[PATCH] Input: pwm-beeper: support customized freq for SND_BELL

[Heiko Schocher]

From: Guan Ben <ben.g...@cn.bosch.com>

extend the pwm-beeper driver to support customized frequency
for SND_BELL from device tree.

Signed-off-by: Guan Ben <ben.g...@cn.bosch.com>
Signed-off-by: Mark Jonas <mark.jo...@de.bosch.com>
[h...@denx.de: adapted to 4.10-rc7]
Signed-off-by: Heiko Schocher <h...@denx.de>

---

 .../devicetree/bindings/input/pwm-beeper.txt       |  3 ++
 drivers/input/misc/pwm-beeper.c                    | 36 ++++++++++++++++------
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt 
b/Documentation/devicetree/bindings/input/pwm-beeper.txt
index be332ae..438c6e0 100644
--- a/Documentation/devicetree/bindings/input/pwm-beeper.txt
+++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt
@@ -5,3 +5,6 @@ Registers a PWM device as beeper.
 Required properties:
 - compatible: should be "pwm-beeper"
 - pwms: phandle to the physical PWM device
+
+optional properties:
+- bell-frequency:  bell frequency in Hz
diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
index 5f9655d..99591d5 100644
--- a/drivers/input/misc/pwm-beeper.c
+++ b/drivers/input/misc/pwm-beeper.c
@@ -27,6 +27,7 @@ struct pwm_beeper {
        struct pwm_device *pwm;
        struct work_struct work;
        unsigned long period;
+       unsigned int bell_frequency;
 };
 
 #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
@@ -58,20 +59,17 @@ static int pwm_beeper_event(struct input_dev *input,
        if (type != EV_SND || value < 0)
                return -EINVAL;
 
-       switch (code) {
-       case SND_BELL:
-               value = value ? 1000 : 0;
-               break;
-       case SND_TONE:
-               break;
-       default:
+       if (code != SND_BELL && code != SND_TONE)
                return -EINVAL;
-       }
 
        if (value == 0)
                beeper->period = 0;
-       else
+       else {
+               if (code == SND_BELL)
+                       value = beeper->bell_frequency;
+
                beeper->period = HZ_TO_NANOSECONDS(value);
+       }
 
        schedule_work(&beeper->work);
 
@@ -93,6 +91,25 @@ static void pwm_beeper_close(struct input_dev *input)
        pwm_beeper_stop(beeper);
 }
 
+static void pwm_beeper_init_bell_frequency(struct device *dev,
+                                          struct pwm_beeper *beeper)
+{
+       struct device_node *node;
+       unsigned int bell_frequency = 1000;
+       int error;
+
+       if (IS_ENABLED(CONFIG_OF)) {
+               node = dev->of_node;
+               error = of_property_read_u32(node, "bell-frequency",
+                                            &bell_frequency);
+               if (error < 0)
+                       dev_dbg(dev, "Failed to read bell-frequency, using 
default: %u Hz\n",
+                               bell_frequency);
+       }
+
+       beeper->bell_frequency = bell_frequency;
+}
+
 static int pwm_beeper_probe(struct platform_device *pdev)
 {
        unsigned long pwm_id = (unsigned long)dev_get_platdata(&pdev->dev);
@@ -122,6 +139,7 @@ static int pwm_beeper_probe(struct platform_device *pdev)
        pwm_apply_args(beeper->pwm);
 
        INIT_WORK(&beeper->work, pwm_beeper_work);
+       pwm_beeper_init_bell_frequency(&pdev->dev, beeper);
 
        beeper->input = input_allocate_device();
        if (!beeper->input) {
-- 
2.7.4