Message-ID: <20140908213704.GC24033@core.coreip.homeip.net>
Date:	Mon, 8 Sep 2014 14:37:04 -0700
From:	Dmitry Torokhov <dmitry.torokhov@...il.com>
To:	Jaewon Kim <jaewon02.kim@...sung.com>
Cc:	Samuel Ortiz <sameo@...ux.intel.com>,
	Lee Jones <lee.jones@...aro.org>, linux-kernel@...r.kernel.org,
	linux-input@...r.kernel.org, Chanwoo Choi <cw00.choi@...sung.com>
Subject: Re: [PATCH v3 2/4] Input: misc: Add haptic driver on max77693

On Fri, Sep 05, 2014 at 08:48:20PM +0900, Jaewon Kim wrote:
> This patch add max77693-haptic device driver to support the haptic controller
> on MAX77693. The MAX77693 is a Multifunction device with PMIC, CHARGER, LED,
> MUIC, HAPTIC and the patch is haptic device driver in the MAX77693. This driver
> support external pwm and LRA(Linear Resonant Actuator) motor. User can control
> the haptic driver by using force feedback framework.
> 
> Signed-off-by: Jaewon Kim <jaewon02.kim@...sung.com>
> Acked-by: Chanwoo Choi <cw00.choi@...sung.com>
> ---
>  drivers/input/misc/Kconfig           |   12 ++
>  drivers/input/misc/Makefile          |    1 +
>  drivers/input/misc/max77693-haptic.c |  321 ++++++++++++++++++++++++++++++++++
>  include/linux/mfd/max77693-private.h |    9 +
>  4 files changed, 343 insertions(+)
>  create mode 100644 drivers/input/misc/max77693-haptic.c
> 
> diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
> index 2ff4425..c597c52 100644
> --- a/drivers/input/misc/Kconfig
> +++ b/drivers/input/misc/Kconfig
> @@ -144,6 +144,18 @@ config INPUT_M68K_BEEP
>  	tristate "M68k Beeper support"
>  	depends on M68K
>  
> +config INPUT_MAX77693_HAPTIC
> +	tristate "MAXIM MAX77693 haptic controller support"
> +	depends on MFD_MAX77693 && PWM
> +	select INPUT_FF_MEMLESS
> +	help
> +	  This option enables device driver support for the haptic controller
> +	  on MAXIM MAX77693 chip. This driver supports ff-memless interface
> +	  from input framework.
> +
> +	  To compile this driver as module, choose M here: the
> +	  module will be called max77693-haptic.
> +
>  config INPUT_MAX8925_ONKEY
>  	tristate "MAX8925 ONKEY support"
>  	depends on MFD_MAX8925
> diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
> index 4955ad3..b28570c 100644
> --- a/drivers/input/misc/Makefile
> +++ b/drivers/input/misc/Makefile
> @@ -35,6 +35,7 @@ obj-$(CONFIG_INPUT_IXP4XX_BEEPER)	+= ixp4xx-beeper.o
>  obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
>  obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o
>  obj-$(CONFIG_INPUT_M68K_BEEP)		+= m68kspkr.o
> +obj-$(CONFIG_INPUT_MAX77693_HAPTIC)	+= max77693-haptic.o
>  obj-$(CONFIG_INPUT_MAX8925_ONKEY)	+= max8925_onkey.o
>  obj-$(CONFIG_INPUT_MAX8997_HAPTIC)	+= max8997_haptic.o
>  obj-$(CONFIG_INPUT_MC13783_PWRBUTTON)	+= mc13783-pwrbutton.o
> diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
> new file mode 100644
> index 0000000..d06026b
> --- /dev/null
> +++ b/drivers/input/misc/max77693-haptic.c
> @@ -0,0 +1,321 @@
> +/*
> + * max77693-haptic.c - MAXIM MAX77693 Haptic device driver
> + *
> + * Copyright (C) 2014 Samsung Electronics
> + * Jaewon Kim <jaewon02.kim@...sung.com>
> + *
> + * 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.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/input.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/mfd/max77693.h>
> +#include <linux/mfd/max77693-private.h>
> +
> +#define MAX_MAGNITUDE_SHIFT	16
> +
> +enum max77693_haptic_motor_type {
> +	MAX77693_HAPTIC_ERM = 0,
> +	MAX77693_HAPTIC_LRA,
> +};
> +
> +enum max77693_haptic_pulse_mode {
> +	MAX77693_HAPTIC_EXTERNAL_MODE = 0,
> +	MAX77693_HAPTIC_INTERNAL_MODE,
> +};
> +
> +enum max77693_haptic_pwm_divisor {
> +	MAX77693_HAPTIC_PWM_DIVISOR_32 = 0,
> +	MAX77693_HAPTIC_PWM_DIVISOR_64,
> +	MAX77693_HAPTIC_PWM_DIVISOR_128,
> +	MAX77693_HAPTIC_PWM_DIVISOR_256,
> +};
> +
> +struct max77693_haptic {
> +	struct regmap *regmap_pmic;
> +	struct regmap *regmap_haptic;
> +	struct device *dev;
> +	struct input_dev *input_dev;
> +	struct pwm_device *pwm_dev;
> +	struct regulator *motor_reg;
> +
> +	bool enabled;
> +	unsigned int magnitude;
> +	unsigned int pwm_duty;
> +	enum max77693_haptic_motor_type type;
> +	enum max77693_haptic_pulse_mode mode;
> +	enum max77693_haptic_pwm_divisor pwm_divisor;
> +
> +	struct work_struct work;
> +};
> +
> +static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
> +{
> +	int ret;
> +	int delta = (haptic->pwm_dev->period + haptic->pwm_duty)/2;

Spaces around '/'.

> +
> +	ret = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
> +	if (ret) {
> +		dev_err(haptic->dev, "cannot configuration pwm\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int max77693_haptic_configure(struct max77693_haptic *haptic,
> +						unsigned int enable)

bool?

> +{
> +	int ret;
> +	unsigned int value = 0;
> +

You do not need to initialize value and assign a brand new value to it
immediately after.

> +	value = ((haptic->type << MAX77693_CONFIG2_MODE) |
> +		(enable << MAX77693_CONFIG2_MEN) |
> +		(haptic->mode << MAX77693_CONFIG2_HTYP) |
> +		(haptic->pwm_divisor));
> +
> +	ret = regmap_write(haptic->regmap_haptic,
> +				MAX77693_HAPTIC_REG_CONFIG2, value);
> +	if (ret) {
> +		dev_err(haptic->dev, "cannot write haptic regmap\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int max77693_haptic_lowsys(struct max77693_haptic *haptic,
> +						unsigned int enable)

bool

> +{
> +	int ret;
> +
> +	ret = regmap_update_bits(haptic->regmap_pmic,
> +			MAX77693_PMIC_REG_LSCNFG,
> +			MAX77693_PMIC_LOW_SYS_MASK,
> +			enable << MAX77693_PMIC_LOW_SYS_SHIFT);
> +	if (ret) {
> +		dev_err(haptic->dev, "cannot update pmic regmap\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void max77693_haptic_enable(struct max77693_haptic *haptic)
> +{
> +	int ret;
> +
> +	if (haptic->enabled)
> +		return;
> +
> +	ret = pwm_enable(haptic->pwm_dev);
> +	if (ret) {
> +		dev_err(haptic->dev, "cannot enable haptic pwm device");
> +		return;
> +	}
> +
> +	ret = max77693_haptic_lowsys(haptic, 1);
> +	if (ret)
> +		goto err_enable_lowsys;
> +
> +	ret = max77693_haptic_configure(haptic, 1);
> +	if (ret)
> +		goto err_enable_config;
> +
> +	haptic->enabled = true;
> +
> +	return;
> +
> +err_enable_config:
> +	max77693_haptic_lowsys(haptic, 0);
> +err_enable_lowsys:
> +	pwm_disable(haptic->pwm_dev);
> +}
> +
> +static void max77693_haptic_disable(struct max77693_haptic *haptic)
> +{
> +	int ret;
> +
> +	if (!haptic->enabled)
> +		return;
> +
> +	ret = max77693_haptic_configure(haptic, 0);
> +	if (ret)
> +		return;
> +
> +	ret = max77693_haptic_lowsys(haptic, 0);
> +	if (ret)
> +		goto err_disable_lowsys;
> +
> +	pwm_disable(haptic->pwm_dev);
> +	haptic->enabled = false;
> +
> +	return;
> +
> +err_disable_lowsys:
> +	max77693_haptic_configure(haptic, 1);
> +}
> +
> +static void max77693_haptic_play_work(struct work_struct *work)
> +{
> +	struct max77693_haptic *haptic =
> +			container_of(work, struct max77693_haptic, work);
> +	int ret;
> +
> +	ret = max77693_haptic_set_duty_cycle(haptic);
> +	if (ret) {
> +		dev_err(haptic->dev, "cannot set duty cycle\n");
> +		return;
> +	}
> +
> +	if (haptic->magnitude)
> +		max77693_haptic_enable(haptic);
> +	else
> +		max77693_haptic_disable(haptic);
> +}
> +
> +static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
> +				struct ff_effect *effect)
> +{
> +	struct max77693_haptic *haptic = input_get_drvdata(dev);
> +	uint64_t period_mag_multi;
> +
> +	haptic->magnitude = effect->u.rumble.strong_magnitude;
> +	if (!haptic->magnitude)
> +		haptic->magnitude = effect->u.rumble.weak_magnitude;
> +
> +	/*
> +	 * The magnitude comes from force-feedback interface.
> +	 * The formula convert magnitude to pwm_duty as following:
> +	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
> +	 */
> +	period_mag_multi = (int64_t)(haptic->pwm_dev->period *
> +						haptic->magnitude);
> +	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
> +						MAX_MAGNITUDE_SHIFT);
> +
> +	schedule_work(&haptic->work);
> +
> +	return 0;
> +}
> +
> +static void max77693_haptic_close(struct input_dev *dev)
> +{
> +	struct max77693_haptic *haptic = input_get_drvdata(dev);
> +
> +	cancel_work_sync(&haptic->work);
> +	max77693_haptic_disable(haptic);
> +}
> +
> +static int max77693_haptic_probe(struct platform_device *pdev)
> +{
> +	struct max77693_dev *max77693 = dev_get_drvdata(pdev->dev.parent);
> +	struct max77693_haptic *haptic;
> +	int ret = 0;
> +
> +	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
> +	if (!haptic)
> +		return -ENOMEM;
> +
> +	haptic->regmap_pmic = max77693->regmap;
> +	haptic->regmap_haptic = max77693->regmap_haptic;
> +	haptic->dev = &pdev->dev;
> +	haptic->type = MAX77693_HAPTIC_LRA;
> +	haptic->mode = MAX77693_HAPTIC_EXTERNAL_MODE;
> +	haptic->pwm_divisor = MAX77693_HAPTIC_PWM_DIVISOR_128;
> +
> +	/* Get pwm and regulatot for haptic device */
> +	haptic->pwm_dev = devm_pwm_get(&pdev->dev, NULL);
> +	if (IS_ERR(haptic->pwm_dev)) {
> +		dev_err(&pdev->dev, "failed to get pwm device\n");
> +		return PTR_ERR(haptic->pwm_dev);
> +	}
> +
> +	haptic->motor_reg = devm_regulator_get(&pdev->dev, "haptic");
> +	if (IS_ERR(haptic->motor_reg)) {
> +		dev_err(&pdev->dev, "failed to get regulator\n");
> +		return PTR_ERR(haptic->motor_reg);
> +	}
> +
> +	ret = regulator_enable(haptic->motor_reg);
> +	if (ret) {
> +		dev_err(haptic->dev, "failed to enable regulator\n");
> +		return ret;
> +	}
> +
> +	/* Initialize input device for haptic device */
> +	haptic->input_dev = devm_input_allocate_device(&pdev->dev);
> +	if (!haptic->input_dev) {
> +		dev_err(&pdev->dev, "failed to allocate input device\n");

Hmm.. is it OK for the regulator to stay enabled? Actually, why don't
you put regulator enable/disable in open/close?

> +		return -ENOMEM;
> +	}
> +
> +	haptic->input_dev->name = "max77693-haptic";
> +	haptic->input_dev->id.version = 1;
> +	haptic->input_dev->dev.parent = &pdev->dev;
> +	haptic->input_dev->close = max77693_haptic_close;
> +	input_set_drvdata(haptic->input_dev, haptic);
> +	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
> +
> +	ret = input_ff_create_memless(haptic->input_dev, NULL,
> +				max77693_haptic_play_effect);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to create force-feedback\n");
> +		return ret;
> +	}
> +
> +	ret = input_register_device(haptic->input_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to register input device\n");
> +		return ret;
> +	}
> +
> +	INIT_WORK(&haptic->work, max77693_haptic_play_work);

You need to initialize work before creating input device, otherwise
there is a chance play request would come before work is initialized.

> +
> +	platform_set_drvdata(pdev, haptic);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int max77693_haptic_suspend(struct device *dev)
> +{
> +	struct platform_device *pdev = to_platform_device(dev);
> +	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
> +
> +	max77693_haptic_disable(haptic);
> +
> +	return 0;
> +}

I still think you need resume as well. If for some reason you suspended
vibrating you need to resume and continue vibrating. Sleep should be
transparent to users.

> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(max77693_haptic_pm_ops, max77693_haptic_suspend, NULL);
> +
> +static struct platform_driver max77693_haptic_driver = {
> +	.driver		= {
> +		.name	= "max77693-haptic",
> +		.owner	= THIS_MODULE,
> +		.pm	= &max77693_haptic_pm_ops,
> +	},
> +	.probe		= max77693_haptic_probe,
> +};
> +module_platform_driver(max77693_haptic_driver);
> +
> +MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@...sung.com>");
> +MODULE_DESCRIPTION("MAXIM MAX77693 Haptic driver");
> +MODULE_ALIAS("platform:max77693-haptic");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/max77693-private.h b/include/linux/mfd/max77693-private.h
> index c466ff3..d0e578f 100644
> --- a/include/linux/mfd/max77693-private.h
> +++ b/include/linux/mfd/max77693-private.h
> @@ -251,6 +251,15 @@ enum max77693_haptic_reg {
>  	MAX77693_HAPTIC_REG_END,
>  };
>  
> +/* max77693-pmic LSCNFG configuraton register */
> +#define MAX77693_PMIC_LOW_SYS_MASK      0x80
> +#define MAX77693_PMIC_LOW_SYS_SHIFT     7
> +
> +/* max77693-haptic configuration register */
> +#define MAX77693_CONFIG2_MODE           7
> +#define MAX77693_CONFIG2_MEN            6
> +#define MAX77693_CONFIG2_HTYP           5
> +
>  enum max77693_irq_source {
>  	LED_INT = 0,
>  	TOPSYS_INT,
> -- 
> 1.7.9.5
> 

Thanks.

-- 
Dmitry
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists