[linux.git] / drivers / gpio / gpio-lp3943.c

/*
 * TI/National Semiconductor LP3943 GPIO driver
 *
 * Copyright 2013 Texas Instruments
 *
 * Author: Milo Kim <[email protected]>
 *
 * 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; version 2.
 */

#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/mfd/lp3943.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

enum lp3943_gpios {
	LP3943_GPIO1,
	LP3943_GPIO2,
	LP3943_GPIO3,
	LP3943_GPIO4,
	LP3943_GPIO5,
	LP3943_GPIO6,
	LP3943_GPIO7,
	LP3943_GPIO8,
	LP3943_GPIO9,
	LP3943_GPIO10,
	LP3943_GPIO11,
	LP3943_GPIO12,
	LP3943_GPIO13,
	LP3943_GPIO14,
	LP3943_GPIO15,
	LP3943_GPIO16,
	LP3943_MAX_GPIO,
};

struct lp3943_gpio {
	struct gpio_chip chip;
	struct lp3943 *lp3943;
	u16 input_mask;		/* 1 = GPIO is input direction, 0 = output */
};

static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset)
{
	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
	struct lp3943 *lp3943 = lp3943_gpio->lp3943;

	/* Return an error if the pin is already assigned */
	if (test_and_set_bit(offset, &lp3943->pin_used))
		return -EBUSY;

	return 0;
}

static void lp3943_gpio_free(struct gpio_chip *chip, unsigned offset)
{
	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
	struct lp3943 *lp3943 = lp3943_gpio->lp3943;

	clear_bit(offset, &lp3943->pin_used);
}

static int lp3943_gpio_set_mode(struct lp3943_gpio *lp3943_gpio, u8 offset,
				u8 val)
{
	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;

	return lp3943_update_bits(lp3943, mux[offset].reg, mux[offset].mask,
				  val << mux[offset].shift);
}

static int lp3943_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);

	lp3943_gpio->input_mask |= BIT(offset);

	return lp3943_gpio_set_mode(lp3943_gpio, offset, LP3943_GPIO_IN);
}

static int lp3943_get_gpio_in_status(struct lp3943_gpio *lp3943_gpio,
				     struct gpio_chip *chip, unsigned offset)
{
	u8 addr, read;
	int err;

	switch (offset) {
	case LP3943_GPIO1 ... LP3943_GPIO8:
		addr = LP3943_REG_GPIO_A;
		break;
	case LP3943_GPIO9 ... LP3943_GPIO16:
		addr = LP3943_REG_GPIO_B;
		offset = offset - 8;
		break;
	default:
		return -EINVAL;
	}

	err = lp3943_read_byte(lp3943_gpio->lp3943, addr, &read);
	if (err)
		return err;

	return !!(read & BIT(offset));
}

static int lp3943_get_gpio_out_status(struct lp3943_gpio *lp3943_gpio,
				      struct gpio_chip *chip, unsigned offset)
{
	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
	u8 read;
	int err;

	err = lp3943_read_byte(lp3943, mux[offset].reg, &read);
	if (err)
		return err;

	read = (read & mux[offset].mask) >> mux[offset].shift;

	if (read == LP3943_GPIO_OUT_HIGH)
		return 1;
	else if (read == LP3943_GPIO_OUT_LOW)
		return 0;
	else
		return -EINVAL;
}

static int lp3943_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);

	/*
	 * Limitation:
	 *   LP3943 doesn't have the GPIO direction register. It provides
	 *   only input and output status registers.
	 *   So, direction info is required to handle the 'get' operation.
	 *   This variable is updated whenever the direction is changed and
	 *   it is used here.
	 */

	if (lp3943_gpio->input_mask & BIT(offset))
		return lp3943_get_gpio_in_status(lp3943_gpio, chip, offset);
	else
		return lp3943_get_gpio_out_status(lp3943_gpio, chip, offset);
}

static void lp3943_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
	u8 data;

	if (value)
		data = LP3943_GPIO_OUT_HIGH;
	else
		data = LP3943_GPIO_OUT_LOW;

	lp3943_gpio_set_mode(lp3943_gpio, offset, data);
}

static int lp3943_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
					int value)
{
	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);

	lp3943_gpio_set(chip, offset, value);
	lp3943_gpio->input_mask &= ~BIT(offset);

	return 0;
}

static const struct gpio_chip lp3943_gpio_chip = {
	.label			= "lp3943",
	.owner			= THIS_MODULE,
	.request		= lp3943_gpio_request,
	.free			= lp3943_gpio_free,
	.direction_input	= lp3943_gpio_direction_input,
	.get			= lp3943_gpio_get,
	.direction_output	= lp3943_gpio_direction_output,
	.set			= lp3943_gpio_set,
	.base			= -1,
	.ngpio			= LP3943_MAX_GPIO,
	.can_sleep		= 1,
};

static int lp3943_gpio_probe(struct platform_device *pdev)
{
	struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
	struct lp3943_gpio *lp3943_gpio;

	lp3943_gpio = devm_kzalloc(&pdev->dev, sizeof(*lp3943_gpio),
				GFP_KERNEL);
	if (!lp3943_gpio)
		return -ENOMEM;

	lp3943_gpio->lp3943 = lp3943;
	lp3943_gpio->chip = lp3943_gpio_chip;
	lp3943_gpio->chip.parent = &pdev->dev;

	platform_set_drvdata(pdev, lp3943_gpio);

	return devm_gpiochip_add_data(&pdev->dev, &lp3943_gpio->chip,
				      lp3943_gpio);
}

static const struct of_device_id lp3943_gpio_of_match[] = {
	{ .compatible = "ti,lp3943-gpio", },
	{ }
};
MODULE_DEVICE_TABLE(of, lp3943_gpio_of_match);

static struct platform_driver lp3943_gpio_driver = {
	.probe = lp3943_gpio_probe,
	.driver = {
		.name = "lp3943-gpio",
		.of_match_table = lp3943_gpio_of_match,
	},
};
module_platform_driver(lp3943_gpio_driver);

MODULE_DESCRIPTION("LP3943 GPIO driver");
MODULE_ALIAS("platform:lp3943-gpio");
MODULE_AUTHOR("Milo Kim");
MODULE_LICENSE("GPL");
Commit	Line	Data
0cc59b9d MK	1	/*
	2	* TI/National Semiconductor LP3943 GPIO driver
	3	*
	4	* Copyright 2013 Texas Instruments
	5	*
	6	* Author: Milo Kim <[email protected]>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; version 2.
	11	*/
	12
	13	#include <linux/bitops.h>
	14	#include <linux/err.h>
	15	#include <linux/gpio.h>
	16	#include <linux/i2c.h>
	17	#include <linux/mfd/lp3943.h>
	18	#include <linux/module.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/slab.h>
	21
	22	enum lp3943_gpios {
	23	LP3943_GPIO1,
	24	LP3943_GPIO2,
	25	LP3943_GPIO3,
	26	LP3943_GPIO4,
	27	LP3943_GPIO5,
	28	LP3943_GPIO6,
	29	LP3943_GPIO7,
	30	LP3943_GPIO8,
	31	LP3943_GPIO9,
	32	LP3943_GPIO10,
	33	LP3943_GPIO11,
	34	LP3943_GPIO12,
	35	LP3943_GPIO13,
	36	LP3943_GPIO14,
	37	LP3943_GPIO15,
	38	LP3943_GPIO16,
	39	LP3943_MAX_GPIO,
	40	};
	41
	42	struct lp3943_gpio {
	43	struct gpio_chip chip;
	44	struct lp3943 *lp3943;
	45	u16 input_mask; /* 1 = GPIO is input direction, 0 = output */
	46	};
	47
70aba44b LW	48	static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset)
	49	{
	50	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
	51	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
	52
	53	/* Return an error if the pin is already assigned */
	54	if (test_and_set_bit(offset, &lp3943->pin_used))
	55	return -EBUSY;
	56
	57	return 0;
	58	}
	59
	60	static void lp3943_gpio_free(struct gpio_chip *chip, unsigned offset)
	61	{
	62	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
	63	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
	64
	65	clear_bit(offset, &lp3943->pin_used);
	66	}
	67
0cc59b9d MK	68	static int lp3943_gpio_set_mode(struct lp3943_gpio *lp3943_gpio, u8 offset,
	69	u8 val)
	70	{
	71	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
	72	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
	73
	74	return lp3943_update_bits(lp3943, mux[offset].reg, mux[offset].mask,
	75	val << mux[offset].shift);
	76	}
	77
	78	static int lp3943_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
	79	{
a2f33804	80	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
0cc59b9d MK	81
	82	lp3943_gpio->input_mask \|= BIT(offset);
	83
	84	return lp3943_gpio_set_mode(lp3943_gpio, offset, LP3943_GPIO_IN);
	85	}
	86
	87	static int lp3943_get_gpio_in_status(struct lp3943_gpio *lp3943_gpio,
	88	struct gpio_chip *chip, unsigned offset)
	89	{
	90	u8 addr, read;
	91	int err;
	92
	93	switch (offset) {
	94	case LP3943_GPIO1 ... LP3943_GPIO8:
	95	addr = LP3943_REG_GPIO_A;
	96	break;
	97	case LP3943_GPIO9 ... LP3943_GPIO16:
	98	addr = LP3943_REG_GPIO_B;
	99	offset = offset - 8;
	100	break;
	101	default:
	102	return -EINVAL;
	103	}
	104
	105	err = lp3943_read_byte(lp3943_gpio->lp3943, addr, &read);
	106	if (err)
	107	return err;
	108
	109	return !!(read & BIT(offset));
	110	}
	111
	112	static int lp3943_get_gpio_out_status(struct lp3943_gpio *lp3943_gpio,
	113	struct gpio_chip *chip, unsigned offset)
	114	{
	115	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
	116	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
	117	u8 read;
	118	int err;
	119
	120	err = lp3943_read_byte(lp3943, mux[offset].reg, &read);
	121	if (err)
	122	return err;
	123
	124	read = (read & mux[offset].mask) >> mux[offset].shift;
	125
	126	if (read == LP3943_GPIO_OUT_HIGH)
	127	return 1;
	128	else if (read == LP3943_GPIO_OUT_LOW)
	129	return 0;
	130	else
	131	return -EINVAL;
	132	}
	133
	134	static int lp3943_gpio_get(struct gpio_chip *chip, unsigned offset)
	135	{
a2f33804	136	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
0cc59b9d MK	137
	138	/*
	139	* Limitation:
	140	* LP3943 doesn't have the GPIO direction register. It provides
	141	* only input and output status registers.
	142	* So, direction info is required to handle the 'get' operation.
	143	* This variable is updated whenever the direction is changed and
	144	* it is used here.
	145	*/
	146
	147	if (lp3943_gpio->input_mask & BIT(offset))
	148	return lp3943_get_gpio_in_status(lp3943_gpio, chip, offset);
	149	else
	150	return lp3943_get_gpio_out_status(lp3943_gpio, chip, offset);
	151	}
	152
	153	static void lp3943_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
	154	{
a2f33804	155	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
0cc59b9d MK	156	u8 data;
	157
	158	if (value)
	159	data = LP3943_GPIO_OUT_HIGH;
	160	else
	161	data = LP3943_GPIO_OUT_LOW;
	162
	163	lp3943_gpio_set_mode(lp3943_gpio, offset, data);
	164	}
	165
	166	static int lp3943_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
	167	int value)
	168	{
a2f33804	169	struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip);
0cc59b9d MK	170
	171	lp3943_gpio_set(chip, offset, value);
	172	lp3943_gpio->input_mask &= ~BIT(offset);
	173
	174	return 0;
	175	}
	176
	177	static const struct gpio_chip lp3943_gpio_chip = {
	178	.label = "lp3943",
	179	.owner = THIS_MODULE,
70aba44b LW	180	.request = lp3943_gpio_request,
70aba44b LW	181	.free = lp3943_gpio_free,
0cc59b9d MK	182	.direction_input = lp3943_gpio_direction_input,
	183	.get = lp3943_gpio_get,
	184	.direction_output = lp3943_gpio_direction_output,
	185	.set = lp3943_gpio_set,
	186	.base = -1,
	187	.ngpio = LP3943_MAX_GPIO,
	188	.can_sleep = 1,
	189	};
	190
	191	static int lp3943_gpio_probe(struct platform_device *pdev)
	192	{
	193	struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
	194	struct lp3943_gpio *lp3943_gpio;
	195
	196	lp3943_gpio = devm_kzalloc(&pdev->dev, sizeof(*lp3943_gpio),
	197	GFP_KERNEL);
	198	if (!lp3943_gpio)
	199	return -ENOMEM;
	200
	201	lp3943_gpio->lp3943 = lp3943;
	202	lp3943_gpio->chip = lp3943_gpio_chip;
58383c78	203	lp3943_gpio->chip.parent = &pdev->dev;
0cc59b9d MK	204
	205	platform_set_drvdata(pdev, lp3943_gpio);
	206
4ca75bfe LD	207	return devm_gpiochip_add_data(&pdev->dev, &lp3943_gpio->chip,
4ca75bfe LD	208	lp3943_gpio);
0cc59b9d MK	209	}
	210
	211	static const struct of_device_id lp3943_gpio_of_match[] = {
	212	{ .compatible = "ti,lp3943-gpio", },
	213	{ }
	214	};
	215	MODULE_DEVICE_TABLE(of, lp3943_gpio_of_match);
	216
	217	static struct platform_driver lp3943_gpio_driver = {
	218	.probe = lp3943_gpio_probe,
0cc59b9d MK	219	.driver = {
0cc59b9d MK	220	.name = "lp3943-gpio",
3b1ba0cb	221	.of_match_table = lp3943_gpio_of_match,
0cc59b9d MK	222	},
	223	};
	224	module_platform_driver(lp3943_gpio_driver);
	225
	226	MODULE_DESCRIPTION("LP3943 GPIO driver");
	227	MODULE_ALIAS("platform:lp3943-gpio");
	228	MODULE_AUTHOR("Milo Kim");
	229	MODULE_LICENSE("GPL");