diff options
Diffstat (limited to 'drivers/i2c/mxc_i2c.c')
| -rw-r--r-- | drivers/i2c/mxc_i2c.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c index 9999d9fe5e..5420afbc8e 100644 --- a/drivers/i2c/mxc_i2c.c +++ b/drivers/i2c/mxc_i2c.c @@ -354,9 +354,10 @@ int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus) 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; @@ -380,8 +381,22 @@ int i2c_idle_bus(struct mxc_i2c_bus *i2c_bus) 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); |