On Mon, 17 Nov 2008, Richard Purdie wrote: > On Fri, 2008-10-24 at 16:09 -0700, Trent Piepho wrote: >> + if (template->keep_state) >> + state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low; >> + else >> + state = template->default_state; >> >> state = of_get_property(child, "default-state", NULL); >> led.default_state = state && !strcmp(state, "on"); >> + led.keep_state = state && !strcmp(state, "keep"); >> >> +++ b/include/linux/leds.h >> @@ -138,7 +138,8 @@ struct gpio_led { >> const char *default_trigger; >> unsigned gpio; >> u8 active_low; >> - u8 default_state; >> + u8 default_state; /* 0 = off, 1 = on */ >> + u8 keep_state; /* overrides default_state */ >> }; > > How about something simpler here, just make default state have three > different values - "keep", "on" and "off"? I'm not keen on having two > different state variables like this.
I thought of that, but it ends up being more complex. Instead of just using: static const struct gpio_led myled = { .name = "something", .keep_state = 1, } You'd do something like this: .default_state = LEDS_GPIO_DEFSTATE_KEEP, Is that better? The constants for on/off/keep are one more thing you have to look-up and remember when defining leds. The code in the leds-gpio driver ends up getting more complex to deal with one tristate vs two booleans. This is a patch to change to a tristate. I don't think it's an improvement. More symbols defined, more code, extra stuff to remember when defining leds, and removing the field from struct gpio_led doesn't make it smaller due to padding. diff --git a/drivers/leds/leds-gpio.c b/drivers/leds/leds-gpio.c index bb2a234..8a7303c 100644 --- a/drivers/leds/leds-gpio.c +++ b/drivers/leds/leds-gpio.c @@ -92,10 +92,10 @@ static int __devinit create_gpio_led(const struct gpio_led *template, led_dat->cdev.blink_set = gpio_blink_set; } led_dat->cdev.brightness_set = gpio_led_set; - if (template->keep_state) + if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) state = !!gpio_get_value(led_dat->gpio) ^ led_dat->active_low; else - state = template->default_state; + state = (template->default_state == LEDS_GPIO_DEFSTATE_ON); led_dat->cdev.brightness = state ? LED_FULL : LED_OFF; gpio_direction_output(led_dat->gpio, led_dat->active_low ^ state); @@ -268,8 +268,15 @@ static int __devinit of_gpio_leds_probe(struct of_device *ofdev, led.default_trigger = of_get_property(child, "linux,default-trigger", NULL); state = of_get_property(child, "default-state", NULL); - led.default_state = state && !strcmp(state, "on"); - led.keep_state = state && !strcmp(state, "keep"); + if (state) { + if (!strcmp(state, "keep")) { + led.default_state = LEDS_GPIO_DEFSTATE_KEEP; + } else if(!strcmp(state, "on")) { + led.default_state = LEDS_GPIO_DEFSTATE_ON; + } else { + led.default_state = LEDS_GPIO_DEFSTATE_OFF; + } + } ret = create_gpio_led(&led, &pdata->led_data[pdata->num_leds++], &ofdev->dev, NULL); diff --git a/include/linux/leds.h b/include/linux/leds.h index c51b625..f4a125c 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -138,9 +138,12 @@ struct gpio_led { const char *default_trigger; unsigned gpio; u8 active_low; - u8 default_state; /* 0 = off, 1 = on */ - u8 keep_state; /* overrides default_state */ + u8 default_state; + /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */ }; +#define LEDS_GPIO_DEFSTATE_OFF 0 +#define LEDS_GPIO_DEFSTATE_ON 1 +#define LEDS_GPIO_DEFSTATE_KEEP 2 struct gpio_led_platform_data { int num_leds; _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev