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[PATCH v9 0/8] add i2c driver supported for rk3399

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  [PATCH v9 0/8] add i2c driver supported for rk3399 David Wu <david.wu@rock-chips.com> - 2016-05-12 10:00 +0200
    [PATCH v9 4/8] i2c: rk3x: Change SoC data to not use array David Wu <david.wu@rock-chips.com> - 2016-05-12 10:00 +0200
    [PATCH v9 2/8] i2c: rk3x: use struct "rk3x_i2c_calced_timings" David Wu <david.wu@rock-chips.com> - 2016-05-12 10:00 +0200
    [PATCH v9 3/8] i2c: rk3x: Remove redundant rk3x_i2c_clean_ipd() David Wu <david.wu@rock-chips.com> - 2016-05-12 10:00 +0200
    [PATCH v9 1/8] i2c: rk3x: add documentation to fields in "struct rk3x_i2c" David Wu <david.wu@rock-chips.com> - 2016-05-12 10:00 +0200
    [PATCH v9 8/8] i2c: rk3x: support fast-mode plus for rk3399 David Wu <david.wu@rock-chips.com> - 2016-05-12 10:10 +0200
    Re: [PATCH v9 0/8] add i2c driver supported for rk3399 Heiko Stuebner <heiko@sntech.de> - 2016-05-14 13:40 +0200

#1399729 — [PATCH v9 0/8] add i2c driver supported for rk3399

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                      | 495 +++++++++++++++++----
 2 files changed, 432 insertions(+), 79 deletions(-)

-- 
1.9.1

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#1399730 — [PATCH v9 4/8] i2c: rk3x: Change SoC data to not use array

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>
---
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

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#1399731 — [PATCH v9 2/8] i2c: rk3x: use struct "rk3x_i2c_calced_timings"

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>
---
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

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#1399732 — [PATCH v9 3/8] i2c: rk3x: Remove redundant rk3x_i2c_clean_ipd()

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>
---
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

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#1399733 — [PATCH v9 1/8] i2c: rk3x: add documentation to fields in "struct rk3x_i2c"

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>
---
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

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#1399737 — [PATCH v9 8/8] i2c: rk3x: support fast-mode plus for rk3399

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>
---
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 673656e..ba4ce39 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
@@ -531,8 +542,10 @@ 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;
 }
 
 /**
@@ -743,9 +756,9 @@ 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

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#1401085

Am Donnerstag, 12. Mai 2016, 15:52:58 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

On a rk3288

Tested-by: Heiko Stuebner <heiko@sntech.de>

to make sure nothing currently working broke - and everything is running 
still fine.


Heiko

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