Patchwork [1/2] i2c: exynos5: add support for HSI2C on Exynos5260 SoC

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Submitter Naveen Krishna Ch
Date Nov. 22, 2013, 6:12 a.m.
Message ID <1385100726-32165-1-git-send-email-ch.naveen@samsung.com>
Download mbox | patch
Permalink /patch/293336/
State Superseded
Headers show

Comments

Naveen Krishna Ch - Nov. 22, 2013, 6:12 a.m.
This patch adds new compatible to support HSI2C module on Exynos5260
HSI2C module on Exynos5260 needs to be reset during during initialization.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
---
 .../devicetree/bindings/i2c/i2c-exynos5.txt        |    6 +++-
 drivers/i2c/busses/i2c-exynos5.c                   |   31 ++++++++++++++++++--
 2 files changed, 34 insertions(+), 3 deletions(-)
Yuvaraj CD - Nov. 22, 2013, 6:46 a.m.
On Fri, Nov 22, 2013 at 11:42 AM, Naveen Krishna Chatradhi
<ch.naveen@samsung.com> wrote:
> This patch adds new compatible to support HSI2C module on Exynos5260
> HSI2C module on Exynos5260 needs to be reset during during initialization.
>
> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
> ---
>  .../devicetree/bindings/i2c/i2c-exynos5.txt        |    6 +++-
>  drivers/i2c/busses/i2c-exynos5.c                   |   31 ++++++++++++++++++--
>  2 files changed, 34 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
> index 056732c..704ab92 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
> @@ -5,7 +5,11 @@ at various speeds ranging from 100khz to 3.4Mhz.
>
>  Required properties:
>    - compatible: value should be.
> -      -> "samsung,exynos5-hsi2c", for i2c compatible with exynos5 hsi2c.
> +       -> "samsung,exynos5-hsi2c", for i2c compatible with HSI2C available on
> +                               Exynos5250/5420 SoCs.
> +       -> "samsung,exynos5260-hsi2c", for i2c compatible with HSI2C available
> +                               on Exynos5260 SoCs.
> +
>    - reg: physical base address of the controller and length of memory mapped
>      region.
>    - interrupts: interrupt number to the cpu.
> diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
> index aca3991..cbb49e2 100644
> --- a/drivers/i2c/busses/i2c-exynos5.c
> +++ b/drivers/i2c/busses/i2c-exynos5.c
> @@ -184,14 +184,35 @@ struct exynos5_i2c {
>          * 2. Fast speed upto 1Mbps
>          */
>         int                     speed_mode;
> +
> +       /* Version of HS-I2C Hardware */
> +       unsigned int            version;
> +};
> +
> +enum hsi2c_version {
> +       EXYNOS_5,
> +       EXYNOS_5260
>  };
>
>  static const struct of_device_id exynos5_i2c_match[] = {
> -       { .compatible = "samsung,exynos5-hsi2c" },
> +       {
> +               .compatible = "samsung,exynos5-hsi2c",
> +               .data = (void *)EXYNOS_5 },
> +       {
> +               .compatible = "samsung,exynos5260-hsi2c",
> +               .data = (void *)EXYNOS_5260 },
>         {},
>  };
>  MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
>
> +static inline unsigned int exynos5_i2c_get_version(struct platform_device *pdev)
> +{
> +       const struct of_device_id *match;
> +
> +       match = of_match_node(exynos5_i2c_match, pdev->dev.of_node);
> +       return (unsigned int)match->data;
> +}
> +
>  static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
>  {
>         writel(readl(i2c->regs + HSI2C_INT_STATUS),
> @@ -692,7 +713,13 @@ static int exynos5_i2c_probe(struct platform_device *pdev)
>         if (ret)
>                 goto err_clk;
>
> -       exynos5_i2c_init(i2c);
> +       i2c->version = exynos5_i2c_get_version(pdev);
> +
> +       /* The HS-I2C core on Exynos5260 needs a reset to start with */
> +       if (i2c->version == EXYNOS_5260)

Is there is any change in the HSI2C IP for EXYNOS5260?
Can you let me know whats the change w.r.t IP and
why it needs reset to start,which was not needed in earlier SOC?

> +               exynos5_i2c_reset(i2c);
> +       else
> +               exynos5_i2c_init(i2c);
>
>         ret = i2c_add_adapter(&i2c->adap);
>         if (ret < 0) {
> --
> 1.7.10.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
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naveen krishna chatradhi - Nov. 22, 2013, 7:32 a.m.
Hello Yuvaraj,

On 22 November 2013 12:16, Yuvaraj Cd <yuvaraj.lkml@gmail.com> wrote:
> On Fri, Nov 22, 2013 at 11:42 AM, Naveen Krishna Chatradhi
> <ch.naveen@samsung.com> wrote:
>> This patch adds new compatible to support HSI2C module on Exynos5260
>> HSI2C module on Exynos5260 needs to be reset during during initialization.
>>
>> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
>> ---
>>  .../devicetree/bindings/i2c/i2c-exynos5.txt        |    6 +++-
>>  drivers/i2c/busses/i2c-exynos5.c                   |   31 ++++++++++++++++++--
>>  2 files changed, 34 insertions(+), 3 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
>> index 056732c..704ab92 100644
>> --- a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
>> +++ b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
>> @@ -5,7 +5,11 @@ at various speeds ranging from 100khz to 3.4Mhz.
>>
>>  Required properties:
>>    - compatible: value should be.
>> -      -> "samsung,exynos5-hsi2c", for i2c compatible with exynos5 hsi2c.
>> +       -> "samsung,exynos5-hsi2c", for i2c compatible with HSI2C available on
>> +                               Exynos5250/5420 SoCs.
>> +       -> "samsung,exynos5260-hsi2c", for i2c compatible with HSI2C available
>> +                               on Exynos5260 SoCs.
>> +
>>    - reg: physical base address of the controller and length of memory mapped
>>      region.
>>    - interrupts: interrupt number to the cpu.
>> diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
>> index aca3991..cbb49e2 100644
>> --- a/drivers/i2c/busses/i2c-exynos5.c
>> +++ b/drivers/i2c/busses/i2c-exynos5.c
>> @@ -184,14 +184,35 @@ struct exynos5_i2c {
>>          * 2. Fast speed upto 1Mbps
>>          */
>>         int                     speed_mode;
>> +
>> +       /* Version of HS-I2C Hardware */
>> +       unsigned int            version;
>> +};
>> +
>> +enum hsi2c_version {
>> +       EXYNOS_5,
>> +       EXYNOS_5260
>>  };
>>
>>  static const struct of_device_id exynos5_i2c_match[] = {
>> -       { .compatible = "samsung,exynos5-hsi2c" },
>> +       {
>> +               .compatible = "samsung,exynos5-hsi2c",
>> +               .data = (void *)EXYNOS_5 },
>> +       {
>> +               .compatible = "samsung,exynos5260-hsi2c",
>> +               .data = (void *)EXYNOS_5260 },
>>         {},
>>  };
>>  MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
>>
>> +static inline unsigned int exynos5_i2c_get_version(struct platform_device *pdev)
>> +{
>> +       const struct of_device_id *match;
>> +
>> +       match = of_match_node(exynos5_i2c_match, pdev->dev.of_node);
>> +       return (unsigned int)match->data;
>> +}
>> +
>>  static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
>>  {
>>         writel(readl(i2c->regs + HSI2C_INT_STATUS),
>> @@ -692,7 +713,13 @@ static int exynos5_i2c_probe(struct platform_device *pdev)
>>         if (ret)
>>                 goto err_clk;
>>
>> -       exynos5_i2c_init(i2c);
>> +       i2c->version = exynos5_i2c_get_version(pdev);
>> +
>> +       /* The HS-I2C core on Exynos5260 needs a reset to start with */
>> +       if (i2c->version == EXYNOS_5260)
>
> Is there is any change in the HSI2C IP for EXYNOS5260?
> Can you let me know whats the change w.r.t IP and
> why it needs reset to start,which was not needed in earlier SOC?

Problem:
While working on HSI2C on uboot for Exynos5260 i faced a problem.
To operate on bus "0" which was default bus
If i try i2c md/mw on channel 0 without selecting the bus using "i2c dev 0"
the transaction was failing. But, the subsequent transactions were passing.

Software Work around:
After looking at the code i found out, resetting the bus for the first
time made it work.

Hardware engg suggestion:
Meanwhile inputs from Hardware engineers are, "HSI2C on Exynos5260 needs a reset
during init."  I've not gone personally into the internals of HSI2C module.

From user manual for Exynos5260, FIFO depth supported is 16bytes
instead of 64bytes.
>
>> +               exynos5_i2c_reset(i2c);
>> +       else
>> +               exynos5_i2c_init(i2c);
>>
>>         ret = i2c_add_adapter(&i2c->adap);
>>         if (ret < 0) {
>> --
>> 1.7.10.4
>>
>> --
>> 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

diff --git a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
index 056732c..704ab92 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt
@@ -5,7 +5,11 @@  at various speeds ranging from 100khz to 3.4Mhz.
 
 Required properties:
   - compatible: value should be.
-      -> "samsung,exynos5-hsi2c", for i2c compatible with exynos5 hsi2c.
+	-> "samsung,exynos5-hsi2c", for i2c compatible with HSI2C available on
+				Exynos5250/5420 SoCs.
+	-> "samsung,exynos5260-hsi2c", for i2c compatible with HSI2C available
+				on Exynos5260 SoCs.
+
   - reg: physical base address of the controller and length of memory mapped
     region.
   - interrupts: interrupt number to the cpu.
diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index aca3991..cbb49e2 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -184,14 +184,35 @@  struct exynos5_i2c {
 	 * 2. Fast speed upto 1Mbps
 	 */
 	int			speed_mode;
+
+	/* Version of HS-I2C Hardware */
+	unsigned int		version;
+};
+
+enum hsi2c_version {
+	EXYNOS_5,
+	EXYNOS_5260
 };
 
 static const struct of_device_id exynos5_i2c_match[] = {
-	{ .compatible = "samsung,exynos5-hsi2c" },
+	{
+		.compatible = "samsung,exynos5-hsi2c",
+		.data = (void *)EXYNOS_5 },
+	{
+		.compatible = "samsung,exynos5260-hsi2c",
+		.data = (void *)EXYNOS_5260 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
 
+static inline unsigned int exynos5_i2c_get_version(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+
+	match = of_match_node(exynos5_i2c_match, pdev->dev.of_node);
+	return (unsigned int)match->data;
+}
+
 static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
 {
 	writel(readl(i2c->regs + HSI2C_INT_STATUS),
@@ -692,7 +713,13 @@  static int exynos5_i2c_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_clk;
 
-	exynos5_i2c_init(i2c);
+	i2c->version = exynos5_i2c_get_version(pdev);
+
+	/* The HS-I2C core on Exynos5260 needs a reset to start with */
+	if (i2c->version == EXYNOS_5260)
+		exynos5_i2c_reset(i2c);
+	else
+		exynos5_i2c_init(i2c);
 
 	ret = i2c_add_adapter(&i2c->adap);
 	if (ret < 0) {