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

From: Mårten Lindahl <redacted>

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 <redacted>
---
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


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On Tue, Feb 16, 2021 at 11:25:38PM +0100, Mårten Lindahl wrote:

From: Mårten Lindahl <redacted>

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 <redacted>
---
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

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On Tue, Feb 16, 2021 at 11:25:38PM +0100, Mårten Lindahl wrote:

From: Mårten Lindahl <redacted>

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 <redacted>

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

On Fri, 26 Feb 2021 at 11:34, Wolfram Sang [off-list ref] wrote:

On Tue, Feb 16, 2021 at 11:25:38PM +0100, Mårten Lindahl wrote:

quoted

From: Mårten Lindahl <redacted>

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 <redacted>

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

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linux-arm-kernel@lists.infradead.org
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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 [off-list ref] wrote:

quoted

On Tue, Feb 16, 2021 at 11:25:38PM +0100, Mårten Lindahl wrote:

quoted

From: Mårten Lindahl <redacted>

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 <redacted>

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.