Re: [PATCH 2/2] LEDS: tca6502: add device-tree support for GPIO configuration.

[Bryan Wu <cooloney@gmail.com>]

On Thu, Oct 31, 2013 at 7:41 PM, NeilBrown <neilb@suse.de> wrote:
>

[PATCH 2/2] LEDS: tca6502: add device-tree support for GPIO configuration.

I think it should be tca6507, right? Typo?

For other parts of this patch, I'm OK for them.

And just a quick scan of the leds-tca6507, I found bunch of typos in
the comments:

* An led-tca6507 device must be provided with platform data.  This data
 * lists for each output: the name, default trigger, and whether the signal
 * is being used as a GPiO rather than an led.  'struct led_plaform_data'

Can we unify to use GPIO and gpio?

 * is used for this.  If 'name' is NULL, the output isn't used.  If 'flags'
 * is TCA6507_MAKE_CPIO, the output is a GPO.

Here should be TCA6507_MAKE_GPIO and GPIO instead of GPO

 * The "struct led_platform_data" can be embedded in a
 * "struct tca6507_platform_data" which adds a 'gpio_base' for the GPiOs,
 * and a 'setup' callback which is called once the GPiOs are available.

Don't use GPiO, please.

Could you please review the code again and submit a cleanup patch to
fix those typos?

Thanks,
-Bryan


> 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.
>
> Signed-off-by: NeilBrown <neilb@suse.de>
>
> 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", &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;
>  }