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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * GPIO driver for Exar XR17V35X chip
 *
 * Copyright (C) 2015 Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
 */
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_device.h>

#define EXAR_OFFSET_MPIOLVL_LO 0x90
#define EXAR_OFFSET_MPIOSEL_LO 0x93
#define EXAR_OFFSET_MPIOLVL_HI 0x96
#define EXAR_OFFSET_MPIOSEL_HI 0x99

#define DRIVER_NAME "gpio_exar"

static DEFINE_IDA(ida_index);

struct exar_gpio_chip {
	struct gpio_chip gpio_chip;
	struct mutex lock;
	int index;
	void __iomem *regs;
	char name[20];
	unsigned int first_pin;
};

static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
			unsigned int offset)
{
	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	int temp;

	mutex_lock(&exar_gpio->lock);
	temp = readb(exar_gpio->regs + reg);
	temp &= ~BIT(offset);
	if (val)
		temp |= BIT(offset);
	writeb(temp, exar_gpio->regs + reg);
	mutex_unlock(&exar_gpio->lock);
}

static int exar_set_direction(struct gpio_chip *chip, int direction,
			      unsigned int offset)
{
	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
		EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
	unsigned int bit  = (offset + exar_gpio->first_pin) % 8;

	exar_update(chip, addr, direction, bit);
	return 0;
}

static int exar_get(struct gpio_chip *chip, unsigned int reg)
{
	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	int value;

	mutex_lock(&exar_gpio->lock);
	value = readb(exar_gpio->regs + reg);
	mutex_unlock(&exar_gpio->lock);

	return value;
}

static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
{
	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
		EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
	unsigned int bit  = (offset + exar_gpio->first_pin) % 8;

	return !!(exar_get(chip, addr) & BIT(bit));
}

static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
{
	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
		EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
	unsigned int bit  = (offset + exar_gpio->first_pin) % 8;

	return !!(exar_get(chip, addr) & BIT(bit));
}

static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
			   int value)
{
	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
		EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
	unsigned int bit  = (offset + exar_gpio->first_pin) % 8;

	exar_update(chip, addr, value, bit);
}

static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
				 int value)
{
	exar_set_value(chip, offset, value);
	return exar_set_direction(chip, 0, offset);
}

static int exar_direction_input(struct gpio_chip *chip, unsigned int offset)
{
	return exar_set_direction(chip, 1, offset);
}

static int gpio_exar_probe(struct platform_device *pdev)
{
	struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent);
	struct exar_gpio_chip *exar_gpio;
	u32 first_pin, ngpios;
	void __iomem *p;
	int index, ret;

	/*
	 * The UART driver must have mapped region 0 prior to registering this
	 * device - use it.
	 */
	p = pcim_iomap_table(pcidev)[0];
	if (!p)
		return -ENOMEM;

	ret = device_property_read_u32(&pdev->dev, "exar,first-pin",
				       &first_pin);
	if (ret)
		return ret;

	ret = device_property_read_u32(&pdev->dev, "ngpios", &ngpios);
	if (ret)
		return ret;

	exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL);
	if (!exar_gpio)
		return -ENOMEM;

	mutex_init(&exar_gpio->lock);

	index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
	if (index < 0)
		goto err_destroy;

	sprintf(exar_gpio->name, "exar_gpio%d", index);
	exar_gpio->gpio_chip.label = exar_gpio->name;
	exar_gpio->gpio_chip.parent = &pdev->dev;
	exar_gpio->gpio_chip.direction_output = exar_direction_output;
	exar_gpio->gpio_chip.direction_input = exar_direction_input;
	exar_gpio->gpio_chip.get_direction = exar_get_direction;
	exar_gpio->gpio_chip.get = exar_get_value;
	exar_gpio->gpio_chip.set = exar_set_value;
	exar_gpio->gpio_chip.base = -1;
	exar_gpio->gpio_chip.ngpio = ngpios;
	exar_gpio->regs = p;
	exar_gpio->index = index;
	exar_gpio->first_pin = first_pin;

	ret = devm_gpiochip_add_data(&pdev->dev,
				     &exar_gpio->gpio_chip, exar_gpio);
	if (ret)
		goto err_destroy;

	platform_set_drvdata(pdev, exar_gpio);

	return 0;

err_destroy:
	ida_simple_remove(&ida_index, index);
	mutex_destroy(&exar_gpio->lock);
	return ret;
}

static int gpio_exar_remove(struct platform_device *pdev)
{
	struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev);

	ida_simple_remove(&ida_index, exar_gpio->index);
	mutex_destroy(&exar_gpio->lock);

	return 0;
}

static struct platform_driver gpio_exar_driver = {
	.probe	= gpio_exar_probe,
	.remove	= gpio_exar_remove,
	.driver	= {
		.name = DRIVER_NAME,
	},
};

module_platform_driver(gpio_exar_driver);

MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_DESCRIPTION("Exar GPIO driver");
MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>");
MODULE_LICENSE("GPL");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
6596e59e SM	2	/*
	3	* GPIO driver for Exar XR17V35X chip
	4	*
	5	* Copyright (C) 2015 Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
6596e59e SM	6	*/
	7	#include <linux/bitops.h>
	8	#include <linux/device.h>
	9	#include <linux/gpio/driver.h>
	10	#include <linux/init.h>
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
	13	#include <linux/pci.h>
	14	#include <linux/platform_device.h>
	15
	16	#define EXAR_OFFSET_MPIOLVL_LO 0x90
	17	#define EXAR_OFFSET_MPIOSEL_LO 0x93
	18	#define EXAR_OFFSET_MPIOLVL_HI 0x96
	19	#define EXAR_OFFSET_MPIOSEL_HI 0x99
	20
	21	#define DRIVER_NAME "gpio_exar"
	22
	23	static DEFINE_IDA(ida_index);
	24
	25	struct exar_gpio_chip {
	26	struct gpio_chip gpio_chip;
	27	struct mutex lock;
	28	int index;
	29	void __iomem *regs;
	30	char name[20];
380b1e2f	31	unsigned int first_pin;
6596e59e SM	32	};
	33
	34	static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
	35	unsigned int offset)
	36	{
	37	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	38	int temp;
	39
	40	mutex_lock(&exar_gpio->lock);
	41	temp = readb(exar_gpio->regs + reg);
	42	temp &= ~BIT(offset);
	43	if (val)
	44	temp \|= BIT(offset);
	45	writeb(temp, exar_gpio->regs + reg);
	46	mutex_unlock(&exar_gpio->lock);
	47	}
	48
	49	static int exar_set_direction(struct gpio_chip *chip, int direction,
	50	unsigned int offset)
	51	{
380b1e2f JK	52	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	53	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
	54	EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
	55	unsigned int bit = (offset + exar_gpio->first_pin) % 8;
6596e59e	56
380b1e2f	57	exar_update(chip, addr, direction, bit);
6596e59e SM	58	return 0;
	59	}
	60
6596e59e SM	61	static int exar_get(struct gpio_chip *chip, unsigned int reg)
	62	{
	63	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	64	int value;
	65
	66	mutex_lock(&exar_gpio->lock);
	67	value = readb(exar_gpio->regs + reg);
	68	mutex_unlock(&exar_gpio->lock);
	69
7f45a875	70	return value;
6596e59e SM	71	}
	72
	73	static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
	74	{
380b1e2f JK	75	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	76	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
	77	EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
	78	unsigned int bit = (offset + exar_gpio->first_pin) % 8;
6596e59e	79
380b1e2f	80	return !!(exar_get(chip, addr) & BIT(bit));
6596e59e SM	81	}
	82
	83	static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
	84	{
380b1e2f JK	85	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	86	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
	87	EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
	88	unsigned int bit = (offset + exar_gpio->first_pin) % 8;
6596e59e	89
380b1e2f	90	return !!(exar_get(chip, addr) & BIT(bit));
6596e59e SM	91	}
	92
	93	static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
	94	int value)
	95	{
380b1e2f JK	96	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	97	unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
	98	EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
	99	unsigned int bit = (offset + exar_gpio->first_pin) % 8;
6596e59e	100
380b1e2f	101	exar_update(chip, addr, value, bit);
6596e59e SM	102	}
6596e59e SM	103
eddeae07 AL	104	static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
	105	int value)
	106	{
	107	exar_set_value(chip, offset, value);
	108	return exar_set_direction(chip, 0, offset);
	109	}
	110
	111	static int exar_direction_input(struct gpio_chip *chip, unsigned int offset)
	112	{
	113	return exar_set_direction(chip, 1, offset);
	114	}
	115
6596e59e SM	116	static int gpio_exar_probe(struct platform_device *pdev)
6596e59e SM	117	{
d3936d74	118	struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent);
6596e59e	119	struct exar_gpio_chip *exar_gpio;
380b1e2f	120	u32 first_pin, ngpios;
6596e59e SM	121	void __iomem *p;
	122	int index, ret;
	123
6596e59e	124	/*
8847f5f9 JK	125	* The UART driver must have mapped region 0 prior to registering this
8847f5f9 JK	126	* device - use it.
6596e59e	127	*/
8847f5f9	128	p = pcim_iomap_table(pcidev)[0];
6596e59e SM	129	if (!p)
	130	return -ENOMEM;
	131
a589e211	132	ret = device_property_read_u32(&pdev->dev, "exar,first-pin",
380b1e2f JK	133	&first_pin);
	134	if (ret)
	135	return ret;
	136
	137	ret = device_property_read_u32(&pdev->dev, "ngpios", &ngpios);
	138	if (ret)
	139	return ret;
	140
5dab5872	141	exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL);
6596e59e SM	142	if (!exar_gpio)
	143	return -ENOMEM;
	144
	145	mutex_init(&exar_gpio->lock);
	146
	147	index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
7ecced09 KL	148	if (index < 0)
7ecced09 KL	149	goto err_destroy;
6596e59e SM	150
	151	sprintf(exar_gpio->name, "exar_gpio%d", index);
	152	exar_gpio->gpio_chip.label = exar_gpio->name;
4076cf08	153	exar_gpio->gpio_chip.parent = &pdev->dev;
6596e59e SM	154	exar_gpio->gpio_chip.direction_output = exar_direction_output;
	155	exar_gpio->gpio_chip.direction_input = exar_direction_input;
	156	exar_gpio->gpio_chip.get_direction = exar_get_direction;
	157	exar_gpio->gpio_chip.get = exar_get_value;
	158	exar_gpio->gpio_chip.set = exar_set_value;
	159	exar_gpio->gpio_chip.base = -1;
380b1e2f	160	exar_gpio->gpio_chip.ngpio = ngpios;
6596e59e SM	161	exar_gpio->regs = p;
6596e59e SM	162	exar_gpio->index = index;
380b1e2f	163	exar_gpio->first_pin = first_pin;
6596e59e	164
5dab5872	165	ret = devm_gpiochip_add_data(&pdev->dev,
6596e59e SM	166	&exar_gpio->gpio_chip, exar_gpio);
	167	if (ret)
	168	goto err_destroy;
	169
	170	platform_set_drvdata(pdev, exar_gpio);
	171
	172	return 0;
	173
	174	err_destroy:
	175	ida_simple_remove(&ida_index, index);
	176	mutex_destroy(&exar_gpio->lock);
	177	return ret;
	178	}
	179
	180	static int gpio_exar_remove(struct platform_device *pdev)
	181	{
	182	struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev);
	183
	184	ida_simple_remove(&ida_index, exar_gpio->index);
	185	mutex_destroy(&exar_gpio->lock);
	186
	187	return 0;
	188	}
	189
	190	static struct platform_driver gpio_exar_driver = {
	191	.probe = gpio_exar_probe,
	192	.remove = gpio_exar_remove,
	193	.driver = {
	194	.name = DRIVER_NAME,
	195	},
	196	};
	197
	198	module_platform_driver(gpio_exar_driver);
	199
	200	MODULE_ALIAS("platform:" DRIVER_NAME);
	201	MODULE_DESCRIPTION("Exar GPIO driver");
	202	MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>");
	203	MODULE_LICENSE("GPL");