2019-05-16 22:42:15

by Kun Yi

Subject: [PATCH 2/2] ledtrig-gpio: 0 is a valid GPIO number

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.

Signed-off-by: Kun Yi <[email protected]>
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

2019-05-17 08:00:48

by Uwe Kleine-König

Subject: Re: [PATCH 2/2] ledtrig-gpio: 0 is a valid GPIO number

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 <[email protected]>
> 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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