From: Hyunhee Kim <redacted>
Date: Wed, 9 Oct 2013 16:21:36 +0900
Subject: [PATCH] Input: add regulator haptic driver

Signed-off-by: Hyunhee Kim <redacted>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Aristeu Rozanski <redacted>

---
 drivers/input/misc/Kconfig            |   10 ++
 drivers/input/misc/Makefile           |    1 +
 drivers/input/misc/regulator-haptic.c |  184
+++++++++++++++++++++++++++++++++
 3 files changed, 195 insertions(+)
 create mode 100644 drivers/input/misc/regulator-haptic.c

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index bb698e1..21b4d5b 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig

@@ -82,6 +82,16 @@ config INPUT_ARIZONA_HAPTICS
 	  To compile this driver as a module, choose M here: the
 	  module will be called arizona-haptics.
 
+config INPUT_REGULATOR_HAPTIC
+	tristate "support haptics on/off using regulator"
+	select INPUT_FF_MEMLESS
+	help
+	  Say Y to enable support for the haptic module. Haptic can be
+	  enabled/disabled by regulator.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called regulator-haptic.
+
 config INPUT_BMA150
 	tristate "BMA150/SMB380 acceleration sensor support"
 	depends on I2C

diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index d7fc17f..106f0bc 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_INPUT_ADXL34X_I2C)		+=

adxl34x-i2c.o
 obj-$(CONFIG_INPUT_ADXL34X_SPI)		+= adxl34x-spi.o
 obj-$(CONFIG_INPUT_APANEL)		+= apanel.o
 obj-$(CONFIG_INPUT_ARIZONA_HAPTICS)	+= arizona-haptics.o
+obj-$(CONFIG_INPUT_REGULATOR_HAPTIC)	+= regulator-haptic.o
 obj-$(CONFIG_INPUT_ATI_REMOTE2)		+= ati_remote2.o
 obj-$(CONFIG_INPUT_ATLAS_BTNS)		+= atlas_btns.o
 obj-$(CONFIG_INPUT_BFIN_ROTARY)		+= bfin_rotary.o

diff --git a/drivers/input/misc/regulator-haptic.c

b/drivers/input/misc/regulator-haptic.c
new file mode 100644
index 0000000..882c8b9

--- /dev/null
+++ b/drivers/input/misc/regulator-haptic.c

@@ -0,0 +1,184 @@
+/*
+ * Regulator haptic driver
+ *
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *
+ * Author: Hyunhee Kim <hyunhee.kim@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/regulator/driver.h>
+
+struct regulator_haptic {
+	struct device *dev;
+	struct input_dev *input_dev;
+	struct work_struct work;
+	bool enabled;
+	struct regulator *regulator;
+	struct mutex mutex;
+	int level;
+};
+
+static void regulator_haptic_toggle(struct regulator_haptic *haptic, bool

enable)
+{
+	int ret;
+
+	mutex_lock(&haptic->mutex);
+	if (enable && !haptic->enabled) {
+		haptic->enabled = true;
+		ret = regulator_enable(haptic->regulator);
+		if (ret)
+			dev_err(haptic->dev, "failed to enable
regulator\n");
+	} else if (!enable && haptic->enabled) {
+		haptic->enabled = false;
+		ret = regulator_disable(haptic->regulator);
+		if (ret)
+			dev_err(haptic->dev, "failed to disable
regulator\n");
+	}
+	mutex_unlock(&haptic->mutex);
+}
+
+static void regulator_haptic_work(struct work_struct *work)
+{
+	struct regulator_haptic *haptic = container_of(work,
+						       struct
regulator_haptic,
+						       work);
+	if (haptic->level)
+		regulator_haptic_toggle(haptic, true);
+	else
+		regulator_haptic_toggle(haptic, false);
+
+}
+
+static int regulator_haptic_play(struct input_dev *input, void *data,
+				struct ff_effect *effect)
+{
+	struct regulator_haptic *haptic = input_get_drvdata(input);
+
+	haptic->level = effect->u.rumble.strong_magnitude;
+	if (!haptic->level)
+		haptic->level = effect->u.rumble.weak_magnitude;
+	schedule_work(&haptic->work);
+
+	return 0;
+}
+
+static void regulator_haptic_close(struct input_dev *input)
+{
+	struct regulator_haptic *haptic = input_get_drvdata(input);
+
+	cancel_work_sync(&haptic->work);
+	regulator_haptic_toggle(haptic, false);
+}
+
+static int regulator_haptic_probe(struct platform_device *pdev)
+{
+	struct regulator_haptic *haptic;
+	struct input_dev *input_dev;
+	int error;
+
+	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
+	if (!haptic) {
+		dev_err(&pdev->dev, "unable to allocate memory for
haptic\n");
+		return -ENOMEM;
+	}
+
+	input_dev = input_allocate_device();
+
+	if (!input_dev) {
+		dev_err(&pdev->dev, "unable to allocate memory\n");
+		error =  -ENOMEM;
+		goto err_kfree_mem;
+	}
+
+	INIT_WORK(&haptic->work, regulator_haptic_work);
+	mutex_init(&haptic->mutex);
+	haptic->input_dev = input_dev;
+	haptic->dev = &pdev->dev;
+	haptic->regulator = regulator_get(&pdev->dev, "haptic");
+
+	if (IS_ERR(haptic->regulator)) {
+		error = PTR_ERR(haptic->regulator);
+		dev_err(&pdev->dev, "unable to get regulator, err: %d\n",
+			error);
+		goto err_ifree_mem;
+	}
+
+	haptic->input_dev->name = "regulator:haptic";
+	haptic->input_dev->dev.parent = &pdev->dev;
+	haptic->input_dev->close = regulator_haptic_close;
+	haptic->enabled = false;
+	input_set_drvdata(haptic->input_dev, haptic);
+	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
+
+	error = input_ff_create_memless(input_dev, NULL,
+				      regulator_haptic_play);
+	if (error) {
+		dev_err(&pdev->dev,
+			"input_ff_create_memless() failed: %d\n",
+			error);
+		goto err_put_regulator;
+	}
+
+	error = input_register_device(haptic->input_dev);
+	if (error) {
+		dev_err(&pdev->dev,
+			"couldn't register input device: %d\n",
+			error);
+		goto err_destroy_ff;
+	}
+
+	platform_set_drvdata(pdev, haptic);
+
+	return 0;
+
+err_destroy_ff:
+	input_ff_destroy(haptic->input_dev);
+err_put_regulator:
+	regulator_put(haptic->regulator);
+err_ifree_mem:
+	input_free_device(haptic->input_dev);
+err_kfree_mem:
+	kfree(haptic);
+
+	return error;
+}
+
+static int regulator_haptic_remove(struct platform_device *pdev)
+{
+	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
+
+	input_unregister_device(haptic->input_dev);
+	regulator_put(haptic->regulator);
+
+	return 0;
+}
+
+static struct of_device_id regulator_haptic_dt_match[] = {
+	{ .compatible = "linux,regulator-haptic" },
+	{},
+};
+
+static struct platform_driver regulator_haptic_driver = {
+	.driver		= {
+		.name	= "regulator-haptic",
+		.owner	= THIS_MODULE,
+		.of_match_table = regulator_haptic_dt_match,
+	},
+
+	.probe		= regulator_haptic_probe,
+	.remove		= regulator_haptic_remove,
+};
+module_platform_driver(regulator_haptic_driver);
+
+MODULE_ALIAS("platform:regulator-haptic");
+MODULE_DESCRIPTION("Regulator haptic driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Hyunhee Kim [off-list ref]");
-- 
1.7.9.5

-----Original Message-----
From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com] 
Sent: Tuesday, October 22, 2013 12:56 AM
To: hyunhee.kim
Cc: broonie@opensource.wolfsonmicro.com; peter.ujfalusi@ti.com;
wfp5p@virginia.edu; linux-input@vger.kernel.org;
linux-kernel@vger.kernel.org; akpm@linux-foundation.org;
kyungmin.park@samsung.com; Aristeu Sergio Rozanski Filho
Subject: Re: [PATCH] Input: add regulator haptic driver

Hi Hyunhee,
 
On Fri, Oct 11, 2013 at 11:26:05AM +0900, hyunhee.kim wrote:

From: Hyunhee Kim <redacted>
Date: Wed, 9 Oct 2013 16:21:36 +0900
Subject: [PATCH] Input: add regulator haptic driver

The regulator haptic driver function can be used to control motor by

on/off

This option should be worded better I think.

+	select INPUT_FF_MEMLESS
+	help
+	  Say Y to enable support for the haptics module for regulator.

And explained better to. Also please add "To compile this driver as a
module..."

Please use dev_err() here and also stick error code into the message.

+	} else if (!enable && haptic->enabled) {
+		haptic->enabled = false;
+		ret = regulator_disable(haptic->regulator);
+		if (ret)
+			pr_err("haptic: %s failed to disable regulator\n",
+				__func__);
+	}
+	mutex_unlock(&haptic->mutex);

I wonder if you want separate functions for regulator_haptic_enable and
regulator_haptic_disable seeing how you are using it later in the code.
If not then ...

+}
+
+static void regulator_haptic_work(struct work_struct *work)
+{
+	struct regulator_haptic *haptic = container_of(work,
+						       struct
regulator_haptic,
+						       work);
+	if (haptic->level)
+		regulator_haptic_enable(haptic, true);
+	else
+		regulator_haptic_enable(haptic, false);

... just say:

	regulator_haptic_toggle(haptic, haptic->level != 0);

+
+}
+
+static int regulator_haptic_play(struct input_dev *input, void *data,
+				struct ff_effect *effect)
+{
+	struct regulator_haptic *haptic = input_get_drvdata(input);
+
+	haptic->level = effect->u.rumble.strong_magnitude;
+	if (!haptic->level)
+		haptic->level = effect->u.rumble.weak_magnitude;
+	schedule_work(&haptic->work);
+
+	return 0;
+}
+
+static void regulator_haptic_close(struct input_dev *input)
+{
+	struct regulator_haptic *haptic = input_get_drvdata(input);
+
+	cancel_work_sync(&haptic->work);
+	regulator_haptic_enable(haptic, false);
+}
+
+static int regulator_haptic_probe(struct platform_device *pdev)
+{
+	struct regulator_haptic *haptic;
+	struct input_dev *input_dev;
+	int error;
+
+	haptic = kzalloc(sizeof(*haptic), GFP_KERNEL);
+	if (!haptic) {
+		dev_err(&pdev->dev, "unable to allocate memory for
haptic\n");
+		return -ENOMEM;
+	}
+
+	input_dev = input_allocate_device();
+
+	if (!input_dev) {
+		dev_err(&pdev->dev, "unable to allocate memory\n");
+		error =  -ENOMEM;
+		goto err_kfree_mem;
+	}
+
+	INIT_WORK(&haptic->work, regulator_haptic_work);
+	mutex_init(&haptic->mutex);
+	haptic->input_dev = input_dev;
+	haptic->dev = &pdev->dev;
+	haptic->regulator = regulator_get(&pdev->dev, "haptic");
+
+	if (IS_ERR(haptic->regulator)) {
+		error = PTR_ERR(haptic->regulator);
+		dev_err(&pdev->dev, "unable to get regulator, err: %d\n",
+			error);
+		goto err_ifree_mem;
+	}
+
+	haptic->input_dev->name = "regulator:haptic";
+	haptic->input_dev->dev.parent = &pdev->dev;
+	haptic->input_dev->close = regulator_haptic_close;
+	haptic->enabled = false;
+	input_set_drvdata(haptic->input_dev, haptic);
+	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
+
+	error = input_ff_create_memless(input_dev, NULL,
+				      regulator_haptic_play);
+	if (error) {
+		dev_err(&pdev->dev,
+			"input_ff_create_memless() failed: %d\n",
+			error);
+		goto err_put_regulator;
+	}
+
+	error = input_register_device(haptic->input_dev);
+	if (error) {
+		dev_err(&pdev->dev,
+			"couldn't register input device: %d\n",
+			error);
+		goto err_destroy_ff;
+	}
+
+	platform_set_drvdata(pdev, haptic);
+
+	return 0;
+
+err_destroy_ff:
+	input_ff_destroy(haptic->input_dev);
+err_put_regulator:
+	regulator_put(haptic->regulator);
+err_ifree_mem:
+	input_free_device(haptic->input_dev);
+err_kfree_mem:
+	kfree(haptic);
+
+	return error;
+}
+
+static int regulator_haptic_remove(struct platform_device *pdev)
+{
+	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
+
+	input_unregister_device(haptic->input_dev);

I think you are leaking reference to regulator and memory allocated for
the haptic structure here. Maybe it should all be converted to devm.

+
+	return 0;
+}
+
+static struct of_device_id regulator_haptic_dt_match[] = {
+	{ .compatible = "linux,regulator-haptic" },
+	{},
+};
+
+static struct platform_driver regulator_haptic_driver = {
+	.driver		= {
+		.name	= "regulator-haptic",
+		.owner	= THIS_MODULE,
+		.of_match_table = regulator_haptic_dt_match,
+	},
+
+	.probe		= regulator_haptic_probe,
+	.remove		= regulator_haptic_remove,
+};
+module_platform_driver(regulator_haptic_driver);
+
+MODULE_ALIAS("platform:regulator-haptic");
+MODULE_DESCRIPTION("Regulator haptic driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Hyunhee Kim [off-list ref]");
-- 
1.7.9.5

Thanks.

-- 
Dmitry