2023-08-11 14:19:01

by Yann Sionneau

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

From: Yann Sionneau <[email protected]>

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 <[email protected]>
Signed-off-by: Yann Sionneau <[email protected]>
---
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

2023-08-11 15:07:42

by Andy Shevchenko

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

On Fri, Aug 11, 2023 at 03:52:01PM +0200, Yann Sionneau wrote:
> From: Yann Sionneau <[email protected]>
>
> 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