[PATCH 2/2] led: Add dts property to specify blinking of the led

[Mikhail Kshevetskiy]

On 7/3/24 12:08, Simon Glass wrote:
> Hi Mikhail,
>
> On Wed, 3 Jul 2024 at 02:02, Mikhail Kshevetskiy
> <mikhail.kshevetskiy at iopsys.eu> wrote:
>> From: Michael Polyntsov <michael.polyntsov at iopsys.eu>
>>
>> The standard property
>>
>>     linux,default-trigger = "pattern";
>>
>> used to get an effect. No blinking parameters can be set yet.
>>
>> Signed-off-by: Michael Polyntsov <michael.polyntsov at iopsys.eu>
>> Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
>> ---
>>  drivers/led/led-uclass.c | 34 ++++++++++++++++++++++++++++++----
>>  1 file changed, 30 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/led/led-uclass.c b/drivers/led/led-uclass.c
>> index d021c3bbf20..78d1a3d152b 100644
>> --- a/drivers/led/led-uclass.c
>> +++ b/drivers/led/led-uclass.c
>> @@ -190,6 +190,9 @@ static int led_post_bind(struct udevice *dev)
>>  {
>>         struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
>>         const char *default_state;
>> +#ifdef CONFIG_LED_BLINK
>> +       const char *trigger;
> It looks like this is not used, so you can drop it and use a local
> variable here?

Unfortunately no, see below.

>
>> +#endif
>>
>>         if (!uc_plat->label)
>>                 uc_plat->label = dev_read_string(dev, "label");
>> @@ -210,6 +213,13 @@ static int led_post_bind(struct udevice *dev)
>>         else
>>                 return 0;
>>
>> +#ifdef CONFIG_LED_BLINK
> if (IS_ENABLED(CONFIG_LED_BLINK)

This is not so easy. The definition of LEDST_BLINK depends on
CONFIG_LED_BLINK, thus this code will not compile if  CONFIG_LED_BLINK
is not defined. We can define LEDST_BLINK unconditionally, but it will
cause an issue in the cmd/led.c.

>> +       trigger = dev_read_string(dev, "linux,default-trigger");
>> +       if (trigger && !strncmp(trigger, "pattern", 7)) {
>> +               uc_plat->default_state = LEDST_BLINK;
>> +       }
> No {} around single lines. You can use patman to send patches and it
> will check this for you (I hope!).
>
>> +#endif
>> +
>>         /*
>>          * In case the LED has default-state DT property, trigger
>>          * probe() to configure its default state during startup.
>> @@ -222,12 +232,28 @@ static int led_post_bind(struct udevice *dev)
>>  static int led_post_probe(struct udevice *dev)
>>  {
>>         struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
>> +       int rc = 0;
>>
>> -       if (uc_plat->default_state == LEDST_ON ||
>> -           uc_plat->default_state == LEDST_OFF)
>> -               led_set_state(dev, uc_plat->default_state);
>> +       switch (uc_plat->default_state) {
>> +       case LEDST_ON:
>> +       case LEDST_OFF:
>> +               rc = led_set_state(dev, uc_plat->default_state);
>> +               break;
>> +#ifdef CONFIG_LED_BLINK
>> +       case LEDST_BLINK: {
> Here again you can use if IS_ENABLED(CONFIG_LED_BLINK) inside the case
> which should produce very similar code size, hopefully the same.
Do you suggest an if inside the handling of "default:" case?
Also see above notes about dependency of LEDST_BLINK on CONFIG_LED_BLINK.
>> +               const int default_period_ms = 1000;
>>
>> -       return 0;
>> +               rc = led_set_period(dev, default_period_ms);
>> +               if (rc == 0)
>> +                       rc = led_set_state(dev, uc_plat->default_state);
>> +               break;
>> +       }
>> +#endif
>> +       default:
>> +               break;
>> +       }
>> +
>> +       return rc;
>>  }
>>
>>  UCLASS_DRIVER(led) = {
>> --
>> 2.39.2
>>
> Regards,
> Simon