[linux-block.git] / drivers / gpio / gpio-mc33880.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * MC33880 high-side/low-side switch GPIO driver
 * Copyright (c) 2009 Intel Corporation
 */

/* Supports:
 * Freescale MC33880 high-side/low-side switch
 */

#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/spi/spi.h>
#include <linux/spi/mc33880.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>
#include <linux/module.h>

#define DRIVER_NAME "mc33880"

/*
 * 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 8


/*
 * Some registers must be read back to modify.
 * To save time we cache them here in memory
 */
struct mc33880 {
	struct mutex	lock;	/* protect from simultaneous accesses */
	u8		port_config;
	struct gpio_chip chip;
	struct spi_device *spi;
};

static int mc33880_write_config(struct mc33880 *mc)
{
	return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
}


static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
{
	if (value)
		mc->port_config |= 1 << offset;
	else
		mc->port_config &= ~(1 << offset);

	return mc33880_write_config(mc);
}


static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct mc33880 *mc = gpiochip_get_data(chip);

	mutex_lock(&mc->lock);

	__mc33880_set(mc, offset, value);

	mutex_unlock(&mc->lock);
}

static int mc33880_probe(struct spi_device *spi)
{
	struct mc33880 *mc;
	struct mc33880_platform_data *pdata;
	int ret;

	pdata = dev_get_platdata(&spi->dev);
	if (!pdata || !pdata->base) {
		dev_dbg(&spi->dev, "incorrect or missing platform data\n");
		return -EINVAL;
	}

	/*
	 * bits_per_word cannot be configured in platform data
	 */
	spi->bits_per_word = 8;

	ret = spi_setup(spi);
	if (ret < 0)
		return ret;

	mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL);
	if (!mc)
		return -ENOMEM;

	mutex_init(&mc->lock);

	spi_set_drvdata(spi, mc);

	mc->spi = spi;

	mc->chip.label = DRIVER_NAME,
	mc->chip.set = mc33880_set;
	mc->chip.base = pdata->base;
	mc->chip.ngpio = PIN_NUMBER;
	mc->chip.can_sleep = true;
	mc->chip.parent = &spi->dev;
	mc->chip.owner = THIS_MODULE;

	mc->port_config = 0x00;
	/* write twice, because during initialisation the first setting
	 * is just for testing SPI communication, and the second is the
	 * "real" configuration
	 */
	ret = mc33880_write_config(mc);
	mc->port_config = 0x00;
	if (!ret)
		ret = mc33880_write_config(mc);

	if (ret) {
		dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n",
			ret);
		goto exit_destroy;
	}

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

	return ret;

exit_destroy:
	mutex_destroy(&mc->lock);
	return ret;
}

static void mc33880_remove(struct spi_device *spi)
{
	struct mc33880 *mc;

	mc = spi_get_drvdata(spi);

	gpiochip_remove(&mc->chip);
	mutex_destroy(&mc->lock);
}

static struct spi_driver mc33880_driver = {
	.driver = {
		.name		= DRIVER_NAME,
	},
	.probe		= mc33880_probe,
	.remove		= mc33880_remove,
};

static int __init mc33880_init(void)
{
	return spi_register_driver(&mc33880_driver);
}
/* register after spi postcore initcall and before
 * subsys initcalls that may rely on these GPIOs
 */
subsys_initcall(mc33880_init);

static void __exit mc33880_exit(void)
{
	spi_unregister_driver(&mc33880_driver);
}
module_exit(mc33880_exit);

MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
82c29810	1	// SPDX-License-Identifier: GPL-2.0-only
1e5db006	2	/*
c103de24	3	* MC33880 high-side/low-side switch GPIO driver
1e5db006	4	* Copyright (c) 2009 Intel Corporation
1e5db006 RR	5	*/
	6
	7	/* Supports:
	8	* Freescale MC33880 high-side/low-side switch
	9	*/
	10
	11	#include <linux/init.h>
	12	#include <linux/mutex.h>
	13	#include <linux/spi/spi.h>
	14	#include <linux/spi/mc33880.h>
03a3f19c	15	#include <linux/gpio/driver.h>
5a0e3ad6	16	#include <linux/slab.h>
bb207ef1	17	#include <linux/module.h>
1e5db006 RR	18
	19	#define DRIVER_NAME "mc33880"
	20
	21	/*
	22	* Pin configurations, see MAX7301 datasheet page 6
	23	*/
	24	#define PIN_CONFIG_MASK 0x03
	25	#define PIN_CONFIG_IN_PULLUP 0x03
	26	#define PIN_CONFIG_IN_WO_PULLUP 0x02
	27	#define PIN_CONFIG_OUT 0x01
	28
	29	#define PIN_NUMBER 8
	30
	31
	32	/*
	33	* Some registers must be read back to modify.
	34	* To save time we cache them here in memory
	35	*/
	36	struct mc33880 {
25985edc	37	struct mutex lock; /* protect from simultaneous accesses */
1e5db006 RR	38	u8 port_config;
	39	struct gpio_chip chip;
	40	struct spi_device *spi;
	41	};
	42
	43	static int mc33880_write_config(struct mc33880 *mc)
	44	{
	45	return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
	46	}
	47
	48
	49	static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
	50	{
	51	if (value)
	52	mc->port_config \|= 1 << offset;
	53	else
	54	mc->port_config &= ~(1 << offset);
	55
	56	return mc33880_write_config(mc);
	57	}
	58
	59
	60	static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
	61	{
609f9692	62	struct mc33880 *mc = gpiochip_get_data(chip);
1e5db006 RR	63
	64	mutex_lock(&mc->lock);
	65
	66	__mc33880_set(mc, offset, value);
	67
	68	mutex_unlock(&mc->lock);
	69	}
	70
3836309d	71	static int mc33880_probe(struct spi_device *spi)
1e5db006 RR	72	{
	73	struct mc33880 *mc;
	74	struct mc33880_platform_data *pdata;
	75	int ret;
	76
e56aee18	77	pdata = dev_get_platdata(&spi->dev);
1e5db006 RR	78	if (!pdata \|\| !pdata->base) {
	79	dev_dbg(&spi->dev, "incorrect or missing platform data\n");
	80	return -EINVAL;
	81	}
	82
	83	/*
	84	* bits_per_word cannot be configured in platform data
	85	*/
	86	spi->bits_per_word = 8;
	87
	88	ret = spi_setup(spi);
	89	if (ret < 0)
	90	return ret;
	91
632d8e55	92	mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL);
1e5db006 RR	93	if (!mc)
	94	return -ENOMEM;
	95
	96	mutex_init(&mc->lock);
	97
493294d4	98	spi_set_drvdata(spi, mc);
1e5db006 RR	99
	100	mc->spi = spi;
	101
	102	mc->chip.label = DRIVER_NAME,
	103	mc->chip.set = mc33880_set;
	104	mc->chip.base = pdata->base;
	105	mc->chip.ngpio = PIN_NUMBER;
9fb1f39e	106	mc->chip.can_sleep = true;
58383c78	107	mc->chip.parent = &spi->dev;
1e5db006 RR	108	mc->chip.owner = THIS_MODULE;
	109
	110	mc->port_config = 0x00;
	111	/* write twice, because during initialisation the first setting
	112	* is just for testing SPI communication, and the second is the
	113	* "real" configuration
	114	*/
	115	ret = mc33880_write_config(mc);
	116	mc->port_config = 0x00;
	117	if (!ret)
	118	ret = mc33880_write_config(mc);
	119
	120	if (ret) {
30db2bd1 JH	121	dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n",
30db2bd1 JH	122	ret);
1e5db006 RR	123	goto exit_destroy;
	124	}
	125
609f9692	126	ret = gpiochip_add_data(&mc->chip, mc);
1e5db006 RR	127	if (ret)
	128	goto exit_destroy;
	129
	130	return ret;
	131
	132	exit_destroy:
1e5db006	133	mutex_destroy(&mc->lock);
1e5db006 RR	134	return ret;
	135	}
	136
a0386bba	137	static void mc33880_remove(struct spi_device *spi)
1e5db006 RR	138	{
1e5db006 RR	139	struct mc33880 *mc;
1e5db006	140
493294d4	141	mc = spi_get_drvdata(spi);
1e5db006	142
9f5132ae	143	gpiochip_remove(&mc->chip);
9f5132ae	144	mutex_destroy(&mc->lock);
1e5db006 RR	145	}
	146
	147	static struct spi_driver mc33880_driver = {
	148	.driver = {
	149	.name = DRIVER_NAME,
1e5db006 RR	150	},
1e5db006 RR	151	.probe = mc33880_probe,
8283c4ff	152	.remove = mc33880_remove,
1e5db006 RR	153	};
	154
	155	static int __init mc33880_init(void)
	156	{
	157	return spi_register_driver(&mc33880_driver);
	158	}
	159	/* register after spi postcore initcall and before
	160	* subsys initcalls that may rely on these GPIOs
	161	*/
	162	subsys_initcall(mc33880_init);
	163
	164	static void __exit mc33880_exit(void)
	165	{
	166	spi_unregister_driver(&mc33880_driver);
	167	}
	168	module_exit(mc33880_exit);
	169
	170	MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
	171	MODULE_LICENSE("GPL v2");
	172