[linux-2.6-block.git] / drivers / gpio / gpio-max730x.c

// SPDX-License-Identifier: GPL-2.0-only
/**
 * Copyright (C) 2006 Juergen Beisert, Pengutronix
 * Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix
 * Copyright (C) 2009 Wolfram Sang, Pengutronix
 *
 * The Maxim MAX7300/1 device is an I2C/SPI driven GPIO expander. There are
 * 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more
 * details
 * Note:
 * - DIN must be stable at the rising edge of clock.
 * - when writing:
 *   - always clock in 16 clocks at once
 *   - at DIN: D15 first, D0 last
 *   - D0..D7 = databyte, D8..D14 = commandbyte
 *   - D15 = low -> write command
 * - when reading
 *   - always clock in 16 clocks at once
 *   - at DIN: D15 first, D0 last
 *   - D0..D7 = dummy, D8..D14 = register address
 *   - D15 = high -> read command
 *   - raise CS and assert it again
 *   - always clock in 16 clocks at once
 *   - at DOUT: D15 first, D0 last
 *   - D0..D7 contains the data from the first cycle
 *
 * The driver exports a standard gpiochip interface
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/spi/max7301.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>

/*
 * Pin configurations, see MAX7301 datasheet page 6
 */
#define PIN_CONFIG_MASK 0x03
#define PIN_CONFIG_IN_PULLUP 0x03
#define PIN_CONFIG_IN_WO_PULLUP 0x02
#define PIN_CONFIG_OUT 0x01

#define PIN_NUMBER 28

static int max7301_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct max7301 *ts = gpiochip_get_data(chip);
	u8 *config;
	u8 offset_bits, pin_config;
	int ret;

	/* First 4 pins are unused in the controller */
	offset += 4;
	offset_bits = (offset & 3) << 1;

	config = &ts->port_config[offset >> 2];

	if (ts->input_pullup_active & BIT(offset))
		pin_config = PIN_CONFIG_IN_PULLUP;
	else
		pin_config = PIN_CONFIG_IN_WO_PULLUP;

	mutex_lock(&ts->lock);

	*config = (*config & ~(PIN_CONFIG_MASK << offset_bits))
			   | (pin_config << offset_bits);

	ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);

	mutex_unlock(&ts->lock);

	return ret;
}

static int __max7301_set(struct max7301 *ts, unsigned offset, int value)
{
	if (value) {
		ts->out_level |= 1 << offset;
		return ts->write(ts->dev, 0x20 + offset, 0x01);
	} else {
		ts->out_level &= ~(1 << offset);
		return ts->write(ts->dev, 0x20 + offset, 0x00);
	}
}

static int max7301_direction_output(struct gpio_chip *chip, unsigned offset,
				    int value)
{
	struct max7301 *ts = gpiochip_get_data(chip);
	u8 *config;
	u8 offset_bits;
	int ret;

	/* First 4 pins are unused in the controller */
	offset += 4;
	offset_bits = (offset & 3) << 1;

	config = &ts->port_config[offset >> 2];

	mutex_lock(&ts->lock);

	*config = (*config & ~(PIN_CONFIG_MASK << offset_bits))
			   | (PIN_CONFIG_OUT << offset_bits);

	ret = __max7301_set(ts, offset, value);

	if (!ret)
		ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);

	mutex_unlock(&ts->lock);

	return ret;
}

static int max7301_get(struct gpio_chip *chip, unsigned offset)
{
	struct max7301 *ts = gpiochip_get_data(chip);
	int config, level = -EINVAL;

	/* First 4 pins are unused in the controller */
	offset += 4;

	mutex_lock(&ts->lock);

	config = (ts->port_config[offset >> 2] >> ((offset & 3) << 1))
			& PIN_CONFIG_MASK;

	switch (config) {
	case PIN_CONFIG_OUT:
		/* Output: return cached level */
		level =  !!(ts->out_level & (1 << offset));
		break;
	case PIN_CONFIG_IN_WO_PULLUP:
	case PIN_CONFIG_IN_PULLUP:
		/* Input: read out */
		level = ts->read(ts->dev, 0x20 + offset) & 0x01;
	}
	mutex_unlock(&ts->lock);

	return level;
}

static void max7301_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct max7301 *ts = gpiochip_get_data(chip);

	/* First 4 pins are unused in the controller */
	offset += 4;

	mutex_lock(&ts->lock);

	__max7301_set(ts, offset, value);

	mutex_unlock(&ts->lock);
}

int __max730x_probe(struct max7301 *ts)
{
	struct device *dev = ts->dev;
	struct max7301_platform_data *pdata;
	int i, ret;

	pdata = dev_get_platdata(dev);

	mutex_init(&ts->lock);
	dev_set_drvdata(dev, ts);

	/* Power up the chip and disable IRQ output */
	ts->write(dev, 0x04, 0x01);

	if (pdata) {
		ts->input_pullup_active = pdata->input_pullup_active;
		ts->chip.base = pdata->base;
	} else {
		ts->chip.base = -1;
	}
	ts->chip.label = dev->driver->name;

	ts->chip.direction_input = max7301_direction_input;
	ts->chip.get = max7301_get;
	ts->chip.direction_output = max7301_direction_output;
	ts->chip.set = max7301_set;

	ts->chip.ngpio = PIN_NUMBER;
	ts->chip.can_sleep = true;
	ts->chip.parent = dev;
	ts->chip.owner = THIS_MODULE;

	ret = gpiochip_add_data(&ts->chip, ts);
	if (ret)
		goto exit_destroy;

	/*
	 * initialize pullups according to platform data and cache the
	 * register values for later use.
	 */
	for (i = 1; i < 8; i++) {
		int j;
		/*
		 * initialize port_config with "0xAA", which means
		 * input with internal pullup disabled. This is needed
		 * to avoid writing zeros (in the inner for loop),
		 * which is not allowed according to the datasheet.
		 */
		ts->port_config[i] = 0xAA;
		for (j = 0; j < 4; j++) {
			int offset = (i - 1) * 4 + j;
			ret = max7301_direction_input(&ts->chip, offset);
			if (ret)
				goto exit_destroy;
		}
	}

	return ret;

exit_destroy:
	mutex_destroy(&ts->lock);
	return ret;
}
EXPORT_SYMBOL_GPL(__max730x_probe);

int __max730x_remove(struct device *dev)
{
	struct max7301 *ts = dev_get_drvdata(dev);

	if (ts == NULL)
		return -ENODEV;

	/* Power down the chip and disable IRQ output */
	ts->write(dev, 0x04, 0x00);
	gpiochip_remove(&ts->chip);
	mutex_destroy(&ts->lock);
	return 0;
}
EXPORT_SYMBOL_GPL(__max730x_remove);

MODULE_AUTHOR("Juergen Beisert, Wolfram Sang");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MAX730x GPIO-Expanders, generic parts");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
e952805d	2	/**
e952805d WS	3	* Copyright (C) 2006 Juergen Beisert, Pengutronix
	4	* Copyright (C) 2008 Guennadi Liakhovetski, Pengutronix
	5	* Copyright (C) 2009 Wolfram Sang, Pengutronix
	6	*
e952805d WS	7	* The Maxim MAX7300/1 device is an I2C/SPI driven GPIO expander. There are
	8	* 28 GPIOs. 8 of them can trigger an interrupt. See datasheet for more
	9	* details
	10	* Note:
	11	* - DIN must be stable at the rising edge of clock.
	12	* - when writing:
	13	* - always clock in 16 clocks at once
	14	* - at DIN: D15 first, D0 last
	15	* - D0..D7 = databyte, D8..D14 = commandbyte
	16	* - D15 = low -> write command
	17	* - when reading
	18	* - always clock in 16 clocks at once
	19	* - at DIN: D15 first, D0 last
	20	* - D0..D7 = dummy, D8..D14 = register address
	21	* - D15 = high -> read command
	22	* - raise CS and assert it again
	23	* - always clock in 16 clocks at once
	24	* - at DOUT: D15 first, D0 last
	25	* - D0..D7 contains the data from the first cycle
	26	*
	27	* The driver exports a standard gpiochip interface
	28	*/
	29
	30	#include <linux/module.h>
	31	#include <linux/init.h>
	32	#include <linux/platform_device.h>
	33	#include <linux/mutex.h>
	34	#include <linux/spi/max7301.h>
25424b86	35	#include <linux/gpio/driver.h>
5a0e3ad6	36	#include <linux/slab.h>
e952805d WS	37
	38	/*
	39	* Pin configurations, see MAX7301 datasheet page 6
	40	*/
	41	#define PIN_CONFIG_MASK 0x03
	42	#define PIN_CONFIG_IN_PULLUP 0x03
	43	#define PIN_CONFIG_IN_WO_PULLUP 0x02
	44	#define PIN_CONFIG_OUT 0x01
	45
	46	#define PIN_NUMBER 28
	47
	48	static int max7301_direction_input(struct gpio_chip *chip, unsigned offset)
	49	{
5e45e019	50	struct max7301 *ts = gpiochip_get_data(chip);
e952805d	51	u8 *config;
4a22b8a4	52	u8 offset_bits, pin_config;
e952805d WS	53	int ret;
	54
	55	/* First 4 pins are unused in the controller */
	56	offset += 4;
	57	offset_bits = (offset & 3) << 1;
	58
	59	config = &ts->port_config[offset >> 2];
	60
4a22b8a4 MKB	61	if (ts->input_pullup_active & BIT(offset))
	62	pin_config = PIN_CONFIG_IN_PULLUP;
	63	else
	64	pin_config = PIN_CONFIG_IN_WO_PULLUP;
	65
e952805d WS	66	mutex_lock(&ts->lock);
e952805d WS	67
e952805d	68	config = (config & ~(PIN_CONFIG_MASK << offset_bits))
4a22b8a4	69	\| (pin_config << offset_bits);
e952805d WS	70
	71	ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);
	72
	73	mutex_unlock(&ts->lock);
	74
	75	return ret;
	76	}
	77
	78	static int __max7301_set(struct max7301 *ts, unsigned offset, int value)
	79	{
	80	if (value) {
	81	ts->out_level \|= 1 << offset;
	82	return ts->write(ts->dev, 0x20 + offset, 0x01);
	83	} else {
	84	ts->out_level &= ~(1 << offset);
	85	return ts->write(ts->dev, 0x20 + offset, 0x00);
	86	}
	87	}
	88
	89	static int max7301_direction_output(struct gpio_chip *chip, unsigned offset,
	90	int value)
	91	{
5e45e019	92	struct max7301 *ts = gpiochip_get_data(chip);
e952805d WS	93	u8 *config;
	94	u8 offset_bits;
	95	int ret;
	96
	97	/* First 4 pins are unused in the controller */
	98	offset += 4;
	99	offset_bits = (offset & 3) << 1;
	100
	101	config = &ts->port_config[offset >> 2];
	102
	103	mutex_lock(&ts->lock);
	104
	105	config = (config & ~(PIN_CONFIG_MASK << offset_bits))
	106	\| (PIN_CONFIG_OUT << offset_bits);
	107
	108	ret = __max7301_set(ts, offset, value);
	109
	110	if (!ret)
	111	ret = ts->write(ts->dev, 0x08 + (offset >> 2), *config);
	112
	113	mutex_unlock(&ts->lock);
	114
	115	return ret;
	116	}
	117
	118	static int max7301_get(struct gpio_chip *chip, unsigned offset)
	119	{
5e45e019	120	struct max7301 *ts = gpiochip_get_data(chip);
e952805d WS	121	int config, level = -EINVAL;
	122
	123	/* First 4 pins are unused in the controller */
	124	offset += 4;
	125
	126	mutex_lock(&ts->lock);
	127
	128	config = (ts->port_config[offset >> 2] >> ((offset & 3) << 1))
	129	& PIN_CONFIG_MASK;
	130
	131	switch (config) {
	132	case PIN_CONFIG_OUT:
	133	/* Output: return cached level */
	134	level = !!(ts->out_level & (1 << offset));
	135	break;
	136	case PIN_CONFIG_IN_WO_PULLUP:
	137	case PIN_CONFIG_IN_PULLUP:
	138	/* Input: read out */
	139	level = ts->read(ts->dev, 0x20 + offset) & 0x01;
	140	}
	141	mutex_unlock(&ts->lock);
	142
	143	return level;
	144	}
	145
	146	static void max7301_set(struct gpio_chip *chip, unsigned offset, int value)
	147	{
5e45e019	148	struct max7301 *ts = gpiochip_get_data(chip);
e952805d WS	149
	150	/* First 4 pins are unused in the controller */
	151	offset += 4;
	152
	153	mutex_lock(&ts->lock);
	154
	155	__max7301_set(ts, offset, value);
	156
	157	mutex_unlock(&ts->lock);
	158	}
	159
3836309d	160	int __max730x_probe(struct max7301 *ts)
e952805d WS	161	{
	162	struct device *dev = ts->dev;
	163	struct max7301_platform_data *pdata;
	164	int i, ret;
	165
e56aee18	166	pdata = dev_get_platdata(dev);
e952805d WS	167
	168	mutex_init(&ts->lock);
	169	dev_set_drvdata(dev, ts);
	170
	171	/* Power up the chip and disable IRQ output */
	172	ts->write(dev, 0x04, 0x01);
	173
8754fccb RS	174	if (pdata) {
	175	ts->input_pullup_active = pdata->input_pullup_active;
	176	ts->chip.base = pdata->base;
	177	} else {
	178	ts->chip.base = -1;
	179	}
e952805d WS	180	ts->chip.label = dev->driver->name;
	181
	182	ts->chip.direction_input = max7301_direction_input;
	183	ts->chip.get = max7301_get;
	184	ts->chip.direction_output = max7301_direction_output;
	185	ts->chip.set = max7301_set;
	186
e952805d	187	ts->chip.ngpio = PIN_NUMBER;
9fb1f39e	188	ts->chip.can_sleep = true;
58383c78	189	ts->chip.parent = dev;
e952805d WS	190	ts->chip.owner = THIS_MODULE;
e952805d WS	191
6f4deb18 CL	192	ret = gpiochip_add_data(&ts->chip, ts);
	193	if (ret)
	194	goto exit_destroy;
	195
e952805d	196	/*
4a22b8a4	197	* initialize pullups according to platform data and cache the
e952805d WS	198	* register values for later use.
	199	*/
	200	for (i = 1; i < 8; i++) {
	201	int j;
4a22b8a4 MKB	202	/*
	203	* initialize port_config with "0xAA", which means
	204	* input with internal pullup disabled. This is needed
	205	* to avoid writing zeros (in the inner for loop),
	206	* which is not allowed according to the datasheet.
	207	*/
e952805d WS	208	ts->port_config[i] = 0xAA;
	209	for (j = 0; j < 4; j++) {
	210	int offset = (i - 1) * 4 + j;
	211	ret = max7301_direction_input(&ts->chip, offset);
	212	if (ret)
	213	goto exit_destroy;
	214	}
	215	}
	216
e952805d WS	217	return ret;
	218
	219	exit_destroy:
e952805d WS	220	mutex_destroy(&ts->lock);
	221	return ret;
	222	}
	223	EXPORT_SYMBOL_GPL(__max730x_probe);
	224
206210ce	225	int __max730x_remove(struct device *dev)
e952805d WS	226	{
e952805d WS	227	struct max7301 *ts = dev_get_drvdata(dev);
e952805d WS	228
	229	if (ts == NULL)
	230	return -ENODEV;
	231
e952805d WS	232	/* Power down the chip and disable IRQ output */
e952805d WS	233	ts->write(dev, 0x04, 0x00);
9f5132ae	234	gpiochip_remove(&ts->chip);
9f5132ae	235	mutex_destroy(&ts->lock);
9f5132ae	236	return 0;
e952805d WS	237	}
e952805d WS	238	EXPORT_SYMBOL_GPL(__max730x_remove);
06ca02b0 RR	239
	240	MODULE_AUTHOR("Juergen Beisert, Wolfram Sang");
	241	MODULE_LICENSE("GPL v2");
	242	MODULE_DESCRIPTION("MAX730x GPIO-Expanders, generic parts");