[PATCH v4] Currently if the SoC needs pinctrl to switch the SCL and SDA from the I2C function to GPI

Yann Sionneau
2023-08-22T13:11:33Z

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.

Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>
---
V3 -> V4:
* Replace `else if` by simply `if`.

V2 -> V3:
* put back 'if (!rinfo->pinctrl)' test since devm_pinctrl_get()
can return NULL if CONFIG_PINCTRL is not set.
* print an error msg when devm_pinctrl_get() returns an error that
is not -EPROBE_DEFER.
* print a dbg msg if devm_pinctrl_get() return NULL.

V1 -> V2:
* remove the unnecessary 'if (!rinfo->pinctrl)' test
* test if return is -EPROBE_DEFER, in that case, return it.
* Reword the commit message according to review

drivers/i2c/busses/i2c-designware-master.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index b720fcc5c10a..4a9fd49c283d 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -17,6 +17,7 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/reset.h>
@@ -855,6 +856,17 @@ 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_err(dev->dev, "getting pinctrl info failed: bus recovery might not work\n");
+ }
+ if (!rinfo->pinctrl)
+ dev_dbg(dev->dev, "pinctrl is disabled, 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