[PATCH 3/4] i2c: Add option to send start condition after deblocking

[Marek Vasut]

On 2/18/20 8:07 AM, Heiko Schocher wrote:
> Hello Marek,

Hi,

> Am 07.02.2020 um 16:57 schrieb Marek Vasut:
>> Add option to send start condition after deblocking SDA.
>>
>> Signed-off-by: Marek Vasut <marex at denx.de>
>> ---
>>   drivers/i2c/i2c-uclass.c | 23 ++++++++++++++++++++---
>>   include/i2c.h            |  4 +++-
>>   2 files changed, 23 insertions(+), 4 deletions(-)
> 
> Reviewed-by: Heiko Schocher <hs at denx.de>
> 
>> diff --git a/drivers/i2c/i2c-uclass.c b/drivers/i2c/i2c-uclass.c
>> index 86f529241f..e9ec388576 100644
>> --- 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 7c92042c58..059200115a 100644
>> --- 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
> 
> Is there a tab missing? If so I can add it, when applying this patch.

Nope, if you add tab, the formatting starts to look real awful.
You can add a space if you feel very inclined to do so, but it would
still look ugly.