Re: [PATCH 2/2] ledtrig-gpio: 0 is a valid GPIO number
From: Uwe Kleine-König
Date: Fri May 17 2019 - 02:29:47 EST
On Thu, May 16, 2019 at 02:42:09PM -0700, Kun Yi wrote:
> GPIO number 0 is a valid case to handle. Use -1 as initial value
> and use gpio_is_valid() to determine validity of the GPIO
> number.
I think it's more sensible to convert to gpiod instead.
Best regards
Uwe
> Signed-off-by: Kun Yi <kunyi@xxxxxxxxxx>
> Change-Id: I4a29f98b237fd0d8ba4dd2a28219d4429f2ccfff
> ---
> drivers/leds/trigger/ledtrig-gpio.c | 16 +++++-----------
> 1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/leds/trigger/ledtrig-gpio.c b/drivers/leds/trigger/ledtrig-gpio.c
> index f6d50e031492..48d8ef8538bd 100644
> --- a/drivers/leds/trigger/ledtrig-gpio.c
> +++ b/drivers/leds/trigger/ledtrig-gpio.c
> @@ -22,7 +22,7 @@ struct gpio_trig_data {
>
> unsigned desired_brightness; /* desired brightness when led is on */
> unsigned inverted; /* true when gpio is inverted */
> - unsigned gpio; /* gpio that triggers the leds */
> + int gpio; /* gpio that triggers the leds */
> };
>
> static irqreturn_t gpio_trig_irq(int irq, void *_led)
> @@ -114,13 +114,12 @@ static ssize_t gpio_trig_gpio_show(struct device *dev,
> {
> struct gpio_trig_data *gpio_data = led_trigger_get_drvdata(dev);
>
> - return sprintf(buf, "%u\n", gpio_data->gpio);
> + return sprintf(buf, "%d\n", gpio_data->gpio);
> }
>
> -static inline void free_used_gpio_if_valid(unsigned int gpio,
> - struct led_classdev *led)
> +static inline void free_used_gpio_if_valid(int gpio, struct led_classdev *led)
> {
> - if (gpio == 0)
> + if (!gpio_is_valid(gpio))
> return;
>
> free_irq(gpio_to_irq(gpio), led);
> @@ -144,12 +143,6 @@ static ssize_t gpio_trig_gpio_store(struct device *dev,
> if (gpio_data->gpio == gpio)
> return n;
>
> - if (!gpio) {
> - free_used_gpio_if_valid(gpio_data->gpio, led);
> - gpio_data->gpio = 0;
> - return n;
> - }
> -
> ret = gpio_request(gpio, "ledtrig-gpio");
> if (ret) {
> dev_err(dev, "gpio_request failed with error %d\n", ret);
> @@ -195,6 +188,7 @@ static int gpio_trig_activate(struct led_classdev *led)
> return -ENOMEM;
>
> gpio_data->led = led;
> + gpio_data->gpio = -1;
> led_set_trigger_data(led, gpio_data);
>
> return 0;
> --
> 2.21.0.1020.gf2820cf01a-goog
>
>
--
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