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

[Frieder Schrempf]

This patch adds the devicetree bindings to set the volume levels
and the default volume level.

Signed-off-by: Frieder Schrempf <frieder.schre...@exceet.de>
---
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