[PATCH 0/3 v2] Updates for exynos4210 and DT-based systems

[PATCH 0/3 v2] Updates for exynos4210 and DT-based systems

[Karol Lewandowski]

Changes since v1:
 - Move unrelated code fragment to separate patch (of_match_ptr())
 - Move device-type handling to separate function and rework its
   internals a bit

This patchset reworks i2c-s3c2410 driver a bit to better handle
device tree-enabled platforms and adds two quirks required by
exynos4210-specific I2C controller used by s5p-hdmi driver.

This patchset is based on "i2c-bjdooks/for-34/i2c/i2c-samsung" branch
taken from:

  git://git.fluff.org/bjdooks/linux.git

Karol Lewandowski (3):
  i2c-s3c2410: Drop unused define
  i2c-s3c2410: Rework device type handling
  i2c-s3c2410: Add HDMIPHY quirk for S3C2440

 .../devicetree/bindings/i2c/samsung-i2c.txt        |   10 ++-
 drivers/i2c/busses/i2c-s3c2410.c                   |   93 +++++++++++++++-----
 2 files changed, 77 insertions(+), 26 deletions(-)

-- 
1.7.9

[PATCH 1/3] i2c-s3c2410: Drop unused define

[Karol Lewandowski]

Use standard of_match_ptr() to avoid defining variable unused
in non device tree builds.

Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/i2c/busses/i2c-s3c2410.c |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 737f721..85e3664 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -1128,8 +1128,6 @@ static const struct of_device_id s3c24xx_i2c_match[] = {
 	{},
 };
 MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
-#else
-#define s3c24xx_i2c_match NULL
 #endif
 
 static struct platform_driver s3c24xx_i2c_driver = {
@@ -1140,7 +1138,7 @@ static struct platform_driver s3c24xx_i2c_driver = {
 		.owner	= THIS_MODULE,
 		.name	= "s3c-i2c",
 		.pm	= S3C24XX_DEV_PM_OPS,
-		.of_match_table = s3c24xx_i2c_match,
+		.of_match_table = of_match_ptr(s3c24xx_i2c_match),
 	},
 };
 
-- 
1.7.9

Re: [PATCH 1/3] i2c-s3c2410: Drop unused define

[Grant Likely]

On Tue, 13 Mar 2012 17:54:37 +0100, Karol Lewandowski <k.lewandowsk@samsung.com> wrote:
> Use standard of_match_ptr() to avoid defining variable unused
> in non device tree builds.
> 
> Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

Acked-by: Grant Likely <grant.likely@secretlab.ca>

> ---
>  drivers/i2c/busses/i2c-s3c2410.c |    4 +---
>  1 files changed, 1 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
> index 737f721..85e3664 100644
> --- a/drivers/i2c/busses/i2c-s3c2410.c
> +++ b/drivers/i2c/busses/i2c-s3c2410.c
> @@ -1128,8 +1128,6 @@ static const struct of_device_id s3c24xx_i2c_match[] = {
>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
> -#else
> -#define s3c24xx_i2c_match NULL
>  #endif
>  
>  static struct platform_driver s3c24xx_i2c_driver = {
> @@ -1140,7 +1138,7 @@ static struct platform_driver s3c24xx_i2c_driver = {
>  		.owner	= THIS_MODULE,
>  		.name	= "s3c-i2c",
>  		.pm	= S3C24XX_DEV_PM_OPS,
> -		.of_match_table = s3c24xx_i2c_match,
> +		.of_match_table = of_match_ptr(s3c24xx_i2c_match),
>  	},
>  };
>  
> -- 
> 1.7.9
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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> More majordomo info at  http://vger.kernel.org/majordomo-info.html
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-- 
Grant Likely, B.Sc, P.Eng.
Secret Lab Technologies,Ltd.

[PATCH 2/3] i2c-s3c2410: Rework device type handling

[Karol Lewandowski]

Reorganize driver a bit to better handle device tree-based systems:

 - move machine type to driver's private structure instead of
   quering platform device variants in runtime

 - replace s3c24xx_i2c_type enum with plain unsigned int that can
   hold not only device type but also hw revision-specific quirks

Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/i2c/busses/i2c-s3c2410.c |   53 +++++++++++++++++++++++---------------
 1 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 85e3664..f84d26f 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -44,8 +44,16 @@
 #include <plat/regs-iic.h>
 #include <plat/iic.h>
 
-/* i2c controller state */
+#ifdef CONFIG_OF
+static const struct of_device_id s3c24xx_i2c_match[];
+#endif
+
+/* reserve lower 8 bits for device type, use remaining space for hw quirks */
+#define TYPE_BITS		0x000000ff
+#define TYPE_S3C2410		0x00000001
+#define TYPE_S3C2440		0x00000002
 
+/* i2c controller state */
 enum s3c24xx_i2c_state {
 	STATE_IDLE,
 	STATE_START,
@@ -54,14 +62,10 @@ enum s3c24xx_i2c_state {
 	STATE_STOP
 };
 
-enum s3c24xx_i2c_type {
-	TYPE_S3C2410,
-	TYPE_S3C2440,
-};
-
 struct s3c24xx_i2c {
 	spinlock_t		lock;
 	wait_queue_head_t	wait;
+	unsigned int            type;
 	unsigned int		suspended:1;
 
 	struct i2c_msg		*msg;
@@ -88,26 +92,32 @@ struct s3c24xx_i2c {
 #endif
 };
 
-/* default platform data removed, dev should always carry data. */
-
-/* s3c24xx_i2c_is2440()
+/* s3c24xx_i2c_is_type()
  *
- * return true is this is an s3c2440
+ * return true if this controller is of specified type
 */
 
-static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
+static inline int s3c24xx_i2c_is_type(struct s3c24xx_i2c *i2c, unsigned int type)
 {
-	struct platform_device *pdev = to_platform_device(i2c->dev);
-	enum s3c24xx_i2c_type type;
+	return (i2c->type & TYPE_BITS) == type;
+}
+
+/* s3c24xx_get_device_type
+ *
+ * Get controller type either from device tree or platform device variant.
+*/
 
+static inline unsigned int s3c24xx_get_device_type(struct platform_device *pdev)
+{
 #ifdef CONFIG_OF
-	if (i2c->dev->of_node)
-		return of_device_is_compatible(i2c->dev->of_node,
-				"samsung,s3c2440-i2c");
+	if (pdev->dev.of_node) {
+		const struct of_device_id *match;
+		match = of_match_node(&s3c24xx_i2c_match[0], pdev->dev.of_node);
+		return (unsigned int)match->data;
+	}
 #endif
 
-	type = platform_get_device_id(pdev)->driver_data;
-	return type == TYPE_S3C2440;
+	return platform_get_device_id(pdev)->driver_data;
 }
 
 /* s3c24xx_i2c_master_complete
@@ -676,7 +686,7 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
 
 	writel(iiccon, i2c->regs + S3C2410_IICCON);
 
-	if (s3c24xx_i2c_is2440(i2c)) {
+	if (s3c24xx_i2c_is_type(i2c, TYPE_S3C2440)) {
 		unsigned long sda_delay;
 
 		if (pdata->sda_delay) {
@@ -906,6 +916,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 		goto err_noclk;
 	}
 
+	i2c->type = s3c24xx_get_device_type(pdev);
 	if (pdata)
 		memcpy(i2c->pdata, pdata, sizeof(*pdata));
 	else
@@ -1123,8 +1134,8 @@ MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
 
 #ifdef CONFIG_OF
 static const struct of_device_id s3c24xx_i2c_match[] = {
-	{ .compatible = "samsung,s3c2410-i2c" },
-	{ .compatible = "samsung,s3c2440-i2c" },
+	{ .compatible = "samsung,s3c2410-i2c", .data = (void *)TYPE_S3C2410 },
+	{ .compatible = "samsung,s3c2440-i2c", .data = (void *)TYPE_S3C2440 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
-- 
1.7.9

Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Mark Brown]

On Tue, Mar 13, 2012 at 05:54:38PM +0100, Karol Lewandowski wrote:

>  - replace s3c24xx_i2c_type enum with plain unsigned int that can
>    hold not only device type but also hw revision-specific quirks

Would it not be clearer to just have explicit flags for the quirks (eg,
as a set of bitfield flags)?

Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Karol Lewandowski]

On 14.03.2012 18:29, Mark Brown wrote:

> On Tue, Mar 13, 2012 at 05:54:38PM +0100, Karol Lewandowski wrote:
> 
>>  - replace s3c24xx_i2c_type enum with plain unsigned int that can
>>    hold not only device type but also hw revision-specific quirks
> 
> Would it not be clearer to just have explicit flags for the quirks (eg,
> as a set of bitfield flags)?


That would work on runtime but we also need to initialize this
somehow.  The way it was done today on non-dt platforms is via platform
device variants, i.e. (taken from 3rd patch):

@@ -1128,6 +1161,9 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
 	}, {
 		.name		= "s3c2440-i2c",
 		.driver_data	= TYPE_S3C2440,
+	}, {
+		.name		= "s3c2440-hdmiphy-i2c",
+		.driver_data	= TYPE_S3C2440 | FLAG_HDMIPHY | FLAG_NO_GPIO,

Ability to address above scenario was sole motivation for this change.
Without it one would need either need separate type (e.g. 
TYPE_S3C2440_HDMIPHY) or setting flags based just on device name.

Introducing separate type (TYPE_S3C2440_HDMIPHY) has been our original
attempt to solve this issue.  However, this required adding explicit
checks to driver code all over the place (if (type == S3C2400 ||
type == S3c2440_HDMIPHY).

Thus, I felt that sqeezing quirks into type is a bit cleaner approach.

Regards,
-- 
Karol Lewandowski | Samsung Poland R&D Center | Linux/Platform

Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Mark Brown]

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On Thu, Mar 15, 2012 at 11:04:56AM +0100, Karol Lewandowski wrote:

> Introducing separate type (TYPE_S3C2440_HDMIPHY) has been our original
> attempt to solve this issue.  However, this required adding explicit
> checks to driver code all over the place (if (type == S3C2400 ||
> type == S3c2440_HDMIPHY).

Another option is to change the type to be a pointer to a struct with
quirk flags in it.

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Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Karol Lewandowski]

On 15.03.2012 13:56, Mark Brown wrote:

> On Thu, Mar 15, 2012 at 11:04:56AM +0100, Karol Lewandowski wrote:
> 
>> Introducing separate type (TYPE_S3C2440_HDMIPHY) has been our original
>> attempt to solve this issue.  However, this required adding explicit
>> checks to driver code all over the place (if (type == S3C2400 ||
>> type == S3c2440_HDMIPHY).
> 
> Another option is to change the type to be a pointer to a struct with
> quirk flags in it.


Sure, that's possible.   However, I don't find it any simpler than
using  bitmasks.  Quite to contrary - I consider it redundant to
bring new structure into existence when simple uint does the trick
just fine (IMHO, of course).

If you consider code to be inherently less readable because of this
approach I'll rework it.  If it's not a such big deal for you I would
prefer to keep it as is.

Thanks!
-- 
Karol Lewandowski | Samsung Poland R&D Center | Linux/Platform

Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Mark Brown]

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On Thu, Mar 15, 2012 at 05:54:33PM +0100, Karol Lewandowski wrote:

> If you consider code to be inherently less readable because of this
> approach I'll rework it.  If it's not a such big deal for you I would
> prefer to keep it as is.

The thing that was causing me to think the code was funny was mainly the
fact that we're now combining both quirk based selection and chip type
based selection into the same bitmask.  If the chip types were quirks
it'd probably not have looked odd, and that might just be a case of
renaming them - I can't remember what they do.

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Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Karol Lewandowski]

On 19.03.2012 20:55, Mark Brown wrote:

> On Thu, Mar 15, 2012 at 05:54:33PM +0100, Karol Lewandowski wrote:
> 
>> If you consider code to be inherently less readable because of this
>> approach I'll rework it.  If it's not a such big deal for you I would
>> prefer to keep it as is.
> 
> The thing that was causing me to think the code was funny was mainly the
> fact that we're now combining both quirk based selection and chip type
> based selection into the same bitmask.  If the chip types were quirks
> it'd probably not have looked odd, and that might just be a case of
> renaming them - I can't remember what they do.


What do you think about following changes, then?

diff --git a/drivers/i2c/busses/i2c-s3c2410.c
b/drivers/i2c/busses/i2c-s3c2410.c
index fa5f8c4..18c9760 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -48,12 +48,9 @@
 static const struct of_device_id s3c24xx_i2c_match[];
 #endif

-/* reserve lower 8 bits for device type, use remaining space for hw
quirks */
-#define TYPE_BITS		0x000000ff
-#define TYPE_S3C2410		0x00000001
-#define TYPE_S3C2440		0x00000002
-#define FLAG_HDMIPHY		0x00000100
-#define FLAG_NO_GPIO		0x00000200
+#define QUIRK_S3C2440		(1 << 0)
+#define QUIRK_HDMIPHY		(1 << 1)
+#define QUIRK_NO_GPIO		(1 << 2)

 /* i2c controller state */
 enum s3c24xx_i2c_state {
@@ -67,7 +64,7 @@ enum s3c24xx_i2c_state {
 struct s3c24xx_i2c {
 	spinlock_t		lock;
 	wait_queue_head_t	wait;
-	unsigned int            type;
+	unsigned int            quirks;
 	unsigned int		suspended:1;

 	struct i2c_msg		*msg;
@@ -94,22 +91,12 @@ struct s3c24xx_i2c {
 #endif
 };

-/* s3c24xx_i2c_is_type()
- *
- * return true if this controller is of specified type
-*/
-
-static inline int s3c24xx_i2c_is_type(struct s3c24xx_i2c *i2c, unsigned
int type)
-{
-	return (i2c->type & TYPE_BITS) == type;
-}
-
-/* s3c24xx_get_device_type
+/* s3c24xx_get_device_quirks
  *
  * Get controller type either from device tree or platform device variant.
 */

-static inline unsigned int s3c24xx_get_device_type(struct
platform_device *pdev)
+static inline unsigned int s3c24xx_get_device_quirks(struct
platform_device *pdev)
 {
 #ifdef CONFIG_OF
         if (pdev->dev.of_node) {
@@ -487,7 +474,7 @@ static int s3c24xx_i2c_set_master(struct s3c24xx_i2c
*i2c)
 	 * the hangup is expected to happen, so waiting 400 ms
 	 * causes only unnecessary system hangup
 	 */
-	if (i2c->type & FLAG_HDMIPHY)
+	if (i2c->quirks & QUIRK_HDMIPHY)
 		timeout = 10;

 	while (timeout-- > 0) {
@@ -500,7 +487,7 @@ static int s3c24xx_i2c_set_master(struct s3c24xx_i2c
*i2c)
 	}

 	/* hang-up of bus dedicated for HDMIPHY occurred, resetting */
-	if (i2c->type & FLAG_HDMIPHY) {
+	if (i2c->quirks & QUIRK_HDMIPHY) {
 		writel(0, i2c->regs + S3C2410_IICCON);
 		writel(0, i2c->regs + S3C2410_IICSTAT);
 		writel(0, i2c->regs + S3C2410_IICDS);
@@ -704,7 +691,7 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c
*i2c, unsigned int *got)

 	writel(iiccon, i2c->regs + S3C2410_IICCON);

-	if (s3c24xx_i2c_is_type(i2c, TYPE_S3C2440)) {
+	if (i2c->quirks & QUIRK_S3C2440) {
 		unsigned long sda_delay;

 		if (pdata->sda_delay) {
@@ -789,7 +776,7 @@ static int s3c24xx_i2c_parse_dt_gpio(struct
s3c24xx_i2c *i2c)
 {
 	int idx, gpio, ret;

-	if (i2c->type & FLAG_NO_GPIO)
+	if (i2c->quirks & QUIRK_NO_GPIO)
 		return 0;

 	for (idx = 0; idx < 2; idx++) {
@@ -817,7 +804,7 @@ static void s3c24xx_i2c_dt_gpio_free(struct
s3c24xx_i2c *i2c)
 {
 	unsigned int idx;

-	if (i2c->type & FLAG_NO_GPIO)
+	if (i2c->quirks & QUIRK_NO_GPIO)
 		return;

 	for (idx = 0; idx < 2; idx++)
@@ -898,10 +885,10 @@ s3c24xx_i2c_parse_dt(struct device_node *np,
struct s3c24xx_i2c *i2c)
 	pdata->bus_num = -1; /* i2c bus number is dynamically assigned */

 	if (of_get_property(np, "samsung,i2c-quirk-hdmiphy", NULL))
-		i2c->type |= FLAG_HDMIPHY;
+		i2c->quirks |= QUIRK_HDMIPHY;

 	if (of_get_property(np, "samsung,i2c-no-gpio", NULL))
-		i2c->type |= FLAG_NO_GPIO;
+		i2c->quirks |= QUIRK_NO_GPIO;

 	of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay);
 	of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
@@ -948,7 +935,7 @@ static int s3c24xx_i2c_probe(struct platform_device
*pdev)
 		goto err_noclk;
 	}

-	i2c->type = s3c24xx_get_device_type(pdev);
+	i2c->quirks = s3c24xx_get_device_quirks(pdev);
 	if (pdata)
 		memcpy(i2c->pdata, pdata, sizeof(*pdata));
 	else
@@ -1156,21 +1143,21 @@ static const struct dev_pm_ops
s3c24xx_i2c_dev_pm_ops = {
 static struct platform_device_id s3c24xx_driver_ids[] = {
 	{
 		.name		= "s3c2410-i2c",
-		.driver_data	= TYPE_S3C2410,
+		.driver_data	= 0,
 	}, {
 		.name		= "s3c2440-i2c",
-		.driver_data	= TYPE_S3C2440,
+		.driver_data	= QUIRK_S3C2440,
 	}, {
 		.name		= "s3c2440-hdmiphy-i2c",
-		.driver_data	= TYPE_S3C2440 | FLAG_HDMIPHY | FLAG_NO_GPIO,
+		.driver_data	= QUIRK_S3C2440 | QUIRK_HDMIPHY | QUIRK_NO_GPIO,
 	}, { },
 };
 MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);

 #ifdef CONFIG_OF
 static const struct of_device_id s3c24xx_i2c_match[] = {
-	{ .compatible = "samsung,s3c2410-i2c", .data = (void *)TYPE_S3C2410 },
-	{ .compatible = "samsung,s3c2440-i2c", .data = (void *)TYPE_S3C2440 },
+	{ .compatible = "samsung,s3c2410-i2c", .data = (void *)0 },
+	{ .compatible = "samsung,s3c2440-i2c", .data = (void *)QUIRK_S3C2440 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);


Regards,
-- 
Karol Lewandowski | Samsung Poland R&D Center | Linux/Platform

Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Mark Brown]

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On Wed, Mar 21, 2012 at 11:33:58AM +0100, Karol Lewandowski wrote:

> What do you think about following changes, then?

That looks reasonable.

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Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Karol Lewandowski]

On 21.03.2012 12:50, Mark Brown wrote:

> On Wed, Mar 21, 2012 at 11:33:58AM +0100, Karol Lewandowski wrote:
> 
>> What do you think about following changes, then?
> 
> That looks reasonable.


Thanks. I'll incorporate this change and post whole patchset again.

Regards,
-- 
Karol Lewandowski | Samsung Poland R&D Center | Linux/Platform

[PATCH 3/3] i2c-s3c2410: Add HDMIPHY quirk for S3C2440

[Karol Lewandowski]

This patch adds support for s3c2440 I2C bus controller dedicated HDMIPHY device on
Exynos4 platform. Some quirks are introduced due to differences between HDMIPHY
and other I2C controllers on Exynos4.  These differences are:
- no GPIOs, HDMIPHY is inside the SoC and the controller is connected
  internally
- due to unknown reason (probably HW bug in HDMIPHY and/or the controller) a
  transfer fails to finish. The controller hangs after sending the last byte,
  the workaround for this bug is resetting the controller after each transfer

Signed-off-by: Tomasz Stanislawski <t.stanislaws-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Signed-off-by: Karol Lewandowski <k.lewandowsk-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Tested-by: Tomasz Stanislawski <t.stanislaws-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Signed-off-by: Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
---
 .../devicetree/bindings/i2c/samsung-i2c.txt        |   10 ++++-
 drivers/i2c/busses/i2c-s3c2410.c                   |   36 ++++++++++++++++++++
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
index 38832c7..ac0917c 100644
--- a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
@@ -10,14 +10,20 @@ Required properties:
     region.
   - interrupts: interrupt number to the cpu.
   - samsung,i2c-sda-delay: Delay (in ns) applied to data line (SDA) edges.
-  - gpios: The order of the gpios should be the following: <SDA, SCL>.
-    The gpio specifier depends on the gpio controller.
 
 Optional properties:
+  - gpios: The order of the gpios should be the following: <SDA, SCL>.
+    The gpio specifier depends on the gpio controller. Required in all cases
+    except when "samsung,i2c-no-gpio" is also specified.
+  - samsung,i2c-no-gpio: input/output lines of the controller are
+    permanently wired to the respective client, there are no gpio
+    lines that need to be configured to enable this controller
   - samsung,i2c-slave-addr: Slave address in multi-master enviroment. If not
     specified, default value is 0.
   - samsung,i2c-max-bus-freq: Desired frequency in Hz of the bus. If not
     specified, the default value in Hz is 100000.
+  - samsung,i2c-quirk-hdmiphy: Quirk for HDMI PHY block on S3C2440 -
+    reduce timeout and reset controller when doing transefers
 
 Example:
 
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index f84d26f..23bf7fa 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -52,6 +52,8 @@ static const struct of_device_id s3c24xx_i2c_match[];
 #define TYPE_BITS		0x000000ff
 #define TYPE_S3C2410		0x00000001
 #define TYPE_S3C2440		0x00000002
+#define FLAG_HDMIPHY		0x00000100
+#define FLAG_NO_GPIO		0x00000200
 
 /* i2c controller state */
 enum s3c24xx_i2c_state {
@@ -481,6 +483,13 @@ static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
 	unsigned long iicstat;
 	int timeout = 400;
 
+	/* the timeout for HDMIPHY is reduced to 10 ms because
+	 * the hangup is expected to happen, so waiting 400 ms
+	 * causes only unnecessary system hangup
+	 */
+	if (i2c->type & FLAG_HDMIPHY)
+		timeout = 10;
+
 	while (timeout-- > 0) {
 		iicstat = readl(i2c->regs + S3C2410_IICSTAT);
 
@@ -490,6 +499,15 @@ static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
 		msleep(1);
 	}
 
+	/* hang-up of bus dedicated for HDMIPHY occurred, resetting */
+	if (i2c->type & FLAG_HDMIPHY) {
+		writel(0, i2c->regs + S3C2410_IICCON);
+		writel(0, i2c->regs + S3C2410_IICSTAT);
+		writel(0, i2c->regs + S3C2410_IICDS);
+
+		return 0;
+	}
+
 	return -ETIMEDOUT;
 }
 
@@ -771,6 +789,9 @@ static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c)
 {
 	int idx, gpio, ret;
 
+	if (i2c->type & FLAG_NO_GPIO)
+		return 0;
+
 	for (idx = 0; idx < 2; idx++) {
 		gpio = of_get_gpio(i2c->dev->of_node, idx);
 		if (!gpio_is_valid(gpio)) {
@@ -795,6 +816,10 @@ free_gpio:
 static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c)
 {
 	unsigned int idx;
+
+	if (i2c->type & FLAG_NO_GPIO)
+		return;
+
 	for (idx = 0; idx < 2; idx++)
 		gpio_free(i2c->gpios[idx]);
 }
@@ -871,6 +896,14 @@ s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
 		return;
 
 	pdata->bus_num = -1; /* i2c bus number is dynamically assigned */
+
+	if (s3c24xx_i2c_is_type(i2c, TYPE_S3C2440) &&
+	    of_get_property(np, "samsung,i2c-quirk-hdmiphy", NULL))
+		i2c->type |= FLAG_HDMIPHY;
+
+	if (of_get_property(np, "samsung,i2c-no-gpio", NULL))
+		i2c->type |= FLAG_NO_GPIO;
+
 	of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay);
 	of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
 	of_property_read_u32(np, "samsung,i2c-max-bus-freq",
@@ -1128,6 +1161,9 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
 	}, {
 		.name		= "s3c2440-i2c",
 		.driver_data	= TYPE_S3C2440,
+	}, {
+		.name		= "s3c2440-hdmiphy-i2c",
+		.driver_data	= TYPE_S3C2440 | FLAG_HDMIPHY | FLAG_NO_GPIO,
 	}, { },
 };
 MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
-- 
1.7.9

Re: [PATCH 3/3] i2c-s3c2410: Add HDMIPHY quirk for S3C2440

[Tomasz Stanislawski]

Hi Karol,
Please refer to comments below,

Regards,
Tomasz Stanislawski

On 03/13/2012 05:54 PM, Karol Lewandowski wrote:
> This patch adds support for s3c2440 I2C bus controller dedicated HDMIPHY device on
> Exynos4 platform. Some quirks are introduced due to differences between HDMIPHY
> and other I2C controllers on Exynos4.  These differences are:
> - no GPIOs, HDMIPHY is inside the SoC and the controller is connected
>   internally
> - due to unknown reason (probably HW bug in HDMIPHY and/or the controller) a
>   transfer fails to finish. The controller hangs after sending the last byte,
>   the workaround for this bug is resetting the controller after each transfer
> 
> Signed-off-by: Tomasz Stanislawski <t.stanislaws-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Signed-off-by: Karol Lewandowski <k.lewandowsk-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Tested-by: Tomasz Stanislawski <t.stanislaws-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Signed-off-by: Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> ---
>  .../devicetree/bindings/i2c/samsung-i2c.txt        |   10 ++++-
>  drivers/i2c/busses/i2c-s3c2410.c                   |   36 ++++++++++++++++++++
>  2 files changed, 44 insertions(+), 2 deletions(-)
> 
[snip]
> @@ -871,6 +896,14 @@ s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
>  		return;
>  
>  	pdata->bus_num = -1; /* i2c bus number is dynamically assigned */
> +
> +	if (s3c24xx_i2c_is_type(i2c, TYPE_S3C2440) &&

I think that type checking should be removed because hdmiphy quirk is something
orthogonal to the controller type.

> +	    of_get_property(np, "samsung,i2c-quirk-hdmiphy", NULL))
> +		i2c->type |= FLAG_HDMIPHY;
> +
> +	if (of_get_property(np, "samsung,i2c-no-gpio", NULL))
> +		i2c->type |= FLAG_NO_GPIO;
> +
>  	of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay);
>  	of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
>  	of_property_read_u32(np, "samsung,i2c-max-bus-freq",
> @@ -1128,6 +1161,9 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
>  	}, {
>  		.name		= "s3c2440-i2c",
>  		.driver_data	= TYPE_S3C2440,
> +	}, {
> +		.name		= "s3c2440-hdmiphy-i2c",
> +		.driver_data	= TYPE_S3C2440 | FLAG_HDMIPHY | FLAG_NO_GPIO,
>  	}, { },
>  };
>  MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);

Re: [PATCH 3/3] i2c-s3c2410: Add HDMIPHY quirk for S3C2440

[Karol Lewandowski]

On 13.03.2012 18:27, Tomasz Stanislawski wrote:

> Hi Karol,
> Please refer to comments below,
> 
> Regards,
> Tomasz Stanislawski
> 
> On 03/13/2012 05:54 PM, Karol Lewandowski wrote:
>> This patch adds support for s3c2440 I2C bus controller dedicated HDMIPHY device on
>> Exynos4 platform. Some quirks are introduced due to differences between HDMIPHY
>> and other I2C controllers on Exynos4.  These differences are:
>> - no GPIOs, HDMIPHY is inside the SoC and the controller is connected
>>   internally
>> - due to unknown reason (probably HW bug in HDMIPHY and/or the controller) a
>>   transfer fails to finish. The controller hangs after sending the last byte,
>>   the workaround for this bug is resetting the controller after each transfer
>>
>> Signed-off-by: Tomasz Stanislawski <t.stanislaws-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>> Signed-off-by: Karol Lewandowski <k.lewandowsk-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>> Tested-by: Tomasz Stanislawski <t.stanislaws-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>> Signed-off-by: Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>> ---
>>  .../devicetree/bindings/i2c/samsung-i2c.txt        |   10 ++++-
>>  drivers/i2c/busses/i2c-s3c2410.c                   |   36 ++++++++++++++++++++
>>  2 files changed, 44 insertions(+), 2 deletions(-)
>>
> [snip]
>> @@ -871,6 +896,14 @@ s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
>>  		return;
>>  
>>  	pdata->bus_num = -1; /* i2c bus number is dynamically assigned */
>> +
>> +	if (s3c24xx_i2c_is_type(i2c, TYPE_S3C2440) &&
> 
> I think that type checking should be removed because hdmiphy quirk is something
> orthogonal to the controller type.


Ok, I'll drop this test and resend patch in a minute.

Thanks!
-- 
Karol Lewandowski | Samsung Poland R&D Center | Linux/Platform

[PATCH] i2c-s3c2410: Add HDMIPHY quirk for S3C2440

[Karol Lewandowski]

This patch adds support for s3c2440 I2C bus controller dedicated HDMIPHY device on
Exynos4 platform. Some quirks are introduced due to differences between HDMIPHY
and other I2C controllers on Exynos4.  These differences are:
- no GPIOs, HDMIPHY is inside the SoC and the controller is connected
  internally
- due to unknown reason (probably HW bug in HDMIPHY and/or the controller) a
  transfer fails to finish. The controller hangs after sending the last byte,
  the workaround for this bug is resetting the controller after each transfer

Signed-off-by: Tomasz Stanislawski <t.stanislaws-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Signed-off-by: Karol Lewandowski <k.lewandowsk-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Tested-by: Tomasz Stanislawski <t.stanislaws-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
Signed-off-by: Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
---
 .../devicetree/bindings/i2c/samsung-i2c.txt        |   11 +++++-
 drivers/i2c/busses/i2c-s3c2410.c                   |   35 ++++++++++++++++++++
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
index 38832c7..c6670f9 100644
--- a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
@@ -10,14 +10,21 @@ Required properties:
     region.
   - interrupts: interrupt number to the cpu.
   - samsung,i2c-sda-delay: Delay (in ns) applied to data line (SDA) edges.
-  - gpios: The order of the gpios should be the following: <SDA, SCL>.
-    The gpio specifier depends on the gpio controller.
 
 Optional properties:
+  - gpios: The order of the gpios should be the following: <SDA, SCL>.
+    The gpio specifier depends on the gpio controller. Required in all cases
+    except when "samsung,i2c-no-gpio" is also specified.
+  - samsung,i2c-no-gpio: input/output lines of the controller are
+    permanently wired to the respective client, there are no gpio
+    lines that need to be configured to enable this controller
   - samsung,i2c-slave-addr: Slave address in multi-master enviroment. If not
     specified, default value is 0.
   - samsung,i2c-max-bus-freq: Desired frequency in Hz of the bus. If not
     specified, the default value in Hz is 100000.
+  - samsung,i2c-quirk-hdmiphy: Quirk for HDMI PHY block found on
+    Exynos4 platform - reduce timeout and reset controller after each
+    transfer
 
 Example:
 
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index f84d26f..fa5f8c4 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -52,6 +52,8 @@ static const struct of_device_id s3c24xx_i2c_match[];
 #define TYPE_BITS		0x000000ff
 #define TYPE_S3C2410		0x00000001
 #define TYPE_S3C2440		0x00000002
+#define FLAG_HDMIPHY		0x00000100
+#define FLAG_NO_GPIO		0x00000200
 
 /* i2c controller state */
 enum s3c24xx_i2c_state {
@@ -481,6 +483,13 @@ static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
 	unsigned long iicstat;
 	int timeout = 400;
 
+	/* the timeout for HDMIPHY is reduced to 10 ms because
+	 * the hangup is expected to happen, so waiting 400 ms
+	 * causes only unnecessary system hangup
+	 */
+	if (i2c->type & FLAG_HDMIPHY)
+		timeout = 10;
+
 	while (timeout-- > 0) {
 		iicstat = readl(i2c->regs + S3C2410_IICSTAT);
 
@@ -490,6 +499,15 @@ static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
 		msleep(1);
 	}
 
+	/* hang-up of bus dedicated for HDMIPHY occurred, resetting */
+	if (i2c->type & FLAG_HDMIPHY) {
+		writel(0, i2c->regs + S3C2410_IICCON);
+		writel(0, i2c->regs + S3C2410_IICSTAT);
+		writel(0, i2c->regs + S3C2410_IICDS);
+
+		return 0;
+	}
+
 	return -ETIMEDOUT;
 }
 
@@ -771,6 +789,9 @@ static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c)
 {
 	int idx, gpio, ret;
 
+	if (i2c->type & FLAG_NO_GPIO)
+		return 0;
+
 	for (idx = 0; idx < 2; idx++) {
 		gpio = of_get_gpio(i2c->dev->of_node, idx);
 		if (!gpio_is_valid(gpio)) {
@@ -795,6 +816,10 @@ free_gpio:
 static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c)
 {
 	unsigned int idx;
+
+	if (i2c->type & FLAG_NO_GPIO)
+		return;
+
 	for (idx = 0; idx < 2; idx++)
 		gpio_free(i2c->gpios[idx]);
 }
@@ -871,6 +896,13 @@ s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
 		return;
 
 	pdata->bus_num = -1; /* i2c bus number is dynamically assigned */
+
+	if (of_get_property(np, "samsung,i2c-quirk-hdmiphy", NULL))
+		i2c->type |= FLAG_HDMIPHY;
+
+	if (of_get_property(np, "samsung,i2c-no-gpio", NULL))
+		i2c->type |= FLAG_NO_GPIO;
+
 	of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay);
 	of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
 	of_property_read_u32(np, "samsung,i2c-max-bus-freq",
@@ -1128,6 +1160,9 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
 	}, {
 		.name		= "s3c2440-i2c",
 		.driver_data	= TYPE_S3C2440,
+	}, {
+		.name		= "s3c2440-hdmiphy-i2c",
+		.driver_data	= TYPE_S3C2440 | FLAG_HDMIPHY | FLAG_NO_GPIO,
 	}, { },
 };
 MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
-- 
1.7.9

Re: [PATCH 0/3 v2] Updates for exynos4210 and DT-based systems

[Kyungmin Park]

+CC another i2c subsystem maintainer, Wolfram Sang.

On 3/14/12, Karol Lewandowski <k.lewandowsk@samsung.com> wrote:
> Changes since v1:
>  - Move unrelated code fragment to separate patch (of_match_ptr())
>  - Move device-type handling to separate function and rework its
>    internals a bit
>
> This patchset reworks i2c-s3c2410 driver a bit to better handle
> device tree-enabled platforms and adds two quirks required by
> exynos4210-specific I2C controller used by s5p-hdmi driver.
>
> This patchset is based on "i2c-bjdooks/for-34/i2c/i2c-samsung" branch
> taken from:
>
>   git://git.fluff.org/bjdooks/linux.git
>
> Karol Lewandowski (3):
>   i2c-s3c2410: Drop unused define
>   i2c-s3c2410: Rework device type handling
>   i2c-s3c2410: Add HDMIPHY quirk for S3C2440
>
>  .../devicetree/bindings/i2c/samsung-i2c.txt        |   10 ++-
>  drivers/i2c/busses/i2c-s3c2410.c                   |   93
> +++++++++++++++-----
>  2 files changed, 77 insertions(+), 26 deletions(-)
>
> --
> 1.7.9
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc"
> in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

[PATCH v3 0/3] i2c-s3c2410: Updates for exynos4210 and DT-based systems

[Karol Lewandowski]

Changes since v2:
 - Merge device type and flags into flat bitmask named quirks -
   Consequently, treat s3c24xx as baseline hardware platform and
   support all hw variations via quirks [Suggested by Mark Brown]

Changes since v1:
 - Move unrelated code fragment to separate patch (of_match_ptr())
   [Suggested by Thomas Abracham]
 - Move device-type handling to separate function and rework its
   internals a bit [likewise]

This patchset reworks i2c-s3c2410 driver a bit to better handle
device tree-enabled platforms and adds two quirks required by
exynos4210-specific I2C controller used by s5p-hdmi driver.

This patchset is based on "i2c-bjdooks/for-34/i2c/i2c-samsung" branch
taken from:

  git://git.fluff.org/bjdooks/linux.git

Karol Lewandowski (3):
  i2c-s3c2410: Drop unused define
  i2c-s3c2410: Rework device type handling
  i2c-s3c2410: Add HDMIPHY quirk for S3C2440

 .../devicetree/bindings/i2c/samsung-i2c.txt        |   11 ++-
 drivers/i2c/busses/i2c-s3c2410.c                   |   86 +++++++++++++------
 2 files changed, 68 insertions(+), 29 deletions(-)

-- 
1.7.9

[PATCH 2/3] i2c-s3c2410: Rework device type handling

[Karol Lewandowski]

Reorganize driver a bit to better handle device tree-based systems:

 - move machine type to driver's private structure instead of
   quering platform device variants in runtime

 - replace s3c24xx_i2c_type enum with unsigned int that holds
   bitmask with revision-specific quirks

Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
 drivers/i2c/busses/i2c-s3c2410.c |   47 ++++++++++++++++++-------------------
 1 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 85e3664..f7b6a14 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -44,8 +44,14 @@
 #include <plat/regs-iic.h>
 #include <plat/iic.h>
 
-/* i2c controller state */
+#ifdef CONFIG_OF
+static const struct of_device_id s3c24xx_i2c_match[];
+#endif
 
+/* Treat S3C2410 as baseline hardware, anything else is supported via quirks */
+#define QUIRK_S3C2440		(1 << 0)
+
+/* i2c controller state */
 enum s3c24xx_i2c_state {
 	STATE_IDLE,
 	STATE_START,
@@ -54,14 +60,10 @@ enum s3c24xx_i2c_state {
 	STATE_STOP
 };
 
-enum s3c24xx_i2c_type {
-	TYPE_S3C2410,
-	TYPE_S3C2440,
-};
-
 struct s3c24xx_i2c {
 	spinlock_t		lock;
 	wait_queue_head_t	wait;
+	unsigned int            quirks;
 	unsigned int		suspended:1;
 
 	struct i2c_msg		*msg;
@@ -88,26 +90,22 @@ struct s3c24xx_i2c {
 #endif
 };
 
-/* default platform data removed, dev should always carry data. */
-
-/* s3c24xx_i2c_is2440()
+/* s3c24xx_get_device_quirks
  *
- * return true is this is an s3c2440
+ * Get controller type either from device tree or platform device variant.
 */
 
-static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
+static inline unsigned int s3c24xx_get_device_quirks(struct platform_device *pdev)
 {
-	struct platform_device *pdev = to_platform_device(i2c->dev);
-	enum s3c24xx_i2c_type type;
-
 #ifdef CONFIG_OF
-	if (i2c->dev->of_node)
-		return of_device_is_compatible(i2c->dev->of_node,
-				"samsung,s3c2440-i2c");
+        if (pdev->dev.of_node) {
+		const struct of_device_id *match;
+		match = of_match_node(&s3c24xx_i2c_match[0], pdev->dev.of_node);
+		return (unsigned int)match->data;
+        }
 #endif
 
-	type = platform_get_device_id(pdev)->driver_data;
-	return type == TYPE_S3C2440;
+	return platform_get_device_id(pdev)->driver_data;
 }
 
 /* s3c24xx_i2c_master_complete
@@ -676,7 +674,7 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
 
 	writel(iiccon, i2c->regs + S3C2410_IICCON);
 
-	if (s3c24xx_i2c_is2440(i2c)) {
+	if (i2c->quirks & QUIRK_S3C2440) {
 		unsigned long sda_delay;
 
 		if (pdata->sda_delay) {
@@ -906,6 +904,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 		goto err_noclk;
 	}
 
+	i2c->quirks = s3c24xx_get_device_quirks(pdev);
 	if (pdata)
 		memcpy(i2c->pdata, pdata, sizeof(*pdata));
 	else
@@ -1113,18 +1112,18 @@ static const struct dev_pm_ops s3c24xx_i2c_dev_pm_ops = {
 static struct platform_device_id s3c24xx_driver_ids[] = {
 	{
 		.name		= "s3c2410-i2c",
-		.driver_data	= TYPE_S3C2410,
+		.driver_data	= 0,
 	}, {
 		.name		= "s3c2440-i2c",
-		.driver_data	= TYPE_S3C2440,
+		.driver_data	= QUIRK_S3C2440,
 	}, { },
 };
 MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
 
 #ifdef CONFIG_OF
 static const struct of_device_id s3c24xx_i2c_match[] = {
-	{ .compatible = "samsung,s3c2410-i2c" },
-	{ .compatible = "samsung,s3c2440-i2c" },
+	{ .compatible = "samsung,s3c2410-i2c", .data = (void *)0 },
+	{ .compatible = "samsung,s3c2440-i2c", .data = (void *)QUIRK_S3C2440 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
-- 
1.7.9

Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Mark Brown]

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On Wed, Mar 21, 2012 at 08:11:52PM +0100, Karol Lewandowski wrote:
> Reorganize driver a bit to better handle device tree-based systems:
> 
>  - move machine type to driver's private structure instead of
>    quering platform device variants in runtime
> 
>  - replace s3c24xx_i2c_type enum with unsigned int that holds
>    bitmask with revision-specific quirks

Reviewed-by: Mark Brown <broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>

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Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Wolfram Sang]

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Hi,

On Wed, Mar 21, 2012 at 08:11:52PM +0100, Karol Lewandowski wrote:
> Reorganize driver a bit to better handle device tree-based systems:
> 
>  - move machine type to driver's private structure instead of
>    quering platform device variants in runtime
> 
>  - replace s3c24xx_i2c_type enum with unsigned int that holds
>    bitmask with revision-specific quirks
> 
> Signed-off-by: Karol Lewandowski <k.lewandowsk-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Signed-off-by: Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>

Okay, so this driver needs to the 'data' field from either
platform_device_id or of_device_id and implements a function for that,
namely s3c24xx_get_device_quirks(). Grant, Rob: I'd think there might be
more drivers in need of that, so maybe it makes sense to have a generic
of-helper function?

> ---
>  drivers/i2c/busses/i2c-s3c2410.c |   47 ++++++++++++++++++-------------------
>  1 files changed, 23 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
> index 85e3664..f7b6a14 100644
> --- a/drivers/i2c/busses/i2c-s3c2410.c
> +++ b/drivers/i2c/busses/i2c-s3c2410.c
> @@ -44,8 +44,14 @@
>  #include <plat/regs-iic.h>
>  #include <plat/iic.h>
>  
> -/* i2c controller state */
> +#ifdef CONFIG_OF
> +static const struct of_device_id s3c24xx_i2c_match[];
> +#endif

Uh, forward declaration with #ifdef. I'd think we should get this simply
to the front.

>  dd
> +/* Treat S3C2410 as baseline hardware, anything else is supported via quirks */
> +#define QUIRK_S3C2440		(1 << 0)

Minor: Is it really a quirk being s3c2440? Maybe FLAG_*, dunno.

> +
> +/* i2c controller state */
>  enum s3c24xx_i2c_state {
>  	STATE_IDLE,
>  	STATE_START,
> @@ -54,14 +60,10 @@ enum s3c24xx_i2c_state {
>  	STATE_STOP
>  };
>  
> -enum s3c24xx_i2c_type {
> -	TYPE_S3C2410,
> -	TYPE_S3C2440,
> -};
> -
>  struct s3c24xx_i2c {
>  	spinlock_t		lock;
>  	wait_queue_head_t	wait;
> +	unsigned int            quirks;
>  	unsigned int		suspended:1;
>  
>  	struct i2c_msg		*msg;
> @@ -88,26 +90,22 @@ struct s3c24xx_i2c {
>  #endif
>  };
>  
> -/* default platform data removed, dev should always carry data. */
> -
> -/* s3c24xx_i2c_is2440()
> +/* s3c24xx_get_device_quirks
>   *
> - * return true is this is an s3c2440
> + * Get controller type either from device tree or platform device variant.
>  */
>  
> -static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
> +static inline unsigned int s3c24xx_get_device_quirks(struct platform_device *pdev)
>  {
> -	struct platform_device *pdev = to_platform_device(i2c->dev);
> -	enum s3c24xx_i2c_type type;
> -
>  #ifdef CONFIG_OF
> -	if (i2c->dev->of_node)
> -		return of_device_is_compatible(i2c->dev->of_node,
> -				"samsung,s3c2440-i2c");
> +        if (pdev->dev.of_node) {
> +		const struct of_device_id *match;
> +		match = of_match_node(&s3c24xx_i2c_match[0], pdev->dev.of_node);

Minor: I think it is more readable to drop the [0]

> +		return (unsigned int)match->data;
> +        }
>  #endif
>  
> -	type = platform_get_device_id(pdev)->driver_data;
> -	return type == TYPE_S3C2440;
> +	return platform_get_device_id(pdev)->driver_data;
>  }
>  
>  /* s3c24xx_i2c_master_complete
> @@ -676,7 +674,7 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
>  
>  	writel(iiccon, i2c->regs + S3C2410_IICCON);
>  
> -	if (s3c24xx_i2c_is2440(i2c)) {
> +	if (i2c->quirks & QUIRK_S3C2440) {
>  		unsigned long sda_delay;
>  
>  		if (pdata->sda_delay) {
> @@ -906,6 +904,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
>  		goto err_noclk;
>  	}
>  
> +	i2c->quirks = s3c24xx_get_device_quirks(pdev);
>  	if (pdata)
>  		memcpy(i2c->pdata, pdata, sizeof(*pdata));
>  	else
> @@ -1113,18 +1112,18 @@ static const struct dev_pm_ops s3c24xx_i2c_dev_pm_ops = {
>  static struct platform_device_id s3c24xx_driver_ids[] = {
>  	{
>  		.name		= "s3c2410-i2c",
> -		.driver_data	= TYPE_S3C2410,
> +		.driver_data	= 0,
>  	}, {
>  		.name		= "s3c2440-i2c",
> -		.driver_data	= TYPE_S3C2440,
> +		.driver_data	= QUIRK_S3C2440,
>  	}, { },
>  };
>  MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
>  
>  #ifdef CONFIG_OF
>  static const struct of_device_id s3c24xx_i2c_match[] = {
> -	{ .compatible = "samsung,s3c2410-i2c" },
> -	{ .compatible = "samsung,s3c2440-i2c" },
> +	{ .compatible = "samsung,s3c2410-i2c", .data = (void *)0 },
> +	{ .compatible = "samsung,s3c2440-i2c", .data = (void *)QUIRK_S3C2440 },

Hmm, the need to sepcify the quirks twice may lead to only one instance
being updated in future patches, but I don't see a way around that,
currently :(

>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
> -- 
> 1.7.9
> 

Thanks,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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_______________________________________________
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Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Karol Lewandowski]

On 17.04.2012 19:31, Wolfram Sang wrote:

> Hi,


Hi Wolfram!

> 
> On Wed, Mar 21, 2012 at 08:11:52PM +0100, Karol Lewandowski wrote:
>> Reorganize driver a bit to better handle device tree-based systems:
>>
>>  - move machine type to driver's private structure instead of
>>    quering platform device variants in runtime
>>
>>  - replace s3c24xx_i2c_type enum with unsigned int that holds
>>    bitmask with revision-specific quirks
>>
>> Signed-off-by: Karol Lewandowski <k.lewandowsk-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
>> Signed-off-by: Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> 
> Okay, so this driver needs to the 'data' field from either
> platform_device_id or of_device_id and implements a function for that,
> namely s3c24xx_get_device_quirks(). Grant, Rob: I'd think there might be
> more drivers in need of that, so maybe it makes sense to have a generic
> of-helper function?
> 
>> ---
>>  drivers/i2c/busses/i2c-s3c2410.c |   47 ++++++++++++++++++-------------------
>>  1 files changed, 23 insertions(+), 24 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
>> index 85e3664..f7b6a14 100644
>> --- a/drivers/i2c/busses/i2c-s3c2410.c
>> +++ b/drivers/i2c/busses/i2c-s3c2410.c
>> @@ -44,8 +44,14 @@
>>  #include <plat/regs-iic.h>
>>  #include <plat/iic.h>
>>  
>> -/* i2c controller state */
>> +#ifdef CONFIG_OF
>> +static const struct of_device_id s3c24xx_i2c_match[];
>> +#endif
> 
> Uh, forward declaration with #ifdef. I'd think we should get this simply
> to the front.


Ok, as I think it's better to have dt and non-dt definitions together
I'll move both of_device_id and platform_device_id to the top.

>> +/* Treat S3C2410 as baseline hardware, anything else is supported via quirks */
>> +#define QUIRK_S3C2440		(1 << 0)
> 
> Minor: Is it really a quirk being s3c2440? Maybe FLAG_*, dunno.


In first version[1] of this patch I've used TYPEs for device types
and FLAGS for quirks. However, I've squashed these into "quirks" after
discussion with Mark[2].

[1] http://permalink.gmane.org/gmane.linux.kernel/1266759
[2] http://permalink.gmane.org/gmane.linux.kernel.samsung-soc/10255


>> -static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
>> +static inline unsigned int s3c24xx_get_device_quirks(struct platform_device *pdev)
>>  {
>> -	struct platform_device *pdev = to_platform_device(i2c->dev);
>> -	enum s3c24xx_i2c_type type;
>> -
>>  #ifdef CONFIG_OF
>> -	if (i2c->dev->of_node)
>> -		return of_device_is_compatible(i2c->dev->of_node,
>> -				"samsung,s3c2440-i2c");
>> +        if (pdev->dev.of_node) {
>> +		const struct of_device_id *match;
>> +		match = of_match_node(&s3c24xx_i2c_match[0], pdev->dev.of_node);
> 
> Minor: I think it is more readable to drop the [0]


I prefer explicit version, but I'll drop [] as both you and Thomas
found implicit version more readable.

[ I'll also drop above CONFIG_OF ifdef, as of_match_node() seem
  to be always defined since v3.2-rc1. ]

Thanks for review!  I'll resubmit updated version shortly.

Regards,
-- 
Karol Lewandowski | Samsung Poland R&D Center | Linux/Platform

Re: [PATCH 2/3] i2c-s3c2410: Rework device type handling

[Wolfram Sang]

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Hi,

> >> Reorganize driver a bit to better handle device tree-based systems:
> >>
> >>  - move machine type to driver's private structure instead of
> >>    quering platform device variants in runtime
> >>
> >>  - replace s3c24xx_i2c_type enum with unsigned int that holds
> >>    bitmask with revision-specific quirks
> >>
> >> Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
> >> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> > 
> > Okay, so this driver needs to the 'data' field from either
> > platform_device_id or of_device_id and implements a function for that,
> > namely s3c24xx_get_device_quirks(). Grant, Rob: I'd think there might be
> > more drivers in need of that, so maybe it makes sense to have a generic
> > of-helper function?

Please wait one or two days before resending. Maybe Grant or Rob find
some time to answer this question. (Yeah, we can fix it later if such a
generic function is introduced somewhen).

> >> -/* i2c controller state */
> >> +#ifdef CONFIG_OF
> >> +static const struct of_device_id s3c24xx_i2c_match[];
> >> +#endif
> > 
> > Uh, forward declaration with #ifdef. I'd think we should get this simply
> > to the front.
> 
> 
> Ok, as I think it's better to have dt and non-dt definitions together
> I'll move both of_device_id and platform_device_id to the top.

Agreed.

> 
> >> +/* Treat S3C2410 as baseline hardware, anything else is supported via quirks */
> >> +#define QUIRK_S3C2440		(1 << 0)
> > 
> > Minor: Is it really a quirk being s3c2440? Maybe FLAG_*, dunno.
> 
> 
> In first version[1] of this patch I've used TYPEs for device types
> and FLAGS for quirks. However, I've squashed these into "quirks" after
> discussion with Mark[2].
> 
> [1] http://permalink.gmane.org/gmane.linux.kernel/1266759
> [2] http://permalink.gmane.org/gmane.linux.kernel.samsung-soc/10255

It's minor, keep the QUIRKs.

> [ I'll also drop above CONFIG_OF ifdef, as of_match_node() seem
>   to be always defined since v3.2-rc1. ]

Great.

Thanks,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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