Re: [PATCH v2] i2c: designware: add support for pinctrl for recovery

From: Jarkko Nikula
Date: Thu Aug 17 2023 - 04:08:31 EST


Hi

On 8/16/23 12:50, Yann Sionneau wrote:
From: Yann Sionneau <ysionneau@xxxxxxxxx>

Currently if the SoC needs pinctrl to switch the SCL and SDA
from the I2C 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@xxxxxxxxx>
Signed-off-by: Yann Sionneau <ysionneau@xxxxxxxxx>

Tested-by from author is needless. Expectation is that author has tested the patch while not always true :-)

@@ -905,6 +906,15 @@ 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 (IS_ERR(rinfo->pinctrl)) {
+ if (PTR_ERR(rinfo->pinctrl) == -EPROBE_DEFER)
+ return PTR_ERR(rinfo->pinctrl);
+
+ rinfo->pinctrl = NULL;
+ dev_info(dev->dev, "can't get pinctrl, bus recovery might not work\n");

I think dev_dbg() suits better here or is it needed at all? End user may not be able to do anything when sees this in dmesg. I.e. more like development time dev_dbg() information.

Does i2c-core-base.c: i2c_gpio_init_pinctrl_recovery() already do dev_info() print when pinctrl & GPIO are set properly making above also kind of needless?

Jarkko