[PATCH v10 4/4] input: pwm-beeper: set volume levels by devicetree

[Manuel Traut <manuel.traut@xxxxxx>]

From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>

Add devicetree bindings to define supported volume levels and the
default volume level.

Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx>
Signed-off-by: Manuel Traut <manuel.traut@xxxxxx>
Tested-by: Manuel Traut <manuel.traut@xxxxxx>
---
 drivers/input/misc/pwm-beeper.c | 73 +++++++++++++++++++++++++--------
 1 file changed, 55 insertions(+), 18 deletions(-)

diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
index 214d3fa0a06d..fc367a249490 100644
--- a/drivers/input/misc/pwm-beeper.c
+++ b/drivers/input/misc/pwm-beeper.c
@@ -93,7 +93,7 @@ static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period)
 
 	state.enabled = true;
 	state.period = period;
-	pwm_set_relative_duty_cycle(&state, beeper->volume_levels[beeper->volume], 1000);
+	pwm_set_relative_duty_cycle(&state, beeper->volume_levels[beeper->volume], 10000);
 
 	error = pwm_apply_state(beeper->pwm, &state);
 	if (error)
@@ -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, i, length;
 	size_t size;
+	u32 value;
 
 	beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL);
 	if (!beeper)
@@ -228,23 +229,59 @@ 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] = 80;
-	beeper->volume_levels[2] = 200;
-	beeper->volume_levels[3] = 400;
-	beeper->volume_levels[4] = 5000;
+	/* determine the number of volume levels */
+	length = device_property_read_u32_array(&pdev->dev, "volume-levels-bp", 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-bp",
+						beeper->volume_levels,
+						beeper->max_volume);
+
+			if (error < 0)
+				return error;
+
+			error = device_property_read_u32(&pdev->dev, "default-volume-level-bp",
+						   &value);
+
+			if (error < 0) {
+				dev_dbg(&pdev->dev, "no default volume specified, using max volume\n");
+				value = beeper->max_volume - 1;
+			} else {
+				for (i = 0; i < length; i++) {
+					if (beeper->volume_levels[i] == value) {
+						value = i;
+						break;
+					}
+				}
+				if (value != i) {
+					dev_dbg(&pdev->dev,
+						"default-volume-level-bp %d invalid, using %d\n",
+						value, beeper->max_volume - 1);
+					value = beeper->max_volume - 1;
+				}
+			}
+		} else {
+			beeper->volume_levels[0] = 5000;
+			value = 0;
+		}
 
-	beeper->volume = beeper->max_volume;
+		beeper->volume = value;
+		beeper->max_volume--;
+	}
 
 	beeper->input = devm_input_allocate_device(dev);
 	if (!beeper->input) {
-- 
2.39.1