Re: [PATCH v3 3/3] input: pwm-beeper: add devicetree bindings to set volume levels

From: Dmitry Torokhov
Date: Thu Jan 19 2017 - 16:30:58 EST


On Thu, Jan 19, 2017 at 04:24:10PM +0100, Frieder Schrempf wrote:
> This patch adds the devicetree bindings to set the volume levels
> and the default volume level.
>
> Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxx>
> ---
> Changes in v3:
> - none
>
> drivers/input/misc/pwm-beeper.c | 49 ++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 46 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
> index 3ed21da..a7f9d70 100644
> --- a/drivers/input/misc/pwm-beeper.c
> +++ b/drivers/input/misc/pwm-beeper.c
> @@ -32,7 +32,7 @@ struct pwm_beeper {
> struct work_struct work;
> unsigned long period;
> unsigned int volume;
> - unsigned int volume_levels[] = {0, 8, 20, 40, 500};
> + unsigned int *volume_levels;
> unsigned int max_volume_level;
> };
>
> @@ -161,8 +161,11 @@ static void pwm_beeper_close(struct input_dev *input)
> static int pwm_beeper_probe(struct platform_device *pdev)
> {
> unsigned long pwm_id = (unsigned long)dev_get_platdata(&pdev->dev);
> + struct device_node *np = pdev->dev.of_node;
> struct pwm_beeper *beeper;
> - int error;
> + struct property *prop;
> + int error, length;
> + u32 value;
>
> beeper = kzalloc(sizeof(*beeper), GFP_KERNEL);
> if (!beeper)
> @@ -188,7 +191,47 @@ static int pwm_beeper_probe(struct platform_device *pdev)
>
> INIT_WORK(&beeper->work, pwm_beeper_work);
>
> - beeper->max_volume_level = ARRAY_SIZE(beeper->volume_levels) - 1;
> + /* determine the number of volume levels */
> + prop = of_find_property(np, "volume-levels", &length);

Please use generic device properties, not OF-specific ones.

> + if (!prop) {
> + dev_dbg(&pdev->dev, "no volume levels specified, using max volume\n");
> + beeper->max_volume_level = 1;
> + } else
> + beeper->max_volume_level = length / sizeof(u32);
> +
> + /* read volume levels from DT property */
> + if (beeper->max_volume_level > 0) {
> + size_t size = sizeof(*beeper->volume_levels) *
> + beeper->max_volume_level;
> +
> + beeper->volume_levels = devm_kzalloc(&(pdev->dev), size,
> + GFP_KERNEL);
> + if (!beeper->volume_levels)
> + return -ENOMEM;
> +
> + if (prop) {
> + error = of_property_read_u32_array(np, "volume-levels",
> + beeper->volume_levels,
> + beeper->max_volume_level);
> +
> + if (error < 0)
> + return error;
> +
> + error = of_property_read_u32(np, "default-volume-level",
> + &value);
> +
> + if (error < 0) {
> + dev_dbg(&pdev->dev, "no default volume specified, using max volume\n");
> + value = beeper->max_volume_level - 1;
> + }
> + } else {
> + beeper->volume_levels[0] = 500;
> + value = 0;
> + }
> +
> + beeper->volume = value;
> + beeper->max_volume_level--;
> + }
>
> beeper->input = input_allocate_device();
> if (!beeper->input) {
> --
> 2.7.4
>

--
Dmitry