[PATCH v10 0/8] add i2c driver supported for rk3399

[PATCH v10 0/8] add i2c driver supported for rk3399

[David Wu]

There are three points differert from others:
 - new method to caculate i2c timings for rk3399
 - pclk and function clk are separated at rk3399
 - add fast-plus mode supported for rk3399

David Wu (8):
  i2c: rk3x: add documentation to fields in "struct rk3x_i2c"
  i2c: rk3x: use struct "rk3x_i2c_calced_timings"
  i2c: rk3x: Remove redundant rk3x_i2c_clean_ipd()
  i2c: rk3x: Change SoC data to not use array
  i2c: rk3x: Move spec timing data to "static const" structs
  dt-bindings: i2c: rk3x: add support for rk3399
  i2c: rk3x: add i2c support for rk3399 soc
  i2c: rk3x: support fast-mode plus for rk3399

 Documentation/devicetree/bindings/i2c/i2c-rk3x.txt |  16 +-
 drivers/i2c/busses/i2c-rk3x.c                      | 498 +++++++++++++++++----
 2 files changed, 434 insertions(+), 80 deletions(-)

-- 
1.9.1

[PATCH v10 1/8] i2c: rk3x: add documentation to fields in "struct rk3x_i2c"

[David Wu]

Add kernel-doc documentation for the elements of the previously
undocumented struct rk3x_i2c.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Change in v10:
- none

Change in v9:
- add commit description.

Change in v8:
- none

 drivers/i2c/busses/i2c-rk3x.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 80bed02..7e45d51 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -90,6 +90,26 @@ struct rk3x_i2c_soc_data {
 	int grf_offset;
 };
 
+/**
+ * struct rk3x_i2c - private data of the controller
+ * @adap: corresponding I2C adapter
+ * @dev: device for this controller
+ * @soc_data: related soc data struct
+ * @regs: virtual memory area
+ * @clk: clock of i2c bus
+ * @clk_rate_nb: i2c clk rate change notify
+ * @t: I2C known timing information
+ * @lock: spinlock for the i2c bus
+ * @wait: the waitqueue to wait for i2c transfer
+ * @busy: the condition for the event to wait for
+ * @msg: current i2c message
+ * @addr: addr of i2c slave device
+ * @mode: mode of i2c transfer
+ * @is_last_msg: flag determines whether it is the last msg in this transfer
+ * @state: state of i2c transfer
+ * @processed: byte length which has been send or received
+ * @error: error code for i2c transfer
+ */
 struct rk3x_i2c {
 	struct i2c_adapter adap;
 	struct device *dev;
@@ -116,7 +136,7 @@ struct rk3x_i2c {
 
 	/* I2C state machine */
 	enum rk3x_i2c_state state;
-	unsigned int processed; /* sent/received bytes */
+	unsigned int processed;
 	int error;
 };
 
-- 
1.9.1

[PATCH v10 2/8] i2c: rk3x: use struct "rk3x_i2c_calced_timings"

[David Wu]

The "div_high" and "div_low" values are always used together.
Group them into a structure to make it easier to pass them
both around. This structure also provides a place for future
calculated timings.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Change in v10:
- none

Change in v9:
- none

Change in v8:
- add commit description.

 drivers/i2c/busses/i2c-rk3x.c | 55 +++++++++++++++++++++++++------------------
 1 file changed, 32 insertions(+), 23 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 7e45d51..1e2677a 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -75,6 +75,16 @@ enum {
 #define WAIT_TIMEOUT      1000 /* ms */
 #define DEFAULT_SCL_RATE  (100 * 1000) /* Hz */
 
+/**
+ * struct rk3x_i2c_calced_timings:
+ * @div_low: Divider output for low
+ * @div_high: Divider output for high
+ */
+struct rk3x_i2c_calced_timings {
+	unsigned long div_low;
+	unsigned long div_high;
+};
+
 enum rk3x_i2c_state {
 	STATE_IDLE,
 	STATE_START,
@@ -454,9 +464,8 @@ out:
  * Calculate divider values for desired SCL frequency
  *
  * @clk_rate: I2C input clock rate
- * @t: Known I2C timing information.
- * @div_low: Divider output for low
- * @div_high: Divider output for high
+ * @t: Known I2C timing information
+ * @t_calc: Caculated rk3x private timings that would be written into regs
  *
  * Returns: 0 on success, -EINVAL if the goal SCL rate is too slow. In that case
  * a best-effort divider value is returned in divs. If the target rate is
@@ -464,8 +473,7 @@ out:
  */
 static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 			      struct i2c_timings *t,
-			      unsigned long *div_low,
-			      unsigned long *div_high)
+			      struct rk3x_i2c_calced_timings *t_calc)
 {
 	unsigned long spec_min_low_ns, spec_min_high_ns;
 	unsigned long spec_setup_start, spec_max_data_hold_ns;
@@ -572,8 +580,8 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 		 * Time needed to meet hold requirements is important.
 		 * Just use that.
 		 */
-		*div_low = min_low_div;
-		*div_high = min_high_div;
+		t_calc->div_low = min_low_div;
+		t_calc->div_high = min_high_div;
 	} else {
 		/*
 		 * We've got to distribute some time among the low and high
@@ -602,25 +610,25 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 
 		/* Give low the "ideal" and give high whatever extra is left */
 		extra_low_div = ideal_low_div - min_low_div;
-		*div_low = ideal_low_div;
-		*div_high = min_high_div + (extra_div - extra_low_div);
+		t_calc->div_low = ideal_low_div;
+		t_calc->div_high = min_high_div + (extra_div - extra_low_div);
 	}
 
 	/*
 	 * Adjust to the fact that the hardware has an implicit "+1".
 	 * NOTE: Above calculations always produce div_low > 0 and div_high > 0.
 	 */
-	*div_low = *div_low - 1;
-	*div_high = *div_high - 1;
+	t_calc->div_low--;
+	t_calc->div_high--;
 
 	/* Maximum divider supported by hw is 0xffff */
-	if (*div_low > 0xffff) {
-		*div_low = 0xffff;
+	if (t_calc->div_low > 0xffff) {
+		t_calc->div_low = 0xffff;
 		ret = -EINVAL;
 	}
 
-	if (*div_high > 0xffff) {
-		*div_high = 0xffff;
+	if (t_calc->div_high > 0xffff) {
+		t_calc->div_high = 0xffff;
 		ret = -EINVAL;
 	}
 
@@ -630,19 +638,21 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
 {
 	struct i2c_timings *t = &i2c->t;
-	unsigned long div_low, div_high;
+	struct rk3x_i2c_calced_timings calc;
 	u64 t_low_ns, t_high_ns;
 	int ret;
 
-	ret = rk3x_i2c_calc_divs(clk_rate, t, &div_low, &div_high);
+	ret = rk3x_i2c_calc_divs(clk_rate, t, &calc);
 	WARN_ONCE(ret != 0, "Could not reach SCL freq %u", t->bus_freq_hz);
 
 	clk_enable(i2c->clk);
-	i2c_writel(i2c, (div_high << 16) | (div_low & 0xffff), REG_CLKDIV);
+	i2c_writel(i2c, (calc.div_high << 16) | (calc.div_low & 0xffff),
+		   REG_CLKDIV);
 	clk_disable(i2c->clk);
 
-	t_low_ns = div_u64(((u64)div_low + 1) * 8 * 1000000000, clk_rate);
-	t_high_ns = div_u64(((u64)div_high + 1) * 8 * 1000000000, clk_rate);
+	t_low_ns = div_u64(((u64)calc.div_low + 1) * 8 * 1000000000, clk_rate);
+	t_high_ns = div_u64(((u64)calc.div_high + 1) * 8 * 1000000000,
+			    clk_rate);
 	dev_dbg(i2c->dev,
 		"CLK %lukhz, Req %uns, Act low %lluns high %lluns\n",
 		clk_rate / 1000,
@@ -672,12 +682,11 @@ static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
 {
 	struct clk_notifier_data *ndata = data;
 	struct rk3x_i2c *i2c = container_of(nb, struct rk3x_i2c, clk_rate_nb);
-	unsigned long div_low, div_high;
+	struct rk3x_i2c_calced_timings calc;
 
 	switch (event) {
 	case PRE_RATE_CHANGE:
-		if (rk3x_i2c_calc_divs(ndata->new_rate, &i2c->t,
-				       &div_low, &div_high) != 0)
+		if (rk3x_i2c_calc_divs(ndata->new_rate, &i2c->t, &calc) != 0)
 			return NOTIFY_STOP;
 
 		/* scale up */
-- 
1.9.1

[PATCH v10 3/8] i2c: rk3x: Remove redundant rk3x_i2c_clean_ipd()

[David Wu]

rk3x_i2c_setup() gets called directly before rk3x_i2c_start(),
and the last thing in setup was to clean the IPD, so no reason
to do it at the beginning of start.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Change in v10:
- none

Change in v9:
- modify commit message

Change in v8:
- none

 drivers/i2c/busses/i2c-rk3x.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 1e2677a..9eeb4e5 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -174,7 +174,6 @@ static void rk3x_i2c_start(struct rk3x_i2c *i2c)
 {
 	u32 val;
 
-	rk3x_i2c_clean_ipd(i2c);
 	i2c_writel(i2c, REG_INT_START, REG_IEN);
 
 	/* enable adapter with correct mode, send START condition */
-- 
1.9.1

[PATCH v10 4/8] i2c: rk3x: Change SoC data to not use array

[David Wu]

Specifying the i2c SoC data in an array provides very little benefit and
gets unwieldly / confusing as the array grows since the next bit of code
needs to refer to elements in the array by their raw integral index.

Let's just create a single 'static const' structure for each SoC so that
we can refer to these structures by ID.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Suggested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Change in v10:
- none

Change in v9:
- none

Change in v8:
- add commit description.

 drivers/i2c/busses/i2c-rk3x.c | 38 ++++++++++++++++++++++++++++++--------
 1 file changed, 30 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 9eeb4e5..d7a871f 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -864,17 +864,39 @@ static const struct i2c_algorithm rk3x_i2c_algorithm = {
 	.functionality		= rk3x_i2c_func,
 };
 
-static struct rk3x_i2c_soc_data soc_data[3] = {
-	{ .grf_offset = 0x154 }, /* rk3066 */
-	{ .grf_offset = 0x0a4 }, /* rk3188 */
-	{ .grf_offset = -1 },    /* no I2C switching needed */
+static const struct rk3x_i2c_soc_data rk3066_soc_data = {
+	.grf_offset = 0x154,
+};
+
+static const struct rk3x_i2c_soc_data rk3188_soc_data = {
+	.grf_offset = 0x0a4,
+};
+
+static const struct rk3x_i2c_soc_data rk3228_soc_data = {
+	.grf_offset = -1,
+};
+
+static const struct rk3x_i2c_soc_data rk3288_soc_data = {
+	.grf_offset = -1,
 };
 
 static const struct of_device_id rk3x_i2c_match[] = {
-	{ .compatible = "rockchip,rk3066-i2c", .data = (void *)&soc_data[0] },
-	{ .compatible = "rockchip,rk3188-i2c", .data = (void *)&soc_data[1] },
-	{ .compatible = "rockchip,rk3228-i2c", .data = (void *)&soc_data[2] },
-	{ .compatible = "rockchip,rk3288-i2c", .data = (void *)&soc_data[2] },
+	{
+		.compatible = "rockchip,rk3066-i2c",
+		.data = (void *)&rk3066_soc_data
+	},
+	{
+		.compatible = "rockchip,rk3188-i2c",
+		.data = (void *)&rk3188_soc_data
+	},
+	{
+		.compatible = "rockchip,rk3228-i2c",
+		.data = (void *)&rk3228_soc_data
+	},
+	{
+		.compatible = "rockchip,rk3288-i2c",
+		.data = (void *)&rk3288_soc_data
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, rk3x_i2c_match);
-- 
1.9.1

[PATCH v10 5/8] i2c: rk3x: Move spec timing data to "static const" structs

[David Wu]

The i2c timing specs are really just constant data. There's no reason
to write code to init them, so move them out to structures. This not
only is a cleaner solution but it will reduce code duplication when we
introduce a new variant of rk3x_i2c_calc_divs() in a future patch.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Suggested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Change in v10:
- none

Change in v9:
- none

Changes in v8:
- add commit description.
- remove the spec values that were not needed, then
  introduce the additional values in the rk3399 patch. 

 drivers/i2c/busses/i2c-rk3x.c | 83 ++++++++++++++++++++++++++++---------------
 1 file changed, 55 insertions(+), 28 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index d7a871f..9791797 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -76,6 +76,34 @@ enum {
 #define DEFAULT_SCL_RATE  (100 * 1000) /* Hz */
 
 /**
+ * struct i2c_spec_values:
+ * @min_low_ns: min LOW period of the SCL clock
+ * @min_high_ns: min HIGH period of the SCL cloc
+ * @min_setup_start_ns: min set-up time for a repeated START conditio
+ * @max_data_hold_ns: max data hold time
+ */
+struct i2c_spec_values {
+	unsigned long min_low_ns;
+	unsigned long min_high_ns;
+	unsigned long min_setup_start_ns;
+	unsigned long max_data_hold_ns;
+};
+
+static const struct i2c_spec_values standard_mode_spec = {
+	.min_low_ns = 4700,
+	.min_high_ns = 4000,
+	.min_setup_start_ns = 4700,
+	.max_data_hold_ns = 3450,
+};
+
+static const struct i2c_spec_values fast_mode_spec = {
+	.min_low_ns = 1300,
+	.min_high_ns = 600,
+	.min_setup_start_ns = 600,
+	.max_data_hold_ns = 900,
+};
+
+/**
  * struct rk3x_i2c_calced_timings:
  * @div_low: Divider output for low
  * @div_high: Divider output for high
@@ -460,6 +488,21 @@ out:
 }
 
 /**
+ * Get timing values of I2C specification
+ *
+ * @speed: Desired SCL frequency
+ *
+ * Returns: Matched i2c spec values.
+ */
+static const struct i2c_spec_values *rk3x_i2c_get_spec(unsigned int speed)
+{
+	if (speed <= 100000)
+		return &standard_mode_spec;
+	else
+		return &fast_mode_spec;
+}
+
+/**
  * Calculate divider values for desired SCL frequency
  *
  * @clk_rate: I2C input clock rate
@@ -474,10 +517,6 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 			      struct i2c_timings *t,
 			      struct rk3x_i2c_calced_timings *t_calc)
 {
-	unsigned long spec_min_low_ns, spec_min_high_ns;
-	unsigned long spec_setup_start, spec_max_data_hold_ns;
-	unsigned long data_hold_buffer_ns;
-
 	unsigned long min_low_ns, min_high_ns;
 	unsigned long max_low_ns, min_total_ns;
 
@@ -489,6 +528,8 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 	unsigned long min_div_for_hold, min_total_div;
 	unsigned long extra_div, extra_low_div, ideal_low_div;
 
+	unsigned long data_hold_buffer_ns = 50;
+	const struct i2c_spec_values *spec;
 	int ret = 0;
 
 	/* Only support standard-mode and fast-mode */
@@ -511,22 +552,8 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 	 *	 This is because the i2c host on Rockchip holds the data line
 	 *	 for half the low time.
 	 */
-	if (t->bus_freq_hz <= 100000) {
-		/* Standard-mode */
-		spec_min_low_ns = 4700;
-		spec_setup_start = 4700;
-		spec_min_high_ns = 4000;
-		spec_max_data_hold_ns = 3450;
-		data_hold_buffer_ns = 50;
-	} else {
-		/* Fast-mode */
-		spec_min_low_ns = 1300;
-		spec_setup_start = 600;
-		spec_min_high_ns = 600;
-		spec_max_data_hold_ns = 900;
-		data_hold_buffer_ns = 50;
-	}
-	min_high_ns = t->scl_rise_ns + spec_min_high_ns;
+	spec = rk3x_i2c_get_spec(t->bus_freq_hz);
+	min_high_ns = t->scl_rise_ns + spec->min_high_ns;
 
 	/*
 	 * Timings for repeated start:
@@ -536,14 +563,14 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 	 * We need to account for those rules in picking our "high" time so
 	 * we meet tSU;STA and tHD;STA times.
 	 */
-	min_high_ns = max(min_high_ns,
-		DIV_ROUND_UP((t->scl_rise_ns + spec_setup_start) * 1000, 875));
-	min_high_ns = max(min_high_ns,
-		DIV_ROUND_UP((t->scl_rise_ns + spec_setup_start +
-			      t->sda_fall_ns + spec_min_high_ns), 2));
-
-	min_low_ns = t->scl_fall_ns + spec_min_low_ns;
-	max_low_ns = spec_max_data_hold_ns * 2 - data_hold_buffer_ns;
+	min_high_ns = max(min_high_ns, DIV_ROUND_UP(
+		(t->scl_rise_ns + spec->min_setup_start_ns) * 1000, 875));
+	min_high_ns = max(min_high_ns, DIV_ROUND_UP(
+		(t->scl_rise_ns + spec->min_setup_start_ns + t->sda_fall_ns +
+		spec->min_high_ns), 2));
+
+	min_low_ns = t->scl_fall_ns + spec->min_low_ns;
+	max_low_ns =  spec->max_data_hold_ns * 2 - data_hold_buffer_ns;
 	min_total_ns = min_low_ns + min_high_ns;
 
 	/* Adjust to avoid overflow */
-- 
1.9.1

[PATCH v10 6/8] dt-bindings: i2c: rk3x: add support for rk3399

[David Wu]

The bus clock and function clock are separated at rk3399,
and others use one clock as the bus clock and function clock.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Change in v10:
- none

Change in v9:
- remove unnecessary "REQUIRED".

Change in v8:
- remove error description.

 Documentation/devicetree/bindings/i2c/i2c-rk3x.txt | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt
index 0b4a85f..bbc5a1e 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-rk3x.txt
@@ -6,10 +6,20 @@ RK3xxx SoCs.
 Required properties :
 
  - reg : Offset and length of the register set for the device
- - compatible : should be "rockchip,rk3066-i2c", "rockchip,rk3188-i2c",
-		"rockchip,rk3228-i2c" or "rockchip,rk3288-i2c".
+ - compatible: should be one of the following:
+   - "rockchip,rk3066-i2c": for rk3066
+   - "rockchip,rk3188-i2c": for rk3188
+   - "rockchip,rk3228-i2c": for rk3228
+   - "rockchip,rk3288-i2c": for rk3288
+   - "rockchip,rk3399-i2c": for rk3399
  - interrupts : interrupt number
- - clocks : parent clock
+ - clocks: See ../clock/clock-bindings.txt
+   - For older hardware (rk3066, rk3188, rk3228, rk3288):
+     - There is one clock that's used both to derive the functional clock
+       for the device and as the bus clock.
+   - For newer hardware (rk3399): specified by name
+     - "i2c": This is used to derive the functional clock.
+     - "pclk": This is the bus clock.
 
 Required on RK3066, RK3188 :
 
-- 
1.9.1

Re: [PATCH v10 6/8] dt-bindings: i2c: rk3x: add support for rk3399

[Rob Herring]

On Mon, May 16, 2016 at 10:04:12PM +0800, David Wu wrote:
> The bus clock and function clock are separated at rk3399,
> and others use one clock as the bus clock and function clock.
> 
> Signed-off-by: David Wu <david.wu@rock-chips.com>
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
> Reviewed-by: Heiko Stuebner <heiko@sntech.de>
> Tested-by: Heiko Stuebner <heiko@sntech.de>
> ---
> Change in v10:
> - none
> 
> Change in v9:
> - remove unnecessary "REQUIRED".
> 
> Change in v8:
> - remove error description.
> 
>  Documentation/devicetree/bindings/i2c/i2c-rk3x.txt | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)

Acked-by: Rob Herring <robh@kernel.org>

[PATCH v10 7/8] i2c: rk3x: add i2c support for rk3399 soc

[David Wu]

- new method to caculate i2c timings for rk3399:
  There was an timing issue about "repeated start" time at the I2C
  controller of version0, controller appears to drop SDA at .875x (7/8)
  programmed clk high. On version 1 of the controller, the rule(.875x)
  isn't enough to meet tSU;STA
  requirements on 100k's Standard-mode. To resolve this issue,
  sda_update_config, start_setup_config and stop_setup_config for I2C
  timing information are added, new rules are designed to calculate
  the timing information at new v1.
- pclk and function clk are separated at rk3399

Signed-off-by: David Wu <david.wu@rock-chips.com>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Change in v10:
- fix the clean of con register in rk3x_i2c_stop()

Change in v9:
- add spin lock for tuning updated in rk3x_i2c_adapt_div() (Doug) 

Changes in v8:
- update tuning in RKI2C_CON register by doing a read-modify-write (Doug)
- new method to use pclk and clk (Doug)

Changes in v7:
- transform into a 9 series patches (Doug)
- drop highspeed with mastercode, and support fast-mode plus (Doug)

 drivers/i2c/busses/i2c-rk3x.c | 294 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 274 insertions(+), 20 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index 9791797..a96b516 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -58,6 +58,12 @@ enum {
 #define REG_CON_LASTACK   BIT(5) /* 1: send NACK after last received byte */
 #define REG_CON_ACTACK    BIT(6) /* 1: stop if NACK is received */
 
+#define REG_CON_TUNING_MASK GENMASK(15, 8)
+
+#define REG_CON_SDA_CFG(cfg) ((cfg) << 8)
+#define REG_CON_STA_CFG(cfg) ((cfg) << 12)
+#define REG_CON_STO_CFG(cfg) ((cfg) << 14)
+
 /* REG_MRXADDR bits */
 #define REG_MRXADDR_VALID(x) BIT(24 + (x)) /* [x*8+7:x*8] of MRX[R]ADDR valid */
 
@@ -77,40 +83,62 @@ enum {
 
 /**
  * struct i2c_spec_values:
+ * @min_hold_start_ns: min hold time (repeated) START condition
  * @min_low_ns: min LOW period of the SCL clock
  * @min_high_ns: min HIGH period of the SCL cloc
  * @min_setup_start_ns: min set-up time for a repeated START conditio
  * @max_data_hold_ns: max data hold time
+ * @min_data_setup_ns: min data set-up time
+ * @min_setup_stop_ns: min set-up time for STOP condition
+ * @min_hold_buffer_ns: min bus free time between a STOP and
+ * START condition
  */
 struct i2c_spec_values {
+	unsigned long min_hold_start_ns;
 	unsigned long min_low_ns;
 	unsigned long min_high_ns;
 	unsigned long min_setup_start_ns;
 	unsigned long max_data_hold_ns;
+	unsigned long min_data_setup_ns;
+	unsigned long min_setup_stop_ns;
+	unsigned long min_hold_buffer_ns;
 };
 
 static const struct i2c_spec_values standard_mode_spec = {
+	.min_hold_start_ns = 4000,
 	.min_low_ns = 4700,
 	.min_high_ns = 4000,
 	.min_setup_start_ns = 4700,
 	.max_data_hold_ns = 3450,
+	.min_data_setup_ns = 250,
+	.min_setup_stop_ns = 4000,
+	.min_hold_buffer_ns = 4700,
 };
 
 static const struct i2c_spec_values fast_mode_spec = {
+	.min_hold_start_ns = 600,
 	.min_low_ns = 1300,
 	.min_high_ns = 600,
 	.min_setup_start_ns = 600,
 	.max_data_hold_ns = 900,
+	.min_data_setup_ns = 100,
+	.min_setup_stop_ns = 600,
+	.min_hold_buffer_ns = 1300,
 };
 
 /**
  * struct rk3x_i2c_calced_timings:
  * @div_low: Divider output for low
  * @div_high: Divider output for high
+ * @tuning: Used to adjust setup/hold data time,
+ * setup/hold start time and setup stop time for
+ * v1's calc_timings, the tuning should all be 0
+ * for old hardware anyone using v0's calc_timings.
  */
 struct rk3x_i2c_calced_timings {
 	unsigned long div_low;
 	unsigned long div_high;
+	unsigned int tuning;
 };
 
 enum rk3x_i2c_state {
@@ -123,9 +151,12 @@ enum rk3x_i2c_state {
 
 /**
  * @grf_offset: offset inside the grf regmap for setting the i2c type
+ * @calc_timings: Callback function for i2c timing information calculated
  */
 struct rk3x_i2c_soc_data {
 	int grf_offset;
+	int (*calc_timings)(unsigned long, struct i2c_timings *,
+			    struct rk3x_i2c_calced_timings *);
 };
 
 /**
@@ -134,7 +165,8 @@ struct rk3x_i2c_soc_data {
  * @dev: device for this controller
  * @soc_data: related soc data struct
  * @regs: virtual memory area
- * @clk: clock of i2c bus
+ * @clk: function clk for rk3399 or function & Bus clks for others
+ * @pclk: Bus clk for rk3399
  * @clk_rate_nb: i2c clk rate change notify
  * @t: I2C known timing information
  * @lock: spinlock for the i2c bus
@@ -156,6 +188,7 @@ struct rk3x_i2c {
 	/* Hardware resources */
 	void __iomem *regs;
 	struct clk *clk;
+	struct clk *pclk;
 	struct notifier_block clk_rate_nb;
 
 	/* Settings */
@@ -200,12 +233,12 @@ static inline void rk3x_i2c_clean_ipd(struct rk3x_i2c *i2c)
  */
 static void rk3x_i2c_start(struct rk3x_i2c *i2c)
 {
-	u32 val;
+	u32 val = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK;
 
 	i2c_writel(i2c, REG_INT_START, REG_IEN);
 
 	/* enable adapter with correct mode, send START condition */
-	val = REG_CON_EN | REG_CON_MOD(i2c->mode) | REG_CON_START;
+	val |= REG_CON_EN | REG_CON_MOD(i2c->mode) | REG_CON_START;
 
 	/* if we want to react to NACK, set ACTACK bit */
 	if (!(i2c->msg->flags & I2C_M_IGNORE_NAK))
@@ -246,7 +279,8 @@ static void rk3x_i2c_stop(struct rk3x_i2c *i2c, int error)
 		 * get the intended effect by resetting its internal state
 		 * and issuing an ordinary START.
 		 */
-		i2c_writel(i2c, 0, REG_CON);
+		ctrl = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK;
+		i2c_writel(i2c, ctrl, REG_CON);
 
 		/* signal that we are finished with the current msg */
 		wake_up(&i2c->wait);
@@ -513,9 +547,9 @@ static const struct i2c_spec_values *rk3x_i2c_get_spec(unsigned int speed)
  * a best-effort divider value is returned in divs. If the target rate is
  * too high, we silently use the highest possible rate.
  */
-static int rk3x_i2c_calc_divs(unsigned long clk_rate,
-			      struct i2c_timings *t,
-			      struct rk3x_i2c_calced_timings *t_calc)
+static int rk3x_i2c_v0_calc_timings(unsigned long clk_rate,
+				    struct i2c_timings *t,
+				    struct rk3x_i2c_calced_timings *t_calc)
 {
 	unsigned long min_low_ns, min_high_ns;
 	unsigned long max_low_ns, min_total_ns;
@@ -661,20 +695,191 @@ static int rk3x_i2c_calc_divs(unsigned long clk_rate,
 	return ret;
 }
 
+/**
+ * Calculate timing values for desired SCL frequency
+ *
+ * @clk_rate: I2C input clock rate
+ * @t: Known I2C timing information
+ * @t_calc: Caculated rk3x private timings that would be written into regs
+ *
+ * Returns: 0 on success, -EINVAL if the goal SCL rate is too slow. In that case
+ * a best-effort divider value is returned in divs. If the target rate is
+ * too high, we silently use the highest possible rate.
+ * The following formulas are v1's method to calculate timings.
+ *
+ * l = divl + 1;
+ * h = divh + 1;
+ * s = sda_update_config + 1;
+ * u = start_setup_config + 1;
+ * p = stop_setup_config + 1;
+ * T = Tclk_i2c;
+ *
+ * tHigh = 8 * h * T;
+ * tLow = 8 * l * T;
+ *
+ * tHD;sda = (l * s + 1) * T;
+ * tSU;sda = [(8 - s) * l + 1] * T;
+ * tI2C = 8 * (l + h) * T;
+ *
+ * tSU;sta = (8h * u + 1) * T;
+ * tHD;sta = [8h * (u + 1) - 1] * T;
+ * tSU;sto = (8h * p + 1) * T;
+ */
+static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate,
+				    struct i2c_timings *t,
+				    struct rk3x_i2c_calced_timings *t_calc)
+{
+	unsigned long min_low_ns, min_high_ns, min_total_ns;
+	unsigned long min_setup_start_ns, min_setup_data_ns;
+	unsigned long min_setup_stop_ns, max_hold_data_ns;
+
+	unsigned long clk_rate_khz, scl_rate_khz;
+
+	unsigned long min_low_div, min_high_div;
+
+	unsigned long min_div_for_hold, min_total_div;
+	unsigned long extra_div, extra_low_div;
+	unsigned long sda_update_cfg, stp_sta_cfg, stp_sto_cfg;
+
+	const struct i2c_spec_values *spec;
+	int ret = 0;
+
+	/* Support standard-mode and fast-mode */
+	if (WARN_ON(t->bus_freq_hz > 400000))
+		t->bus_freq_hz = 400000;
+
+	/* prevent scl_rate_khz from becoming 0 */
+	if (WARN_ON(t->bus_freq_hz < 1000))
+		t->bus_freq_hz = 1000;
+
+	/*
+	 * min_low_ns: The minimum number of ns we need to hold low to
+	 *	       meet I2C specification, should include fall time.
+	 * min_high_ns: The minimum number of ns we need to hold high to
+	 *	        meet I2C specification, should include rise time.
+	 */
+	spec = rk3x_i2c_get_spec(t->bus_freq_hz);
+
+	/* calculate min-divh and min-divl */
+	clk_rate_khz = DIV_ROUND_UP(clk_rate, 1000);
+	scl_rate_khz = t->bus_freq_hz / 1000;
+	min_total_div = DIV_ROUND_UP(clk_rate_khz, scl_rate_khz * 8);
+
+	min_high_ns = t->scl_rise_ns + spec->min_high_ns;
+	min_high_div = DIV_ROUND_UP(clk_rate_khz * min_high_ns, 8 * 1000000);
+
+	min_low_ns = t->scl_fall_ns + spec->min_low_ns;
+	min_low_div = DIV_ROUND_UP(clk_rate_khz * min_low_ns, 8 * 1000000);
+
+	/*
+	 * Final divh and divl must be greater than 0, otherwise the
+	 * hardware would not output the i2c clk.
+	 */
+	min_high_div = (min_high_div < 1) ? 2 : min_high_div;
+	min_low_div = (min_low_div < 1) ? 2 : min_low_div;
+
+	/* These are the min dividers needed for min hold times. */
+	min_div_for_hold = (min_low_div + min_high_div);
+	min_total_ns = min_low_ns + min_high_ns;
+
+	/*
+	 * This is the maximum divider so we don't go over the maximum.
+	 * We don't round up here (we round down) since this is a maximum.
+	 */
+	 if (min_div_for_hold >= min_total_div) {
+		/*
+		 * Time needed to meet hold requirements is important.
+		 * Just use that.
+		 */
+		t_calc->div_low = min_low_div;
+		t_calc->div_high = min_high_div;
+	} else {
+		/*
+		 * We've got to distribute some time among the low and high
+		 * so we don't run too fast.
+		 * We'll try to split things up by the scale of min_low_div and
+		 * min_high_div, biasing slightly towards having a higher div
+		 * for low (spend more time low).
+		 */
+		extra_div = min_total_div - min_div_for_hold;
+		extra_low_div = DIV_ROUND_UP(min_low_div * extra_div,
+					     min_div_for_hold);
+
+		t_calc->div_low = min_low_div + extra_low_div;
+		t_calc->div_high = min_high_div + (extra_div - extra_low_div);
+	}
+
+	/*
+	 * calculate sda data hold count by the rules, data_upd_st:3
+	 * is a appropriate value to reduce calculated times.
+	 */
+	for (sda_update_cfg = 3; sda_update_cfg > 0; sda_update_cfg--) {
+		max_hold_data_ns =  DIV_ROUND_UP((sda_update_cfg
+						 * (t_calc->div_low) + 1)
+						 * 1000000, clk_rate_khz);
+		min_setup_data_ns =  DIV_ROUND_UP(((8 - sda_update_cfg)
+						 * (t_calc->div_low) + 1)
+						 * 1000000, clk_rate_khz);
+		if ((max_hold_data_ns < spec->max_data_hold_ns) &&
+		    (min_setup_data_ns > spec->min_data_setup_ns))
+			break;
+	}
+
+	/* calculate setup start config */
+	min_setup_start_ns = t->scl_rise_ns + spec->min_setup_start_ns;
+	stp_sta_cfg = DIV_ROUND_UP(clk_rate_khz * min_setup_start_ns
+			   - 1000000, 8 * 1000000 * (t_calc->div_high));
+
+	/* calculate setup stop config */
+	min_setup_stop_ns = t->scl_rise_ns + spec->min_setup_stop_ns;
+	stp_sto_cfg = DIV_ROUND_UP(clk_rate_khz * min_setup_stop_ns
+			   - 1000000, 8 * 1000000 * (t_calc->div_high));
+
+	t_calc->tuning = REG_CON_SDA_CFG(--sda_update_cfg) |
+			 REG_CON_STA_CFG(--stp_sta_cfg) |
+			 REG_CON_STO_CFG(--stp_sto_cfg);
+
+	t_calc->div_low--;
+	t_calc->div_high--;
+
+	/* Maximum divider supported by hw is 0xffff */
+	if (t_calc->div_low > 0xffff) {
+		t_calc->div_low = 0xffff;
+		ret = -EINVAL;
+	}
+
+	if (t_calc->div_high > 0xffff) {
+		t_calc->div_high = 0xffff;
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
 static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate)
 {
 	struct i2c_timings *t = &i2c->t;
 	struct rk3x_i2c_calced_timings calc;
 	u64 t_low_ns, t_high_ns;
+	unsigned long flags;
+	u32 val;
 	int ret;
 
-	ret = rk3x_i2c_calc_divs(clk_rate, t, &calc);
+	ret = i2c->soc_data->calc_timings(clk_rate, t, &calc);
 	WARN_ONCE(ret != 0, "Could not reach SCL freq %u", t->bus_freq_hz);
 
-	clk_enable(i2c->clk);
+	clk_enable(i2c->pclk);
+
+	spin_lock_irqsave(&i2c->lock, flags);
+	val = i2c_readl(i2c, REG_CON);
+	val &= ~REG_CON_TUNING_MASK;
+	val |= calc.tuning;
+	i2c_writel(i2c, val, REG_CON);
 	i2c_writel(i2c, (calc.div_high << 16) | (calc.div_low & 0xffff),
 		   REG_CLKDIV);
-	clk_disable(i2c->clk);
+	spin_unlock_irqrestore(&i2c->lock, flags);
+
+	clk_disable(i2c->pclk);
 
 	t_low_ns = div_u64(((u64)calc.div_low + 1) * 8 * 1000000000, clk_rate);
 	t_high_ns = div_u64(((u64)calc.div_high + 1) * 8 * 1000000000,
@@ -712,7 +917,13 @@ static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
 
 	switch (event) {
 	case PRE_RATE_CHANGE:
-		if (rk3x_i2c_calc_divs(ndata->new_rate, &i2c->t, &calc) != 0)
+		/*
+		 * Try the calculation (but don't store the result) ahead of
+		 * time to see if we need to block the clock change.  Timings
+		 * shouldn't actually take effect until rk3x_i2c_adapt_div().
+		 */
+		if (i2c->soc_data->calc_timings(ndata->new_rate, &i2c->t,
+						&calc) != 0)
 			return NOTIFY_STOP;
 
 		/* scale up */
@@ -822,12 +1033,14 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
 {
 	struct rk3x_i2c *i2c = (struct rk3x_i2c *)adap->algo_data;
 	unsigned long timeout, flags;
+	u32 val;
 	int ret = 0;
 	int i;
 
 	spin_lock_irqsave(&i2c->lock, flags);
 
 	clk_enable(i2c->clk);
+	clk_enable(i2c->pclk);
 
 	i2c->is_last_msg = false;
 
@@ -861,7 +1074,9 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
 
 			/* Force a STOP condition without interrupt */
 			i2c_writel(i2c, 0, REG_IEN);
-			i2c_writel(i2c, REG_CON_EN | REG_CON_STOP, REG_CON);
+			val = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK;
+			val |= REG_CON_EN | REG_CON_STOP;
+			i2c_writel(i2c, val, REG_CON);
 
 			i2c->state = STATE_IDLE;
 
@@ -875,7 +1090,9 @@ static int rk3x_i2c_xfer(struct i2c_adapter *adap,
 		}
 	}
 
+	clk_disable(i2c->pclk);
 	clk_disable(i2c->clk);
+
 	spin_unlock_irqrestore(&i2c->lock, flags);
 
 	return ret < 0 ? ret : num;
@@ -893,18 +1110,27 @@ static const struct i2c_algorithm rk3x_i2c_algorithm = {
 
 static const struct rk3x_i2c_soc_data rk3066_soc_data = {
 	.grf_offset = 0x154,
+	.calc_timings = rk3x_i2c_v0_calc_timings,
 };
 
 static const struct rk3x_i2c_soc_data rk3188_soc_data = {
 	.grf_offset = 0x0a4,
+	.calc_timings = rk3x_i2c_v0_calc_timings,
 };
 
 static const struct rk3x_i2c_soc_data rk3228_soc_data = {
 	.grf_offset = -1,
+	.calc_timings = rk3x_i2c_v0_calc_timings,
 };
 
 static const struct rk3x_i2c_soc_data rk3288_soc_data = {
 	.grf_offset = -1,
+	.calc_timings = rk3x_i2c_v0_calc_timings,
+};
+
+static const struct rk3x_i2c_soc_data rk3399_soc_data = {
+	.grf_offset = -1,
+	.calc_timings = rk3x_i2c_v1_calc_timings,
 };
 
 static const struct of_device_id rk3x_i2c_match[] = {
@@ -924,6 +1150,10 @@ static const struct of_device_id rk3x_i2c_match[] = {
 		.compatible = "rockchip,rk3288-i2c",
 		.data = (void *)&rk3288_soc_data
 	},
+	{
+		.compatible = "rockchip,rk3399-i2c",
+		.data = (void *)&rk3399_soc_data
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, rk3x_i2c_match);
@@ -963,12 +1193,6 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 	spin_lock_init(&i2c->lock);
 	init_waitqueue_head(&i2c->wait);
 
-	i2c->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(i2c->clk)) {
-		dev_err(&pdev->dev, "cannot get clock\n");
-		return PTR_ERR(i2c->clk);
-	}
-
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	i2c->regs = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(i2c->regs))
@@ -1022,17 +1246,44 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, i2c);
 
+	if (i2c->soc_data->calc_timings == rk3x_i2c_v0_calc_timings) {
+		/* Only one clock to use for bus clock and peripheral clock */
+		i2c->clk = devm_clk_get(&pdev->dev, NULL);
+		i2c->pclk = i2c->clk;
+	} else {
+		i2c->clk = devm_clk_get(&pdev->dev, "i2c");
+		i2c->pclk = devm_clk_get(&pdev->dev, "pclk");
+	}
+
+	if (IS_ERR(i2c->clk)) {
+		ret = PTR_ERR(i2c->clk);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Can't get bus clk: %d\n", ret);
+		return ret;
+	}
+	if (IS_ERR(i2c->pclk)) {
+		ret = PTR_ERR(i2c->pclk);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Can't get periph clk: %d\n", ret);
+		return ret;
+	}
+
 	ret = clk_prepare(i2c->clk);
 	if (ret < 0) {
-		dev_err(&pdev->dev, "Could not prepare clock\n");
+		dev_err(&pdev->dev, "Can't prepare bus clk: %d\n", ret);
 		return ret;
 	}
+	ret = clk_prepare(i2c->pclk);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Can't prepare periph clock: %d\n", ret);
+		goto err_clk;
+	}
 
 	i2c->clk_rate_nb.notifier_call = rk3x_i2c_clk_notifier_cb;
 	ret = clk_notifier_register(i2c->clk, &i2c->clk_rate_nb);
 	if (ret != 0) {
 		dev_err(&pdev->dev, "Unable to register clock notifier\n");
-		goto err_clk;
+		goto err_pclk;
 	}
 
 	clk_rate = clk_get_rate(i2c->clk);
@@ -1050,6 +1301,8 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
 
 err_clk_notifier:
 	clk_notifier_unregister(i2c->clk, &i2c->clk_rate_nb);
+err_pclk:
+	clk_unprepare(i2c->pclk);
 err_clk:
 	clk_unprepare(i2c->clk);
 	return ret;
@@ -1062,6 +1315,7 @@ static int rk3x_i2c_remove(struct platform_device *pdev)
 	i2c_del_adapter(&i2c->adap);
 
 	clk_notifier_unregister(i2c->clk, &i2c->clk_rate_nb);
+	clk_unprepare(i2c->pclk);
 	clk_unprepare(i2c->clk);
 
 	return 0;
-- 
1.9.1

Re: [PATCH v10 7/8] i2c: rk3x: add i2c support for rk3399 soc

[Doug Anderson]

David,

On Mon, May 16, 2016 at 7:05 AM, David Wu <david.wu@rock-chips.com> wrote:
> - new method to caculate i2c timings for rk3399:
>   There was an timing issue about "repeated start" time at the I2C
>   controller of version0, controller appears to drop SDA at .875x (7/8)
>   programmed clk high. On version 1 of the controller, the rule(.875x)
>   isn't enough to meet tSU;STA
>   requirements on 100k's Standard-mode. To resolve this issue,
>   sda_update_config, start_setup_config and stop_setup_config for I2C
>   timing information are added, new rules are designed to calculate
>   the timing information at new v1.
> - pclk and function clk are separated at rk3399
>
> Signed-off-by: David Wu <david.wu@rock-chips.com>
> Tested-by: Caesar Wang <wxt@rock-chips.com>
> Tested-by: Heiko Stuebner <heiko@sntech.de>
> ---
> Change in v10:
> - fix the clean of con register in rk3x_i2c_stop()
>
> Change in v9:
> - add spin lock for tuning updated in rk3x_i2c_adapt_div() (Doug)
>
> Changes in v8:
> - update tuning in RKI2C_CON register by doing a read-modify-write (Doug)
> - new method to use pclk and clk (Doug)
>
> Changes in v7:
> - transform into a 9 series patches (Doug)
> - drop highspeed with mastercode, and support fast-mode plus (Doug)
>
>  drivers/i2c/busses/i2c-rk3x.c | 294 +++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 274 insertions(+), 20 deletions(-)

Reviewed-by: Douglas Anderson <dianders@chromium.org>

[PATCH v10 8/8] i2c: rk3x: support fast-mode plus for rk3399

[David Wu]

Implement fast mode plus that allows bus speeds of up to 1MHz.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
---
Change in v10:
- none

Change in v9:
- add commit message

Change in v8:
- none

 drivers/i2c/busses/i2c-rk3x.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index a96b516..2938616 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -126,6 +126,17 @@ static const struct i2c_spec_values fast_mode_spec = {
 	.min_hold_buffer_ns = 1300,
 };
 
+static const struct i2c_spec_values fast_mode_plus_spec = {
+	.min_hold_start_ns = 260,
+	.min_low_ns = 500,
+	.min_high_ns = 260,
+	.min_setup_start_ns = 260,
+	.max_data_hold_ns = 400,
+	.min_data_setup_ns = 50,
+	.min_setup_stop_ns = 260,
+	.min_hold_buffer_ns = 500,
+};
+
 /**
  * struct rk3x_i2c_calced_timings:
  * @div_low: Divider output for low
@@ -532,8 +543,10 @@ static const struct i2c_spec_values *rk3x_i2c_get_spec(unsigned int speed)
 {
 	if (speed <= 100000)
 		return &standard_mode_spec;
-	else
+	else if (speed <= 400000)
 		return &fast_mode_spec;
+	else
+		return &fast_mode_plus_spec;
 }
 
 /**
@@ -744,9 +757,9 @@ static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate,
 	const struct i2c_spec_values *spec;
 	int ret = 0;
 
-	/* Support standard-mode and fast-mode */
-	if (WARN_ON(t->bus_freq_hz > 400000))
-		t->bus_freq_hz = 400000;
+	/* Support standard-mode, fast-mode and fast-mode plus */
+	if (WARN_ON(t->bus_freq_hz > 1000000))
+		t->bus_freq_hz = 1000000;
 
 	/* prevent scl_rate_khz from becoming 0 */
 	if (WARN_ON(t->bus_freq_hz < 1000))
-- 
1.9.1

Re: [PATCH v10 0/8] add i2c driver supported for rk3399

[Doug Anderson]

Hi,

On Mon, May 16, 2016 at 6:57 AM, David Wu <david.wu@rock-chips.com> wrote:
> There are three points differert from others:
>  - new method to caculate i2c timings for rk3399
>  - pclk and function clk are separated at rk3399
>  - add fast-plus mode supported for rk3399
>
> David Wu (8):
>   i2c: rk3x: add documentation to fields in "struct rk3x_i2c"
>   i2c: rk3x: use struct "rk3x_i2c_calced_timings"
>   i2c: rk3x: Remove redundant rk3x_i2c_clean_ipd()
>   i2c: rk3x: Change SoC data to not use array
>   i2c: rk3x: Move spec timing data to "static const" structs
>   dt-bindings: i2c: rk3x: add support for rk3399
>   i2c: rk3x: add i2c support for rk3399 soc
>   i2c: rk3x: support fast-mode plus for rk3399
>
>  Documentation/devicetree/bindings/i2c/i2c-rk3x.txt |  16 +-
>  drivers/i2c/busses/i2c-rk3x.c                      | 498 +++++++++++++++++----
>  2 files changed, 434 insertions(+), 80 deletions(-)

I haven't put these on the scope or anything, but I have:

* Tested that my i2c busses on rk3288-veyron still seem to work OK
after these patches.

* Tested that my i2c busses on an rk3399 board seem to work after
these patches (plus device tree changes).

Thus, for the series:

Tested-by: Douglas Anderson <dianders@chromium.org>

...possibly could leave off the Tested-by tag for the last in the
series since I have no Fast Mode Plus devices to test against.  ;)

-Doug

Re: [PATCH v10 0/8] add i2c driver supported for rk3399

[Heiko Stübner]

Hi Wolfram,

Am Montag, 16. Mai 2016, 21:57:35 schrieb David Wu:
> There are three points differert from others:
>  - new method to caculate i2c timings for rk3399
>  - pclk and function clk are separated at rk3399
>  - add fast-plus mode supported for rk3399

this series looks pretty nice now and it seems most everybody is happy with it 
by now. Do you still have it in your inbox to look at, or should David resend 
it again?


Heiko

> David Wu (8):
>   i2c: rk3x: add documentation to fields in "struct rk3x_i2c"
>   i2c: rk3x: use struct "rk3x_i2c_calced_timings"
>   i2c: rk3x: Remove redundant rk3x_i2c_clean_ipd()
>   i2c: rk3x: Change SoC data to not use array
>   i2c: rk3x: Move spec timing data to "static const" structs
>   dt-bindings: i2c: rk3x: add support for rk3399
>   i2c: rk3x: add i2c support for rk3399 soc
>   i2c: rk3x: support fast-mode plus for rk3399
> 
>  Documentation/devicetree/bindings/i2c/i2c-rk3x.txt |  16 +-
>  drivers/i2c/busses/i2c-rk3x.c                      | 498
> +++++++++++++++++---- 2 files changed, 434 insertions(+), 80 deletions(-)

Re: [PATCH v10 0/8] add i2c driver supported for rk3399

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 397 bytes --]


> this series looks pretty nice now and it seems most everybody is happy with it 
> by now. Do you still have it in your inbox to look at, or should David resend 
> it again?

I use patchwork (as stated in MAINTAINERS), so nothing gets lost as long
as it is send to the i2c-list. As long as it still applies, no need to
resend. This series does have priority, thanks to the tags given.


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Re: [PATCH v10 0/8] add i2c driver supported for rk3399

[Heiko Stübner]

Am Donnerstag, 9. Juni 2016, 09:47:53 schrieb Wolfram Sang:
> > this series looks pretty nice now and it seems most everybody is happy
> > with it by now. Do you still have it in your inbox to look at, or should
> > David resend it again?
> 
> I use patchwork (as stated in MAINTAINERS), so nothing gets lost as long
> as it is send to the i2c-list. As long as it still applies, no need to
> resend. This series does have priority, thanks to the tags given.

Just verified that everything still applies against 4.7-rc1 and present boards 
still have working i2c with this series.


Heiko

Re: [PATCH v10 0/8] add i2c driver supported for rk3399

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 1126 bytes --]

On Mon, May 16, 2016 at 09:57:35PM +0800, David Wu wrote:
> There are three points differert from others:
>  - new method to caculate i2c timings for rk3399
>  - pclk and function clk are separated at rk3399
>  - add fast-plus mode supported for rk3399
> 
> David Wu (8):
>   i2c: rk3x: add documentation to fields in "struct rk3x_i2c"
>   i2c: rk3x: use struct "rk3x_i2c_calced_timings"
>   i2c: rk3x: Remove redundant rk3x_i2c_clean_ipd()
>   i2c: rk3x: Change SoC data to not use array
>   i2c: rk3x: Move spec timing data to "static const" structs
>   dt-bindings: i2c: rk3x: add support for rk3399
>   i2c: rk3x: add i2c support for rk3399 soc
>   i2c: rk3x: support fast-mode plus for rk3399
> 
>  Documentation/devicetree/bindings/i2c/i2c-rk3x.txt |  16 +-

Applied whole series to for-next, thanks! This was nicely refactored and
easy to review, thanks. Also thanks to all reviewers who helped this
series. I fixed one checkpatch issue for you, though:

WARNING: Statements should start on a tabstop
#278: FILE: drivers/i2c/busses/i2c-rk3x.c:789:
+	 if (min_div_for_hold >= min_total_div) {


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Re: [PATCH v10 0/8] add i2c driver supported for rk3399

[David.Wu]

Hi Wolfram，

在 2016/6/17 19:56, Wolfram Sang 写道:
> Applied whole series to for-next, thanks! This was nicely refactored and
> easy to review, thanks. Also thanks to all reviewers who helped this
> series. I fixed one checkpatch issue for you, though:
>
> WARNING: Statements should start on a tabstop
> #278: FILE: drivers/i2c/busses/i2c-rk3x.c:789:
> +	 if (min_div_for_hold >= min_total_div) {
>

Thanks for your final review！

Re: [PATCH v10 0/8] add i2c driver supported for rk3399

[David.Wu]

Hi Wolfram，

在 2016/6/17 19:56, Wolfram Sang 写道:
> Applied whole series to for-next, thanks! This was nicely refactored and
> easy to review, thanks. Also thanks to all reviewers who helped this
> series. I fixed one checkpatch issue for you, though:
>
> WARNING: Statements should start on a tabstop
> #278: FILE: drivers/i2c/busses/i2c-rk3x.c:789:
> +	 if (min_div_for_hold >= min_total_div) {
>

Thanks for your final review！