[PATCH 3/3 v6] input: pwm-beeper: add feature to set volume level

From: Manuel Traut
Date: Tue Jan 24 2023 - 06:14:21 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>
---
drivers/input/misc/pwm-beeper.c | 58 +++++++++++++++++++++++----------
1 file changed, 41 insertions(+), 17 deletions(-)

diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
index fadc73e1c89a..f95d6b5899c7 100644
--- a/drivers/input/misc/pwm-beeper.c
+++ b/drivers/input/misc/pwm-beeper.c
@@ -181,8 +181,9 @@ static int pwm_beeper_probe(struct platform_device *pdev)
struct pwm_beeper *beeper;
struct pwm_state state;
u32 bell_frequency;
- int error;
+ int error, length;
size_t size;
+ u32 value;

beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL);
if (!beeper)
@@ -228,23 +229,46 @@ static int pwm_beeper_probe(struct platform_device *pdev)

beeper->bell_frequency = bell_frequency;

- beeper->max_volume = 4;
-
- size = sizeof(*beeper->volume_levels) *
- (beeper->max_volume + 1);
-
- beeper->volume_levels = devm_kzalloc(&(pdev->dev), size,
- GFP_KERNEL);
- if (!beeper->volume_levels)
- return -ENOMEM;
-
- beeper->volume_levels[0] = 0;
- beeper->volume_levels[1] = 8;
- beeper->volume_levels[2] = 20;
- beeper->volume_levels[3] = 40;
- beeper->volume_levels[4] = 500;
+ /* determine the number of volume levels */
+ length = device_property_read_u32_array(&pdev->dev, "volume-levels", NULL, 0);
+ if (length <= 0) {
+ dev_dbg(&pdev->dev, "no volume levels specified, using max volume\n");
+ beeper->max_volume = 1;
+ } else
+ beeper->max_volume = length;
+
+ /* read volume levels from DT property */
+ if (beeper->max_volume > 0) {
+ size = sizeof(*beeper->volume_levels) * beeper->max_volume;
+
+ beeper->volume_levels = devm_kzalloc(&(pdev->dev), size,
+ GFP_KERNEL);
+ if (!beeper->volume_levels)
+ return -ENOMEM;
+
+ if (length > 0) {
+ error = device_property_read_u32_array(&pdev->dev, "volume-levels",
+ beeper->volume_levels,
+ beeper->max_volume);
+
+ if (error < 0)
+ return error;
+
+ error = device_property_read_u32(&pdev->dev, "default-volume-level",
+ &value);
+
+ if (error < 0) {
+ dev_dbg(&pdev->dev, "no default volume specified, using max volume\n");
+ value = beeper->max_volume - 1;
+ }
+ } else {
+ beeper->volume_levels[0] = 500;
+ value = 0;
+ }

- beeper->volume = beeper->max_volume;
+ beeper->volume = value;
+ beeper->max_volume--;
+ }

beeper->input = devm_input_allocate_device(dev);
if (!beeper->input) {
--
2.39.0