i2c: Add option to send start condition after deblocking

Add option to send start condition after deblocking SDA.

Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Heiko Schocher <hs@denx.de>

diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c
index 86f529241f4a89d03125a3754ad9e480bf7a9adf..e9ec3885767a970cb3961705bc5221166d9e7c46 100644 (file)
--- a/drivers/i2c/i2c-uclass.c
+++ b/drivers/i2c/i2c-uclass.c
@@ -504,9 +504,10 @@ static int i2c_gpio_get_pin(struct gpio_desc *pin)
 int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin,
                          struct gpio_desc *scl_pin,
                          unsigned int scl_count,
+                         unsigned int start_count,
                          unsigned int delay)
 {
-       int ret = 0;
+       int i, ret = -EREMOTEIO;
 
        i2c_gpio_set_pin(sda_pin, 1);
        i2c_gpio_set_pin(scl_pin, 1);
@@ -518,8 +519,24 @@ int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin,
                udelay(delay);
                i2c_gpio_set_pin(scl_pin, 0);
                udelay(delay);
-               if (i2c_gpio_get_pin(sda_pin))
+               if (i2c_gpio_get_pin(sda_pin)) {
+                       ret = 0;
                        break;
+               }
+       }
+
+       if (!ret && start_count) {
+               for (i = 0; i < start_count; i++) {
+                       /* Send start condition */
+                       udelay(delay);
+                       i2c_gpio_set_pin(sda_pin, 1);
+                       udelay(delay);
+                       i2c_gpio_set_pin(scl_pin, 1);
+                       udelay(delay);
+                       i2c_gpio_set_pin(sda_pin, 0);
+                       udelay(delay);
+                       i2c_gpio_set_pin(scl_pin, 0);
+               }
        }
 
        /* Then, send I2C stop */
@@ -562,7 +579,7 @@ static int i2c_deblock_gpio(struct udevice *bus)
                goto out_no_pinctrl;
        }
 
-       ret0 = i2c_deblock_gpio_loop(&gpios[PIN_SDA], &gpios[PIN_SCL], 9, 5);
+       ret0 = i2c_deblock_gpio_loop(&gpios[PIN_SDA], &gpios[PIN_SCL], 9, 0, 5);
 
        ret = pinctrl_select_state(bus, "default");
        if (ret) {

diff --git a/include/i2c.h b/include/i2c.h
index 7c92042c5840fca5f67a7607aefdfbc74057dc71..059200115a8e030958350e439c3dc0f37e38c0dd 100644 (file)
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -339,12 +339,14 @@ int i2c_deblock(struct udevice *bus);
  * @sda_pin:   SDA GPIO
  * @scl_pin:   SCL GPIO
  * @scl_count: Number of SCL clock cycles generated to deblock SDA
+ * @start_count:Number of I2C start conditions sent after deblocking SDA
  * @delay:     Delay between SCL clock line changes
  * @return 0 if OK, -ve on error
  */
 struct gpio_desc;
 int i2c_deblock_gpio_loop(struct gpio_desc *sda_pin, struct gpio_desc *scl_pin,
-                         unsigned int scl_count, unsigned int delay);
+                         unsigned int scl_count, unsigned int start_count,
+                         unsigned int delay);
 
 /**
  * struct dm_i2c_ops - driver operations for I2C uclass