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

/*
 * Kontron PLD GPIO driver
 *
 * Copyright (c) 2010-2013 Kontron Europe GmbH
 * Author: Michael Brunner <michael.brunner@kontron.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License 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.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/mfd/kempld.h>

#define KEMPLD_GPIO_MAX_NUM		16
#define KEMPLD_GPIO_MASK(x)		(BIT((x) % 8))
#define KEMPLD_GPIO_DIR_NUM(x)		(0x40 + (x) / 8)
#define KEMPLD_GPIO_LVL_NUM(x)		(0x42 + (x) / 8)
#define KEMPLD_GPIO_EVT_LVL_EDGE	0x46
#define KEMPLD_GPIO_IEN			0x4A

struct kempld_gpio_data {
	struct gpio_chip		chip;
	struct kempld_device_data	*pld;
};

/*
 * Set or clear GPIO bit
 * kempld_get_mutex must be called prior to calling this function.
 */
static void kempld_gpio_bitop(struct kempld_device_data *pld,
			      u8 reg, u8 bit, u8 val)
{
	u8 status;

	status = kempld_read8(pld, reg);
	if (val)
		status |= KEMPLD_GPIO_MASK(bit);
	else
		status &= ~KEMPLD_GPIO_MASK(bit);
	kempld_write8(pld, reg, status);
}

static int kempld_gpio_get_bit(struct kempld_device_data *pld, u8 reg, u8 bit)
{
	u8 status;

	kempld_get_mutex(pld);
	status = kempld_read8(pld, reg);
	kempld_release_mutex(pld);

	return !!(status & KEMPLD_GPIO_MASK(bit));
}

static int kempld_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
	struct kempld_device_data *pld = gpio->pld;

	return !!kempld_gpio_get_bit(pld, KEMPLD_GPIO_LVL_NUM(offset), offset);
}

static void kempld_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
	struct kempld_device_data *pld = gpio->pld;

	kempld_get_mutex(pld);
	kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), offset, value);
	kempld_release_mutex(pld);
}

static int kempld_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
	struct kempld_device_data *pld = gpio->pld;

	kempld_get_mutex(pld);
	kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), offset, 0);
	kempld_release_mutex(pld);

	return 0;
}

static int kempld_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
					int value)
{
	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
	struct kempld_device_data *pld = gpio->pld;

	kempld_get_mutex(pld);
	kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), offset, value);
	kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), offset, 1);
	kempld_release_mutex(pld);

	return 0;
}

static int kempld_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
	struct kempld_device_data *pld = gpio->pld;

	return !kempld_gpio_get_bit(pld, KEMPLD_GPIO_DIR_NUM(offset), offset);
}

static int kempld_gpio_pincount(struct kempld_device_data *pld)
{
	u16 evt, evt_back;

	kempld_get_mutex(pld);

	/* Backup event register as it might be already initialized */
	evt_back = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
	/* Clear event register */
	kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, 0x0000);
	/* Read back event register */
	evt = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
	/* Restore event register */
	kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, evt_back);

	kempld_release_mutex(pld);

	return evt ? __ffs(evt) : 16;
}

static int kempld_gpio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct kempld_device_data *pld = dev_get_drvdata(dev->parent);
	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);
	struct kempld_gpio_data *gpio;
	struct gpio_chip *chip;
	int ret;

	if (pld->info.spec_major < 2) {
		dev_err(dev,
			"Driver only supports GPIO devices compatible to PLD spec. rev. 2.0 or higher\n");
		return -ENODEV;
	}

	gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
	if (!gpio)
		return -ENOMEM;

	gpio->pld = pld;

	platform_set_drvdata(pdev, gpio);

	chip = &gpio->chip;
	chip->label = "gpio-kempld";
	chip->owner = THIS_MODULE;
	chip->parent = dev;
	chip->can_sleep = true;
	if (pdata && pdata->gpio_base)
		chip->base = pdata->gpio_base;
	else
		chip->base = -1;
	chip->direction_input = kempld_gpio_direction_input;
	chip->direction_output = kempld_gpio_direction_output;
	chip->get_direction = kempld_gpio_get_direction;
	chip->get = kempld_gpio_get;
	chip->set = kempld_gpio_set;
	chip->ngpio = kempld_gpio_pincount(pld);
	if (chip->ngpio == 0) {
		dev_err(dev, "No GPIO pins detected\n");
		return -ENODEV;
	}

	ret = devm_gpiochip_add_data(dev, chip, gpio);
	if (ret) {
		dev_err(dev, "Could not register GPIO chip\n");
		return ret;
	}

	dev_info(dev, "GPIO functionality initialized with %d pins\n",
		 chip->ngpio);

	return 0;
}

static struct platform_driver kempld_gpio_driver = {
	.driver = {
		.name = "kempld-gpio",
	},
	.probe		= kempld_gpio_probe,
};

module_platform_driver(kempld_gpio_driver);

MODULE_DESCRIPTION("KEM PLD GPIO Driver");
MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:kempld-gpio");
Commit	Line	Data
d22fcde0 GR	1	/*
	2	* Kontron PLD GPIO driver
	3	*
	4	* Copyright (c) 2010-2013 Kontron Europe GmbH
	5	* Author: Michael Brunner <michael.brunner@kontron.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License 2 as published
	9	* by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*/
	16
	17	#include <linux/init.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/bitops.h>
	21	#include <linux/errno.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/gpio.h>
	24	#include <linux/mfd/kempld.h>
	25
	26	#define KEMPLD_GPIO_MAX_NUM 16
459b8180	27	#define KEMPLD_GPIO_MASK(x) (BIT((x) % 8))
d22fcde0 GR	28	#define KEMPLD_GPIO_DIR_NUM(x) (0x40 + (x) / 8)
	29	#define KEMPLD_GPIO_LVL_NUM(x) (0x42 + (x) / 8)
	30	#define KEMPLD_GPIO_EVT_LVL_EDGE 0x46
	31	#define KEMPLD_GPIO_IEN 0x4A
	32
	33	struct kempld_gpio_data {
	34	struct gpio_chip chip;
	35	struct kempld_device_data *pld;
	36	};
	37
	38	/*
	39	* Set or clear GPIO bit
	40	* kempld_get_mutex must be called prior to calling this function.
	41	*/
	42	static void kempld_gpio_bitop(struct kempld_device_data *pld,
	43	u8 reg, u8 bit, u8 val)
	44	{
	45	u8 status;
	46
	47	status = kempld_read8(pld, reg);
	48	if (val)
2e7f6122	49	status \|= KEMPLD_GPIO_MASK(bit);
d22fcde0	50	else
2e7f6122	51	status &= ~KEMPLD_GPIO_MASK(bit);
d22fcde0 GR	52	kempld_write8(pld, reg, status);
	53	}
	54
	55	static int kempld_gpio_get_bit(struct kempld_device_data *pld, u8 reg, u8 bit)
	56	{
	57	u8 status;
	58
	59	kempld_get_mutex(pld);
	60	status = kempld_read8(pld, reg);
	61	kempld_release_mutex(pld);
	62
2e7f6122	63	return !!(status & KEMPLD_GPIO_MASK(bit));
d22fcde0 GR	64	}
	65
	66	static int kempld_gpio_get(struct gpio_chip *chip, unsigned offset)
	67	{
1f89bccd	68	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	69	struct kempld_device_data *pld = gpio->pld;
d22fcde0 GR	70
e9639436	71	return !!kempld_gpio_get_bit(pld, KEMPLD_GPIO_LVL_NUM(offset), offset);
d22fcde0 GR	72	}
	73
	74	static void kempld_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
	75	{
1f89bccd	76	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	77	struct kempld_device_data *pld = gpio->pld;
	78
	79	kempld_get_mutex(pld);
2e7f6122	80	kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), offset, value);
d22fcde0 GR	81	kempld_release_mutex(pld);
	82	}
	83
	84	static int kempld_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
	85	{
1f89bccd	86	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	87	struct kempld_device_data *pld = gpio->pld;
	88
	89	kempld_get_mutex(pld);
2e7f6122	90	kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), offset, 0);
d22fcde0 GR	91	kempld_release_mutex(pld);
	92
	93	return 0;
	94	}
	95
	96	static int kempld_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
	97	int value)
	98	{
1f89bccd	99	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	100	struct kempld_device_data *pld = gpio->pld;
	101
	102	kempld_get_mutex(pld);
2e7f6122 BM	103	kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), offset, value);
2e7f6122 BM	104	kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), offset, 1);
d22fcde0 GR	105	kempld_release_mutex(pld);
	106
	107	return 0;
	108	}
	109
	110	static int kempld_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
	111	{
1f89bccd	112	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	113	struct kempld_device_data *pld = gpio->pld;
d22fcde0 GR	114
f230e8ff	115	return !kempld_gpio_get_bit(pld, KEMPLD_GPIO_DIR_NUM(offset), offset);
d22fcde0 GR	116	}
	117
	118	static int kempld_gpio_pincount(struct kempld_device_data *pld)
	119	{
	120	u16 evt, evt_back;
	121
	122	kempld_get_mutex(pld);
	123
	124	/* Backup event register as it might be already initialized */
	125	evt_back = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
	126	/* Clear event register */
	127	kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, 0x0000);
	128	/* Read back event register */
	129	evt = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
	130	/* Restore event register */
	131	kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, evt_back);
	132
	133	kempld_release_mutex(pld);
	134
	135	return evt ? __ffs(evt) : 16;
	136	}
	137
	138	static int kempld_gpio_probe(struct platform_device *pdev)
	139	{
	140	struct device *dev = &pdev->dev;
	141	struct kempld_device_data *pld = dev_get_drvdata(dev->parent);
e56aee18	142	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);
d22fcde0 GR	143	struct kempld_gpio_data *gpio;
	144	struct gpio_chip *chip;
	145	int ret;
	146
	147	if (pld->info.spec_major < 2) {
	148	dev_err(dev,
	149	"Driver only supports GPIO devices compatible to PLD spec. rev. 2.0 or higher\n");
	150	return -ENODEV;
	151	}
	152
	153	gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
afeb7b45	154	if (!gpio)
d22fcde0 GR	155	return -ENOMEM;
	156
	157	gpio->pld = pld;
	158
	159	platform_set_drvdata(pdev, gpio);
	160
	161	chip = &gpio->chip;
	162	chip->label = "gpio-kempld";
	163	chip->owner = THIS_MODULE;
58383c78	164	chip->parent = dev;
9fb1f39e	165	chip->can_sleep = true;
d22fcde0 GR	166	if (pdata && pdata->gpio_base)
	167	chip->base = pdata->gpio_base;
	168	else
	169	chip->base = -1;
	170	chip->direction_input = kempld_gpio_direction_input;
	171	chip->direction_output = kempld_gpio_direction_output;
	172	chip->get_direction = kempld_gpio_get_direction;
	173	chip->get = kempld_gpio_get;
	174	chip->set = kempld_gpio_set;
	175	chip->ngpio = kempld_gpio_pincount(pld);
	176	if (chip->ngpio == 0) {
	177	dev_err(dev, "No GPIO pins detected\n");
	178	return -ENODEV;
	179	}
	180
7b697b3a	181	ret = devm_gpiochip_add_data(dev, chip, gpio);
d22fcde0 GR	182	if (ret) {
	183	dev_err(dev, "Could not register GPIO chip\n");
	184	return ret;
	185	}
	186
	187	dev_info(dev, "GPIO functionality initialized with %d pins\n",
	188	chip->ngpio);
	189
	190	return 0;
	191	}
	192
d22fcde0 GR	193	static struct platform_driver kempld_gpio_driver = {
d22fcde0 GR	194	.driver = {
81e9df2c	195	.name = "kempld-gpio",
d22fcde0 GR	196	},
d22fcde0 GR	197	.probe = kempld_gpio_probe,
d22fcde0 GR	198	};
	199
	200	module_platform_driver(kempld_gpio_driver);
	201
	202	MODULE_DESCRIPTION("KEM PLD GPIO Driver");
	203	MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>");
	204	MODULE_LICENSE("GPL");
9288ecad	205	MODULE_ALIAS("platform:kempld-gpio");