> > From the viewpoint of a GPIO consumer, we don't care the base GPIO number.
> > That is required when a GPIO controller is added.
> > Just check '/sys/kernel/debug/gpio' and use available GPIOs for LEDs.
>
> Hmm. I'm using leds-gpio, and it certainly does seem to care about GPIO
> numbers. As a point of reference, here's what I'm doing to set up my
> drive activity LEDs:
>
> #define N5550_ICH_GPIO_BASE 195
>
> #define N5550_DISK_ACT_0_GPIO (N5550_ICH_GPIO_BASE + 0)
> #define N5550_DISK_ACT_1_GPIO (N5550_ICH_GPIO_BASE + 2)
> #define N5550_DISK_ACT_2_GPIO (N5550_ICH_GPIO_BASE + 3)
> #define N5550_DISK_ACT_3_GPIO (N5550_ICH_GPIO_BASE + 4)
> #define N5550_DISK_ACT_4_GPIO (N5550_ICH_GPIO_BASE + 5)
>
> static struct gpio_led n5550_disk_act_leds[5] = {
> {
> .name = "n5550:green:disk-act-0",
> .default_trigger = "thecus-ahci-0",
> .gpio = N5550_DISK_ACT_0_GPIO,
> .active_low = 1,
> .default_state = LEDS_GPIO_DEFSTATE_OFF,
> },
> {
> .name = "n5550:green:disk-act-1",
> .default_trigger = "thecus-ahci-1",
> .gpio = N5550_DISK_ACT_1_GPIO,
> .active_low = 1,
> .default_state = LEDS_GPIO_DEFSTATE_OFF,
> },
> {
> .name = "n5550:green:disk-act-2",
> .default_trigger = "thecus-ahci-2",
> .gpio = N5550_DISK_ACT_2_GPIO,
> .active_low = 1,
> .default_state = LEDS_GPIO_DEFSTATE_OFF,
> },
> {
> .name = "n5550:green:disk-act-3",
> .default_trigger = "thecus-ahci-3",
> .gpio = N5550_DISK_ACT_3_GPIO,
> .active_low = 1,
> .default_state = LEDS_GPIO_DEFSTATE_OFF,
> },
> {
> .name = "n5550:green:disk-act-4",
> .default_trigger = "thecus-ahci-4",
> .gpio = N5550_DISK_ACT_4_GPIO,
> .active_low = 1,
> .default_state = LEDS_GPIO_DEFSTATE_OFF,
> },
> };
>
> As you can see, every LED has a GPIO number (.gpio), which comes from
> the chip's GPIO base, and that number gets hardcoded into the setup
> code. If the ich_gpio driver ever "dynamically" selects a base other
> than 195, the LEDs won't work.
It sounds you want to make the LED platform data flexible, right?
> I just seems very fragile, and I can't help thinking that there must be
> a better way. Maybe a module parameter ...
If you can use .dtb file in your system, it may be possible to use just offset
values with GPIO controller, ich_gpio. Then, no hardcoded GPIO is required.
For example, leds-gpio can be created with the DT below.
leds {
compatible = "gpio-leds";
hdd0 {
label = " n5550:green:disk-act-0";
gpios = <&ich_gpio 0 1>; /* offset 0, active low */
linux,default-trigger = " thecus-ahci-0";
default-state = "off";
};
.
.
.
hdd4 {
label = " n5550:green:disk-act-4";
gpios = <&ich_gpio 4 1>; /* offset 4, active low */
linux,default-trigger = " thecus-ahci-4";
default-state = "off";
};
};
Then, we don't care the base number of the ich_gpio controller.
However, ich_gpio driver should support the GPIO DT structure.
I've not checked it yet.
Best regards,
Milo
--
To unsubscribe from this list: send the line "unsubscribe linux-leds" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
