On Fri, Nov 01, 2013 at 02:41:20AM +0000, NeilBrown wrote:
>
> The 7 lines driven by the TCA6507 can either drive LEDs or act as output-only
> GPIOs.
>
> To make this distinction in devicetree we use the "compatible" property.
>
> If the device attached to a line is "compatible" with "gpio", we treat it
> like a GPIO. If it is "compatible" with "led" (or if no "compatible" value
> is set) we treat it like an LED.
I'm nto sure I understand the purpose of this.
Are these lines all GPIOs, some of which happen to by attached to LEDs?
If so, why is handlnig the device as a gpio-controller and using the
gpio-leds binding not sufficient?
THanksm
Mark.
>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
>
> diff --git a/Documentation/devicetree/bindings/leds/tca6507.txt b/Documentation/devicetree/bindings/leds/tca6507.txt
> index 80ff3dfb1f32..d7221b84987c 100644
> --- a/Documentation/devicetree/bindings/leds/tca6507.txt
> +++ b/Documentation/devicetree/bindings/leds/tca6507.txt
> @@ -2,6 +2,13 @@ LEDs connected to tca6507
>
> Required properties:
> - compatible : should be : "ti,tca6507".
> +- #address-cells: must be 1
> +- #size-cells: must be 0
> +- reg: typically 0x45.
> +
> +Optional properties:
> +- gpio-controller: allows lines to be used as output-only GPIOs.
> +- #gpio-cells: if present, must be 0.
>
> Each led is represented as a sub-node of the ti,tca6507 device.
>
> @@ -10,6 +17,7 @@ LED sub-node properties:
> - reg : number of LED line (could be from 0 to 6)
> - linux,default-trigger : (optional)
> see Documentation/devicetree/bindings/leds/common.txt
> +- compatible: either "led" (the default) or "gpio".
>
> Examples:
>
> @@ -19,6 +27,9 @@ tca6507@45 {
> #size-cells = <0>;
> reg = <0x45>;
>
> + gpio-controller;
> + #gpio-cells = <2>;
> +
> led0: red-aux@0 {
> label = "red:aux";
> reg = <0x0>;
> @@ -29,5 +40,10 @@ tca6507@45 {
> reg = <0x5>;
> linux,default-trigger = "default-on";
> };
> +
> + wifi-reset@6 {
> + reg = <0x6>;
> + compatible = "gpio";
> + };
> };
>
> diff --git a/drivers/leds/leds-tca6507.c b/drivers/leds/leds-tca6507.c
> index f5063f447463..93a2b1759054 100644
> --- a/drivers/leds/leds-tca6507.c
> +++ b/drivers/leds/leds-tca6507.c
> @@ -638,6 +638,9 @@ static int tca6507_probe_gpios(struct i2c_client *client,
> tca->gpio.direction_output = tca6507_gpio_direction_output;
> tca->gpio.set = tca6507_gpio_set_value;
> tca->gpio.dev = &client->dev;
> +#ifdef CONFIG_OF_GPIO
> + tca->gpio.of_node = of_node_get(client->dev.of_node);
> +#endif
> err = gpiochip_add(&tca->gpio);
> if (err) {
> tca->gpio.ngpio = 0;
> @@ -696,6 +699,8 @@ tca6507_led_dt_init(struct i2c_client *client)
> led.default_trigger =
> of_get_property(child, "linux,default-trigger", NULL);
> led.flags = 0;
> + if (of_property_match_string(child, "compatible", "gpio") >= 0)
> + led.flags |= TCA6507_MAKE_GPIO;
> ret = of_property_read_u32(child, "reg", ®);
> if (ret != 0 || reg < 0 || reg >= NUM_LEDS)
> continue;
> @@ -709,6 +714,7 @@ tca6507_led_dt_init(struct i2c_client *client)
>
> pdata->leds.leds = tca_leds;
> pdata->leds.num_leds = NUM_LEDS;
> + pdata->gpio_base = -1;
>
> return pdata;
> }
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