[PATCH v3 00/13] drm: bridge: Add Samsung MIPI DSIM bridge

[PATCH v3 00/13] drm: bridge: Add Samsung MIPI DSIM bridge

[Jagan Teki]

This series supports common bridge support for Samsung MIPI DSIM
which is used in Exynos and i.MX8MM SoC's.

Previous v2 can be available here [1].

The final bridge supports both the Exynos and i.MX8MM DSI devices.

On, summary this patch-set break the entire DSIM driver into
- platform specific glue code for platform ops, component_ops.
- common bridge driver which handle platform glue init and invoke.

Patch 0001:	Restore proper bridge chain in exynos_dsi

Patch 0002: 	Samsung DSIM bridge

Patch 0003:	Common lookup code for OF-graph or child

Patch 0004: 	plat_data quirk flag via driver_data

Patch 0005/11:  bridge fixes, atomic API's

Patch 0012:	document fsl,imx8mm-mipi-dsim

Patch 0013:	add i.MX8MM DSIM support

Tested in Engicam i.Core MX8M Mini SoM.

Anyone interested, please have a look on this repo [2]

[2] https://github.com/openedev/kernel/tree/imx8mm-dsi-v2 
[1] https://patchwork.kernel.org/project/dri-devel/cover/20220504114021.33265-1-jagan@amarulasolutions.com/

Any inputs?
Jagan.

Jagan Teki (12):
  drm: bridge: Add Samsung DSIM bridge driver
  drm: bridge: samsung-dsim: Lookup OF-graph or Child node devices
  drm: bridge: samsung-dsim: Handle platform init via driver_data
  drm: bridge: samsung-dsim: Mark PHY as optional
  drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()
  drm: bridge: samsung-dsim: Fix PLL_P (PMS_P) offset
  drm: bridge: samsung-dsim: Add module init, exit
  drm: bridge: samsung-dsim: Add atomic_check
  drm: bridge: samsung-dsim: Add atomic_get_input_bus_fmts
  drm: bridge: samsung-dsim: Add input_bus_flags
  dt-bindings: display: exynos: dsim: Add NXP i.MX8MM support
  drm: bridge: samsung-dsim: Add i.MX8MM support

Marek Szyprowski (1):
  drm: exynos: dsi: Restore proper bridge chain order

 .../bindings/display/exynos/exynos_dsim.txt   |    1 +
 MAINTAINERS                                   |    8 +
 drivers/gpu/drm/bridge/Kconfig                |   12 +
 drivers/gpu/drm/bridge/Makefile               |    1 +
 drivers/gpu/drm/bridge/samsung-dsim.c         | 1850 +++++++++++++++++
 drivers/gpu/drm/exynos/Kconfig                |    1 +
 drivers/gpu/drm/exynos/exynos_drm_dsi.c       | 1717 +--------------
 include/drm/bridge/samsung-dsim.h             |  106 +
 8 files changed, 2042 insertions(+), 1654 deletions(-)
 create mode 100644 drivers/gpu/drm/bridge/samsung-dsim.c
 create mode 100644 include/drm/bridge/samsung-dsim.h

-- 
2.25.1

[PATCH v3 01/13] drm: exynos: dsi: Restore proper bridge chain order

[Jagan Teki]

From: Marek Szyprowski <m.szyprowski@samsung.com>

Restore the proper bridge chain by finding the previous bridge
in the chain instead of passing NULL.

This establishes a proper bridge chain while attaching downstream
bridges.

v3:
* new patch

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/exynos/exynos_drm_dsi.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index ec673223d6b7..e5b1540c4ae4 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -1428,7 +1428,8 @@ static int exynos_dsi_attach(struct drm_bridge *bridge,
 {
 	struct exynos_dsi *dsi = bridge_to_dsi(bridge);
 
-	return drm_bridge_attach(bridge->encoder, dsi->out_bridge, NULL, flags);
+	return drm_bridge_attach(bridge->encoder, dsi->out_bridge, bridge,
+				 flags);
 }
 
 static const struct drm_bridge_funcs exynos_dsi_bridge_funcs = {
@@ -1474,7 +1475,10 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
 
 	drm_bridge_add(&dsi->bridge);
 
-	drm_bridge_attach(encoder, &dsi->bridge, NULL, 0);
+	drm_bridge_attach(encoder, &dsi->bridge,
+			  list_first_entry_or_null(&encoder->bridge_chain,
+						   struct drm_bridge,
+						   chain_node), 0);
 
 	/*
 	 * This is a temporary solution and should be made by more generic way.
-- 
2.25.1

[PATCH v3 03/13] drm: bridge: samsung-dsim: Lookup OF-graph or Child node devices

[Jagan Teki]

The child devices in MIPI DSI can be binding with OF-graph
and also via child nodes.

The OF-graph interface represents the child devices via
remote and associated endpoint numbers like

dsi {
   compatible = "fsl,imx8mm-mipi-dsim";

   ports {
	port@0 {
	     reg = <0>;

	     dsi_in_lcdif: endpoint@0 {
		  reg = <0>;
		  remote-endpoint = <&lcdif_out_dsi>;
	     };
	};

	port@1 {
	     reg = <1>;

	     dsi_out_bridge: endpoint {
		  remote-endpoint = <&bridge_in_dsi>;
	     };
	};
};

The child node interface represents the child devices via
conventional child nodes on given DSI parent like

dsi {
   compatible = "samsung,exynos5433-mipi-dsi";

   ports {
        port@0 {
             reg = <0>;

             dsi_to_mic: endpoint {
                  remote-endpoint = <&mic_to_dsi>;
             };
        };
   };

   panel@0 {
        reg = <0>;
   };
};

As Samsung DSIM bridge is common DSI IP across all Exynos DSI
and NXP i.MX8M host controllers, this patch adds support to
lookup the child devices whether its bindings on the associated
host represent OF-graph or child node interfaces.

v3:
* none

v2:
* new patch

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 38 +++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 21975ed513bd..20db345abf8b 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1357,18 +1357,52 @@ static int samsung_dsim_host_attach(struct mipi_dsi_host *host,
 	struct samsung_dsim *dsi = host_to_dsi(host);
 	const struct samsung_dsim_plat_data *pdata = dsi->plat_data;
 	struct device *dev = dsi->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *remote;
 	struct drm_panel *panel;
 	int ret;
 
-	panel = of_drm_find_panel(device->dev.of_node);
+	/**
+	 * Devices can also be child nodes when we also control that device
+	 * through the upstream device (ie, MIPI-DCS for a MIPI-DSI device).
+	 *
+	 * Lookup for a child node of the given parent that isn't either port
+	 * or ports.
+	 */
+	for_each_available_child_of_node(np, remote) {
+		if (of_node_name_eq(remote, "port") ||
+		    of_node_name_eq(remote, "ports"))
+			continue;
+
+		goto of_find_panel_or_bridge;
+	}
+
+	/*
+	 * of_graph_get_remote_node() produces a noisy error message if port
+	 * node isn't found and the absence of the port is a legit case here,
+	 * so at first we silently check whether graph presents in the
+	 * device-tree node.
+	 */
+	if (!of_graph_is_present(np))
+		return -ENODEV;
+
+	remote = of_graph_get_remote_node(np, 1, 0);
+
+of_find_panel_or_bridge:
+	if (!remote)
+		return -ENODEV;
+
+	panel = of_drm_find_panel(remote);
 	if (!IS_ERR(panel)) {
 		dsi->out_bridge = devm_drm_panel_bridge_add(dev, panel);
 	} else {
-		dsi->out_bridge = of_drm_find_bridge(device->dev.of_node);
+		dsi->out_bridge = of_drm_find_bridge(remote);
 		if (!dsi->out_bridge)
 			dsi->out_bridge = ERR_PTR(-EINVAL);
 	}
 
+	of_node_put(remote);
+
 	if (IS_ERR(dsi->out_bridge)) {
 		ret = PTR_ERR(dsi->out_bridge);
 		DRM_DEV_ERROR(dev, "failed to find the bridge: %d\n", ret);
-- 
2.25.1

[PATCH v3 04/13] drm: bridge: samsung-dsim: Handle platform init via driver_data

[Jagan Teki]

In order to make a common Samsung DSIM bridge driver some platform
specific glue code needs to maintain separately as it is hard to
maintain platform specific glue and conventional component_ops on
the drm bridge drivers side.

This patch is trying to support that glue code initialization based
on the DSIM_QUIRK_PLAT_DATA set from respective driver_data.

So, the platforms which enable DSIM_QUIRK_PLAT_DATA flags will handle
all platform specific initialization via samsung_dsim_plat_probe.

The platform probe is responsible to
- initialize samsung_dsim_plat_data and install hooks
- initialize component_ops
- preserve samsung_dsim structure pointer

v3:
* update samsung_dsim_plat_probe return value
* add plat_data quirk to handle platform init

v2:
* fix samsung_dsim_plat_probe return pointer

v1:
* use platform_init instead of exynos_specific
* handle component_ops in glue code

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 16 ++++++++++++++--
 include/drm/bridge/samsung-dsim.h     |  5 +++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 20db345abf8b..4d5f72de2240 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -369,6 +369,7 @@ static const struct samsung_dsim_driver_data exynos3_dsi_driver_data = {
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
 	.reg_values = reg_values,
+	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
 
 static const struct samsung_dsim_driver_data exynos4_dsi_driver_data = {
@@ -381,6 +382,7 @@ static const struct samsung_dsim_driver_data exynos4_dsi_driver_data = {
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
 	.reg_values = reg_values,
+	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
 
 static const struct samsung_dsim_driver_data exynos5_dsi_driver_data = {
@@ -391,6 +393,7 @@ static const struct samsung_dsim_driver_data exynos5_dsi_driver_data = {
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
 	.reg_values = reg_values,
+	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
 
 static const struct samsung_dsim_driver_data exynos5433_dsi_driver_data = {
@@ -402,6 +405,7 @@ static const struct samsung_dsim_driver_data exynos5433_dsi_driver_data = {
 	.wait_for_reset = 0,
 	.num_bits_resol = 12,
 	.reg_values = exynos5433_reg_values,
+	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
 
 static const struct samsung_dsim_driver_data exynos5422_dsi_driver_data = {
@@ -413,6 +417,7 @@ static const struct samsung_dsim_driver_data exynos5422_dsi_driver_data = {
 	.wait_for_reset = 1,
 	.num_bits_resol = 12,
 	.reg_values = exynos5422_reg_values,
+	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
 
 static const struct of_device_id samsung_dsim_of_match[] = {
@@ -1609,7 +1614,11 @@ static int samsung_dsim_probe(struct platform_device *pdev)
 	dsi->bridge.of_node = dev->of_node;
 	dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
 
-	ret = samsung_dsim_plat_probe(dsi);
+	if (dsi->driver_data->quirks & DSIM_QUIRK_PLAT_DATA)
+		ret = samsung_dsim_plat_probe(dsi);
+	else
+		ret = mipi_dsi_host_register(&dsi->dsi_host);
+
 	if (ret)
 		goto err_disable_runtime;
 
@@ -1627,7 +1636,10 @@ static int samsung_dsim_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 
-	samsung_dsim_plat_remove(dsi);
+	if (dsi->driver_data->quirks & DSIM_QUIRK_PLAT_DATA)
+		samsung_dsim_plat_remove(dsi);
+	else
+		mipi_dsi_host_unregister(&dsi->dsi_host);
 
 	return 0;
 }
diff --git a/include/drm/bridge/samsung-dsim.h b/include/drm/bridge/samsung-dsim.h
index 2e245bffd1b6..97fdee5ef5df 100644
--- a/include/drm/bridge/samsung-dsim.h
+++ b/include/drm/bridge/samsung-dsim.h
@@ -33,6 +33,10 @@ struct samsung_dsim_transfer {
 	u16 rx_done;
 };
 
+enum samsung_dsim_quirks {
+	DSIM_QUIRK_PLAT_DATA		= BIT(0),
+};
+
 struct samsung_dsim_driver_data {
 	const unsigned int *reg_ofs;
 	unsigned int plltmr_reg;
@@ -43,6 +47,7 @@ struct samsung_dsim_driver_data {
 	unsigned int wait_for_reset;
 	unsigned int num_bits_resol;
 	const unsigned int *reg_values;
+	enum samsung_dsim_quirks quirks;
 };
 
 struct samsung_dsim_host_ops {
-- 
2.25.1

[PATCH v3 05/13] drm: bridge: samsung-dsim: Mark PHY as optional

[Jagan Teki]

In i.MX8M Mini/Nano SoC the DSI Phy requires a MIPI DPHY bit
to reset in order to activate the PHY and that can be done via
upstream i.MX8M blk-ctrl driver.

So, mark the phy get as optional.

v3, v2:
* none

v1:
* new patch

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 4d5f72de2240..9b74a3f98a17 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1583,7 +1583,7 @@ static int samsung_dsim_probe(struct platform_device *pdev)
 	if (IS_ERR(dsi->reg_base))
 		return PTR_ERR(dsi->reg_base);
 
-	dsi->phy = devm_phy_get(dev, "dsim");
+	dsi->phy = devm_phy_optional_get(dev, "dsim");
 	if (IS_ERR(dsi->phy)) {
 		dev_info(dev, "failed to get dsim phy\n");
 		return PTR_ERR(dsi->phy);
-- 
2.25.1

[PATCH v3 06/13] drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()

[Jagan Teki]

Host transfer() in DSI master will invoke only when the DSI commands
are sent from DSI devices like DSI Panel or DSI bridges and this
host transfer wouldn't invoke for I2C-based-DSI bridge drivers.

Handling DSI host initialization in transfer calls misses the
controller setup for I2C configured DSI bridges.

This patch adds the DSI initialization from transfer to bridge
pre_enable as the bridge pre_enable API is invoked by core as
it is common across all classes of DSI device drivers.

v3:
* none

v2:
* check initialized state in samsung_dsim_init

v1:
* keep DSI init in host transfer

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 9b74a3f98a17..b07909a52f2d 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1258,6 +1258,9 @@ static int samsung_dsim_init(struct samsung_dsim *dsi)
 {
 	const struct samsung_dsim_driver_data *driver_data = dsi->driver_data;
 
+	if (dsi->state & DSIM_STATE_INITIALIZED)
+		return 0;
+
 	samsung_dsim_reset(dsi);
 	samsung_dsim_enable_irq(dsi);
 
@@ -1270,6 +1273,8 @@ static int samsung_dsim_init(struct samsung_dsim *dsi)
 	samsung_dsim_set_phy_ctrl(dsi);
 	samsung_dsim_init_link(dsi);
 
+	dsi->state |= DSIM_STATE_INITIALIZED;
+
 	return 0;
 }
 
@@ -1289,6 +1294,10 @@ static void samsung_dsim_atomic_pre_enable(struct drm_bridge *bridge,
 	}
 
 	dsi->state |= DSIM_STATE_ENABLED;
+
+	ret = samsung_dsim_init(dsi);
+	if (ret)
+		return;
 }
 
 static void samsung_dsim_atomic_enable(struct drm_bridge *bridge,
@@ -1464,12 +1473,9 @@ static ssize_t samsung_dsim_host_transfer(struct mipi_dsi_host *host,
 	if (!(dsi->state & DSIM_STATE_ENABLED))
 		return -EINVAL;
 
-	if (!(dsi->state & DSIM_STATE_INITIALIZED)) {
-		ret = samsung_dsim_init(dsi);
-		if (ret)
-			return ret;
-		dsi->state |= DSIM_STATE_INITIALIZED;
-	}
+	ret = samsung_dsim_init(dsi);
+	if (ret)
+		return ret;
 
 	ret = mipi_dsi_create_packet(&xfer.packet, msg);
 	if (ret < 0)
-- 
2.25.1

[PATCH v3 07/13] drm: bridge: samsung-dsim: Fix PLL_P (PMS_P) offset

[Jagan Teki]

The i.MX 8M Mini Applications Processor Reference Manual, Rev. 3, 11/2020
with 13.7.10.1 Master PLL PMS Value setting Register mentioned PMS_P offset
range from BIT[18-13] and the upstream driver is using the same offset.

However, offset 13 is not working on i.MX8M Mini platforms but downstream
NXP driver is using 14 [1] and it is working with i.MX8M Mini SoC.

Not sure about whether it is reference manual documentation or something
else but this patch trusts the downstream code and fixes the PLL_P offset.

[1] https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/gpu/drm/bridge/sec-dsim.c?h=imx_5.4.47_2.2.0#n211

v3, v2:
* none

v1:
* updated commit message
* add downstream driver link

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 10 ++++++++--
 include/drm/bridge/samsung-dsim.h     |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index b07909a52f2d..5eb594ea0bdf 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -168,7 +168,7 @@
 /* DSIM_PLLCTRL */
 #define DSIM_FREQ_BAND(x)		((x) << 24)
 #define DSIM_PLL_EN			(1 << 23)
-#define DSIM_PLL_P(x)			((x) << 13)
+#define DSIM_PLL_P(x, offset)		((x) << (offset))
 #define DSIM_PLL_M(x)			((x) << 4)
 #define DSIM_PLL_S(x)			((x) << 1)
 
@@ -368,6 +368,7 @@ static const struct samsung_dsim_driver_data exynos3_dsi_driver_data = {
 	.max_freq = 1000,
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
+	.pll_p_offset = 13,
 	.reg_values = reg_values,
 	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
@@ -381,6 +382,7 @@ static const struct samsung_dsim_driver_data exynos4_dsi_driver_data = {
 	.max_freq = 1000,
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
+	.pll_p_offset = 13,
 	.reg_values = reg_values,
 	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
@@ -392,6 +394,7 @@ static const struct samsung_dsim_driver_data exynos5_dsi_driver_data = {
 	.max_freq = 1000,
 	.wait_for_reset = 1,
 	.num_bits_resol = 11,
+	.pll_p_offset = 13,
 	.reg_values = reg_values,
 	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
@@ -404,6 +407,7 @@ static const struct samsung_dsim_driver_data exynos5433_dsi_driver_data = {
 	.max_freq = 1500,
 	.wait_for_reset = 0,
 	.num_bits_resol = 12,
+	.pll_p_offset = 13,
 	.reg_values = exynos5433_reg_values,
 	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
@@ -416,6 +420,7 @@ static const struct samsung_dsim_driver_data exynos5422_dsi_driver_data = {
 	.max_freq = 1500,
 	.wait_for_reset = 1,
 	.num_bits_resol = 12,
+	.pll_p_offset = 13,
 	.reg_values = exynos5422_reg_values,
 	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
@@ -563,7 +568,8 @@ static unsigned long samsung_dsim_set_pll(struct samsung_dsim *dsi,
 	writel(driver_data->reg_values[PLL_TIMER],
 			dsi->reg_base + driver_data->plltmr_reg);
 
-	reg = DSIM_PLL_EN | DSIM_PLL_P(p) | DSIM_PLL_M(m) | DSIM_PLL_S(s);
+	reg = DSIM_PLL_EN | DSIM_PLL_P(p, driver_data->pll_p_offset) |
+	      DSIM_PLL_M(m) | DSIM_PLL_S(s);
 
 	if (driver_data->has_freqband) {
 		static const unsigned long freq_bands[] = {
diff --git a/include/drm/bridge/samsung-dsim.h b/include/drm/bridge/samsung-dsim.h
index 97fdee5ef5df..c852d7b9981e 100644
--- a/include/drm/bridge/samsung-dsim.h
+++ b/include/drm/bridge/samsung-dsim.h
@@ -46,6 +46,7 @@ struct samsung_dsim_driver_data {
 	unsigned int max_freq;
 	unsigned int wait_for_reset;
 	unsigned int num_bits_resol;
+	unsigned int pll_p_offset;
 	const unsigned int *reg_values;
 	enum samsung_dsim_quirks quirks;
 };
-- 
2.25.1

[PATCH v3 08/13] drm: bridge: samsung-dsim: Add module init, exit

[Jagan Teki]

Add module init and exit functions for the bridge to register
and unregister dsi_driver.

Exynos drm driver stack will register the platform_driver separately
in the common of it's exynos_drm_drv.c including dsi_driver.

Register again would return -EBUSY, so return 0 for such cases as
dsi_driver is already registered.

v3, v2, v1:
* none

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 5eb594ea0bdf..5a0fea30e9e8 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1737,6 +1737,28 @@ struct platform_driver dsi_driver = {
 	},
 };
 
+static int __init samsung_mipi_dsim_init(void)
+{
+	int ret;
+
+	ret = platform_driver_register(&dsi_driver);
+
+	/**
+	 * Exynos drm driver stack will register the platform_driver
+	 * separately in the common of it's exynos_drm_drv.c including
+	 * dsi_driver. Register again would return -EBUSY, so return 0
+	 * for such cases as dsi_driver is already registered.
+	 */
+	return ret == -EBUSY ? 0 : ret;
+}
+module_init(samsung_mipi_dsim_init);
+
+static void __exit samsung_mipi_dsim_exit(void)
+{
+	platform_driver_unregister(&dsi_driver);
+}
+module_exit(samsung_mipi_dsim_exit);
+
 MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
 MODULE_DESCRIPTION("Samsung MIPI DSIM controller bridge");
 MODULE_LICENSE("GPL");
-- 
2.25.1

[PATCH v3 09/13] drm: bridge: samsung-dsim: Add atomic_check

[Jagan Teki]

Explicit fixing up of mode_flags is required for DSIM present
in i.MX8M SoC.

At least the LCDIF + DSIM needs active low sync polarities in
order to correlate the correct sync flags of the surrounding
components in the chain to make sure the whole pipeline can
work properly.

So, add DSIM_QUIRK_FIXUP_SYNC_POL to handle this fixup via bridge
atomic_check.

v3:
* add DSIM_QUIRK_FIXUP_SYNC_POL to handle mode_flasg fixup

v2:
* none

v1:
* fix mode flags in atomic_check instead of mode_fixup

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 18 ++++++++++++++++++
 include/drm/bridge/samsung-dsim.h     |  1 +
 2 files changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 5a0fea30e9e8..376e9682e130 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1339,6 +1339,23 @@ static void samsung_dsim_atomic_post_disable(struct drm_bridge *bridge,
 	pm_runtime_put_sync(dsi->dev);
 }
 
+static int samsung_dsim_atomic_check(struct drm_bridge *bridge,
+				     struct drm_bridge_state *bridge_state,
+				     struct drm_crtc_state *crtc_state,
+				     struct drm_connector_state *conn_state)
+{
+	struct samsung_dsim *dsi = bridge_to_dsi(bridge);
+	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
+
+	if (dsi->driver_data->quirks & DSIM_QUIRK_FIXUP_SYNC_POL) {
+		/* At least LCDIF + DSIM needs active low sync */
+		adjusted_mode->flags |= (DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC);
+		adjusted_mode->flags &= ~(DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
+	}
+
+	return 0;
+}
+
 static void samsung_dsim_mode_set(struct drm_bridge *bridge,
 				  const struct drm_display_mode *mode,
 				  const struct drm_display_mode *adjusted_mode)
@@ -1361,6 +1378,7 @@ static const struct drm_bridge_funcs samsung_dsim_bridge_funcs = {
 	.atomic_duplicate_state		= drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state		= drm_atomic_helper_bridge_destroy_state,
 	.atomic_reset			= drm_atomic_helper_bridge_reset,
+	.atomic_check			= samsung_dsim_atomic_check,
 	.atomic_pre_enable		= samsung_dsim_atomic_pre_enable,
 	.atomic_enable			= samsung_dsim_atomic_enable,
 	.atomic_disable			= samsung_dsim_atomic_disable,
diff --git a/include/drm/bridge/samsung-dsim.h b/include/drm/bridge/samsung-dsim.h
index c852d7b9981e..4eacaf18e00a 100644
--- a/include/drm/bridge/samsung-dsim.h
+++ b/include/drm/bridge/samsung-dsim.h
@@ -35,6 +35,7 @@ struct samsung_dsim_transfer {
 
 enum samsung_dsim_quirks {
 	DSIM_QUIRK_PLAT_DATA		= BIT(0),
+	DSIM_QUIRK_FIXUP_SYNC_POL	= BIT(1),
 };
 
 struct samsung_dsim_driver_data {
-- 
2.25.1

[PATCH v3 10/13] drm: bridge: samsung-dsim: Add atomic_get_input_bus_fmts

[Jagan Teki]

Finding the right input bus format throughout the pipeline is hard
so add atomic_get_input_bus_fmts callback and initialize with the
default RGB888_1X24 bus format on DSI-end.

This format can be used in pipeline for negotiating bus format between
the DSI-end of this bridge and the other component closer to pipeline
components.

v3:
* include media-bus-format.h

v2:
* none

v1:
* new patch

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 28 +++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 376e9682e130..2584343b767a 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -15,6 +15,7 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/irq.h>
+#include <linux/media-bus-format.h>
 #include <linux/of_device.h>
 #include <linux/phy/phy.h>
 
@@ -1339,6 +1340,32 @@ static void samsung_dsim_atomic_post_disable(struct drm_bridge *bridge,
 	pm_runtime_put_sync(dsi->dev);
 }
 
+#define MAX_INPUT_SEL_FORMATS	1
+
+static u32 *
+samsung_dsim_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+				       struct drm_bridge_state *bridge_state,
+				       struct drm_crtc_state *crtc_state,
+				       struct drm_connector_state *conn_state,
+				       u32 output_fmt,
+				       unsigned int *num_input_fmts)
+{
+	u32 *input_fmts;
+
+	*num_input_fmts = 0;
+
+	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
+			     GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	/* This is the DSI-end bus format */
+	input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+	*num_input_fmts = 1;
+
+	return input_fmts;
+}
+
 static int samsung_dsim_atomic_check(struct drm_bridge *bridge,
 				     struct drm_bridge_state *bridge_state,
 				     struct drm_crtc_state *crtc_state,
@@ -1378,6 +1405,7 @@ static const struct drm_bridge_funcs samsung_dsim_bridge_funcs = {
 	.atomic_duplicate_state		= drm_atomic_helper_bridge_duplicate_state,
 	.atomic_destroy_state		= drm_atomic_helper_bridge_destroy_state,
 	.atomic_reset			= drm_atomic_helper_bridge_reset,
+	.atomic_get_input_bus_fmts	= samsung_dsim_atomic_get_input_bus_fmts,
 	.atomic_check			= samsung_dsim_atomic_check,
 	.atomic_pre_enable		= samsung_dsim_atomic_pre_enable,
 	.atomic_enable			= samsung_dsim_atomic_enable,
-- 
2.25.1

[PATCH v3 11/13] drm: bridge: samsung-dsim: Add input_bus_flags

[Jagan Teki]

eLCDIF is expecting to have input_bus_flags as DE_LOW in order to
set active low during valid data transfer on each horizontal line.

Add DE_LOW flag via drm bridge timings.

v3, v2:
* none

v1:
* none

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 2584343b767a..ef439b49f2b8 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1591,6 +1591,10 @@ __weak void samsung_dsim_plat_remove(struct samsung_dsim *priv)
 {
 }
 
+static const struct drm_bridge_timings samsung_dsim_bridge_timings = {
+	.input_bus_flags = DRM_BUS_FLAG_DE_LOW,
+};
+
 static int samsung_dsim_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1670,6 +1674,7 @@ static int samsung_dsim_probe(struct platform_device *pdev)
 
 	dsi->bridge.funcs = &samsung_dsim_bridge_funcs;
 	dsi->bridge.of_node = dev->of_node;
+	dsi->bridge.timings = &samsung_dsim_bridge_timings;
 	dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
 
 	if (dsi->driver_data->quirks & DSIM_QUIRK_PLAT_DATA)
-- 
2.25.1

[PATCH v3 12/13] dt-bindings: display: exynos: dsim: Add NXP i.MX8MM support

[Jagan Teki]

Samsung MIPI DSIM bridge can also be found in i.MX8MM SoC.

Add dt-bingings for it.

v3:
* collect Rob Acked-by

v2:
* updated comments

v1:
* new patch

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 Documentation/devicetree/bindings/display/exynos/exynos_dsim.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/display/exynos/exynos_dsim.txt b/Documentation/devicetree/bindings/display/exynos/exynos_dsim.txt
index be377786e8cd..8efcf4728e0b 100644
--- a/Documentation/devicetree/bindings/display/exynos/exynos_dsim.txt
+++ b/Documentation/devicetree/bindings/display/exynos/exynos_dsim.txt
@@ -7,6 +7,7 @@ Required properties:
 		"samsung,exynos5410-mipi-dsi" /* for Exynos5410/5420/5440 SoCs */
 		"samsung,exynos5422-mipi-dsi" /* for Exynos5422/5800 SoCs */
 		"samsung,exynos5433-mipi-dsi" /* for Exynos5433 SoCs */
+		"fsl,imx8mm-mipi-dsim" /* for i.MX8M Mini SoCs */
   - reg: physical base address and length of the registers set for the device
   - interrupts: should contain DSI interrupt
   - clocks: list of clock specifiers, must contain an entry for each required
-- 
2.25.1

[PATCH v3 13/13] drm: bridge: samsung-dsim: Add i.MX8MM support

[Jagan Teki]

Samsung MIPI DSIM master can also be found in i.MX8MM SoC.

Add compatible and associated driver_data for it.

v3:
* enable DSIM_QUIRK_FIXUP_SYNC_POL quirk

v2:
* collect Laurent r-b

v1:
* none

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 35 +++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index ef439b49f2b8..3b859b61f493 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -360,6 +360,24 @@ static const unsigned int exynos5433_reg_values[] = {
 	[PHYTIMING_HS_TRAIL] = DSIM_PHYTIMING2_HS_TRAIL(0x0c),
 };
 
+static const unsigned int imx8mm_dsim_reg_values[] = {
+	[RESET_TYPE] = DSIM_SWRST,
+	[PLL_TIMER] = 500,
+	[STOP_STATE_CNT] = 0xf,
+	[PHYCTRL_ULPS_EXIT] = 0,
+	[PHYCTRL_VREG_LP] = 0,
+	[PHYCTRL_SLEW_UP] = 0,
+	[PHYTIMING_LPX] = DSIM_PHYTIMING_LPX(0x06),
+	[PHYTIMING_HS_EXIT] = DSIM_PHYTIMING_HS_EXIT(0x0b),
+	[PHYTIMING_CLK_PREPARE] = DSIM_PHYTIMING1_CLK_PREPARE(0x07),
+	[PHYTIMING_CLK_ZERO] = DSIM_PHYTIMING1_CLK_ZERO(0x26),
+	[PHYTIMING_CLK_POST] = DSIM_PHYTIMING1_CLK_POST(0x0d),
+	[PHYTIMING_CLK_TRAIL] = DSIM_PHYTIMING1_CLK_TRAIL(0x08),
+	[PHYTIMING_HS_PREPARE] = DSIM_PHYTIMING2_HS_PREPARE(0x08),
+	[PHYTIMING_HS_ZERO] = DSIM_PHYTIMING2_HS_ZERO(0x0d),
+	[PHYTIMING_HS_TRAIL] = DSIM_PHYTIMING2_HS_TRAIL(0x0b),
+};
+
 static const struct samsung_dsim_driver_data exynos3_dsi_driver_data = {
 	.reg_ofs = exynos_reg_ofs,
 	.plltmr_reg = 0x50,
@@ -426,6 +444,19 @@ static const struct samsung_dsim_driver_data exynos5422_dsi_driver_data = {
 	.quirks = DSIM_QUIRK_PLAT_DATA,
 };
 
+static const struct samsung_dsim_driver_data imx8mm_dsi_driver_data = {
+	.reg_ofs = exynos5433_reg_ofs,
+	.plltmr_reg = 0xa0,
+	.has_clklane_stop = 1,
+	.num_clks = 2,
+	.max_freq = 2100,
+	.wait_for_reset = 0,
+	.num_bits_resol = 12,
+	.pll_p_offset = 14,
+	.reg_values = imx8mm_dsim_reg_values,
+	.quirks = DSIM_QUIRK_FIXUP_SYNC_POL,
+};
+
 static const struct of_device_id samsung_dsim_of_match[] = {
 	{
 		.compatible = "samsung,exynos3250-mipi-dsi",
@@ -447,6 +478,10 @@ static const struct of_device_id samsung_dsim_of_match[] = {
 		.compatible = "samsung,exynos5433-mipi-dsi",
 		.data = &exynos5433_dsi_driver_data
 	},
+	{
+		.compatible = "fsl,imx8mm-mipi-dsim",
+		.data = &imx8mm_dsi_driver_data
+	},
 	{ /* sentinel. */ }
 };
 
-- 
2.25.1

Re: [PATCH v3 00/13] drm: bridge: Add Samsung MIPI DSIM bridge

[Alexander Stein]

Hi Jagan,

thanks for the update.

Am Mittwoch, 20. Juli 2022, 17:51:57 CEST schrieb Jagan Teki:
> This series supports common bridge support for Samsung MIPI DSIM
> which is used in Exynos and i.MX8MM SoC's.
> 
> Previous v2 can be available here [1].
> 
> The final bridge supports both the Exynos and i.MX8MM DSI devices.
> 
> On, summary this patch-set break the entire DSIM driver into
> - platform specific glue code for platform ops, component_ops.
> - common bridge driver which handle platform glue init and invoke.
> 
> Patch 0001:	Restore proper bridge chain in exynos_dsi
> 
> Patch 0002: 	Samsung DSIM bridge
> 
> Patch 0003:	Common lookup code for OF-graph or child
> 
> Patch 0004: 	plat_data quirk flag via driver_data
> 
> Patch 0005/11:  bridge fixes, atomic API's
> 
> Patch 0012:	document fsl,imx8mm-mipi-dsim
> 
> Patch 0013:	add i.MX8MM DSIM support
> 
> Tested in Engicam i.Core MX8M Mini SoM.
> 
> Anyone interested, please have a look on this repo [2]
> 
> [2] https://github.com/openedev/kernel/tree/imx8mm-dsi-v2

I suspect you meant https://github.com/openedev/kernel/tree/imx8mm-dsi-v3

Using this v3:
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
on TQMa8MxML + MBa8Mx.

> [1]
> https://patchwork.kernel.org/project/dri-devel/cover/20220504114021.33265-1
> -jagan@amarulasolutions.com/
> 
> Any inputs?
> Jagan.
> 
> Jagan Teki (12):
>   drm: bridge: Add Samsung DSIM bridge driver
>   drm: bridge: samsung-dsim: Lookup OF-graph or Child node devices
>   drm: bridge: samsung-dsim: Handle platform init via driver_data
>   drm: bridge: samsung-dsim: Mark PHY as optional
>   drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()
>   drm: bridge: samsung-dsim: Fix PLL_P (PMS_P) offset
>   drm: bridge: samsung-dsim: Add module init, exit
>   drm: bridge: samsung-dsim: Add atomic_check
>   drm: bridge: samsung-dsim: Add atomic_get_input_bus_fmts
>   drm: bridge: samsung-dsim: Add input_bus_flags
>   dt-bindings: display: exynos: dsim: Add NXP i.MX8MM support
>   drm: bridge: samsung-dsim: Add i.MX8MM support
> 
> Marek Szyprowski (1):
>   drm: exynos: dsi: Restore proper bridge chain order
> 
>  .../bindings/display/exynos/exynos_dsim.txt   |    1 +
>  MAINTAINERS                                   |    8 +
>  drivers/gpu/drm/bridge/Kconfig                |   12 +
>  drivers/gpu/drm/bridge/Makefile               |    1 +
>  drivers/gpu/drm/bridge/samsung-dsim.c         | 1850 +++++++++++++++++
>  drivers/gpu/drm/exynos/Kconfig                |    1 +
>  drivers/gpu/drm/exynos/exynos_drm_dsi.c       | 1717 +--------------
>  include/drm/bridge/samsung-dsim.h             |  106 +
>  8 files changed, 2042 insertions(+), 1654 deletions(-)
>  create mode 100644 drivers/gpu/drm/bridge/samsung-dsim.c
>  create mode 100644 include/drm/bridge/samsung-dsim.h

Re: [PATCH v3 08/13] drm: bridge: samsung-dsim: Add module init, exit

[Marek Szyprowski]

Hi Jagan,

On 20.07.2022 17:52, Jagan Teki wrote:
> Add module init and exit functions for the bridge to register
> and unregister dsi_driver.
>
> Exynos drm driver stack will register the platform_driver separately
> in the common of it's exynos_drm_drv.c including dsi_driver.
>
> Register again would return -EBUSY, so return 0 for such cases as
> dsi_driver is already registered.

I've already pointed that this is a bad style solution. It will also not 
work in the following cases:

1. exynos drm and samsung-dsim compiled as modules - samsung-dsim 
module, once loaded, will register the driver and exynos_drm won't be 
able to register the exynos_dsi.

2. multi-arch case - if one compiles a kernel (disto-style) with drivers 
for both supported architectures (exynos and imx) - in such case it will 
not work on imx, because exynos_drm driver will always register 
exynos_dsi driver first (even if the kernel is booted on non-exynos board).

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [PATCH v3 08/13] drm: bridge: samsung-dsim: Add module init, exit

[Jagan Teki]

Hi Marek,

On Thu, Jul 21, 2022 at 4:39 PM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
>
> Hi Jagan,
>
> On 20.07.2022 17:52, Jagan Teki wrote:
> > Add module init and exit functions for the bridge to register
> > and unregister dsi_driver.
> >
> > Exynos drm driver stack will register the platform_driver separately
> > in the common of it's exynos_drm_drv.c including dsi_driver.
> >
> > Register again would return -EBUSY, so return 0 for such cases as
> > dsi_driver is already registered.
>
> I've already pointed that this is a bad style solution. It will also not
> work in the following cases:

Yes, I have seen it in v2. (sending again since its part of the series
and resolved other issues on v2)

>
> 1. exynos drm and samsung-dsim compiled as modules - samsung-dsim
> module, once loaded, will register the driver and exynos_drm won't be
> able to register the exynos_dsi.
>
> 2. multi-arch case - if one compiles a kernel (disto-style) with drivers
> for both supported architectures (exynos and imx) - in such case it will
> not work on imx, because exynos_drm driver will always register
> exynos_dsi driver first (even if the kernel is booted on non-exynos board).

Okay. I need to check the best way to handle this - so far this seems
new. any suggestions, please let me know.

Thanks,
Jagan.

Re: [PATCH v3 06/13] drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()

[Marek Szyprowski]

On 20.07.2022 17:52, Jagan Teki wrote:
> Host transfer() in DSI master will invoke only when the DSI commands
> are sent from DSI devices like DSI Panel or DSI bridges and this
> host transfer wouldn't invoke for I2C-based-DSI bridge drivers.
>
> Handling DSI host initialization in transfer calls misses the
> controller setup for I2C configured DSI bridges.
>
> This patch adds the DSI initialization from transfer to bridge
> pre_enable as the bridge pre_enable API is invoked by core as
> it is common across all classes of DSI device drivers.

This is still problematic in case of Exynos. Without a workaround like this

https://github.com/mszyprow/linux/commit/11bbfc61272da9610dd5c574bb8ef838dc150961

the display on the all real DSI panels on my Exynos based boards is broken.


>
> v3:
> * none
>
> v2:
> * check initialized state in samsung_dsim_init
>
> v1:
> * keep DSI init in host transfer
>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>   drivers/gpu/drm/bridge/samsung-dsim.c | 18 ++++++++++++------
>   1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index 9b74a3f98a17..b07909a52f2d 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -1258,6 +1258,9 @@ static int samsung_dsim_init(struct samsung_dsim *dsi)
>   {
>   	const struct samsung_dsim_driver_data *driver_data = dsi->driver_data;
>   
> +	if (dsi->state & DSIM_STATE_INITIALIZED)
> +		return 0;
> +
>   	samsung_dsim_reset(dsi);
>   	samsung_dsim_enable_irq(dsi);
>   
> @@ -1270,6 +1273,8 @@ static int samsung_dsim_init(struct samsung_dsim *dsi)
>   	samsung_dsim_set_phy_ctrl(dsi);
>   	samsung_dsim_init_link(dsi);
>   
> +	dsi->state |= DSIM_STATE_INITIALIZED;
> +
>   	return 0;
>   }
>   
> @@ -1289,6 +1294,10 @@ static void samsung_dsim_atomic_pre_enable(struct drm_bridge *bridge,
>   	}
>   
>   	dsi->state |= DSIM_STATE_ENABLED;
> +
> +	ret = samsung_dsim_init(dsi);
> +	if (ret)
> +		return;
>   }
>   
>   static void samsung_dsim_atomic_enable(struct drm_bridge *bridge,
> @@ -1464,12 +1473,9 @@ static ssize_t samsung_dsim_host_transfer(struct mipi_dsi_host *host,
>   	if (!(dsi->state & DSIM_STATE_ENABLED))
>   		return -EINVAL;
>   
> -	if (!(dsi->state & DSIM_STATE_INITIALIZED)) {
> -		ret = samsung_dsim_init(dsi);
> -		if (ret)
> -			return ret;
> -		dsi->state |= DSIM_STATE_INITIALIZED;
> -	}
> +	ret = samsung_dsim_init(dsi);
> +	if (ret)
> +		return ret;
>   
>   	ret = mipi_dsi_create_packet(&xfer.packet, msg);
>   	if (ret < 0)

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [PATCH v3 06/13] drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()

[Dave Stevenson]

Hi Jagan and Marek.

On Fri, 22 Jul 2022 at 16:35, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
>
> On 20.07.2022 17:52, Jagan Teki wrote:
> > Host transfer() in DSI master will invoke only when the DSI commands
> > are sent from DSI devices like DSI Panel or DSI bridges and this
> > host transfer wouldn't invoke for I2C-based-DSI bridge drivers.
> >
> > Handling DSI host initialization in transfer calls misses the
> > controller setup for I2C configured DSI bridges.
> >
> > This patch adds the DSI initialization from transfer to bridge
> > pre_enable as the bridge pre_enable API is invoked by core as
> > it is common across all classes of DSI device drivers.
>
> This is still problematic in case of Exynos. Without a workaround like this
>
> https://github.com/mszyprow/linux/commit/11bbfc61272da9610dd5c574bb8ef838dc150961
>
> the display on the all real DSI panels on my Exynos based boards is broken.

I'd queried on the other thread trying to address DSI operation [1] as
to whether the test for STOP_STATE (presumably LP-11) at [2] was
actually valid, but had no response.
There is no need to check for bus contention at that point, but should
it happen the driver doesn't write the registers in lines 862-868
having returned -EFAULT at line 853. The controller is therefore only
partially initialised.

I may be misinterpreting what that code is waiting for though, or the
hardware may require some further state before it can be initialised.

  Dave

[1] https://www.mail-archive.com/dri-devel@lists.freedesktop.org/msg397703.html
[2] https://github.com/mszyprow/linux/blob/11bbfc61272da9610dd5c574bb8ef838dc150961/drivers/gpu/drm/bridge/samsung-dsim.c#L850

> >
> > v3:
> > * none
> >
> > v2:
> > * check initialized state in samsung_dsim_init
> >
> > v1:
> > * keep DSI init in host transfer
> >
> > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > ---
> >   drivers/gpu/drm/bridge/samsung-dsim.c | 18 ++++++++++++------
> >   1 file changed, 12 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> > index 9b74a3f98a17..b07909a52f2d 100644
> > --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> > @@ -1258,6 +1258,9 @@ static int samsung_dsim_init(struct samsung_dsim *dsi)
> >   {
> >       const struct samsung_dsim_driver_data *driver_data = dsi->driver_data;
> >
> > +     if (dsi->state & DSIM_STATE_INITIALIZED)
> > +             return 0;
> > +
> >       samsung_dsim_reset(dsi);
> >       samsung_dsim_enable_irq(dsi);
> >
> > @@ -1270,6 +1273,8 @@ static int samsung_dsim_init(struct samsung_dsim *dsi)
> >       samsung_dsim_set_phy_ctrl(dsi);
> >       samsung_dsim_init_link(dsi);
> >
> > +     dsi->state |= DSIM_STATE_INITIALIZED;
> > +
> >       return 0;
> >   }
> >
> > @@ -1289,6 +1294,10 @@ static void samsung_dsim_atomic_pre_enable(struct drm_bridge *bridge,
> >       }
> >
> >       dsi->state |= DSIM_STATE_ENABLED;
> > +
> > +     ret = samsung_dsim_init(dsi);
> > +     if (ret)
> > +             return;
> >   }
> >
> >   static void samsung_dsim_atomic_enable(struct drm_bridge *bridge,
> > @@ -1464,12 +1473,9 @@ static ssize_t samsung_dsim_host_transfer(struct mipi_dsi_host *host,
> >       if (!(dsi->state & DSIM_STATE_ENABLED))
> >               return -EINVAL;
> >
> > -     if (!(dsi->state & DSIM_STATE_INITIALIZED)) {
> > -             ret = samsung_dsim_init(dsi);
> > -             if (ret)
> > -                     return ret;
> > -             dsi->state |= DSIM_STATE_INITIALIZED;
> > -     }
> > +     ret = samsung_dsim_init(dsi);
> > +     if (ret)
> > +             return ret;
> >
> >       ret = mipi_dsi_create_packet(&xfer.packet, msg);
> >       if (ret < 0)
>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>

Re: [PATCH v3 02/13] drm: bridge: Add Samsung DSIM bridge driver

[Krzysztof Kozlowski]

On 20/07/2022 17:51, Jagan Teki wrote:
> 
> v1:
> * Don't maintain component_ops in bridge driver
> * Don't maintain platform glue code in bridge driver
> * Add platform-specific glue code and make a common bridge
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>  MAINTAINERS                             |    8 +
>  drivers/gpu/drm/bridge/Kconfig          |   12 +
>  drivers/gpu/drm/bridge/Makefile         |    1 +
>  drivers/gpu/drm/bridge/samsung-dsim.c   | 1684 ++++++++++++++++++++++
>  drivers/gpu/drm/exynos/Kconfig          |    1 +
>  drivers/gpu/drm/exynos/exynos_drm_dsi.c | 1715 +----------------------
>  include/drm/bridge/samsung-dsim.h       |   99 ++
>  7 files changed, 1865 insertions(+), 1655 deletions(-)
>  create mode 100644 drivers/gpu/drm/bridge/samsung-dsim.c
>  create mode 100644 include/drm/bridge/samsung-dsim.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0f9366144d31..d796fa8c7be0 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6546,6 +6546,14 @@ T:	git git://anongit.freedesktop.org/drm/drm-misc
>  F:	Documentation/devicetree/bindings/display/panel/samsung,lms397kf04.yaml
>  F:	drivers/gpu/drm/panel/panel-samsung-db7430.c
>  
> +DRM DRIVER FOR SAMSUNG MIPI DSIM BRIDGE
> +M:	Jagan Teki <jagan@amarulasolutions.com>

You also need:
L: dri-devel@lists.freedesktop.org

and probably also at least Inki Dae as maintainer as well:
M: Inki Dae <inki.dae@samsung.com

> +M:	Marek Szyprowski <m.szyprowski@samsung.com>
> +S:	Maintained
> +T:	git git://anongit.freedesktop.org/drm/drm-misc
> +F:	drivers/gpu/drm/bridge/samsung-dsim.c
> +F:	include/drm/bridge/samsung-dsim.h


Best regards,
Krzysztof

Re: [PATCH v3 06/13] drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()

[Jagan Teki]

Hi Dave,

On Fri, Jul 22, 2022 at 9:35 PM Dave Stevenson
<dave.stevenson@raspberrypi.com> wrote:
>
> Hi Jagan and Marek.
>
> On Fri, 22 Jul 2022 at 16:35, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
> >
> > On 20.07.2022 17:52, Jagan Teki wrote:
> > > Host transfer() in DSI master will invoke only when the DSI commands
> > > are sent from DSI devices like DSI Panel or DSI bridges and this
> > > host transfer wouldn't invoke for I2C-based-DSI bridge drivers.
> > >
> > > Handling DSI host initialization in transfer calls misses the
> > > controller setup for I2C configured DSI bridges.
> > >
> > > This patch adds the DSI initialization from transfer to bridge
> > > pre_enable as the bridge pre_enable API is invoked by core as
> > > it is common across all classes of DSI device drivers.
> >
> > This is still problematic in case of Exynos. Without a workaround like this
> >
> > https://github.com/mszyprow/linux/commit/11bbfc61272da9610dd5c574bb8ef838dc150961
> >
> > the display on the all real DSI panels on my Exynos based boards is broken.
>
> I'd queried on the other thread trying to address DSI operation [1] as
> to whether the test for STOP_STATE (presumably LP-11) at [2] was
> actually valid, but had no response.
> There is no need to check for bus contention at that point, but should
> it happen the driver doesn't write the registers in lines 862-868
> having returned -EFAULT at line 853. The controller is therefore only
> partially initialised.

Can you link me if you have any updated series on this? or the
existing one is the latest one itself?

Thanks,
Jagan.

Re: [PATCH v3 06/13] drm: bridge: samsung-dsim: Add DSI init in bridge pre_enable()

[Dave Stevenson]

Hi Jagan

On Mon, 29 Aug 2022 at 19:31, Jagan Teki <jagan@amarulasolutions.com> wrote:
>
> Hi Dave,
>
> On Fri, Jul 22, 2022 at 9:35 PM Dave Stevenson
> <dave.stevenson@raspberrypi.com> wrote:
> >
> > Hi Jagan and Marek.
> >
> > On Fri, 22 Jul 2022 at 16:35, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
> > >
> > > On 20.07.2022 17:52, Jagan Teki wrote:
> > > > Host transfer() in DSI master will invoke only when the DSI commands
> > > > are sent from DSI devices like DSI Panel or DSI bridges and this
> > > > host transfer wouldn't invoke for I2C-based-DSI bridge drivers.
> > > >
> > > > Handling DSI host initialization in transfer calls misses the
> > > > controller setup for I2C configured DSI bridges.
> > > >
> > > > This patch adds the DSI initialization from transfer to bridge
> > > > pre_enable as the bridge pre_enable API is invoked by core as
> > > > it is common across all classes of DSI device drivers.
> > >
> > > This is still problematic in case of Exynos. Without a workaround like this
> > >
> > > https://github.com/mszyprow/linux/commit/11bbfc61272da9610dd5c574bb8ef838dc150961
> > >
> > > the display on the all real DSI panels on my Exynos based boards is broken.
> >
> > I'd queried on the other thread trying to address DSI operation [1] as
> > to whether the test for STOP_STATE (presumably LP-11) at [2] was
> > actually valid, but had no response.
> > There is no need to check for bus contention at that point, but should
> > it happen the driver doesn't write the registers in lines 862-868
> > having returned -EFAULT at line 853. The controller is therefore only
> > partially initialised.
>
> Can you link me if you have any updated series on this? or the
> existing one is the latest one itself?

I've not updated my patch set as I didn't think there had been any
significant review comments to action -
https://patchwork.freedesktop.org/series/100252/ is still the latest.

Sam had suggested changing upstream to prev/next, but seeing as no one
else has expressed a view on that I didn't see much point in
respinning. If others agree with Sam, then I'll do it.

Checking I do note that the suggested change to drop
drm_bridge_chain_* API has been done by Sam. I don't see that having
been merged, but once it is patch 1 needs to be dropped / reworked.

I don't have any Exynos hardware, so can't really help out on the DSI
issues there other than making suggestions by inspection of the code.

  Dave

> Thanks,
> Jagan.