[PATCH 1/2] i2c: exynos5: simplify clock frequency handling

[PATCH 1/2] i2c: exynos5: simplify clock frequency handling

[Andrzej Hajda]

There is no need to keep separate settings for high and fast speed clock.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
---
 drivers/i2c/busses/i2c-exynos5.c | 45 +++++++++++-----------------------------
 1 file changed, 12 insertions(+), 33 deletions(-)

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 04127b8..54df9e6 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -168,8 +168,6 @@
  */
 #define HSI2C_HS_TX_CLOCK	1000000
 #define HSI2C_FS_TX_CLOCK	100000
-#define HSI2C_HIGH_SPD		1
-#define HSI2C_FAST_SPD		0
 
 #define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
 
@@ -200,15 +198,7 @@ struct exynos5_i2c {
 	int			trans_done;
 
 	/* Controller operating frequency */
-	unsigned int		fs_clock;
-	unsigned int		hs_clock;
-
-	/*
-	 * HSI2C Controller can operate in
-	 * 1. High speed upto 3.4Mbps
-	 * 2. Fast speed upto 1Mbps
-	 */
-	int			speed_mode;
+	unsigned int		op_clock;
 
 	/* Version of HS-I2C Hardware */
 	struct exynos_hsi2c_variant	*variant;
@@ -279,7 +269,7 @@ static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
  * Returns 0 on success, -EINVAL if the cycle length cannot
  * be calculated.
  */
-static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
+static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, bool hs_timings)
 {
 	u32 i2c_timing_s1;
 	u32 i2c_timing_s2;
@@ -292,8 +282,9 @@ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
 	unsigned int t_sr_release;
 	unsigned int t_ftl_cycle;
 	unsigned int clkin = clk_get_rate(i2c->clk);
-	unsigned int op_clk = (mode == HSI2C_HIGH_SPD) ?
-				i2c->hs_clock : i2c->fs_clock;
+	unsigned int op_clk = hs_timings ? i2c->op_clock :
+		(i2c->op_clock >= HSI2C_HS_TX_CLOCK) ? HSI2C_FS_TX_CLOCK :
+		i2c->op_clock;
 	int div, clk_cycle, temp;
 
 	/*
@@ -344,7 +335,7 @@ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
 		div, t_sr_release);
 	dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd);
 
-	if (mode == HSI2C_HIGH_SPD) {
+	if (hs_timings) {
 		writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1);
 		writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2);
 		writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3);
@@ -364,14 +355,14 @@ static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c)
 	 * Configure the Fast speed timing values
 	 * Even the High Speed mode initially starts with Fast mode
 	 */
-	if (exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD)) {
+	if (exynos5_i2c_set_timing(i2c, false)) {
 		dev_err(i2c->dev, "HSI2C FS Clock set up failed\n");
 		return -EINVAL;
 	}
 
 	/* configure the High speed timing values */
-	if (i2c->speed_mode == HSI2C_HIGH_SPD) {
-		if (exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD)) {
+	if (i2c->op_clock >= HSI2C_HS_TX_CLOCK) {
+		if (exynos5_i2c_set_timing(i2c, true)) {
 			dev_err(i2c->dev, "HSI2C HS Clock set up failed\n");
 			return -EINVAL;
 		}
@@ -397,7 +388,7 @@ static void exynos5_i2c_init(struct exynos5_i2c *i2c)
 					i2c->regs + HSI2C_CTL);
 	writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL);
 
-	if (i2c->speed_mode == HSI2C_HIGH_SPD) {
+	if (i2c->op_clock >= HSI2C_HS_TX_CLOCK) {
 		writel(HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr)),
 					i2c->regs + HSI2C_ADDR);
 		i2c_conf |= HSI2C_HS_MODE;
@@ -734,26 +725,14 @@ static int exynos5_i2c_probe(struct platform_device *pdev)
 	struct device_node *np = pdev->dev.of_node;
 	struct exynos5_i2c *i2c;
 	struct resource *mem;
-	unsigned int op_clock;
 	int ret;
 
 	i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL);
 	if (!i2c)
 		return -ENOMEM;
 
-	if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
-		i2c->speed_mode = HSI2C_FAST_SPD;
-		i2c->fs_clock = HSI2C_FS_TX_CLOCK;
-	} else {
-		if (op_clock >= HSI2C_HS_TX_CLOCK) {
-			i2c->speed_mode = HSI2C_HIGH_SPD;
-			i2c->fs_clock = HSI2C_FS_TX_CLOCK;
-			i2c->hs_clock = op_clock;
-		} else {
-			i2c->speed_mode = HSI2C_FAST_SPD;
-			i2c->fs_clock = op_clock;
-		}
-	}
+	if (of_property_read_u32(np, "clock-frequency", &i2c->op_clock))
+		i2c->op_clock = HSI2C_FS_TX_CLOCK;
 
 	strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name));
 	i2c->adap.owner   = THIS_MODULE;
-- 
2.7.4

[PATCH 2/2] i2c: exynos5: de-duplicate error logs on clock setup

[Andrzej Hajda]

In case of clock setup error it is enough to log it once.
Moreover patch simplifies clock setup routines.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
---
 drivers/i2c/busses/i2c-exynos5.c | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 54df9e6..bc2b5db 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -309,7 +309,8 @@ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, bool hs_timings)
 	div = temp / 512;
 	clk_cycle = temp / (div + 1) - 2;
 	if (temp < 4 || div >= 256 || clk_cycle < 2) {
-		dev_warn(i2c->dev, "Failed to calculate divisor");
+		dev_err(i2c->dev, "%s clock set-up failed\n",
+			hs_timings ? "HS" : "FS");
 		return -EINVAL;
 	}
 
@@ -351,24 +352,13 @@ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, bool hs_timings)
 
 static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c)
 {
-	/*
-	 * Configure the Fast speed timing values
-	 * Even the High Speed mode initially starts with Fast mode
-	 */
-	if (exynos5_i2c_set_timing(i2c, false)) {
-		dev_err(i2c->dev, "HSI2C FS Clock set up failed\n");
-		return -EINVAL;
-	}
+	/* always set Fast Speed timings */
+	int ret = exynos5_i2c_set_timing(i2c, false);
 
-	/* configure the High speed timing values */
-	if (i2c->op_clock >= HSI2C_HS_TX_CLOCK) {
-		if (exynos5_i2c_set_timing(i2c, true)) {
-			dev_err(i2c->dev, "HSI2C HS Clock set up failed\n");
-			return -EINVAL;
-		}
-	}
+	if (ret < 0 || i2c->op_clock < HSI2C_HS_TX_CLOCK)
+		return ret;
 
-	return 0;
+	return exynos5_i2c_set_timing(i2c, true);
 }
 
 /*
-- 
2.7.4

Re: [PATCH 2/2] i2c: exynos5: de-duplicate error logs on clock setup

[Javier Martinez Canillas]

Hello Andrzej,

On 02/24/2017 08:16 AM, Andrzej Hajda wrote:
> In case of clock setup error it is enough to log it once.
> Moreover patch simplifies clock setup routines.
> 
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
> ---

Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America

Re: [PATCH 2/2] i2c: exynos5: de-duplicate error logs on clock setup

[Wolfram Sang]

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On Fri, Feb 24, 2017 at 12:16:02PM +0100, Andrzej Hajda wrote:
> In case of clock setup error it is enough to log it once.
> Moreover patch simplifies clock setup routines.
> 
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>

Applied to for-next, thanks!


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Re: [PATCH 1/2] i2c: exynos5: simplify clock frequency handling

[Andrzej Hajda]

Hi Wolfram,

Gently ping on both patches.

Regards
Andrzej

On 24.02.2017 12:16, Andrzej Hajda wrote:
> There is no need to keep separate settings for high and fast speed clock.
>
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
> ---
>  drivers/i2c/busses/i2c-exynos5.c | 45 +++++++++++-----------------------------
>  1 file changed, 12 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
> index 04127b8..54df9e6 100644
> --- a/drivers/i2c/busses/i2c-exynos5.c
> +++ b/drivers/i2c/busses/i2c-exynos5.c
> @@ -168,8 +168,6 @@
>   */
>  #define HSI2C_HS_TX_CLOCK	1000000
>  #define HSI2C_FS_TX_CLOCK	100000
> -#define HSI2C_HIGH_SPD		1
> -#define HSI2C_FAST_SPD		0
>  
>  #define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
>  
> @@ -200,15 +198,7 @@ struct exynos5_i2c {
>  	int			trans_done;
>  
>  	/* Controller operating frequency */
> -	unsigned int		fs_clock;
> -	unsigned int		hs_clock;
> -
> -	/*
> -	 * HSI2C Controller can operate in
> -	 * 1. High speed upto 3.4Mbps
> -	 * 2. Fast speed upto 1Mbps
> -	 */
> -	int			speed_mode;
> +	unsigned int		op_clock;
>  
>  	/* Version of HS-I2C Hardware */
>  	struct exynos_hsi2c_variant	*variant;
> @@ -279,7 +269,7 @@ static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
>   * Returns 0 on success, -EINVAL if the cycle length cannot
>   * be calculated.
>   */
> -static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
> +static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, bool hs_timings)
>  {
>  	u32 i2c_timing_s1;
>  	u32 i2c_timing_s2;
> @@ -292,8 +282,9 @@ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
>  	unsigned int t_sr_release;
>  	unsigned int t_ftl_cycle;
>  	unsigned int clkin = clk_get_rate(i2c->clk);
> -	unsigned int op_clk = (mode == HSI2C_HIGH_SPD) ?
> -				i2c->hs_clock : i2c->fs_clock;
> +	unsigned int op_clk = hs_timings ? i2c->op_clock :
> +		(i2c->op_clock >= HSI2C_HS_TX_CLOCK) ? HSI2C_FS_TX_CLOCK :
> +		i2c->op_clock;
>  	int div, clk_cycle, temp;
>  
>  	/*
> @@ -344,7 +335,7 @@ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
>  		div, t_sr_release);
>  	dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd);
>  
> -	if (mode == HSI2C_HIGH_SPD) {
> +	if (hs_timings) {
>  		writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1);
>  		writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2);
>  		writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3);
> @@ -364,14 +355,14 @@ static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c)
>  	 * Configure the Fast speed timing values
>  	 * Even the High Speed mode initially starts with Fast mode
>  	 */
> -	if (exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD)) {
> +	if (exynos5_i2c_set_timing(i2c, false)) {
>  		dev_err(i2c->dev, "HSI2C FS Clock set up failed\n");
>  		return -EINVAL;
>  	}
>  
>  	/* configure the High speed timing values */
> -	if (i2c->speed_mode == HSI2C_HIGH_SPD) {
> -		if (exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD)) {
> +	if (i2c->op_clock >= HSI2C_HS_TX_CLOCK) {
> +		if (exynos5_i2c_set_timing(i2c, true)) {
>  			dev_err(i2c->dev, "HSI2C HS Clock set up failed\n");
>  			return -EINVAL;
>  		}
> @@ -397,7 +388,7 @@ static void exynos5_i2c_init(struct exynos5_i2c *i2c)
>  					i2c->regs + HSI2C_CTL);
>  	writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL);
>  
> -	if (i2c->speed_mode == HSI2C_HIGH_SPD) {
> +	if (i2c->op_clock >= HSI2C_HS_TX_CLOCK) {
>  		writel(HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr)),
>  					i2c->regs + HSI2C_ADDR);
>  		i2c_conf |= HSI2C_HS_MODE;
> @@ -734,26 +725,14 @@ static int exynos5_i2c_probe(struct platform_device *pdev)
>  	struct device_node *np = pdev->dev.of_node;
>  	struct exynos5_i2c *i2c;
>  	struct resource *mem;
> -	unsigned int op_clock;
>  	int ret;
>  
>  	i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL);
>  	if (!i2c)
>  		return -ENOMEM;
>  
> -	if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
> -		i2c->speed_mode = HSI2C_FAST_SPD;
> -		i2c->fs_clock = HSI2C_FS_TX_CLOCK;
> -	} else {
> -		if (op_clock >= HSI2C_HS_TX_CLOCK) {
> -			i2c->speed_mode = HSI2C_HIGH_SPD;
> -			i2c->fs_clock = HSI2C_FS_TX_CLOCK;
> -			i2c->hs_clock = op_clock;
> -		} else {
> -			i2c->speed_mode = HSI2C_FAST_SPD;
> -			i2c->fs_clock = op_clock;
> -		}
> -	}
> +	if (of_property_read_u32(np, "clock-frequency", &i2c->op_clock))
> +		i2c->op_clock = HSI2C_FS_TX_CLOCK;
>  
>  	strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name));
>  	i2c->adap.owner   = THIS_MODULE;

Re: [PATCH 1/2] i2c: exynos5: simplify clock frequency handling

[Javier Martinez Canillas]

Hello Andrzej,

On 02/24/2017 08:16 AM, Andrzej Hajda wrote:
> There is no need to keep separate settings for high and fast speed clock.
> 
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
> ---
>  drivers/i2c/busses/i2c-exynos5.c | 45 +++++++++++-----------------------------
>  1 file changed, 12 insertions(+), 33 deletions(-)
> 

Patch looks good to me:

Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>

I've also tested it on an Exynos5800 Peach Pi Chromebook and the
I2C devices are working properly after this change:

Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America

Re: [PATCH 1/2] i2c: exynos5: simplify clock frequency handling

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 233 bytes --]

On Fri, Feb 24, 2017 at 12:16:01PM +0100, Andrzej Hajda wrote:
> There is no need to keep separate settings for high and fast speed clock.
> 
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>

Applied to for-next, thanks!


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