[PATCH] i2c: designware: add support for pinctrl for recovery

[PATCH] i2c: designware: add support for pinctrl for recovery

[Yann Sionneau]

From: Yann Sionneau <ysionneau@kalray.eu>

Currently if the SoC needs pinctrl to switch the scl and sda
from hw function to gpio function, the recovery won't work.

scl-gpio = <>;
sda-gpio = <>;

Are not enough for some SoCs to have a working recovery.
Some need:

scl-gpio = <>;
sda-gpio = <>;
pinctrl-names = "default", "recovery";
pinctrl-0 = <&i2c_pins_hw>;
pinctrl-1 = <&i2c_pins_gpio>;

The driver was not filling rinfo->pinctrl with the device node
pinctrl data which is needed by generic recovery code.

Tested-by: Yann Sionneau <ysionneau@kalray.eu>
Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>
---
 drivers/i2c/busses/i2c-designware-master.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index bee296cd74e6..b55c19b2515a 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -20,6 +20,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/reset.h>
+#include <linux/pinctrl/consumer.h>
 
 #include "i2c-designware-core.h"
 
@@ -841,6 +842,12 @@ static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
 		return PTR_ERR(gpio);
 	rinfo->sda_gpiod = gpio;
 
+	rinfo->pinctrl = devm_pinctrl_get(dev->dev);
+	if (!rinfo->pinctrl || IS_ERR(rinfo->pinctrl)) {
+		rinfo->pinctrl = NULL;
+		dev_info(dev->dev, "can't get pinctrl, bus recovery might not work\n");
+	}
+
 	rinfo->recover_bus = i2c_generic_scl_recovery;
 	rinfo->prepare_recovery = i2c_dw_prepare_recovery;
 	rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
-- 
2.17.1

Re: [PATCH] i2c: designware: add support for pinctrl for recovery

[Andy Shevchenko]

On Fri, Aug 11, 2023 at 03:52:01PM +0200, Yann Sionneau wrote:
> From: Yann Sionneau <ysionneau@kalray.eu>
> 
> Currently if the SoC needs pinctrl to switch the scl and sda

SCL
SDA

> from hw function to gpio function, the recovery won't work.

from the I2C

GPIO

> scl-gpio = <>;
> sda-gpio = <>;
> 
> Are not enough for some SoCs to have a working recovery.
> Some need:
> 
> scl-gpio = <>;
> sda-gpio = <>;
> pinctrl-names = "default", "recovery";
> pinctrl-0 = <&i2c_pins_hw>;
> pinctrl-1 = <&i2c_pins_gpio>;
> 
> The driver was not filling rinfo->pinctrl with the device node
> pinctrl data which is needed by generic recovery code.

...

>  #include <linux/pm_runtime.h>
>  #include <linux/regmap.h>
>  #include <linux/reset.h>
> +#include <linux/pinctrl/consumer.h>

Keep this in order.

...

> +	rinfo->pinctrl = devm_pinctrl_get(dev->dev);
> +	if (!rinfo->pinctrl || IS_ERR(rinfo->pinctrl)) {

It's not possible to have it NULL, why a dead code?

> +		rinfo->pinctrl = NULL;
> +		dev_info(dev->dev, "can't get pinctrl, bus recovery might not work\n");
> +	}

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] i2c: designware: add support for pinctrl for recovery

[Yann Sionneau]

Le 11/08/2023 à 16:36, Andy Shevchenko a écrit :

> On Fri, Aug 11, 2023 at 03:52:01PM +0200, Yann Sionneau wrote:
>> From: Yann Sionneau <ysionneau@kalray.eu>
>>
>> Currently if the SoC needs pinctrl to switch the scl and sda
> SCL
> SDA
ack
>
>> from hw function to gpio function, the recovery won't work.
> from the I2C
>
> GPIO
ack
>>   #include <linux/pm_runtime.h>
>>   #include <linux/regmap.h>
>>   #include <linux/reset.h>
>> +#include <linux/pinctrl/consumer.h>
> Keep this in order.
Ok
>
> ...
>
>> +	rinfo->pinctrl = devm_pinctrl_get(dev->dev);
>> +	if (!rinfo->pinctrl || IS_ERR(rinfo->pinctrl)) {
> It's not possible to have it NULL, why a dead code?

Woops, I thought NULL was possible, you are right: it's impossible.

I will also add handling of -EPROBE_DEFER error.

Thanks for the review.

Regards,

-- 

Yann