[PATCH v2] i2c: exynos5: Preserve high speed master code

[PATCH v2] i2c: exynos5: Preserve high speed master code

[Mårten Lindahl]

From: Mårten Lindahl <martenli@axis.com>

When the driver starts to send a message with the MASTER_ID field
set (high speed), the whole I2C_ADDR register is overwritten including
MASTER_ID as the SLV_ADDR_MAS field is set.

This patch preserves already written fields in I2C_ADDR when writing
SLV_ADDR_MAS.

Signed-off-by: Mårten Lindahl <martenli@axis.com>
---
v2:
- Change commit message as the problem is not in the controller but in
  the driver.
- Use MASTER_ID macro instead of reading back register contents.

 drivers/i2c/busses/i2c-exynos5.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 20a9881a0d6c..5ac30d95650c 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -606,6 +606,7 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
 	u32 i2c_ctl;
 	u32 int_en = 0;
 	u32 i2c_auto_conf = 0;
+	u32 i2c_addr = 0;
 	u32 fifo_ctl;
 	unsigned long flags;
 	unsigned short trig_lvl;
@@ -640,7 +641,12 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
 		int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
 	}
 
-	writel(HSI2C_SLV_ADDR_MAS(i2c->msg->addr), i2c->regs + HSI2C_ADDR);
+	i2c_addr = HSI2C_SLV_ADDR_MAS(i2c->msg->addr);
+
+	if (i2c->op_clock >= I2C_MAX_FAST_MODE_PLUS_FREQ)
+		i2c_addr |= HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr));
+
+	writel(i2c_addr, i2c->regs + HSI2C_ADDR);
 
 	writel(fifo_ctl, i2c->regs + HSI2C_FIFO_CTL);
 	writel(i2c_ctl, i2c->regs + HSI2C_CTL);
-- 
2.11.0

Re: [PATCH v2] i2c: exynos5: Preserve high speed master code

[Krzysztof Kozlowski]

On Tue, Feb 16, 2021 at 11:25:38PM +0100, Mårten Lindahl wrote:
> From: Mårten Lindahl <martenli@axis.com>
> 
> When the driver starts to send a message with the MASTER_ID field
> set (high speed), the whole I2C_ADDR register is overwritten including
> MASTER_ID as the SLV_ADDR_MAS field is set.
> 
> This patch preserves already written fields in I2C_ADDR when writing
> SLV_ADDR_MAS.
> 
> Signed-off-by: Mårten Lindahl <martenli@axis.com>
> ---
> v2:
> - Change commit message as the problem is not in the controller but in
>   the driver.
> - Use MASTER_ID macro instead of reading back register contents.
> 
>  drivers/i2c/busses/i2c-exynos5.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Krzysztof Kozlowski <krzk@kernel.org>

Best regards,
Krzysztof

Re: [PATCH v2] i2c: exynos5: Preserve high speed master code

[Wolfram Sang]

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On Tue, Feb 16, 2021 at 11:25:38PM +0100, Mårten Lindahl wrote:
> From: Mårten Lindahl <martenli@axis.com>
> 
> When the driver starts to send a message with the MASTER_ID field
> set (high speed), the whole I2C_ADDR register is overwritten including
> MASTER_ID as the SLV_ADDR_MAS field is set.
> 
> This patch preserves already written fields in I2C_ADDR when writing
> SLV_ADDR_MAS.
> 
> Signed-off-by: Mårten Lindahl <martenli@axis.com>

Looks good. Is there a Fixes-tag we could apply?


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Re: [PATCH v2] i2c: exynos5: Preserve high speed master code

[Krzysztof Kozlowski]

On Fri, 26 Feb 2021 at 11:34, Wolfram Sang <wsa@kernel.org> wrote:
>
> On Tue, Feb 16, 2021 at 11:25:38PM +0100, Mårten Lindahl wrote:
> > From: Mårten Lindahl <martenli@axis.com>
> >
> > When the driver starts to send a message with the MASTER_ID field
> > set (high speed), the whole I2C_ADDR register is overwritten including
> > MASTER_ID as the SLV_ADDR_MAS field is set.
> >
> > This patch preserves already written fields in I2C_ADDR when writing
> > SLV_ADDR_MAS.
> >
> > Signed-off-by: Mårten Lindahl <martenli@axis.com>
>
> Looks good. Is there a Fixes-tag we could apply?

The first commit, 2013 :)
Fixes: 8a73cd4cfa15 ("i2c: exynos5: add High Speed I2C controller driver")

Best regards,
Krzysztof

Re: [PATCH v2] i2c: exynos5: Preserve high speed master code

[Wolfram Sang]

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On Fri, Feb 26, 2021 at 11:40:00AM +0100, Krzysztof Kozlowski wrote:
> On Fri, 26 Feb 2021 at 11:34, Wolfram Sang <wsa@kernel.org> wrote:
> >
> > On Tue, Feb 16, 2021 at 11:25:38PM +0100, Mårten Lindahl wrote:
> > > From: Mårten Lindahl <martenli@axis.com>
> > >
> > > When the driver starts to send a message with the MASTER_ID field
> > > set (high speed), the whole I2C_ADDR register is overwritten including
> > > MASTER_ID as the SLV_ADDR_MAS field is set.
> > >
> > > This patch preserves already written fields in I2C_ADDR when writing
> > > SLV_ADDR_MAS.
> > >
> > > Signed-off-by: Mårten Lindahl <martenli@axis.com>
> >
> > Looks good. Is there a Fixes-tag we could apply?
> 
> The first commit, 2013 :)
> Fixes: 8a73cd4cfa15 ("i2c: exynos5: add High Speed I2C controller driver")

Thanks! Applied to for-current.


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