i2c: add 'set_sda' to bus_recovery_info

This will be needed when we want to create STOP conditions, too, later.
Create the needed fields and populate them for the GPIO case if the GPIO
is set to output.
Tested-by: NPhil Reid <preid@electromag.com.au>
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

drivers/i2c/i2c-core-base.c

@@ -147,6 +147,11 @@ static int get_sda_gpio_value(struct i2c_adapter *adap)
 	return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod);
 }
 
+static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
+{
+	gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
+}
+
 /*
  * We are generating clock pulses. ndelay() determines durating of clk pulses.
  * We will generate clock with rate 100 KHz and so duration of both clock levels
@@ -225,8 +230,12 @@ static void i2c_init_recovery(struct i2c_adapter *adap)
 	if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) {
 		bri->get_scl = get_scl_gpio_value;
 		bri->set_scl = set_scl_gpio_value;
-		if (bri->sda_gpiod)
+		if (bri->sda_gpiod) {
 			bri->get_sda = get_sda_gpio_value;
+			/* FIXME: add proper flag instead of '0' once available */
+			if (gpiod_get_direction(bri->sda_gpiod) == 0)
+				bri->set_sda = set_sda_gpio_value;
+		}
 		return;
 	}
 

include/linux/i2c.h

@@ -551,6 +551,9 @@ struct i2c_timings {
  * @get_sda: This gets current value of SDA line. Optional for generic SCL
  *      recovery. Populated internally, if sda_gpio is a valid GPIO, for generic
  *      GPIO recovery.
+ * @set_sda: This sets/clears the SDA line. Optional for generic SCL recovery.
+ *	Populated internally, if sda_gpio is a valid GPIO, for generic GPIO
+ *	recovery.
  * @prepare_recovery: This will be called before starting recovery. Platform may
  *	configure padmux here for SDA/SCL line or something else they want.
  * @unprepare_recovery: This will be called after completing recovery. Platform
@@ -564,6 +567,7 @@ struct i2c_bus_recovery_info {
 	int (*get_scl)(struct i2c_adapter *adap);
 	void (*set_scl)(struct i2c_adapter *adap, int val);
 	int (*get_sda)(struct i2c_adapter *adap);
+	void (*set_sda)(struct i2c_adapter *adap, int val);
 
 	void (*prepare_recovery)(struct i2c_adapter *adap);
 	void (*unprepare_recovery)(struct i2c_adapter *adap);