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

Heiko Schocher
2017-02-07T05:21:44Z

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

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

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