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

/*
 * TI/National Semiconductor LP3943 GPIO driver
 *
 * Copyright 2013 Texas Instruments
 *
 * Author: Milo Kim <milo.kim@ti.com>
 *
 * 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 inline struct lp3943_gpio *to_lp3943_gpio(struct gpio_chip *_chip)
{
	return container_of(_chip, struct lp3943_gpio, chip);
}

static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset)
{
	struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(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 = to_lp3943_gpio(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 = to_lp3943_gpio(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 = to_lp3943_gpio(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 = to_lp3943_gpio(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 = to_lp3943_gpio(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.dev = &pdev->dev;

	platform_set_drvdata(pdev, lp3943_gpio);

	return gpiochip_add(&lp3943_gpio->chip);
}

static int lp3943_gpio_remove(struct platform_device *pdev)
{
	struct lp3943_gpio *lp3943_gpio = platform_get_drvdata(pdev);

	gpiochip_remove(&lp3943_gpio->chip);
	return 0;
}

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,
	.remove = lp3943_gpio_remove,
	.driver = {
		.name = "lp3943-gpio",
		.owner = THIS_MODULE,
		.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 <milo.kim@ti.com>
	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
	48	static inline struct lp3943_gpio to_lp3943_gpio(struct gpio_chip _chip)
	49	{
	50	return container_of(_chip, struct lp3943_gpio, chip);
	51	}
	52
	53	static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset)
	54	{
	55	struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
	56	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
	57
	58	/* Return an error if the pin is already assigned */
	59	if (test_and_set_bit(offset, &lp3943->pin_used))
	60	return -EBUSY;
	61
	62	return 0;
	63	}
	64
65	static void lp3943_gpio_free(struct gpio_chip *chip, unsigned offset)
66	{
67	struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
68	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
69
70	clear_bit(offset, &lp3943->pin_used);
71	}
72
73	static int lp3943_gpio_set_mode(struct lp3943_gpio *lp3943_gpio, u8 offset,
74	u8 val)
75	{
76	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
77	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
78
79	return lp3943_update_bits(lp3943, mux[offset].reg, mux[offset].mask,
80	val << mux[offset].shift);
81	}
82
83	static int lp3943_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
84	{
85	struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
86
87	lp3943_gpio->input_mask \|= BIT(offset);
88
89	return lp3943_gpio_set_mode(lp3943_gpio, offset, LP3943_GPIO_IN);
90	}
91
92	static int lp3943_get_gpio_in_status(struct lp3943_gpio *lp3943_gpio,
93	struct gpio_chip *chip, unsigned offset)
94	{
95	u8 addr, read;
96	int err;
97
98	switch (offset) {
99	case LP3943_GPIO1 ... LP3943_GPIO8:
100	addr = LP3943_REG_GPIO_A;
101	break;
102	case LP3943_GPIO9 ... LP3943_GPIO16:
103	addr = LP3943_REG_GPIO_B;
104	offset = offset - 8;
105	break;
106	default:
107	return -EINVAL;
108	}
109
110	err = lp3943_read_byte(lp3943_gpio->lp3943, addr, &read);
111	if (err)
112	return err;
113
114	return !!(read & BIT(offset));
115	}
116
117	static int lp3943_get_gpio_out_status(struct lp3943_gpio *lp3943_gpio,
118	struct gpio_chip *chip, unsigned offset)
119	{
120	struct lp3943 *lp3943 = lp3943_gpio->lp3943;
121	const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
122	u8 read;
123	int err;
124
125	err = lp3943_read_byte(lp3943, mux[offset].reg, &read);
126	if (err)
127	return err;
128
129	read = (read & mux[offset].mask) >> mux[offset].shift;
130
131	if (read == LP3943_GPIO_OUT_HIGH)
132	return 1;
133	else if (read == LP3943_GPIO_OUT_LOW)
134	return 0;
135	else
136	return -EINVAL;
137	}
138
139	static int lp3943_gpio_get(struct gpio_chip *chip, unsigned offset)
140	{
141	struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
142
143	/*
144	* Limitation:
145	* LP3943 doesn't have the GPIO direction register. It provides
146	* only input and output status registers.
147	* So, direction info is required to handle the 'get' operation.
148	* This variable is updated whenever the direction is changed and
149	* it is used here.
150	*/
151
152	if (lp3943_gpio->input_mask & BIT(offset))
153	return lp3943_get_gpio_in_status(lp3943_gpio, chip, offset);
154	else
155	return lp3943_get_gpio_out_status(lp3943_gpio, chip, offset);
156	}
157
158	static void lp3943_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
159	{
160	struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
161	u8 data;
162
163	if (value)
164	data = LP3943_GPIO_OUT_HIGH;
165	else
166	data = LP3943_GPIO_OUT_LOW;
167
168	lp3943_gpio_set_mode(lp3943_gpio, offset, data);
169	}
170
171	static int lp3943_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
172	int value)
173	{
174	struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
175
176	lp3943_gpio_set(chip, offset, value);
177	lp3943_gpio->input_mask &= ~BIT(offset);
178
179	return 0;
180	}
181
182	static const struct gpio_chip lp3943_gpio_chip = {
183	.label = "lp3943",
184	.owner = THIS_MODULE,
185	.request = lp3943_gpio_request,
186	.free = lp3943_gpio_free,
187	.direction_input = lp3943_gpio_direction_input,
188	.get = lp3943_gpio_get,
189	.direction_output = lp3943_gpio_direction_output,
190	.set = lp3943_gpio_set,
191	.base = -1,
192	.ngpio = LP3943_MAX_GPIO,
193	.can_sleep = 1,
194	};
195
196	static int lp3943_gpio_probe(struct platform_device *pdev)
197	{
198	struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
199	struct lp3943_gpio *lp3943_gpio;
200
201	lp3943_gpio = devm_kzalloc(&pdev->dev, sizeof(*lp3943_gpio),
202	GFP_KERNEL);
203	if (!lp3943_gpio)
204	return -ENOMEM;
205
206	lp3943_gpio->lp3943 = lp3943;
207	lp3943_gpio->chip = lp3943_gpio_chip;
208	lp3943_gpio->chip.dev = &pdev->dev;
209
210	platform_set_drvdata(pdev, lp3943_gpio);
211
212	return gpiochip_add(&lp3943_gpio->chip);
213	}
214
215	static int lp3943_gpio_remove(struct platform_device *pdev)
216	{
217	struct lp3943_gpio *lp3943_gpio = platform_get_drvdata(pdev);
218
9f5132ae	219	gpiochip_remove(&lp3943_gpio->chip);
9f5132ae	220	return 0;
0cc59b9d MK	221	}
	222
	223	static const struct of_device_id lp3943_gpio_of_match[] = {
	224	{ .compatible = "ti,lp3943-gpio", },
	225	{ }
	226	};
	227	MODULE_DEVICE_TABLE(of, lp3943_gpio_of_match);
	228
	229	static struct platform_driver lp3943_gpio_driver = {
	230	.probe = lp3943_gpio_probe,
	231	.remove = lp3943_gpio_remove,
	232	.driver = {
	233	.name = "lp3943-gpio",
	234	.owner = THIS_MODULE,
3b1ba0cb	235	.of_match_table = lp3943_gpio_of_match,
0cc59b9d MK	236	},
	237	};
	238	module_platform_driver(lp3943_gpio_driver);
	239
	240	MODULE_DESCRIPTION("LP3943 GPIO driver");
	241	MODULE_ALIAS("platform:lp3943-gpio");
	242	MODULE_AUTHOR("Milo Kim");
	243	MODULE_LICENSE("GPL");