Re: [PATCH] Input: add regulator haptic driver

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Hyunhee,
 
On Fri, Oct 11, 2013 at 11:26:05AM +0900, hyunhee.kim wrote:
> From: Hyunhee Kim <hyunhee.kim@samsung.com>
> 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
> regulator.
> User can control the haptic driver by using force feedback framework.
> 
> Signed-off-by: Hyunhee Kim <hyunhee.kim@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>  drivers/input/misc/Kconfig            |    6 ++
>  drivers/input/misc/Makefile           |    1 +
>  drivers/input/misc/regulator-haptic.c |  185
> +++++++++++++++++++++++++++++++++
>  3 files changed, 192 insertions(+)
>  create mode 100644 drivers/input/misc/regulator-haptic.c
> 
> diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
> index bb698e1..f391cd7 100644
> --- a/drivers/input/misc/Kconfig
> +++ b/drivers/input/misc/Kconfig
> @@ -82,6 +82,12 @@ 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 "regulator haptics support"

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..."

> +
>  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..29f57ea
> --- /dev/null
> +++ b/drivers/input/misc/regulator-haptic.c
> @@ -0,0 +1,185 @@
> +/*
> + * 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_enable(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)
> +			pr_err("haptic: %s failed to enable regulator\n",
> +				__func__);

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 <hyunhee.kim@samsung.com>");
> -- 
> 1.7.9.5
> 
> 

Thanks.

-- 
Dmitry