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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * GPIO driver for Exar XR17V35X chip
 *
 * Copyright (C) 2015 Sudip Mukherjee <[email protected]>
 */

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/regmap.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

/*
 * The Device Configuration and UART Configuration Registers
 * for each UART channel take 1KB of memory address space.
 */
#define EXAR_UART_CHANNEL_SIZE 0x400

#define DRIVER_NAME "gpio_exar"

static DEFINE_IDA(ida_index);

struct exar_gpio_chip {
	struct gpio_chip gpio_chip;
	struct regmap *regmap;
	int index;
	char name[20];
	unsigned int first_pin;
	/*
	 * The offset to the cascaded device's (if existing)
	 * Device Configuration Registers.
	 */
	unsigned int cascaded_offset;
};

static unsigned int
exar_offset_to_sel_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset)
{
	unsigned int pin = exar_gpio->first_pin + (offset % 16);
	unsigned int cascaded = offset / 16;
	unsigned int addr = pin / 8 ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;

	return addr + (cascaded ? exar_gpio->cascaded_offset : 0);
}

static unsigned int
exar_offset_to_lvl_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset)
{
	unsigned int pin = exar_gpio->first_pin + (offset % 16);
	unsigned int cascaded = offset / 16;
	unsigned int addr = pin / 8 ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;

	return addr + (cascaded ? exar_gpio->cascaded_offset : 0);
}

static unsigned int
exar_offset_to_bit(struct exar_gpio_chip *exar_gpio, unsigned int offset)
{
	unsigned int pin = exar_gpio->first_pin + (offset % 16);

	return pin % 8;
}

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 = exar_offset_to_sel_addr(exar_gpio, offset);
	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);

	if (regmap_test_bits(exar_gpio->regmap, addr, BIT(bit)))
		return GPIO_LINE_DIRECTION_IN;

	return GPIO_LINE_DIRECTION_OUT;
}

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 = exar_offset_to_lvl_addr(exar_gpio, offset);
	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);

	return !!(regmap_test_bits(exar_gpio->regmap, 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 = exar_offset_to_lvl_addr(exar_gpio, offset);
	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);

	if (value)
		regmap_set_bits(exar_gpio->regmap, addr, BIT(bit));
	else
		regmap_clear_bits(exar_gpio->regmap, addr, BIT(bit));
}

static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
				 int value)
{
	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset);
	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);

	exar_set_value(chip, offset, value);
	regmap_clear_bits(exar_gpio->regmap, addr, BIT(bit));

	return 0;
}

static int exar_direction_input(struct gpio_chip *chip, unsigned int offset)
{
	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset);
	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);

	regmap_set_bits(exar_gpio->regmap, addr, BIT(bit));

	return 0;
}

static void exar_devm_ida_free(void *data)
{
	struct exar_gpio_chip *exar_gpio = data;

	ida_free(&ida_index, exar_gpio->index);
}

static const struct regmap_config exar_regmap_config = {
	.name		= "exar-gpio",
	.reg_bits	= 16,
	.val_bits	= 8,
	.io_port	= true,
};

static int gpio_exar_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct pci_dev *pcidev = to_pci_dev(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(dev, "exar,first-pin", &first_pin);
	if (ret)
		return ret;

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

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

	/*
	 * If cascaded, secondary xr17v354 or xr17v358 have the same amount
	 * of MPIOs as their primaries and the last 4 bits of the primary's
	 * PCI Device ID is the number of its UART channels.
	 */
	if (pcidev->device & GENMASK(15, 12)) {
		ngpios += ngpios;
		exar_gpio->cascaded_offset = (pcidev->device & GENMASK(3, 0)) *
				EXAR_UART_CHANNEL_SIZE;
	}

	/*
	 * We don't need to check the return values of mmio regmap operations (unless
	 * the regmap has a clock attached which is not the case here).
	 */
	exar_gpio->regmap = devm_regmap_init_mmio(dev, p, &exar_regmap_config);
	if (IS_ERR(exar_gpio->regmap))
		return PTR_ERR(exar_gpio->regmap);

	index = ida_alloc(&ida_index, GFP_KERNEL);
	if (index < 0)
		return index;

	ret = devm_add_action_or_reset(dev, exar_devm_ida_free, exar_gpio);
	if (ret)
		return ret;

	sprintf(exar_gpio->name, "exar_gpio%d", index);
	exar_gpio->gpio_chip.label = exar_gpio->name;
	exar_gpio->gpio_chip.parent = 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->index = index;
	exar_gpio->first_pin = first_pin;

	ret = devm_gpiochip_add_data(dev, &exar_gpio->gpio_chip, exar_gpio);
	if (ret)
		return ret;

	return 0;
}

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

module_platform_driver(gpio_exar_driver);

MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_DESCRIPTION("Exar GPIO driver");
MODULE_AUTHOR("Sudip Mukherjee <[email protected]>");
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 <[email protected]>
6596e59e	6	*/
1bfaf129	7
6596e59e SM	8	#include <linux/bitops.h>
	9	#include <linux/device.h>
	10	#include <linux/gpio/driver.h>
26ced453	11	#include <linux/idr.h>
6596e59e SM	12	#include <linux/init.h>
	13	#include <linux/kernel.h>
	14	#include <linux/module.h>
	15	#include <linux/pci.h>
	16	#include <linux/platform_device.h>
36fb7218	17	#include <linux/regmap.h>
6596e59e SM	18
	19	#define EXAR_OFFSET_MPIOLVL_LO 0x90
	20	#define EXAR_OFFSET_MPIOSEL_LO 0x93
	21	#define EXAR_OFFSET_MPIOLVL_HI 0x96
	22	#define EXAR_OFFSET_MPIOSEL_HI 0x99
	23
5134272f QC	24	/*
	25	* The Device Configuration and UART Configuration Registers
	26	* for each UART channel take 1KB of memory address space.
	27	*/
	28	#define EXAR_UART_CHANNEL_SIZE 0x400
	29
6596e59e SM	30	#define DRIVER_NAME "gpio_exar"
	31
	32	static DEFINE_IDA(ida_index);
	33
	34	struct exar_gpio_chip {
	35	struct gpio_chip gpio_chip;
36fb7218	36	struct regmap *regmap;
6596e59e	37	int index;
6596e59e	38	char name[20];
380b1e2f	39	unsigned int first_pin;
5134272f QC	40	/*
	41	* The offset to the cascaded device's (if existing)
	42	* Device Configuration Registers.
	43	*/
	44	unsigned int cascaded_offset;
6596e59e SM	45	};
6596e59e SM	46
696868d0 BG	47	static unsigned int
	48	exar_offset_to_sel_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset)
	49	{
5134272f QC	50	unsigned int pin = exar_gpio->first_pin + (offset % 16);
	51	unsigned int cascaded = offset / 16;
	52	unsigned int addr = pin / 8 ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
	53
	54	return addr + (cascaded ? exar_gpio->cascaded_offset : 0);
696868d0 BG	55	}
	56
	57	static unsigned int
	58	exar_offset_to_lvl_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset)
	59	{
5134272f QC	60	unsigned int pin = exar_gpio->first_pin + (offset % 16);
	61	unsigned int cascaded = offset / 16;
	62	unsigned int addr = pin / 8 ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
	63
	64	return addr + (cascaded ? exar_gpio->cascaded_offset : 0);
696868d0 BG	65	}
	66
	67	static unsigned int
	68	exar_offset_to_bit(struct exar_gpio_chip *exar_gpio, unsigned int offset)
	69	{
5134272f QC	70	unsigned int pin = exar_gpio->first_pin + (offset % 16);
	71
	72	return pin % 8;
696868d0 BG	73	}
696868d0 BG	74
6596e59e SM	75	static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
6596e59e SM	76	{
380b1e2f	77	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
696868d0 BG	78	unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset);
696868d0 BG	79	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
6596e59e	80
36fb7218	81	if (regmap_test_bits(exar_gpio->regmap, addr, BIT(bit)))
e42615ec MV	82	return GPIO_LINE_DIRECTION_IN;
	83
	84	return GPIO_LINE_DIRECTION_OUT;
6596e59e SM	85	}
	86
	87	static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
	88	{
380b1e2f	89	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
696868d0 BG	90	unsigned int addr = exar_offset_to_lvl_addr(exar_gpio, offset);
696868d0 BG	91	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
6596e59e	92
36fb7218	93	return !!(regmap_test_bits(exar_gpio->regmap, addr, BIT(bit)));
6596e59e SM	94	}
	95
	96	static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
	97	int value)
	98	{
380b1e2f	99	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
696868d0 BG	100	unsigned int addr = exar_offset_to_lvl_addr(exar_gpio, offset);
696868d0 BG	101	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
6596e59e	102
36fb7218 BG	103	if (value)
	104	regmap_set_bits(exar_gpio->regmap, addr, BIT(bit));
	105	else
	106	regmap_clear_bits(exar_gpio->regmap, addr, BIT(bit));
6596e59e SM	107	}
6596e59e SM	108
eddeae07 AL	109	static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
	110	int value)
	111	{
36fb7218 BG	112	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	113	unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset);
	114	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
	115
eddeae07	116	exar_set_value(chip, offset, value);
36fb7218 BG	117	regmap_clear_bits(exar_gpio->regmap, addr, BIT(bit));
	118
	119	return 0;
eddeae07 AL	120	}
	121
	122	static int exar_direction_input(struct gpio_chip *chip, unsigned int offset)
	123	{
36fb7218 BG	124	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	125	unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset);
	126	unsigned int bit = exar_offset_to_bit(exar_gpio, offset);
	127
	128	regmap_set_bits(exar_gpio->regmap, addr, BIT(bit));
	129
	130	return 0;
eddeae07 AL	131	}
eddeae07 AL	132
5300ebb6 BG	133	static void exar_devm_ida_free(void *data)
	134	{
	135	struct exar_gpio_chip *exar_gpio = data;
	136
	137	ida_free(&ida_index, exar_gpio->index);
	138	}
	139
36fb7218 BG	140	static const struct regmap_config exar_regmap_config = {
	141	.name = "exar-gpio",
	142	.reg_bits = 16,
	143	.val_bits = 8,
b4e83d36	144	.io_port = true,
36fb7218 BG	145	};
36fb7218 BG	146
6596e59e SM	147	static int gpio_exar_probe(struct platform_device *pdev)
6596e59e SM	148	{
0c2c7e13 BG	149	struct device *dev = &pdev->dev;
0c2c7e13 BG	150	struct pci_dev *pcidev = to_pci_dev(dev->parent);
6596e59e	151	struct exar_gpio_chip *exar_gpio;
380b1e2f	152	u32 first_pin, ngpios;
6596e59e SM	153	void __iomem *p;
	154	int index, ret;
	155
6596e59e	156	/*
8847f5f9 JK	157	* The UART driver must have mapped region 0 prior to registering this
8847f5f9 JK	158	* device - use it.
6596e59e	159	*/
8847f5f9	160	p = pcim_iomap_table(pcidev)[0];
6596e59e SM	161	if (!p)
	162	return -ENOMEM;
	163
0c2c7e13	164	ret = device_property_read_u32(dev, "exar,first-pin", &first_pin);
380b1e2f JK	165	if (ret)
	166	return ret;
	167
0c2c7e13	168	ret = device_property_read_u32(dev, "ngpios", &ngpios);
380b1e2f JK	169	if (ret)
	170	return ret;
	171
0c2c7e13	172	exar_gpio = devm_kzalloc(dev, sizeof(*exar_gpio), GFP_KERNEL);
6596e59e SM	173	if (!exar_gpio)
	174	return -ENOMEM;
	175
5134272f QC	176	/*
	177	* If cascaded, secondary xr17v354 or xr17v358 have the same amount
	178	* of MPIOs as their primaries and the last 4 bits of the primary's
	179	* PCI Device ID is the number of its UART channels.
	180	*/
	181	if (pcidev->device & GENMASK(15, 12)) {
	182	ngpios += ngpios;
	183	exar_gpio->cascaded_offset = (pcidev->device & GENMASK(3, 0)) *
	184	EXAR_UART_CHANNEL_SIZE;
	185	}
	186
36fb7218 BG	187	/*
	188	* We don't need to check the return values of mmio regmap operations (unless
	189	* the regmap has a clock attached which is not the case here).
	190	*/
	191	exar_gpio->regmap = devm_regmap_init_mmio(dev, p, &exar_regmap_config);
	192	if (IS_ERR(exar_gpio->regmap))
	193	return PTR_ERR(exar_gpio->regmap);
6596e59e	194
8e27c2ae	195	index = ida_alloc(&ida_index, GFP_KERNEL);
36fb7218 BG	196	if (index < 0)
36fb7218 BG	197	return index;
6596e59e	198
5300ebb6 BG	199	ret = devm_add_action_or_reset(dev, exar_devm_ida_free, exar_gpio);
	200	if (ret)
	201	return ret;
	202
6596e59e SM	203	sprintf(exar_gpio->name, "exar_gpio%d", index);
6596e59e SM	204	exar_gpio->gpio_chip.label = exar_gpio->name;
0c2c7e13	205	exar_gpio->gpio_chip.parent = dev;
6596e59e SM	206	exar_gpio->gpio_chip.direction_output = exar_direction_output;
	207	exar_gpio->gpio_chip.direction_input = exar_direction_input;
	208	exar_gpio->gpio_chip.get_direction = exar_get_direction;
	209	exar_gpio->gpio_chip.get = exar_get_value;
	210	exar_gpio->gpio_chip.set = exar_set_value;
	211	exar_gpio->gpio_chip.base = -1;
380b1e2f	212	exar_gpio->gpio_chip.ngpio = ngpios;
6596e59e	213	exar_gpio->index = index;
380b1e2f	214	exar_gpio->first_pin = first_pin;
6596e59e	215
0c2c7e13	216	ret = devm_gpiochip_add_data(dev, &exar_gpio->gpio_chip, exar_gpio);
6596e59e	217	if (ret)
5300ebb6	218	return ret;
6596e59e	219
6596e59e SM	220	return 0;
	221	}
	222
	223	static struct platform_driver gpio_exar_driver = {
	224	.probe = gpio_exar_probe,
6596e59e SM	225	.driver = {
	226	.name = DRIVER_NAME,
	227	},
	228	};
	229
	230	module_platform_driver(gpio_exar_driver);
	231
	232	MODULE_ALIAS("platform:" DRIVER_NAME);
	233	MODULE_DESCRIPTION("Exar GPIO driver");
	234	MODULE_AUTHOR("Sudip Mukherjee <[email protected]>");
	235	MODULE_LICENSE("GPL");