On 02/20/2017 02:37 AM, Heiko Schocher wrote:
From: Guan Ben <ben.guan@xxxxxxxxxxxx>
extend the pwm-beeper driver to support customized frequency
for SND_BELL from device tree.
Signed-off-by: Guan Ben <ben.guan@xxxxxxxxxxxx>
Signed-off-by: Mark Jonas <mark.jonas@xxxxxxxxxxxx>
[hs@xxxxxxx: adapted to 4.10-rc7]
Signed-off-by: Heiko Schocher <hs@xxxxxxx>
---
Changes in v2:
- add comment from Rob Herring:
rename property name "bell-frequency" to "beeper-hz"
Is there a separate patch for the devicetree bindings documentation?
- add comment from Dmitry Torokhov:
use device_property_read_u32() instead of of_property_read_u32()
- rebased against c470abd4fde40ea6a0846a2beab642a578c0b8cd
Linux 4.10
.../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..4e4e128 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:
+- beeper-hz: bell frequency in Hz
diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
index 5f9655d..5ea6fda 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;
This would be much simpler if you just changed the single line above:
value = value ? beeper->bell_frequency : 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 err;
+
+ if (IS_ENABLED(CONFIG_OF)) {
I don't think the check for CONFIG_OF is needed when using
device_property_read_u32().
+ node = dev->of_node;
node variable is never used
+ err = device_property_read_u32(dev, "beeper-hz",
+ &bell_frequency);
Does the device_property_read_u32() function guarantee that
bell_frequency is not modified when err < 0 ?
+ if (err < 0)
+ dev_dbg(dev, "Failed to read beeper-hz, using default: %u Hz\n",
"Failed" sounds like an error, but this is a perfectly normal thing to
happen. Maybe better to say "'beeper-hz' not specified, 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);
This function is so simple, it could just be done inline here.
beeper->input = input_allocate_device();
if (!beeper->input) {
--
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