path: root/drivers/leds/leds-max77693.c

/*
 * LED Flash class driver for the flash cell of max77693 mfd.
 *
 *	Copyright (C) 2015, Samsung Electronics Co., Ltd.
 *
 *	Authors: Jacek Anaszewski <j.anaszewski@samsung.com>
 *		 Andrzej Hajda <a.hajda@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/led-class-flash.h>
#include <linux/mfd/max77693.h>
#include <linux/mfd/max77693-common.h>
#include <linux/mfd/max77693-private.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <media/v4l2-flash-led-class.h>

#define MODE_OFF		0
#define MODE_FLASH(a)		(1 << (a))
#define MODE_TORCH(a)		(1 << (2 + (a)))
#define MODE_FLASH_EXTERNAL(a)	(1 << (4 + (a)))

#define MODE_FLASH_MASK		(MODE_FLASH(FLED1) | MODE_FLASH(FLED2) | \
				 MODE_FLASH_EXTERNAL(FLED1) | \
				 MODE_FLASH_EXTERNAL(FLED2))
#define MODE_TORCH_MASK		(MODE_TORCH(FLED1) | MODE_TORCH(FLED2))

#define FLED1_IOUT		(1 << 0)
#define FLED2_IOUT		(1 << 1)

enum max77693_fled {
	FLED1,
	FLED2,
};

enum max77693_led_mode {
	FLASH,
	TORCH,
};

struct max77693_led_config_data {
	const char *label[2];
	u32 iout_torch_max[2];
	u32 iout_flash_max[2];
	u32 flash_timeout_max[2];
	u32 num_leds;
	u32 boost_mode;
	u32 boost_vout;
	u32 low_vsys;
};

struct max77693_sub_led {
	/* corresponding FLED output identifier */
	int fled_id;
	/* corresponding LED Flash class device */
	struct led_classdev_flash fled_cdev;
	/* V4L2 Flash device */
	struct v4l2_flash *v4l2_flash;

	/* brightness cache */
	unsigned int torch_brightness;
	/* flash timeout cache */
	unsigned int flash_timeout;
	/* flash faults that may have occurred */
	u32 flash_faults;
};

struct max77693_led_device {
	/* parent mfd regmap */
	struct regmap *regmap;
	/* platform device data */
	struct platform_device *pdev;
	/* secures access to the device */
	struct mutex lock;

	/* sub led data */
	struct max77693_sub_led sub_leds[2];

	/* maximum torch current values for FLED outputs */
	u32 iout_torch_max[2];
	/* maximum flash current values for FLED outputs */
	u32 iout_flash_max[2];

	/* current flash timeout cache */
	unsigned int current_flash_timeout;
	/* ITORCH register cache */
	u8 torch_iout_reg;
	/* mode of fled outputs */
	unsigned int mode_flags;
	/* recently strobed fled */
	int strobing_sub_led_id;
	/* bitmask of FLED outputs use state (bit 0. - FLED1, bit 1. - FLED2) */
	u8 fled_mask;
	/* FLED modes that can be set */
	u8 allowed_modes;

	/* arrangement of current outputs */
	bool iout_joint;
};

static u8 max77693_led_iout_to_reg(u32 ua)
{
	if (ua < FLASH_IOUT_MIN)
		ua = FLASH_IOUT_MIN;
	return (ua - FLASH_IOUT_MIN) / FLASH_IOUT_STEP;
}

static u8 max77693_flash_timeout_to_reg(u32 us)
{
	return (us - FLASH_TIMEOUT_MIN) / FLASH_TIMEOUT_STEP;
}

static inline struct max77693_sub_led *flcdev_to_sub_led(
					struct led_classdev_flash *fled_cdev)
{
	return container_of(fled_cdev, struct max77693_sub_led, fled_cdev);
}

static inline struct max77693_led_device *sub_led_to_led(
					struct max77693_sub_led *sub_led)
{
	return container_of(sub_led, struct max77693_led_device,
				sub_leds[sub_led->fled_id]);
}

static inline u8 max77693_led_vsys_to_reg(u32 mv)
{
	return ((mv - MAX_FLASH1_VSYS_MIN) / MAX_FLASH1_VSYS_STEP) << 2;
}

static inline u8 max77693_led_vout_to_reg(u32 mv)
{
	return (mv - FLASH_VOUT_MIN) / FLASH_VOUT_STEP + FLASH_VOUT_RMIN;
}

static inline bool max77693_fled_used(struct max77693_led_device *led,
					 int fled_id)
{
	u8 fled_bit = (fled_id == FLED1) ? FLED1_IOUT : FLED2_IOUT;

	return led->fled_mask & fled_bit;
}

static int max77693_set_mode_reg(struct max77693_led_device *led, u8 mode)
{
	struct regmap *rmap = led->regmap;
	int ret, v = 0, i;

	for (i = FLED1; i <= FLED2; ++i) {
		if (mode & MODE_TORCH(i))
			v |= FLASH_EN_ON << TORCH_EN_SHIFT(i);

		if (mode & MODE_FLASH(i)) {
			v |= FLASH_EN_ON << FLASH_EN_SHIFT(i);
		} else if (mode & MODE_FLASH_EXTERNAL(i)) {
			v |= FLASH_EN_FLASH << FLASH_EN_SHIFT(i);
			/*
			 * Enable hw triggering also for torch mode, as some
			 * camera sensors use torch led to fathom ambient light
			 * conditions before strobing the flash.
			 */
			v |= FLASH_EN_TORCH << TORCH_EN_SHIFT(i);
		}
	}

	/* Reset the register only prior setting flash modes */
	if (mode & ~(MODE_TORCH(FLED1) | MODE_TORCH(FLED2))) {
		ret = regmap_write(rmap, MAX77693_LED_REG_FLASH_EN, 0);
		if (ret < 0)
			return ret;
	}

	return regmap_write(rmap, MAX77693_LED_REG_FLASH_EN, v);
}

static int max77693_add_mode(struct max77693_led_device *led, u8 mode)
{
	u8 new_mode_flags;
	int i, ret;

	if (led->iout_joint)
		/* Span the mode on FLED2 for joint iouts case */
		mode |= (mode << 1);

	/*
	 * FLASH_EXTERNAL mode activates FLASHEN and TORCHEN pins in the device.
	 * Corresponding register bit fields interfere with SW triggered modes,
	 * thus clear them to ensure proper device configuration.
	 */
	for (i = FLED1; i <= FLED2; ++i)
		if (mode & MODE_FLASH_EXTERNAL(i))
			led->mode_flags &= (~MODE_TORCH(i) & ~MODE_FLASH(i));

	new_mode_flags = mode | led->mode_flags;
	new_mode_flags &= led->allowed_modes;

	if (new_mode_flags<