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authorCodrin Ciubotariu <codrin.ciubotariu@microchip.com>2020-08-04 12:59:24 +0300
committerWolfram Sang <wsa@kernel.org>2020-08-05 12:52:27 +0300
commit75820314de26b00aaea0d0e79269c0d17914c5c4 (patch)
tree95465e05785b86ace95b5dc94cec2c43ee92db24 /include/linux/i2c.h
parentdb36e827d8762eaa6aacd2c918a55ac487aa2501 (diff)
downloadlinux-75820314de26b00aaea0d0e79269c0d17914c5c4.tar.xz
i2c: core: add generic I2C GPIO recovery
Multiple I2C bus drivers use similar bindings to obtain information needed for I2C recovery. For example, for platforms using device-tree, the properties look something like this: &i2c { ... pinctrl-names = "default", "gpio"; pinctrl-0 = <&pinctrl_i2c_default>; pinctrl-1 = <&pinctrl_i2c_gpio>; sda-gpios = <&pio 0 GPIO_ACTIVE_HIGH>; scl-gpios = <&pio 1 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; ... } For this reason, we can add this common initialization in the core. This way, other I2C bus drivers will be able to support GPIO recovery just by providing a pointer to platform's pinctrl and calling i2c_recover_bus() when SDA is stuck low. Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com> [wsa: inverted one logic for better readability, minor update to kdoc] Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'include/linux/i2c.h')
-rw-r--r--include/linux/i2c.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 8ea9c3f86dba..d387d3786429 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -606,6 +606,14 @@ struct i2c_timings {
* may configure padmux here for SDA/SCL line or something else they want.
* @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
* @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
+ * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
+ * Optional.
+ * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
+ * to the I2C bus. Optional. Populated internally for GPIO recovery, if
+ * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
+ * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
+ * GPIOs. Optional. Populated internally for GPIO recovery, if this state
+ * is called "gpio" or "recovery" and pinctrl is valid.
*/
struct i2c_bus_recovery_info {
int (*recover_bus)(struct i2c_adapter *adap);
@@ -622,6 +630,9 @@ struct i2c_bus_recovery_info {
/* gpio recovery */
struct gpio_desc *scl_gpiod;
struct gpio_desc *sda_gpiod;
+ struct pinctrl *pinctrl;
+ struct pinctrl_state *pins_default;
+ struct pinctrl_state *pins_gpio;
};
int i2c_recover_bus(struct i2c_adapter *adap);