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

/*
 * 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>

#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 simultanous 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 = container_of(chip, struct mc33880, chip);

	mutex_lock(&mc->lock);

	__mc33880_set(mc, offset, value);

	mutex_unlock(&mc->lock);
}

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

	pdata = spi->dev.platform_data;
	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 = kzalloc(sizeof(struct mc33880), GFP_KERNEL);
	if (!mc)
		return -ENOMEM;

	mutex_init(&mc->lock);

	dev_set_drvdata(&spi->dev, 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 = 1;
	mc->chip.dev = &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) {
		printk(KERN_ERR "Failed writing to " DRIVER_NAME ": %d\n", ret);
		goto exit_destroy;
	}

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

	return ret;

exit_destroy:
	dev_set_drvdata(&spi->dev, NULL);
	mutex_destroy(&mc->lock);
	kfree(mc);
	return ret;
}

static int __devexit mc33880_remove(struct spi_device *spi)
{
	struct mc33880 *mc;
	int ret;

	mc = dev_get_drvdata(&spi->dev);
	if (mc == NULL)
		return -ENODEV;

	dev_set_drvdata(&spi->dev, NULL);

	ret = gpiochip_remove(&mc->chip);
	if (!ret) {
		mutex_destroy(&mc->lock);
		kfree(mc);
	} else
		dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
			ret);

	return ret;
}

static struct spi_driver mc33880_driver = {
	.driver = {
		.name		= DRIVER_NAME,
		.owner		= THIS_MODULE,
	},
	.probe		= mc33880_probe,
	.remove		= __devexit_p(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 RR	1	/*
	2	* mc33880.c MC33880 high-side/low-side switch GPIO driver
	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>
1e5db006 RR	29
	30	#define DRIVER_NAME "mc33880"
	31
	32	/*
	33	* Pin configurations, see MAX7301 datasheet page 6
	34	*/
	35	#define PIN_CONFIG_MASK 0x03
	36	#define PIN_CONFIG_IN_PULLUP 0x03
	37	#define PIN_CONFIG_IN_WO_PULLUP 0x02
	38	#define PIN_CONFIG_OUT 0x01
	39
	40	#define PIN_NUMBER 8
	41
	42
	43	/*
	44	* Some registers must be read back to modify.
	45	* To save time we cache them here in memory
	46	*/
	47	struct mc33880 {
	48	struct mutex lock; /* protect from simultanous accesses */
	49	u8 port_config;
	50	struct gpio_chip chip;
	51	struct spi_device *spi;
	52	};
	53
	54	static int mc33880_write_config(struct mc33880 *mc)
	55	{
	56	return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
	57	}
	58
	59
	60	static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
	61	{
	62	if (value)
	63	mc->port_config \|= 1 << offset;
	64	else
	65	mc->port_config &= ~(1 << offset);
	66
	67	return mc33880_write_config(mc);
	68	}
	69
	70
	71	static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
	72	{
	73	struct mc33880 *mc = container_of(chip, struct mc33880, chip);
	74
	75	mutex_lock(&mc->lock);
	76
	77	__mc33880_set(mc, offset, value);
	78
	79	mutex_unlock(&mc->lock);
	80	}
	81
	82	static int __devinit mc33880_probe(struct spi_device *spi)
	83	{
	84	struct mc33880 *mc;
	85	struct mc33880_platform_data *pdata;
	86	int ret;
	87
	88	pdata = spi->dev.platform_data;
	89	if (!pdata \|\| !pdata->base) {
	90	dev_dbg(&spi->dev, "incorrect or missing platform data\n");
	91	return -EINVAL;
	92	}
93
94	/*
95	* bits_per_word cannot be configured in platform data
96	*/
97	spi->bits_per_word = 8;
98
99	ret = spi_setup(spi);
100	if (ret < 0)
101	return ret;
102
103	mc = kzalloc(sizeof(struct mc33880), GFP_KERNEL);
104	if (!mc)
105	return -ENOMEM;
106
107	mutex_init(&mc->lock);
108
109	dev_set_drvdata(&spi->dev, mc);
110
111	mc->spi = spi;
112
113	mc->chip.label = DRIVER_NAME,
114	mc->chip.set = mc33880_set;
115	mc->chip.base = pdata->base;
116	mc->chip.ngpio = PIN_NUMBER;
117	mc->chip.can_sleep = 1;
118	mc->chip.dev = &spi->dev;
119	mc->chip.owner = THIS_MODULE;
120
121	mc->port_config = 0x00;
122	/* write twice, because during initialisation the first setting
123	* is just for testing SPI communication, and the second is the
124	* "real" configuration
125	*/
126	ret = mc33880_write_config(mc);
127	mc->port_config = 0x00;
128	if (!ret)
129	ret = mc33880_write_config(mc);
130
131	if (ret) {
132	printk(KERN_ERR "Failed writing to " DRIVER_NAME ": %d\n", ret);
133	goto exit_destroy;
134	}
135
136	ret = gpiochip_add(&mc->chip);
137	if (ret)
138	goto exit_destroy;
139
140	return ret;
141
142	exit_destroy:
143	dev_set_drvdata(&spi->dev, NULL);
144	mutex_destroy(&mc->lock);
145	kfree(mc);
146	return ret;
147	}
148
fc1599f7	149	static int __devexit mc33880_remove(struct spi_device *spi)
1e5db006 RR	150	{
	151	struct mc33880 *mc;
	152	int ret;
	153
	154	mc = dev_get_drvdata(&spi->dev);
	155	if (mc == NULL)
	156	return -ENODEV;
	157
	158	dev_set_drvdata(&spi->dev, NULL);
	159
	160	ret = gpiochip_remove(&mc->chip);
	161	if (!ret) {
	162	mutex_destroy(&mc->lock);
	163	kfree(mc);
	164	} else
	165	dev_err(&spi->dev, "Failed to remove the GPIO controller: %d\n",
	166	ret);
	167
	168	return ret;
	169	}
	170
	171	static struct spi_driver mc33880_driver = {
	172	.driver = {
	173	.name = DRIVER_NAME,
	174	.owner = THIS_MODULE,
	175	},
	176	.probe = mc33880_probe,
	177	.remove = __devexit_p(mc33880_remove),
	178	};
	179
	180	static int __init mc33880_init(void)
	181	{
	182	return spi_register_driver(&mc33880_driver);
	183	}
	184	/* register after spi postcore initcall and before
	185	* subsys initcalls that may rely on these GPIOs
	186	*/
	187	subsys_initcall(mc33880_init);
	188
	189	static void __exit mc33880_exit(void)
	190	{
	191	spi_unregister_driver(&mc33880_driver);
	192	}
	193	module_exit(mc33880_exit);
	194
	195	MODULE_AUTHOR("Mocean Laboratories <[email protected]>");
	196	MODULE_LICENSE("GPL v2");
	197