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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Kontron PLD GPIO driver
 *
 * Copyright (c) 2010-2013 Kontron Europe GmbH
 * Author: Michael Brunner <[email protected]>
 */

#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/driver.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 <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:kempld-gpio");
Commit	Line	Data
9f806850	1	// SPDX-License-Identifier: GPL-2.0-only
d22fcde0 GR	2	/*
	3	* Kontron PLD GPIO driver
	4	*
	5	* Copyright (c) 2010-2013 Kontron Europe GmbH
	6	* Author: Michael Brunner <[email protected]>
d22fcde0 GR	7	*/
	8
	9	#include <linux/init.h>
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/bitops.h>
	13	#include <linux/errno.h>
	14	#include <linux/platform_device.h>
430f6499	15	#include <linux/gpio/driver.h>
d22fcde0 GR	16	#include <linux/mfd/kempld.h>
	17
	18	#define KEMPLD_GPIO_MAX_NUM 16
459b8180	19	#define KEMPLD_GPIO_MASK(x) (BIT((x) % 8))
d22fcde0 GR	20	#define KEMPLD_GPIO_DIR_NUM(x) (0x40 + (x) / 8)
	21	#define KEMPLD_GPIO_LVL_NUM(x) (0x42 + (x) / 8)
	22	#define KEMPLD_GPIO_EVT_LVL_EDGE 0x46
	23	#define KEMPLD_GPIO_IEN 0x4A
	24
	25	struct kempld_gpio_data {
	26	struct gpio_chip chip;
	27	struct kempld_device_data *pld;
	28	};
	29
	30	/*
	31	* Set or clear GPIO bit
	32	* kempld_get_mutex must be called prior to calling this function.
	33	*/
	34	static void kempld_gpio_bitop(struct kempld_device_data *pld,
	35	u8 reg, u8 bit, u8 val)
	36	{
	37	u8 status;
	38
	39	status = kempld_read8(pld, reg);
	40	if (val)
2e7f6122	41	status \|= KEMPLD_GPIO_MASK(bit);
d22fcde0	42	else
2e7f6122	43	status &= ~KEMPLD_GPIO_MASK(bit);
d22fcde0 GR	44	kempld_write8(pld, reg, status);
	45	}
	46
	47	static int kempld_gpio_get_bit(struct kempld_device_data *pld, u8 reg, u8 bit)
	48	{
	49	u8 status;
	50
	51	kempld_get_mutex(pld);
	52	status = kempld_read8(pld, reg);
	53	kempld_release_mutex(pld);
	54
2e7f6122	55	return !!(status & KEMPLD_GPIO_MASK(bit));
d22fcde0 GR	56	}
	57
	58	static int kempld_gpio_get(struct gpio_chip *chip, unsigned offset)
	59	{
1f89bccd	60	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	61	struct kempld_device_data *pld = gpio->pld;
d22fcde0 GR	62
e9639436	63	return !!kempld_gpio_get_bit(pld, KEMPLD_GPIO_LVL_NUM(offset), offset);
d22fcde0 GR	64	}
	65
	66	static void kempld_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
	67	{
1f89bccd	68	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	69	struct kempld_device_data *pld = gpio->pld;
	70
	71	kempld_get_mutex(pld);
2e7f6122	72	kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), offset, value);
d22fcde0 GR	73	kempld_release_mutex(pld);
	74	}
	75
	76	static int kempld_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
	77	{
1f89bccd	78	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	79	struct kempld_device_data *pld = gpio->pld;
	80
	81	kempld_get_mutex(pld);
2e7f6122	82	kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), offset, 0);
d22fcde0 GR	83	kempld_release_mutex(pld);
	84
	85	return 0;
	86	}
	87
	88	static int kempld_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
	89	int value)
	90	{
1f89bccd	91	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	92	struct kempld_device_data *pld = gpio->pld;
	93
	94	kempld_get_mutex(pld);
2e7f6122 BM	95	kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), offset, value);
2e7f6122 BM	96	kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), offset, 1);
d22fcde0 GR	97	kempld_release_mutex(pld);
	98
	99	return 0;
	100	}
	101
	102	static int kempld_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
	103	{
1f89bccd	104	struct kempld_gpio_data *gpio = gpiochip_get_data(chip);
d22fcde0 GR	105	struct kempld_device_data *pld = gpio->pld;
d22fcde0 GR	106
f230e8ff	107	return !kempld_gpio_get_bit(pld, KEMPLD_GPIO_DIR_NUM(offset), offset);
d22fcde0 GR	108	}
	109
	110	static int kempld_gpio_pincount(struct kempld_device_data *pld)
	111	{
	112	u16 evt, evt_back;
	113
	114	kempld_get_mutex(pld);
	115
	116	/* Backup event register as it might be already initialized */
	117	evt_back = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
	118	/* Clear event register */
	119	kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, 0x0000);
	120	/* Read back event register */
	121	evt = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
	122	/* Restore event register */
	123	kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, evt_back);
	124
	125	kempld_release_mutex(pld);
	126
	127	return evt ? __ffs(evt) : 16;
	128	}
	129
	130	static int kempld_gpio_probe(struct platform_device *pdev)
	131	{
	132	struct device *dev = &pdev->dev;
	133	struct kempld_device_data *pld = dev_get_drvdata(dev->parent);
e56aee18	134	struct kempld_platform_data *pdata = dev_get_platdata(pld->dev);
d22fcde0 GR	135	struct kempld_gpio_data *gpio;
	136	struct gpio_chip *chip;
	137	int ret;
	138
	139	if (pld->info.spec_major < 2) {
	140	dev_err(dev,
	141	"Driver only supports GPIO devices compatible to PLD spec. rev. 2.0 or higher\n");
	142	return -ENODEV;
	143	}
	144
	145	gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
afeb7b45	146	if (!gpio)
d22fcde0 GR	147	return -ENOMEM;
	148
	149	gpio->pld = pld;
	150
	151	platform_set_drvdata(pdev, gpio);
	152
	153	chip = &gpio->chip;
	154	chip->label = "gpio-kempld";
	155	chip->owner = THIS_MODULE;
58383c78	156	chip->parent = dev;
9fb1f39e	157	chip->can_sleep = true;
d22fcde0 GR	158	if (pdata && pdata->gpio_base)
	159	chip->base = pdata->gpio_base;
	160	else
	161	chip->base = -1;
	162	chip->direction_input = kempld_gpio_direction_input;
	163	chip->direction_output = kempld_gpio_direction_output;
	164	chip->get_direction = kempld_gpio_get_direction;
	165	chip->get = kempld_gpio_get;
	166	chip->set = kempld_gpio_set;
	167	chip->ngpio = kempld_gpio_pincount(pld);
	168	if (chip->ngpio == 0) {
	169	dev_err(dev, "No GPIO pins detected\n");
	170	return -ENODEV;
	171	}
	172
7b697b3a	173	ret = devm_gpiochip_add_data(dev, chip, gpio);
d22fcde0 GR	174	if (ret) {
	175	dev_err(dev, "Could not register GPIO chip\n");
	176	return ret;
	177	}
	178
	179	dev_info(dev, "GPIO functionality initialized with %d pins\n",
	180	chip->ngpio);
	181
	182	return 0;
	183	}
	184
d22fcde0 GR	185	static struct platform_driver kempld_gpio_driver = {
d22fcde0 GR	186	.driver = {
81e9df2c	187	.name = "kempld-gpio",
d22fcde0 GR	188	},
d22fcde0 GR	189	.probe = kempld_gpio_probe,
d22fcde0 GR	190	};
	191
	192	module_platform_driver(kempld_gpio_driver);
	193
	194	MODULE_DESCRIPTION("KEM PLD GPIO Driver");
	195	MODULE_AUTHOR("Michael Brunner <[email protected]>");
	196	MODULE_LICENSE("GPL");
9288ecad	197	MODULE_ALIAS("platform:kempld-gpio");