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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/input/misc/pwm-beeper.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/input/misc/pwm-beeper.c')
-rw-r--r-- | drivers/input/misc/pwm-beeper.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c new file mode 100644 index 000000000..d6b124777 --- /dev/null +++ b/drivers/input/misc/pwm-beeper.c @@ -0,0 +1,262 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> + * PWM beeper driver + */ + +#include <linux/input.h> +#include <linux/regulator/consumer.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/pwm.h> +#include <linux/slab.h> +#include <linux/workqueue.h> + +struct pwm_beeper { + struct input_dev *input; + struct pwm_device *pwm; + struct regulator *amplifier; + struct work_struct work; + unsigned long period; + unsigned int bell_frequency; + bool suspended; + bool amplifier_on; +}; + +#define HZ_TO_NANOSECONDS(x) (1000000000UL/(x)) + +static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period) +{ + struct pwm_state state; + int error; + + pwm_get_state(beeper->pwm, &state); + + state.enabled = true; + state.period = period; + pwm_set_relative_duty_cycle(&state, 50, 100); + + error = pwm_apply_state(beeper->pwm, &state); + if (error) + return error; + + if (!beeper->amplifier_on) { + error = regulator_enable(beeper->amplifier); + if (error) { + pwm_disable(beeper->pwm); + return error; + } + + 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); + unsigned long period = READ_ONCE(beeper->period); + + if (period) + pwm_beeper_on(beeper, period); + else + pwm_beeper_off(beeper); +} + +static int pwm_beeper_event(struct input_dev *input, + unsigned int type, unsigned int code, int value) +{ + struct pwm_beeper *beeper = input_get_drvdata(input); + + if (type != EV_SND || value < 0) + return -EINVAL; + + switch (code) { + case SND_BELL: + value = value ? beeper->bell_frequency : 0; + break; + case SND_TONE: + break; + default: + return -EINVAL; + } + + if (value == 0) + beeper->period = 0; + else + beeper->period = HZ_TO_NANOSECONDS(value); + + if (!beeper->suspended) + schedule_work(&beeper->work); + + return 0; +} + +static void pwm_beeper_stop(struct pwm_beeper *beeper) +{ + cancel_work_sync(&beeper->work); + pwm_beeper_off(beeper); +} + +static void pwm_beeper_close(struct input_dev *input) +{ + struct pwm_beeper *beeper = input_get_drvdata(input); + + pwm_beeper_stop(beeper); +} + +static int pwm_beeper_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct pwm_beeper *beeper; + struct pwm_state state; + u32 bell_frequency; + int error; + + beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL); + if (!beeper) + return -ENOMEM; + + beeper->pwm = devm_pwm_get(dev, NULL); + if (IS_ERR(beeper->pwm)) { + error = PTR_ERR(beeper->pwm); + if (error != -EPROBE_DEFER) + dev_err(dev, "Failed to request PWM device: %d\n", + error); + return error; + } + + /* Sync up PWM state and ensure it is off. */ + pwm_init_state(beeper->pwm, &state); + state.enabled = false; + error = pwm_apply_state(beeper->pwm, &state); + if (error) { + dev_err(dev, "failed to apply initial PWM state: %d\n", + error); + return error; + } + + 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); + + error = device_property_read_u32(dev, "beeper-hz", &bell_frequency); + if (error) { + bell_frequency = 1000; + dev_dbg(dev, + "failed to parse 'beeper-hz' property, using default: %uHz\n", + bell_frequency); + } + + beeper->bell_frequency = bell_frequency; + + beeper->input = devm_input_allocate_device(dev); + if (!beeper->input) { + dev_err(dev, "Failed to allocate input device\n"); + return -ENOMEM; + } + + beeper->input->name = "pwm-beeper"; + beeper->input->phys = "pwm/input0"; + beeper->input->id.bustype = BUS_HOST; + beeper->input->id.vendor = 0x001f; + beeper->input->id.product = 0x0001; + beeper->input->id.version = 0x0100; + + input_set_capability(beeper->input, EV_SND, SND_TONE); + input_set_capability(beeper->input, EV_SND, SND_BELL); + + beeper->input->event = pwm_beeper_event; + beeper->input->close = pwm_beeper_close; + + input_set_drvdata(beeper->input, beeper); + + error = input_register_device(beeper->input); + if (error) { + dev_err(dev, "Failed to register input device: %d\n", error); + return error; + } + + platform_set_drvdata(pdev, beeper); + + return 0; +} + +static int __maybe_unused pwm_beeper_suspend(struct device *dev) +{ + struct pwm_beeper *beeper = dev_get_drvdata(dev); + + /* + * Spinlock is taken here is not to protect write to + * beeper->suspended, but to ensure that pwm_beeper_event + * does not re-submit work once flag is set. + */ + spin_lock_irq(&beeper->input->event_lock); + beeper->suspended = true; + spin_unlock_irq(&beeper->input->event_lock); + + pwm_beeper_stop(beeper); + + return 0; +} + +static int __maybe_unused pwm_beeper_resume(struct device *dev) +{ + struct pwm_beeper *beeper = dev_get_drvdata(dev); + + spin_lock_irq(&beeper->input->event_lock); + beeper->suspended = false; + spin_unlock_irq(&beeper->input->event_lock); + + /* Let worker figure out if we should resume beeping */ + schedule_work(&beeper->work); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops, + pwm_beeper_suspend, pwm_beeper_resume); + +#ifdef CONFIG_OF +static const struct of_device_id pwm_beeper_match[] = { + { .compatible = "pwm-beeper", }, + { }, +}; +MODULE_DEVICE_TABLE(of, pwm_beeper_match); +#endif + +static struct platform_driver pwm_beeper_driver = { + .probe = pwm_beeper_probe, + .driver = { + .name = "pwm-beeper", + .pm = &pwm_beeper_pm_ops, + .of_match_table = of_match_ptr(pwm_beeper_match), + }, +}; +module_platform_driver(pwm_beeper_driver); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("PWM beeper driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:pwm-beeper"); |