not
> > > have any choice but to modify its parent rate.
> > =

> > Logically it makes sense to always propagate the rate-change request up
> > to the parent for a fixed-factor clock if we desire to change its rate.
> > However, I wonder if doing this for all users of fixed-factor-clock in
> > DT is safe? Some users may be counting on it not changing.
> > =

> > There are 397 instances of fixed-factor-clock in .dts[i] today, so this
> > change worries me a bit.
> =

> Understood.
> =

> > =

> > > =

> > > Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> > > =

> > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > > ---
> > >  drivers/clk/clk-fixed-factor.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > =

> > > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-f=
actor.c
> > > index 75cd6c792cb8..3363abd9b4ae 100644
> > > --- a/drivers/clk/clk-fixed-factor.c
> > > +++ b/drivers/clk/clk-fixed-factor.c
> > > @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct devi=
ce_node *node)
> > >         of_property_read_string(node, "clock-output-names", &clk_name=
);
> > >         parent_name =3D of_clk_get_parent_name(node, 0);
> > >  =

> > > -       clk =3D clk_register_fixed_factor(NULL, clk_name, parent_name=
, 0,
> > > +       clk =3D clk_register_fixed_factor(NULL, clk_name, parent_name,
> > > +                                       CLK_SET_RATE_PARENT,
> > =

> > An alternative would be to pass in the flags you want, somehow. For the
> > clock you are trying to fix, is it inside of the SoC or external? If it
> > is internal, and part of a larger clock controller driver, is this for
> > the legacy style allwinner clock drivers that put everything in DT?
> =

> It is :(
> =

> What we could do, is have an extra compatible for that clock (like
> "allwinner,sun4i-a10-pll3-x2" in that case), and set the flag only for
> that compatible.
> =

> Would that work for you

Yes, I think that is the best way forward.

> =

> > If not, it would better to initialize it statically and shove this
> > flag into the struct clk_init_data storage.
> =

> Hopefully, yes, that should be addressed by the new framework, but I
> need reviews to get it merged ;)

Will do!

Regards,
Mike

> =

> Thanks!
> Maxime
> =

> -- =

> Maxime Ripard, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com

[PATCH 01/20] clk: fixed-factor: Pass clk rates change to the parent

[Michael Turquette]

Quoting Maxime Ripard (2016-06-20 01:54:58)
> On Fri, Jun 17, 2016 at 04:05:33PM -0700, Michael Turquette wrote:
> > Quoting Maxime Ripard (2016-05-16 05:47:01)
> > > A fixed factor clock, if it needs to change its rate, by definition do not
> > > have any choice but to modify its parent rate.
> > 
> > Logically it makes sense to always propagate the rate-change request up
> > to the parent for a fixed-factor clock if we desire to change its rate.
> > However, I wonder if doing this for all users of fixed-factor-clock in
> > DT is safe? Some users may be counting on it not changing.
> > 
> > There are 397 instances of fixed-factor-clock in .dts[i] today, so this
> > change worries me a bit.
> 
> Understood.
> 
> > 
> > > 
> > > Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen
> > > 
> > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > > ---
> > >  drivers/clk/clk-fixed-factor.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
> > > index 75cd6c792cb8..3363abd9b4ae 100644
> > > --- a/drivers/clk/clk-fixed-factor.c
> > > +++ b/drivers/clk/clk-fixed-factor.c
> > > @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node)
> > >         of_property_read_string(node, "clock-output-names", &clk_name);
> > >         parent_name = of_clk_get_parent_name(node, 0);
> > >  
> > > -       clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0,
> > > +       clk = clk_register_fixed_factor(NULL, clk_name, parent_name,
> > > +                                       CLK_SET_RATE_PARENT,
> > 
> > An alternative would be to pass in the flags you want, somehow. For the
> > clock you are trying to fix, is it inside of the SoC or external? If it
> > is internal, and part of a larger clock controller driver, is this for
> > the legacy style allwinner clock drivers that put everything in DT?
> 
> It is :(
> 
> What we could do, is have an extra compatible for that clock (like
> "allwinner,sun4i-a10-pll3-x2" in that case), and set the flag only for
> that compatible.
> 
> Would that work for you

Yes, I think that is the best way forward.

> 
> > If not, it would better to initialize it statically and shove this
> > flag into the struct clk_init_data storage.
> 
> Hopefully, yes, that should be addressed by the new framework, but I
> need reviews to get it merged ;)

Will do!

Regards,
Mike

> 
> Thanks!
> Maxime
> 
> -- 
> Maxime Ripard, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com

Re: [PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Michael Turquette]

Quoting Maxime Ripard (2016-05-16 05:47:02)
> In the current multiplier base clock implementation, if the
> CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
> multiplier computed remains within the boundaries of our clock.
> 
> This means that if the clock we want to reach is below the parent rate,
> or if the multiplier is above the maximum that we can reach, we will end up
> with a completely bogus one that the clock cannot achieve.
> 
> Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Applied.

Regards,
Mike

> ---
>  drivers/clk/clk-multiplier.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/clk-multiplier.c b/drivers/clk/clk-multiplier.c
> index 9e449c7b751c..dc037c957acd 100644
> --- a/drivers/clk/clk-multiplier.c
> +++ b/drivers/clk/clk-multiplier.c
> @@ -52,14 +52,28 @@ static unsigned long __bestmult(struct clk_hw *hw, unsigned long rate,
>                                 unsigned long *best_parent_rate,
>                                 u8 width, unsigned long flags)
>  {
> +       struct clk_multiplier *mult = to_clk_multiplier(hw);
>         unsigned long orig_parent_rate = *best_parent_rate;
>         unsigned long parent_rate, current_rate, best_rate = ~0;
>         unsigned int i, bestmult = 0;
> +       unsigned int maxmult = (1 << width) - 1;
> +
> +       if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
> +               bestmult = rate / orig_parent_rate;
> +
> +               /* Make sure we don't end up with a 0 multiplier */
> +               if ((bestmult == 0) &&
> +                   !(mult->flags & CLK_MULTIPLIER_ZERO_BYPASS))
> +                       bestmult = 1;
>  
> -       if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT))
> -               return rate / *best_parent_rate;
> +               /* Make sure we don't overflow the multiplier */
> +               if (bestmult > maxmult)
> +                       bestmult = maxmult;
> +
> +               return bestmult;
> +       }
>  
> -       for (i = 1; i < ((1 << width) - 1); i++) {
> +       for (i = 1; i < maxmult; i++) {
>                 if (rate == orig_parent_rate * i) {
>                         /*
>                          * This is the best case for us if we have a
> -- 
> 2.8.2
> 
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Re: [PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Michael Turquette]

Quoting Maxime Ripard (2016-05-16 05:47:02)
> In the current multiplier base clock implementation, if the
> CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
> multiplier computed remains within the boundaries of our clock.
> =

> This means that if the clock we want to reach is below the parent rate,
> or if the multiplier is above the maximum that we can reach, we will end =
up
> with a completely bogus one that the clock cannot achieve.
> =

> Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Applied.

Regards,
Mike

> ---
>  drivers/clk/clk-multiplier.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
> =

> diff --git a/drivers/clk/clk-multiplier.c b/drivers/clk/clk-multiplier.c
> index 9e449c7b751c..dc037c957acd 100644
> --- a/drivers/clk/clk-multiplier.c
> +++ b/drivers/clk/clk-multiplier.c
> @@ -52,14 +52,28 @@ static unsigned long __bestmult(struct clk_hw *hw, un=
signed long rate,
>                                 unsigned long *best_parent_rate,
>                                 u8 width, unsigned long flags)
>  {
> +       struct clk_multiplier *mult =3D to_clk_multiplier(hw);
>         unsigned long orig_parent_rate =3D *best_parent_rate;
>         unsigned long parent_rate, current_rate, best_rate =3D ~0;
>         unsigned int i, bestmult =3D 0;
> +       unsigned int maxmult =3D (1 << width) - 1;
> +
> +       if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
> +               bestmult =3D rate / orig_parent_rate;
> +
> +               /* Make sure we don't end up with a 0 multiplier */
> +               if ((bestmult =3D=3D 0) &&
> +                   !(mult->flags & CLK_MULTIPLIER_ZERO_BYPASS))
> +                       bestmult =3D 1;
>  =

> -       if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT))
> -               return rate / *best_parent_rate;
> +               /* Make sure we don't overflow the multiplier */
> +               if (bestmult > maxmult)
> +                       bestmult =3D maxmult;
> +
> +               return bestmult;
> +       }
>  =

> -       for (i =3D 1; i < ((1 << width) - 1); i++) {
> +       for (i =3D 1; i < maxmult; i++) {
>                 if (rate =3D=3D orig_parent_rate * i) {
>                         /*
>                          * This is the best case for us if we have a
> -- =

> 2.8.2
>=20

[PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Michael Turquette]

Quoting Maxime Ripard (2016-05-16 05:47:02)
> In the current multiplier base clock implementation, if the
> CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
> multiplier computed remains within the boundaries of our clock.
> 
> This means that if the clock we want to reach is below the parent rate,
> or if the multiplier is above the maximum that we can reach, we will end up
> with a completely bogus one that the clock cannot achieve.
> 
> Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Applied.

Regards,
Mike

> ---
>  drivers/clk/clk-multiplier.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/clk-multiplier.c b/drivers/clk/clk-multiplier.c
> index 9e449c7b751c..dc037c957acd 100644
> --- a/drivers/clk/clk-multiplier.c
> +++ b/drivers/clk/clk-multiplier.c
> @@ -52,14 +52,28 @@ static unsigned long __bestmult(struct clk_hw *hw, unsigned long rate,
>                                 unsigned long *best_parent_rate,
>                                 u8 width, unsigned long flags)
>  {
> +       struct clk_multiplier *mult = to_clk_multiplier(hw);
>         unsigned long orig_parent_rate = *best_parent_rate;
>         unsigned long parent_rate, current_rate, best_rate = ~0;
>         unsigned int i, bestmult = 0;
> +       unsigned int maxmult = (1 << width) - 1;
> +
> +       if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
> +               bestmult = rate / orig_parent_rate;
> +
> +               /* Make sure we don't end up with a 0 multiplier */
> +               if ((bestmult == 0) &&
> +                   !(mult->flags & CLK_MULTIPLIER_ZERO_BYPASS))
> +                       bestmult = 1;
>  
> -       if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT))
> -               return rate / *best_parent_rate;
> +               /* Make sure we don't overflow the multiplier */
> +               if (bestmult > maxmult)
> +                       bestmult = maxmult;
> +
> +               return bestmult;
> +       }
>  
> -       for (i = 1; i < ((1 << width) - 1); i++) {
> +       for (i = 1; i < maxmult; i++) {
>                 if (rate == orig_parent_rate * i) {
>                         /*
>                          * This is the best case for us if we have a
> -- 
> 2.8.2
> 

Re: [PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Maxime Ripard]

[-- Attachment #1.1: Type: text/plain, Size: 933 bytes --]

On Mon, Jun 20, 2016 at 01:50:30PM -0700, Michael Turquette wrote:
> Quoting Maxime Ripard (2016-05-16 05:47:02)
> > In the current multiplier base clock implementation, if the
> > CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
> > multiplier computed remains within the boundaries of our clock.
> > 
> > This means that if the clock we want to reach is below the parent rate,
> > or if the multiplier is above the maximum that we can reach, we will end up
> > with a completely bogus one that the clock cannot achieve.
> > 
> > Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> Applied.

Thanks, but apparently you merged it in clk-next, while it should go
in clk-fixes, shouldn't it?

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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_______________________________________________
dri-devel mailing list
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Re: [PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 933 bytes --]

On Mon, Jun 20, 2016 at 01:50:30PM -0700, Michael Turquette wrote:
> Quoting Maxime Ripard (2016-05-16 05:47:02)
> > In the current multiplier base clock implementation, if the
> > CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
> > multiplier computed remains within the boundaries of our clock.
> > 
> > This means that if the clock we want to reach is below the parent rate,
> > or if the multiplier is above the maximum that we can reach, we will end up
> > with a completely bogus one that the clock cannot achieve.
> > 
> > Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> Applied.

Thanks, but apparently you merged it in clk-next, while it should go
in clk-fixes, shouldn't it?

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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[PATCH 02/20] clk: multiplier: Prevent the multiplier from under / over flowing

[Maxime Ripard]

On Mon, Jun 20, 2016 at 01:50:30PM -0700, Michael Turquette wrote:
> Quoting Maxime Ripard (2016-05-16 05:47:02)
> > In the current multiplier base clock implementation, if the
> > CLK_SET_RATE_PARENT flag isn't set, the code will not make sure that the
> > multiplier computed remains within the boundaries of our clock.
> > 
> > This means that if the clock we want to reach is below the parent rate,
> > or if the multiplier is above the maximum that we can reach, we will end up
> > with a completely bogus one that the clock cannot achieve.
> > 
> > Fixes: f2e0a53271a4 ("clk: Add a basic multiplier clock")
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> 
> Applied.

Thanks, but apparently you merged it in clk-next, while it should go
in clk-fixes, shouldn't it?

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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