[PATCH v3] Input: pwm-beeper: support customized freq for SND_BELL

Heiko Schocher
2017-03-01T05:39:50Z

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>

Acked-by: Rob Herring <robh@kernel.org>
---

Changes in v3:
- add comment from David Lechner:
- readd the switch statement, instead using if / then
- remove check IS_ENABLED(CONFIG_OF)
- remove not used node variable
- change warning string from "Failed to read beeper-hz" to
"'beeper-hz' not specified"
- remove function pwm_beeper_init_bell_frequency() as it is
to simple.
- checked that device_property_read_u32() does not modify the
bell_frequency, if the property "beeper_hz" is not defined.
- add comment from Rob Herring:
- add Acked-by from Rob Herring
Rob also mentioned to remove the IS_ENABLED(CONFIG_OF) check
and node variable is unused.

Changes in v2:
- add comment from Rob Herring:
rename property name "bell-frequency" to "beeper-hz"
- add comment from Dmitry Torokhov:
use device_property_read_u32() instead of of_property_read_u32()
- rebased against c470abd4fde40ea6a0846a2beab642a578c0b8cd
Linux 4.10

Documentation/devicetree/bindings/input/pwm-beeper.txt | 3 +++
drivers/input/misc/pwm-beeper.c | 11 ++++++++++-
2 files changed, 13 insertions(+), 1 deletion(-)

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..f2fcd50 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))
@@ -60,7 +61,7 @@ static int pwm_beeper_event(struct input_dev *input,

switch (code) {
case SND_BELL:
- value = value ? 1000 : 0;
+ value = value ? beeper->bell_frequency : 0;
break;
case SND_TONE:
break;
@@ -97,6 +98,7 @@ static int pwm_beeper_probe(struct platform_device *pdev)
{
unsigned long pwm_id = (unsigned long)dev_get_platdata(&pdev->dev);
struct pwm_beeper *beeper;
+ unsigned int bell_frequency = 1000;
int error;

beeper = kzalloc(sizeof(*beeper), GFP_KERNEL);
@@ -122,6 +124,13 @@ static int pwm_beeper_probe(struct platform_device *pdev)
pwm_apply_args(beeper->pwm);

INIT_WORK(&beeper->work, pwm_beeper_work);
+ error = device_property_read_u32(&pdev->dev, "beeper-hz",
+ &bell_frequency);
+ if (error < 0)
+ dev_dbg(&pdev->dev, "'beeper-hz' not specified, using default: %u Hz\n",
+ bell_frequency);
+
+ beeper->bell_frequency = bell_frequency;

beeper->input = input_allocate_device();
if (!beeper->input) {
--
2.7.4