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

[Sebastian Reichel]

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