[PATCHv2 1/2] Input: pwm-vibra: new driver

From: Sebastian Reichel
Date: Wed May 03 2017 - 07:12:04 EST


Provide a simple driver for PWM controllable vibrators. It
will be used by Motorola Droid 4.

Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxxxx>
---
Changes since PATCHv1:
- move driver removal code to input->close function
- mark PM functions __maybe_unused and drop #ifdef CONFIG_PM_SLEEP
- remove duplicate NULL check for vibrator in probe function
- cancel work in suspend function
---
.../devicetree/bindings/input/pwm-vibrator.txt | 60 ++++
drivers/input/misc/Kconfig | 11 +
drivers/input/misc/Makefile | 1 +
drivers/input/misc/pwm-vibra.c | 343 +++++++++++++++++++++
4 files changed, 415 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/pwm-vibrator.txt
create mode 100644 drivers/input/misc/pwm-vibra.c

diff --git a/Documentation/devicetree/bindings/input/pwm-vibrator.txt b/Documentation/devicetree/bindings/input/pwm-vibrator.txt
new file mode 100644
index 000000000000..c35be4691366
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/pwm-vibrator.txt
@@ -0,0 +1,60 @@
+* PWM vibrator device tree bindings
+
+Registers a PWM device as vibrator.
+
+Required properties:
+- compatible: should be
+ * "pwm-vibrator"
+ For vibrators controlled using the PWM channel's duty cycle (higher duty means
+ the vibrator becomes stronger).
+ * "motorola,mapphone-pwm-vibrator"
+ For vibrator found in Motorola Droid 4. This vibrator generates a pulse for
+ every rising edge, so its controlled using a duty cycle of 50% and changing
+ the period time.
+- pwm-names: Should contain "enable" and optionally "direction"
+- pwms: Should contain a PWM handle for each entry in pwm-names
+
+Example from Motorola Droid 4:
+
+&omap4_pmx_core {
+ vibrator_direction_pin: pinmux_vibrator_direction_pin {
+ pinctrl-single,pins = <
+ OMAP4_IOPAD(0x1ce, PIN_OUTPUT | MUX_MODE1) /* dmtimer8_pwm_evt (gpio_27) */
+ >;
+ };
+
+ vibrator_enable_pin: pinmux_vibrator_enable_pin {
+ pinctrl-single,pins = <
+ OMAP4_IOPAD(0X1d0, PIN_OUTPUT | MUX_MODE1) /* dmtimer9_pwm_evt (gpio_28) */
+ >;
+ };
+};
+
+/ {
+ pwm8: dmtimer-pwm {
+ pinctrl-names = "default";
+ pinctrl-0 = <&vibrator_direction_pin>;
+
+ compatible = "ti,omap-dmtimer-pwm";
+ #pwm-cells = <3>;
+ ti,timers = <&timer8>;
+ ti,clock-source = <0x01>;
+ };
+
+ pwm9: dmtimer-pwm {
+ pinctrl-names = "default";
+ pinctrl-0 = <&vibrator_enable_pin>;
+
+ compatible = "ti,omap-dmtimer-pwm";
+ #pwm-cells = <3>;
+ ti,timers = <&timer9>;
+ ti,clock-source = <0x01>;
+ };
+
+ vibrator {
+ compatible = "pwm-vibrator";
+ pwms = <&pwm8 0 1000000000 0>,
+ <&pwm9 0 1000000000 0>;
+ pwm-names = "enable", "direction";
+ };
+};
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 5b6c52210d20..d8e0b25eb217 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -571,6 +571,17 @@ config INPUT_PWM_BEEPER
To compile this driver as a module, choose M here: the module will be
called pwm-beeper.

+config INPUT_PWM_VIBRA
+ tristate "PWM vibrator support"
+ depends on PWM
+ help
+ Say Y here to get support for PWM based vibrator devices.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the module will be
+ called pwm-vibra.
+
config INPUT_GPIO_ROTARY_ENCODER
tristate "Rotary encoders connected to GPIO pins"
depends on GPIOLIB || COMPILE_TEST
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index b10523f2878e..9a6517f5458c 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_INPUT_PM8XXX_VIBRATOR) += pm8xxx-vibrator.o
obj-$(CONFIG_INPUT_PMIC8XXX_PWRKEY) += pmic8xxx-pwrkey.o
obj-$(CONFIG_INPUT_POWERMATE) += powermate.o
obj-$(CONFIG_INPUT_PWM_BEEPER) += pwm-beeper.o
+obj-$(CONFIG_INPUT_PWM_VIBRA) += pwm-vibra.o
obj-$(CONFIG_INPUT_RB532_BUTTON) += rb532_button.o
obj-$(CONFIG_INPUT_REGULATOR_HAPTIC) += regulator-haptic.o
obj-$(CONFIG_INPUT_RETU_PWRBUTTON) += retu-pwrbutton.o
diff --git a/drivers/input/misc/pwm-vibra.c b/drivers/input/misc/pwm-vibra.c
new file mode 100644
index 000000000000..878a483f93ff
--- /dev/null
+++ b/drivers/input/misc/pwm-vibra.c
@@ -0,0 +1,343 @@
+/*
+ * PWM vibrator driver
+ *
+ * Copyright (C) 2017 Collabora Ltd.
+ *
+ * Based on previous work from:
+ * Copyright (C) 2012 Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
+ *
+ * Based on PWM beeper driver:
+ * Copyright (C) 2010, Lars-Peter Clausen <lars@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#define DEBUG
+
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+/**
+ * Motorola Droid 4 (also known as mapphone), has a vibrator, which pulses
+ * 1x on rising edge. Increasing the pwm period results in more pulses per
+ * second, but reduces intensity. There is also a second channel to control
+ * the vibrator's rotation direction to increase effect. The following
+ * numbers were determined manually. Going below 12.5 Hz means, clearly
+ * noticeable pauses and at 30 Hz the vibration is just barely noticable
+ * anymore.
+ */
+#define MAPPHONE_MIN_FREQ 125 /* 12.5 Hz */
+#define MAPPHONE_MAX_FREQ 300 /* 30.0 Hz */
+
+struct pwm_vibrator_hw {
+ void (*setup_pwm)(u16 level, struct pwm_state *);
+ void (*setup_pwm_dir)(u16 level, struct pwm_state *);
+};
+
+struct pwm_vibrator {
+ struct input_dev *input;
+ struct pwm_device *pwm;
+ struct pwm_device *pwm_dir;
+ struct regulator *vcc;
+
+ struct work_struct play_work;
+ u16 level;
+
+ const struct pwm_vibrator_hw *hw;
+};
+
+static void pwm_vibrator_setup_generic(u16 level, struct pwm_state *state)
+{
+ /* period is configured by platform, duty cycle controls strength */
+ pwm_set_relative_duty_cycle(state, level, 0xffff);
+}
+
+static void pwm_vibrator_setup_dir_generic(u16 level, struct pwm_state *state)
+{
+ /* period is configured by platform, duty cycle controls strength */
+ pwm_set_relative_duty_cycle(state, 50, 100);
+}
+
+static struct pwm_vibrator_hw pwm_vib_hw_generic = {
+ .setup_pwm = pwm_vibrator_setup_generic,
+ .setup_pwm_dir = pwm_vibrator_setup_dir_generic,
+};
+
+static void pwm_vibrator_setup_mapphone(u16 level, struct pwm_state *state)
+{
+ unsigned int freq;
+
+ /* convert [0, 0xffff] -> [MAPPHONE_MAX_FREQ, MAPPHONE_MIN_FREQ] */
+ freq = 0xffff - level;
+ freq *= MAPPHONE_MAX_FREQ - MAPPHONE_MIN_FREQ;
+ freq /= 0xffff;
+ freq += MAPPHONE_MIN_FREQ;
+
+ state->period = DIV_ROUND_CLOSEST_ULL((u64) NSEC_PER_SEC * 10, freq);
+ pwm_set_relative_duty_cycle(state, 50, 100);
+}
+
+static struct pwm_vibrator_hw pwm_vib_hw_mapphone = {
+ .setup_pwm = pwm_vibrator_setup_mapphone,
+ .setup_pwm_dir = pwm_vibrator_setup_mapphone,
+};
+
+static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
+{
+ struct device *pdev = vibrator->input->dev.parent;
+ struct pwm_state state;
+ int err;
+
+ dev_dbg(pdev, "start vibrator with level=0x%04x", vibrator->level);
+
+ err = regulator_enable(vibrator->vcc);
+ if (err) {
+ dev_err(pdev, "failed to enable regulator: %d", err);
+ return err;
+ }
+
+ pwm_get_state(vibrator->pwm, &state);
+ state.enabled = true;
+
+ vibrator->hw->setup_pwm(vibrator->level, &state);
+ dev_dbg(pdev, "period=%u", state.period);
+
+ err = pwm_apply_state(vibrator->pwm, &state);
+ if (err) {
+ dev_err(pdev, "failed to apply pwm state: %d", err);
+ return err;
+ }
+
+ if (vibrator->pwm_dir) {
+ pwm_get_state(vibrator->pwm_dir, &state);
+ state.enabled = true;
+
+ /* always control via period */
+ vibrator->hw->setup_pwm_dir(vibrator->level, &state);
+
+ err = pwm_apply_state(vibrator->pwm_dir, &state);
+ if (err) {
+ dev_err(pdev, "failed to apply dir-pwm state: %d", err);
+ pwm_disable(vibrator->pwm);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
+{
+ struct device *pdev = vibrator->input->dev.parent;
+
+ dev_dbg(pdev, "stop vibrator");
+
+ regulator_disable(vibrator->vcc);
+
+ if (vibrator->pwm_dir)
+ pwm_disable(vibrator->pwm_dir);
+ pwm_disable(vibrator->pwm);
+}
+
+static void vibra_play_work(struct work_struct *work)
+{
+ struct pwm_vibrator *vibrator = container_of(work,
+ struct pwm_vibrator, play_work);
+
+ if (vibrator->level)
+ pwm_vibrator_start(vibrator);
+ else
+ pwm_vibrator_stop(vibrator);
+}
+
+static int pwm_vibrator_play_effect(struct input_dev *dev, void *data,
+ struct ff_effect *effect)
+{
+ struct pwm_vibrator *vibrator = input_get_drvdata(dev);
+
+ vibrator->level = effect->u.rumble.strong_magnitude;
+ if (!vibrator->level)
+ vibrator->level = effect->u.rumble.weak_magnitude;
+
+ schedule_work(&vibrator->play_work);
+
+ return 0;
+}
+
+static void pwm_vibrator_close(struct input_dev *input)
+{
+ struct pwm_vibrator *vibrator = input_get_drvdata(input);
+
+ cancel_work_sync(&vibrator->play_work);
+ pwm_vibrator_stop(vibrator);
+}
+
+static int pwm_vibrator_probe(struct platform_device *pdev)
+{
+ struct pwm_vibrator *vibrator;
+ struct input_dev *input;
+ struct pwm_state state;
+ int err;
+
+ vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
+ if (!vibrator)
+ return -ENOMEM;
+
+ input = devm_input_allocate_device(&pdev->dev);
+ if (!input)
+ return -ENOMEM;
+
+ vibrator->input = input;
+
+ vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
+ err = PTR_ERR_OR_ZERO(vibrator->vcc);
+ if (err) {
+ if (err != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "Failed to request regulator: %d",
+ err);
+ return err;
+ }
+
+ vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
+ err = PTR_ERR_OR_ZERO(vibrator->pwm);
+ if (err) {
+ if (err != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "Failed to request main pwm: %d",
+ err);
+ return err;
+ }
+
+ INIT_WORK(&vibrator->play_work, vibra_play_work);
+
+ /* Sync up PWM state and ensure it is off. */
+ pwm_init_state(vibrator->pwm, &state);
+ state.enabled = false;
+ err = pwm_apply_state(vibrator->pwm, &state);
+ if (err) {
+ dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
+ err);
+ return err;
+ }
+
+ vibrator->pwm_dir = devm_pwm_get(&pdev->dev, "direction");
+ err = PTR_ERR_OR_ZERO(vibrator->pwm_dir);
+ if (err == -ENODATA) {
+ vibrator->pwm_dir = NULL;
+ } else if (err == -EPROBE_DEFER) {
+ return err;
+ } else if (err) {
+ dev_err(&pdev->dev, "Failed to request direction pwm: %d", err);
+ return err;
+ } else {
+ /* Sync up PWM state and ensure it is off. */
+ pwm_init_state(vibrator->pwm_dir, &state);
+ state.enabled = false;
+ err = pwm_apply_state(vibrator->pwm_dir, &state);
+ if (err) {
+ dev_err(&pdev->dev, "failed to apply initial PWM state: %d",
+ err);
+ return err;
+ }
+ }
+
+ vibrator->hw = of_device_get_match_data(&pdev->dev);
+ if (!vibrator->hw)
+ vibrator->hw = &pwm_vib_hw_generic;
+
+ input->name = "pwm-vibrator";
+ input->id.bustype = BUS_HOST;
+ input->dev.parent = &pdev->dev;
+ input->close = pwm_vibrator_close;
+
+ input_set_drvdata(input, vibrator);
+ input_set_capability(input, EV_FF, FF_RUMBLE);
+
+ err = input_ff_create_memless(input, NULL, pwm_vibrator_play_effect);
+ if (err) {
+ dev_err(&pdev->dev, "Couldn't create FF dev: %d", err);
+ return err;
+ }
+
+ err = input_register_device(input);
+ if (err) {
+ dev_err(&pdev->dev, "Couldn't register input dev: %d", err);
+ return err;
+ }
+
+ platform_set_drvdata(pdev, vibrator);
+
+ return 0;
+}
+
+static int __maybe_unused pwm_vibrator_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct pwm_vibrator *vibrator = platform_get_drvdata(pdev);
+ struct input_dev *input = vibrator->input;
+ unsigned long flags;
+
+ spin_lock_irqsave(&input->event_lock, flags);
+ cancel_work_sync(&vibrator->play_work);
+ if (vibrator->level)
+ pwm_vibrator_stop(vibrator);
+ spin_unlock_irqrestore(&input->event_lock, flags);
+
+ return 0;
+}
+
+static int __maybe_unused pwm_vibrator_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct pwm_vibrator *vibrator = platform_get_drvdata(pdev);
+ struct input_dev *input = vibrator->input;
+ unsigned long flags;
+
+ spin_lock_irqsave(&input->event_lock, flags);
+ if (vibrator->level)
+ pwm_vibrator_start(vibrator);
+ spin_unlock_irqrestore(&input->event_lock, flags);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(pwm_vibrator_pm_ops,
+ pwm_vibrator_suspend, pwm_vibrator_resume);
+
+#ifdef CONFIG_OF
+
+#define PWM_VIB_COMPAT(of_compatible, cfg) { \
+ .compatible = of_compatible, \
+ .data = &cfg, \
+}
+
+static const struct of_device_id pwm_vibra_dt_match_table[] = {
+ PWM_VIB_COMPAT("pwm-vibrator", pwm_vib_hw_generic),
+ PWM_VIB_COMPAT("motorola,mapphone-pwm-vibrator", pwm_vib_hw_mapphone),
+ {},
+};
+MODULE_DEVICE_TABLE(of, pwm_vibra_dt_match_table);
+#endif
+
+static struct platform_driver pwm_vibrator_driver = {
+ .probe = pwm_vibrator_probe,
+ .driver = {
+ .name = "pwm-vibrator",
+ .pm = &pwm_vibrator_pm_ops,
+ .of_match_table = of_match_ptr(pwm_vibra_dt_match_table),
+ },
+};
+module_platform_driver(pwm_vibrator_driver);
+
+MODULE_AUTHOR("Sebastian Reichel <sre@xxxxxxxxxx>");
+MODULE_DESCRIPTION("PWM vibrator driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pwm-vibrator");
--
2.11.0