int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus)
{
struct udevice *bus = i2c_bus->bus;
+ struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
struct gpio_desc *scl_gpio = &i2c_bus->scl_gpio;
struct gpio_desc *sda_gpio = &i2c_bus->sda_gpio;
- int sda, scl;
+ int sda, scl, idle_sclks;
int i, ret = 0;
ulong elapsed, start_time;
if ((sda & scl) == 1)
goto exit; /* Bus is idle already */
+ /*
+ * In most cases it is just enough to generate 8 + 1 SCLK
+ * clocks to recover I2C slave device from 'stuck' state
+ * (when for example SW reset was performed, in the middle of
+ * I2C transmission).
+ *
+ * However, there are devices which send data in packets of
+ * N bytes (N > 1). In such case we do need N * 8 + 1 SCLK
+ * clocks.
+ */
+ idle_sclks = 8 + 1;
+
+ if (i2c->max_transaction_bytes > 0)
+ idle_sclks = i2c->max_transaction_bytes * 8 + 1;
/* Send high and low on the SCL line */
- for (i = 0; i < 9; i++) {
+ for (i = 0; i < idle_sclks; i++) {
dm_gpio_set_dir_flags(scl_gpio, GPIOD_IS_OUT);
dm_gpio_set_value(scl_gpio, 0);
udelay(50);