diff options
author | David Lechner <david@lechnology.com> | 2017-01-16 04:09:43 +0300 |
---|---|---|
committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-01-22 11:23:22 +0300 |
commit | 9e54924432783bfb21e905e0bf7042556bcb4b90 (patch) | |
tree | 7ddeb37703ff995a06ee4e77f3c429256a3320cc /drivers/input | |
parent | 62481881401246859d9bd06b7c7b9a391c78892c (diff) | |
download | linux-9e54924432783bfb21e905e0bf7042556bcb4b90.tar.xz |
Input: pwm-beeper - add optional amplifier regulator
This adds an optional regulator to the pwm-beeper device. This regulator
acts as an amplifier. The amplifier is only enabled while beeping in order
to reduce power consumption.
Tested on LEGO MINDSTORMS EV3, which has a speaker connected to PWM through
an amplifier.
Signed-off-by: David Lechner <david@lechnology.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
-rw-r--r-- | drivers/input/misc/pwm-beeper.c | 63 |
1 files changed, 50 insertions, 13 deletions
diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c index 069d594554bd..ad9b231e8468 100644 --- a/drivers/input/misc/pwm-beeper.c +++ b/drivers/input/misc/pwm-beeper.c @@ -14,6 +14,7 @@ */ #include <linux/input.h> +#include <linux/regulator/consumer.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/of.h> @@ -25,30 +26,59 @@ struct pwm_beeper { struct input_dev *input; struct pwm_device *pwm; + struct regulator *amplifier; struct work_struct work; unsigned long period; bool suspended; + bool amplifier_on; }; #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) -static void __pwm_beeper_set(struct pwm_beeper *beeper) +static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period) { - unsigned long period = beeper->period; + int error; + + error = pwm_config(beeper->pwm, period / 2, period); + if (error) + return error; + + error = pwm_enable(beeper->pwm); + if (error) + return error; + + if (!beeper->amplifier_on) { + error = regulator_enable(beeper->amplifier); + if (error) { + pwm_disable(beeper->pwm); + return error; + } - if (period) { - pwm_config(beeper->pwm, period / 2, period); - pwm_enable(beeper->pwm); - } else - pwm_disable(beeper->pwm); + beeper->amplifier_on = true; + } + + return 0; +} + +static void pwm_beeper_off(struct pwm_beeper *beeper) +{ + if (beeper->amplifier_on) { + regulator_disable(beeper->amplifier); + beeper->amplifier_on = false; + } + + pwm_disable(beeper->pwm); } static void pwm_beeper_work(struct work_struct *work) { - struct pwm_beeper *beeper = - container_of(work, struct pwm_beeper, work); + struct pwm_beeper *beeper = container_of(work, struct pwm_beeper, work); + unsigned long period = READ_ONCE(beeper->period); - __pwm_beeper_set(beeper); + if (period) + pwm_beeper_on(beeper, period); + else + pwm_beeper_off(beeper); } static int pwm_beeper_event(struct input_dev *input, @@ -83,9 +113,7 @@ static int pwm_beeper_event(struct input_dev *input, static void pwm_beeper_stop(struct pwm_beeper *beeper) { cancel_work_sync(&beeper->work); - - if (beeper->period) - pwm_disable(beeper->pwm); + pwm_beeper_off(beeper); } static void pwm_beeper_close(struct input_dev *input) @@ -120,6 +148,15 @@ static int pwm_beeper_probe(struct platform_device *pdev) */ pwm_apply_args(beeper->pwm); + beeper->amplifier = devm_regulator_get(dev, "amp"); + if (IS_ERR(beeper->amplifier)) { + error = PTR_ERR(beeper->amplifier); + if (error != -EPROBE_DEFER) + dev_err(dev, "Failed to get 'amp' regulator: %d\n", + error); + return error; + } + INIT_WORK(&beeper->work, pwm_beeper_work); beeper->input = devm_input_allocate_device(dev); |