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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/input/misc/pwm-beeper.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/input/misc/pwm-beeper.c')
-rw-r--r--drivers/input/misc/pwm-beeper.c253
1 files changed, 253 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..0e19e97d9
--- /dev/null
+++ b/drivers/input/misc/pwm-beeper.c
@@ -0,0 +1,253 @@
+// 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_might_sleep(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))
+ return dev_err_probe(dev, PTR_ERR(beeper->pwm), "Failed to request PWM device\n");
+
+ /* Sync up PWM state and ensure it is off. */
+ pwm_init_state(beeper->pwm, &state);
+ state.enabled = false;
+ error = pwm_apply_might_sleep(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))
+ return dev_err_probe(dev, PTR_ERR(beeper->amplifier),
+ "Failed to get 'amp' regulator\n");
+
+ 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 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.
+ */
+ scoped_guard(spinlock_irq, &beeper->input->event_lock) {
+ beeper->suspended = true;
+ }
+
+ pwm_beeper_stop(beeper);
+
+ return 0;
+}
+
+static int pwm_beeper_resume(struct device *dev)
+{
+ struct pwm_beeper *beeper = dev_get_drvdata(dev);
+
+ scoped_guard(spinlock_irq, &beeper->input->event_lock) {
+ beeper->suspended = false;
+ }
+
+ /* Let worker figure out if we should resume beeping */
+ schedule_work(&beeper->work);
+
+ return 0;
+}
+
+static DEFINE_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 = pm_sleep_ptr(&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");