Re: [PATCH v3 2/2] input: add driver support for MAX8997-haptic

[Dmitry Torokhov]

Hi Chanwoo,

On Mon, Mar 12, 2012 at 05:31:21PM +0900, Chanwoo Choi wrote:
> +
> +static int __devexit max8997_haptic_remove(struct platform_device *pdev)
> +{
> +	struct max8997_haptic *chip = platform_get_drvdata(pdev);
> +
> +	destroy_work_on_stack(&chip->work);

This does not make sense because:

- chip->work is not on stack
- even if you "destroy" work nothing stops play effect to schedule a new
  one - you need to cancel work in close method.

> +	input_unregister_device(chip->input_dev);
> +	regulator_put(chip->regulator);
> +
> +	if (chip->mode == MAX8997_EXTERNAL_MODE)
> +		pwm_free(chip->pwm);
> +
> +	kfree(chip);
> +
> +	return 0;
> +}
> +
> +static int max8997_haptic_suspend(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct max8997_haptic *chip = platform_get_drvdata(pdev);
> +	struct input_dev *input_dev = chip->input_dev;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&input_dev->event_lock, flags);
> +	max8997_haptic_enable(chip, false);
> +	spin_unlock_irqrestore(&input_dev->event_lock, flags);
> +

This is not proper locking between playing effect and suspend. Now that
you are using workqueue you need to synchronize access with it, not with
play_effect method.

Does the following patch work for you?

Thanks.

-- 
Dmitry


Input: add driver support for MAX8997-haptic

From: Donggeun Kim <dg77.kim@xxxxxxxxxxx>

The MAX8997-haptic function can be used to control motor. User can
control the haptic driver by using force feedback framework.

Signed-off-by: Donggeun Kim <dg77.kim@xxxxxxxxxxx>
Signed-off-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>
---

 drivers/input/misc/Kconfig          |   12 +
 drivers/input/misc/Makefile         |    1 
 drivers/input/misc/max8997_haptic.c |  407 +++++++++++++++++++++++++++++++++++
 include/linux/mfd/max8997.h         |   53 ++++-
 4 files changed, 472 insertions(+), 1 deletions(-)
 create mode 100644 drivers/input/misc/max8997_haptic.c


diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 2337c3e..ee077a4 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -134,6 +134,18 @@ config INPUT_MAX8925_ONKEY
 	  To compile this driver as a module, choose M here: the module
 	  will be called max8925_onkey.
 
+config INPUT_MAX8997_HAPTIC
+	tristate "MAXIM MAX8997 haptic controller support"
+	depends on HAVE_PWM && MFD_MAX8997
+	select INPUT_FF_MEMLESS
+	help
+	  This option enables device driver support for the haptic controller
+	  on MAXIM MAX8997 chip. This driver supports ff-memless interface
+	  from input framework.
+
+	  To compile this driver as module, choose M here: the
+	  module will be called max8997-haptic.
+
 config INPUT_MC13783_PWRBUTTON
 	tristate "MC13783 ON buttons"
 	depends on MFD_MC13783
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index a6d8de0..f55cdf4 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
 obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o
 obj-$(CONFIG_INPUT_M68K_BEEP)		+= m68kspkr.o
 obj-$(CONFIG_INPUT_MAX8925_ONKEY)	+= max8925_onkey.o
+obj-$(CONFIG_INPUT_MAX8997_HAPTIC)	+= max8997_haptic.o
 obj-$(CONFIG_INPUT_MC13783_PWRBUTTON)	+= mc13783-pwrbutton.o
 obj-$(CONFIG_INPUT_MMA8450)		+= mma8450.o
 obj-$(CONFIG_INPUT_MPU3050)		+= mpu3050.o
diff --git a/drivers/input/misc/max8997_haptic.c b/drivers/input/misc/max8997_haptic.c
new file mode 100644
index 0000000..d968c37
--- /dev/null
+++ b/drivers/input/misc/max8997_haptic.c
@@ -0,0 +1,407 @@
+/*
+ * MAX8997-haptic controller driver
+ *
+ * Copyright (C) 2012 Samsung Electronics
+ * Donggeun Kim <dg77.kim@xxxxxxxxxxx>
+ *
+ * This program is not provided / owned by Maxim Integrated Products.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/pwm.h>
+#include <linux/input.h>
+#include <linux/mfd/max8997-private.h>
+#include <linux/mfd/max8997.h>
+#include <linux/regulator/consumer.h>
+
+/* Haptic configuration 2 register */
+#define MAX8997_MOTOR_TYPE_SHIFT	7
+#define MAX8997_ENABLE_SHIFT		6
+#define MAX8997_MODE_SHIFT		5
+
+/* Haptic driver configuration register */
+#define MAX8997_CYCLE_SHIFT		6
+#define MAX8997_SIG_PERIOD_SHIFT	4
+#define MAX8997_SIG_DUTY_SHIFT		2
+#define MAX8997_PWM_DUTY_SHIFT		0
+
+struct max8997_haptic {
+	struct device *dev;
+	struct i2c_client *client;
+	struct input_dev *input_dev;
+	struct regulator *regulator;
+
+	struct work_struct work;
+	struct mutex mutex;
+
+	bool enabled;
+	unsigned int level;
+
+	struct pwm_device *pwm;
+	unsigned int pwm_period;
+	enum max8997_haptic_pwm_divisor pwm_divisor;
+
+	enum max8997_haptic_motor_type type;
+	enum max8997_haptic_pulse_mode mode;
+
+	unsigned int internal_mode_pattern;
+	unsigned int pattern_cycle;
+	unsigned int pattern_signal_period;
+};
+
+static int max8997_haptic_set_duty_cycle(struct max8997_haptic *chip)
+{
+	int ret = 0;
+
+	if (chip->mode == MAX8997_EXTERNAL_MODE) {
+		unsigned int duty = chip->pwm_period * chip->level / 100;
+		ret = pwm_config(chip->pwm, duty, chip->pwm_period);
+	} else {
+		int i;
+		u8 duty_index = 0;
+
+		for (i = 0; i <= 64; i++) {
+			if (chip->level <= i * 100 / 64) {
+				duty_index = i;
+				break;
+			}
+		}
+		switch (chip->internal_mode_pattern) {
+		case 0:
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_SIGPWMDC1, duty_index);
+			break;
+		case 1:
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_SIGPWMDC2, duty_index);
+			break;
+		case 2:
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_SIGPWMDC3, duty_index);
+			break;
+		case 3:
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_SIGPWMDC4, duty_index);
+			break;
+		default:
+			break;
+		}
+	}
+	return ret;
+}
+
+static void max8997_haptic_configure(struct max8997_haptic *chip)
+{
+	u8 value;
+
+	value = chip->type << MAX8997_MOTOR_TYPE_SHIFT |
+		chip->enabled << MAX8997_ENABLE_SHIFT |
+		chip->mode << MAX8997_MODE_SHIFT | chip->pwm_divisor;
+	max8997_write_reg(chip->client, MAX8997_HAPTIC_REG_CONF2, value);
+
+	if (chip->mode == MAX8997_INTERNAL_MODE && chip->enabled) {
+		value = chip->internal_mode_pattern << MAX8997_CYCLE_SHIFT |
+			chip->internal_mode_pattern << MAX8997_SIG_PERIOD_SHIFT |
+			chip->internal_mode_pattern << MAX8997_SIG_DUTY_SHIFT |
+			chip->internal_mode_pattern << MAX8997_PWM_DUTY_SHIFT;
+		max8997_write_reg(chip->client,
+			MAX8997_HAPTIC_REG_DRVCONF, value);
+
+		switch (chip->internal_mode_pattern) {
+		case 0:
+			value = chip->pattern_cycle << 4;
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_CYCLECONF1, value);
+			value = chip->pattern_signal_period;
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_SIGCONF1, value);
+			break;
+
+		case 1:
+			value = chip->pattern_cycle;
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_CYCLECONF1, value);
+			value = chip->pattern_signal_period;
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_SIGCONF2, value);
+			break;
+
+		case 2:
+			value = chip->pattern_cycle << 4;
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_CYCLECONF2, value);
+			value = chip->pattern_signal_period;
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_SIGCONF3, value);
+			break;
+
+		case 3:
+			value = chip->pattern_cycle;
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_CYCLECONF2, value);
+			value = chip->pattern_signal_period;
+			max8997_write_reg(chip->client,
+				MAX8997_HAPTIC_REG_SIGCONF4, value);
+			break;
+
+		default:
+			break;
+		}
+	}
+}
+
+static void max8997_haptic_enable(struct max8997_haptic *chip)
+{
+	int error;
+
+	mutex_lock(&chip->mutex);
+
+	error = max8997_haptic_set_duty_cycle(chip);
+	if (error) {
+		dev_err(chip->dev, "set_pwm_cycle failed, error: %d\n", error);
+		goto out;
+	}
+
+	if (!chip->enabled) {
+		regulator_enable(chip->regulator);
+		max8997_haptic_configure(chip);
+		if (chip->mode == MAX8997_EXTERNAL_MODE)
+			pwm_enable(chip->pwm);
+		chip->enabled = true;
+	}
+
+out:
+	mutex_unlock(&chip->mutex);
+}
+
+static void max8997_haptic_disable(struct max8997_haptic *chip)
+{
+	mutex_lock(&chip->mutex);
+
+	if (chip->enabled) {
+		max8997_haptic_configure(chip);
+		if (chip->mode == MAX8997_EXTERNAL_MODE)
+			pwm_disable(chip->pwm);
+		regulator_disable(chip->regulator);
+		chip->enabled = false;
+	}
+
+	mutex_unlock(&chip->mutex);
+}
+
+static void max8997_haptic_play_effect_work(struct work_struct *work)
+{
+	struct max8997_haptic *chip =
+			container_of(work, struct max8997_haptic, work);
+
+	if (chip->level)
+		max8997_haptic_enable(chip);
+	else
+		max8997_haptic_disable(chip);
+}
+
+static int max8997_haptic_play_effect(struct input_dev *dev, void *data,
+				  struct ff_effect *effect)
+{
+	struct max8997_haptic *chip = input_get_drvdata(dev);
+
+	chip->level = effect->u.rumble.strong_magnitude;
+	if (!chip->level)
+		chip->level = effect->u.rumble.weak_magnitude;
+
+	schedule_work(&chip->work);
+
+	return 0;
+}
+
+static void max8997_haptic_close(struct input_dev *dev)
+{
+	struct max8997_haptic *chip = input_get_drvdata(dev);
+
+	cancel_work_sync(&chip->work);
+	max8997_haptic_disable(chip);
+}
+
+static int __devinit max8997_haptic_probe(struct platform_device *pdev)
+{
+	struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
+	const struct max8997_platform_data *pdata =
+					dev_get_platdata(iodev->dev);
+	const struct max8997_haptic_platform_data *haptic_pdata =
+					pdata->haptic_pdata;
+	struct max8997_haptic *chip;
+	struct input_dev *input_dev;
+	int error;
+
+	if (!haptic_pdata) {
+		dev_err(&pdev->dev, "no haptic platform data\n");
+		return -EINVAL;
+	}
+
+	chip = kzalloc(sizeof(struct max8997_haptic), GFP_KERNEL);
+	input_dev = input_allocate_device();
+	if (!chip || !input_dev) {
+		dev_err(&pdev->dev, "unable to allocate memory\n");
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	INIT_WORK(&chip->work, max8997_haptic_play_effect_work);
+	mutex_init(&chip->mutex);
+
+	chip->client = iodev->haptic;
+	chip->dev = &pdev->dev;
+	chip->input_dev = input_dev;
+	chip->pwm_period = haptic_pdata->pwm_period;
+	chip->type = haptic_pdata->type;
+	chip->mode = haptic_pdata->mode;
+	chip->pwm_divisor = haptic_pdata->pwm_divisor;
+
+	switch (chip->mode) {
+	case MAX8997_INTERNAL_MODE:
+		chip->internal_mode_pattern =
+				haptic_pdata->internal_mode_pattern;
+		chip->pattern_cycle = haptic_pdata->pattern_cycle;
+		chip->pattern_signal_period =
+				haptic_pdata->pattern_signal_period;
+		break;
+
+	case MAX8997_EXTERNAL_MODE:
+		chip->pwm = pwm_request(haptic_pdata->pwm_channel_id,
+					"max8997-haptic");
+		if (IS_ERR(chip->pwm)) {
+			error = PTR_ERR(chip->pwm);
+			dev_err(&pdev->dev,
+				"unable to request PWM for haptic, error: %d\n",
+				error);
+			goto err_free_mem;
+		}
+		break;
+
+	default:
+		dev_err(&pdev->dev,
+			"Invalid chip mode specified (%d)\n", chip->mode);
+		error = -EINVAL;
+		goto err_free_mem;
+	}
+
+	chip->regulator = regulator_get(&pdev->dev, "inmotor");
+	if (IS_ERR(chip->regulator)) {
+		error = PTR_ERR(chip->regulator);
+		dev_err(&pdev->dev,
+			"unable to get regulator, error: %d\n",
+			error);
+		goto err_free_pwm;
+	}
+
+	input_dev->name = "max8997-haptic";
+	input_dev->id.version = 1;
+	input_dev->dev.parent = &pdev->dev;
+	input_dev->close = max8997_haptic_close;
+	input_set_drvdata(input_dev, chip);
+	input_set_capability(input_dev, EV_FF, FF_RUMBLE);
+
+	error = input_ff_create_memless(input_dev, NULL,
+				max8997_haptic_play_effect);
+	if (error) {
+		dev_err(&pdev->dev,
+			"unable to create FF device, error: %d\n",
+			error);
+		goto err_put_regulator;
+	}
+
+	error = input_register_device(input_dev);
+	if (error) {
+		dev_err(&pdev->dev,
+			"unable to register input device, error: %d\n",
+			error);
+		goto err_destroy_ff;
+	}
+
+	platform_set_drvdata(pdev, chip);
+	return 0;
+
+err_destroy_ff:
+	input_ff_destroy(input_dev);
+err_put_regulator:
+	regulator_put(chip->regulator);
+err_free_pwm:
+	if (chip->mode == MAX8997_EXTERNAL_MODE)
+		pwm_free(chip->pwm);
+err_free_mem:
+	input_free_device(input_dev);
+	kfree(chip);
+
+	return error;
+}
+
+static int __devexit max8997_haptic_remove(struct platform_device *pdev)
+{
+	struct max8997_haptic *chip = platform_get_drvdata(pdev);
+
+	input_unregister_device(chip->input_dev);
+	regulator_put(chip->regulator);
+
+	if (chip->mode == MAX8997_EXTERNAL_MODE)
+		pwm_free(chip->pwm);
+
+	kfree(chip);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max8997_haptic_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct max8997_haptic *chip = platform_get_drvdata(pdev);
+
+	max8997_haptic_disable(chip);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(max8997_haptic_pm_ops, max8997_haptic_suspend, NULL);
+
+static const struct platform_device_id max8997_haptic_id[] = {
+	{ "max8997-haptic", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, max8997_haptic_id);
+
+static struct platform_driver max8997_haptic_driver = {
+	.driver	= {
+		.name	= "max8997-haptic",
+		.owner	= THIS_MODULE,
+		.pm	= &max8997_haptic_pm_ops,
+	},
+	.probe		= max8997_haptic_probe,
+	.remove		= __devexit_p(max8997_haptic_remove),
+	.id_table	= max8997_haptic_id,
+};
+module_platform_driver(max8997_haptic_driver);
+
+MODULE_ALIAS("platform:max8997-haptic");
+MODULE_AUTHOR("Donggeun Kim <dg77.kim@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("max8997_haptic driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/max8997.h b/include/linux/mfd/max8997.h
index fff5905..28726dd 100644
--- a/include/linux/mfd/max8997.h
+++ b/include/linux/mfd/max8997.h
@@ -131,6 +131,55 @@ struct max8997_muic_platform_data {
 	int num_init_data;
 };
 
+enum max8997_haptic_motor_type {
+	MAX8997_HAPTIC_ERM,
+	MAX8997_HAPTIC_LRA,
+};
+
+enum max8997_haptic_pulse_mode {
+	MAX8997_EXTERNAL_MODE,
+	MAX8997_INTERNAL_MODE,
+};
+
+enum max8997_haptic_pwm_divisor {
+	MAX8997_PWM_DIVISOR_32,
+	MAX8997_PWM_DIVISOR_64,
+	MAX8997_PWM_DIVISOR_128,
+	MAX8997_PWM_DIVISOR_256,
+};
+
+/**
+ * max8997_haptic_platform_data
+ * @pwm_channel_id: channel number of PWM device
+ *		    valid for MAX8997_EXTERNAL_MODE
+ * @pwm_period: period in nano second for PWM device
+ *		valid for MAX8997_EXTERNAL_MODE
+ * @type: motor type
+ * @mode: pulse mode
+ *     MAX8997_EXTERNAL_MODE: external PWM device is used to control motor
+ *     MAX8997_INTERNAL_MODE: internal pulse generator is used to control motor
+ * @pwm_divisor: divisor for external PWM device
+ * @internal_mode_pattern: internal mode pattern for internal mode
+ *     [0 - 3]: valid pattern number
+ * @pattern_cycle: the number of cycles of the waveform
+ *		   for the internal mode pattern
+ *     [0 - 15]: available cycles
+ * @pattern_signal_period: period of the waveform for the internal mode pattern
+ *     [0 - 255]: available period
+ */
+struct max8997_haptic_platform_data {
+	unsigned int pwm_channel_id;
+	unsigned int pwm_period;
+
+	enum max8997_haptic_motor_type type;
+	enum max8997_haptic_pulse_mode mode;
+	enum max8997_haptic_pwm_divisor pwm_divisor;
+
+	unsigned int internal_mode_pattern;
+	unsigned int pattern_cycle;
+	unsigned int pattern_signal_period;
+};
+
 enum max8997_led_mode {
 	MAX8997_NONE,
 	MAX8997_FLASH_MODE,
@@ -192,7 +241,9 @@ struct max8997_platform_data {
 	/* ---- MUIC ---- */
 	struct max8997_muic_platform_data *muic_pdata;
 
-	/* HAPTIC: Not implemented */
+	/* ---- HAPTIC ---- */
+	struct max8997_haptic_platform_data *haptic_pdata;
+
 	/* RTC: Not implemented */
 	/* ---- LED ---- */
 	struct max8997_led_platform_data *led_pdata;
--
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