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

From: Frieder Schrempf
Date: Thu Jan 19 2017 - 10:26:33 EST


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);
+ 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