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

/*
 * MC33880 high-side/low-side switch GPIO driver
 * Copyright (c) 2009 Intel Corporation
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* 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.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 int mc33880_remove(struct spi_device *spi)
{
	struct mc33880 *mc;

	mc = spi_get_drvdata(spi);
	if (!mc)
		return -ENODEV;

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

	return 0;
}

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 <[email protected]>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
1e5db006	1	/*
c103de24	2	* MC33880 high-side/low-side switch GPIO driver
1e5db006 RR	3	* Copyright (c) 2009 Intel Corporation
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	17	*/
	18
	19	/* Supports:
	20	* Freescale MC33880 high-side/low-side switch
	21	*/
	22
	23	#include <linux/init.h>
	24	#include <linux/mutex.h>
	25	#include <linux/spi/spi.h>
	26	#include <linux/spi/mc33880.h>
	27	#include <linux/gpio.h>
5a0e3ad6	28	#include <linux/slab.h>
bb207ef1	29	#include <linux/module.h>
1e5db006 RR	30
	31	#define DRIVER_NAME "mc33880"
	32
	33	/*
	34	* Pin configurations, see MAX7301 datasheet page 6
	35	*/
	36	#define PIN_CONFIG_MASK 0x03
	37	#define PIN_CONFIG_IN_PULLUP 0x03
	38	#define PIN_CONFIG_IN_WO_PULLUP 0x02
	39	#define PIN_CONFIG_OUT 0x01
	40
	41	#define PIN_NUMBER 8
	42
	43
	44	/*
	45	* Some registers must be read back to modify.
	46	* To save time we cache them here in memory
	47	*/
	48	struct mc33880 {
25985edc	49	struct mutex lock; /* protect from simultaneous accesses */
1e5db006 RR	50	u8 port_config;
	51	struct gpio_chip chip;
	52	struct spi_device *spi;
	53	};
	54
	55	static int mc33880_write_config(struct mc33880 *mc)
	56	{
	57	return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
	58	}
	59
	60
	61	static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
	62	{
	63	if (value)
	64	mc->port_config \|= 1 << offset;
	65	else
	66	mc->port_config &= ~(1 << offset);
	67
	68	return mc33880_write_config(mc);
	69	}
	70
	71
	72	static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
	73	{
609f9692	74	struct mc33880 *mc = gpiochip_get_data(chip);
1e5db006 RR	75
	76	mutex_lock(&mc->lock);
	77
	78	__mc33880_set(mc, offset, value);
	79
	80	mutex_unlock(&mc->lock);
	81	}
	82
3836309d	83	static int mc33880_probe(struct spi_device *spi)
1e5db006 RR	84	{
	85	struct mc33880 *mc;
	86	struct mc33880_platform_data *pdata;
	87	int ret;
	88
e56aee18	89	pdata = dev_get_platdata(&spi->dev);
1e5db006 RR	90	if (!pdata \|\| !pdata->base) {
	91	dev_dbg(&spi->dev, "incorrect or missing platform data\n");
	92	return -EINVAL;
	93	}
	94
	95	/*
	96	* bits_per_word cannot be configured in platform data
	97	*/
	98	spi->bits_per_word = 8;
	99
	100	ret = spi_setup(spi);
	101	if (ret < 0)
	102	return ret;
	103
632d8e55	104	mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL);
1e5db006 RR	105	if (!mc)
	106	return -ENOMEM;
	107
	108	mutex_init(&mc->lock);
	109
493294d4	110	spi_set_drvdata(spi, mc);
1e5db006 RR	111
	112	mc->spi = spi;
	113
	114	mc->chip.label = DRIVER_NAME,
	115	mc->chip.set = mc33880_set;
	116	mc->chip.base = pdata->base;
	117	mc->chip.ngpio = PIN_NUMBER;
9fb1f39e	118	mc->chip.can_sleep = true;
58383c78	119	mc->chip.parent = &spi->dev;
1e5db006 RR	120	mc->chip.owner = THIS_MODULE;
	121
	122	mc->port_config = 0x00;
	123	/* write twice, because during initialisation the first setting
	124	* is just for testing SPI communication, and the second is the
	125	* "real" configuration
	126	*/
	127	ret = mc33880_write_config(mc);
	128	mc->port_config = 0x00;
	129	if (!ret)
	130	ret = mc33880_write_config(mc);
	131
	132	if (ret) {
30db2bd1 JH	133	dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n",
30db2bd1 JH	134	ret);
1e5db006 RR	135	goto exit_destroy;
	136	}
	137
609f9692	138	ret = gpiochip_add_data(&mc->chip, mc);
1e5db006 RR	139	if (ret)
	140	goto exit_destroy;
	141
	142	return ret;
	143
	144	exit_destroy:
1e5db006	145	mutex_destroy(&mc->lock);
1e5db006 RR	146	return ret;
	147	}
	148
206210ce	149	static int mc33880_remove(struct spi_device *spi)
1e5db006 RR	150	{
1e5db006 RR	151	struct mc33880 *mc;
1e5db006	152
493294d4	153	mc = spi_get_drvdata(spi);
afeb7b45	154	if (!mc)
1e5db006 RR	155	return -ENODEV;
1e5db006 RR	156
9f5132ae	157	gpiochip_remove(&mc->chip);
9f5132ae	158	mutex_destroy(&mc->lock);
1e5db006	159
9f5132ae	160	return 0;
1e5db006 RR	161	}
	162
	163	static struct spi_driver mc33880_driver = {
	164	.driver = {
	165	.name = DRIVER_NAME,
1e5db006 RR	166	},
1e5db006 RR	167	.probe = mc33880_probe,
8283c4ff	168	.remove = mc33880_remove,
1e5db006 RR	169	};
	170
	171	static int __init mc33880_init(void)
	172	{
	173	return spi_register_driver(&mc33880_driver);
	174	}
	175	/* register after spi postcore initcall and before
	176	* subsys initcalls that may rely on these GPIOs
	177	*/
	178	subsys_initcall(mc33880_init);
	179
	180	static void __exit mc33880_exit(void)
	181	{
	182	spi_unregister_driver(&mc33880_driver);
	183	}
	184	module_exit(mc33880_exit);
	185
	186	MODULE_AUTHOR("Mocean Laboratories <[email protected]>");
	187	MODULE_LICENSE("GPL v2");
	188