* [PATCH] i2c: exynos5: Preserve high speed master code
@ 2021-02-15 19:03 Mårten Lindahl
2021-02-16 7:51 ` Krzysztof Kozlowski
0 siblings, 1 reply; 6+ messages in thread
From: Mårten Lindahl @ 2021-02-15 19:03 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: kernel, Mårten Lindahl, linux-i2c, linux-arm-kernel,
linux-samsung-soc, linux-kernel
From: Mårten Lindahl <martenli@axis.com>
When the controller 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>
---
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..f2d04c241299 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 |= readl(i2c->regs + HSI2C_ADDR);
+
+ 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
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: exynos5: Preserve high speed master code
2021-02-15 19:03 [PATCH] i2c: exynos5: Preserve high speed master code Mårten Lindahl
@ 2021-02-16 7:51 ` Krzysztof Kozlowski
2021-02-16 22:09 ` Marten Lindahl
0 siblings, 1 reply; 6+ messages in thread
From: Krzysztof Kozlowski @ 2021-02-16 7:51 UTC (permalink / raw)
To: Mårten Lindahl
Cc: kernel, Mårten Lindahl, linux-i2c, linux-arm-kernel,
linux-samsung-soc, linux-kernel
On Mon, Feb 15, 2021 at 08:03:21PM +0100, Mårten Lindahl wrote:
> From: Mårten Lindahl <martenli@axis.com>
>
> When the controller 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.
Are you here describing bug in driver or hardware (the controller?)?
Looking at the code, I think the driver, but description got me
confused.
>
> This patch preserves already written fields in I2C_ADDR when writing
> SLV_ADDR_MAS.
>
> Signed-off-by: Mårten Lindahl <martenli@axis.com>
> ---
> 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..f2d04c241299 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 |= readl(i2c->regs + HSI2C_ADDR);
Any reason why not "|= MASTER_ID(i2c->adap.nr)" here instead of more
expensive IO read? It's quite important because your current code will
bitwise-or old I2C slave address with a new one... This should break
during tests with multiple I2C slave devices, shouldn't it?
On which HW did you test it?
Best regards,
Krzysztof
> +
> + writel(i2c_addr, i2c->regs + HSI2C_ADDR);
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: exynos5: Preserve high speed master code
2021-02-16 7:51 ` Krzysztof Kozlowski
@ 2021-02-16 22:09 ` Marten Lindahl
2021-02-17 8:07 ` Krzysztof Kozlowski
0 siblings, 1 reply; 6+ messages in thread
From: Marten Lindahl @ 2021-02-16 22:09 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: linux-i2c, linux-arm-kernel, linux-samsung-soc, linux-kernel, kernel
Hi Krzysztof!
Thank you for your comments! Please see my reply below.
I will send v2 in a moment.
On Tue, Feb 16, 2021 at 08:51:41AM +0100, Krzysztof Kozlowski wrote:
> On Mon, Feb 15, 2021 at 08:03:21PM +0100, Mårten Lindahl wrote:
> > From: Mårten Lindahl <martenli@axis.com>
> >
> > When the controller 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.
>
> Are you here describing bug in driver or hardware (the controller?)?
> Looking at the code, I think the driver, but description got me
> confused.
>
Yes, it is the driver. I will change.
> >
> > This patch preserves already written fields in I2C_ADDR when writing
> > SLV_ADDR_MAS.
> >
> > Signed-off-by: Mårten Lindahl <martenli@axis.com>
> > ---
> > 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..f2d04c241299 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 |= readl(i2c->regs + HSI2C_ADDR);
>
> Any reason why not "|= MASTER_ID(i2c->adap.nr)" here instead of more
> expensive IO read? It's quite important because your current code will
> bitwise-or old I2C slave address with a new one... This should break
> during tests with multiple I2C slave devices, shouldn't it?
>
You are correct. It is better to use the macro instead, and yes,
safer too. I only have one device that supports high speed i2c, but
I get your point. It could potentially break.
> On which HW did you test it?
I used an Artpec development board as master and INA230EVM board
as slave.
>
> Best regards,
> Krzysztof
>
Best regards
Mårten
>
> > +
> > + writel(i2c_addr, i2c->regs + HSI2C_ADDR);
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: exynos5: Preserve high speed master code
2021-02-16 22:09 ` Marten Lindahl
@ 2021-02-17 8:07 ` Krzysztof Kozlowski
2021-02-17 8:32 ` Jesper Nilsson
0 siblings, 1 reply; 6+ messages in thread
From: Krzysztof Kozlowski @ 2021-02-17 8:07 UTC (permalink / raw)
To: Marten Lindahl
Cc: linux-i2c, linux-arm-kernel, linux-samsung-soc, linux-kernel, kernel
On Tue, Feb 16, 2021 at 11:09:33PM +0100, Marten Lindahl wrote:
> > Any reason why not "|= MASTER_ID(i2c->adap.nr)" here instead of more
> > expensive IO read? It's quite important because your current code will
> > bitwise-or old I2C slave address with a new one... This should break
> > during tests with multiple I2C slave devices, shouldn't it?
> >
>
> You are correct. It is better to use the macro instead, and yes,
> safer too. I only have one device that supports high speed i2c, but
> I get your point. It could potentially break.
>
> > On which HW did you test it?
>
> I used an Artpec development board as master and INA230EVM board
> as slave.
Artpec development board with? What SoC?
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: exynos5: Preserve high speed master code
2021-02-17 8:07 ` Krzysztof Kozlowski
@ 2021-02-17 8:32 ` Jesper Nilsson
2021-02-17 8:43 ` Krzysztof Kozlowski
0 siblings, 1 reply; 6+ messages in thread
From: Jesper Nilsson @ 2021-02-17 8:32 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: Mårten Lindahl, linux-samsung-soc, kernel, linux-i2c,
linux-arm-kernel, linux-kernel
On Wed, Feb 17, 2021 at 09:07:47AM +0100, Krzysztof Kozlowski wrote:
> On Tue, Feb 16, 2021 at 11:09:33PM +0100, Marten Lindahl wrote:
> > > Any reason why not "|= MASTER_ID(i2c->adap.nr)" here instead of more
> > > expensive IO read? It's quite important because your current code will
> > > bitwise-or old I2C slave address with a new one... This should break
> > > during tests with multiple I2C slave devices, shouldn't it?
> > >
> >
> > You are correct. It is better to use the macro instead, and yes,
> > safer too. I only have one device that supports high speed i2c, but
> > I get your point. It could potentially break.
> >
> > > On which HW did you test it?
> >
> > I used an Artpec development board as master and INA230EVM board
> > as slave.
>
> Artpec development board with? What SoC?
The ARTPEC-line of SoC:s are Axis Communications own ASICs, in the latest iteration
it's a Cortex-53 and includes instances of the exynos5 HSI2C ip.
> Best regards,
> Krzysztof
/^JN - Jesper Nilsson
--
Jesper Nilsson -- jesper.nilsson@axis.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: exynos5: Preserve high speed master code
2021-02-17 8:32 ` Jesper Nilsson
@ 2021-02-17 8:43 ` Krzysztof Kozlowski
0 siblings, 0 replies; 6+ messages in thread
From: Krzysztof Kozlowski @ 2021-02-17 8:43 UTC (permalink / raw)
To: Jesper Nilsson
Cc: Mårten Lindahl, linux-samsung-soc, kernel, linux-i2c,
linux-arm-kernel, linux-kernel
On Wed, Feb 17, 2021 at 09:32:11AM +0100, Jesper Nilsson wrote:
> On Wed, Feb 17, 2021 at 09:07:47AM +0100, Krzysztof Kozlowski wrote:
> > On Tue, Feb 16, 2021 at 11:09:33PM +0100, Marten Lindahl wrote:
> > > > Any reason why not "|= MASTER_ID(i2c->adap.nr)" here instead of more
> > > > expensive IO read? It's quite important because your current code will
> > > > bitwise-or old I2C slave address with a new one... This should break
> > > > during tests with multiple I2C slave devices, shouldn't it?
> > > >
> > >
> > > You are correct. It is better to use the macro instead, and yes,
> > > safer too. I only have one device that supports high speed i2c, but
> > > I get your point. It could potentially break.
> > >
> > > > On which HW did you test it?
> > >
> > > I used an Artpec development board as master and INA230EVM board
> > > as slave.
> >
> > Artpec development board with? What SoC?
>
> The ARTPEC-line of SoC:s are Axis Communications own ASICs, in the latest iteration
> it's a Cortex-53 and includes instances of the exynos5 HSI2C ip.
Cool! Good to see that this code is re-used. :)
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 6+ messages in thread
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2021-02-15 19:03 [PATCH] i2c: exynos5: Preserve high speed master code Mårten Lindahl
2021-02-16 7:51 ` Krzysztof Kozlowski
2021-02-16 22:09 ` Marten Lindahl
2021-02-17 8:07 ` Krzysztof Kozlowski
2021-02-17 8:32 ` Jesper Nilsson
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