[mirror_ubuntu-artful-kernel.git] / drivers / gpio / gpio-exar.c

/*
 * GPIO driver for Exar XR17V35X chip
 *
 * Copyright (C) 2015 Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
 *
 * 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.
 */
#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);

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