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

/*
 * GPIO driver for Exar XR17V35X chip
 *
 * Copyright (C) 2015 Sudip Mukherjee <[email protected]>
 *
 * 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];
};

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)
{
	unsigned int bank = offset / 8;
	unsigned int addr;

	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
	exar_update(chip, addr, direction, offset % 8);
	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)
{
	unsigned int bank = offset / 8;
	unsigned int addr;
	int val;

	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
	val = exar_get(chip, addr) & BIT(offset % 8);

	return !!val;
}

static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
{
	unsigned int bank = offset / 8;
	unsigned int addr;
	int val;

	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
	val = exar_get(chip, addr) & BIT(offset % 8);

	return !!val;
}

static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
			   int value)
{
	unsigned int bank = offset / 8;
	unsigned int addr;

	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
	exar_update(chip, addr, value, offset % 8);
}

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;
	void __iomem *p;
	int index, ret;

	/*
	 * Map the pci device to get the register addresses.
	 * We will need to read and write those registers to control
	 * the GPIO pins.
	 * Using managed functions will save us from unmaping on exit.
	 * As the device is enabled using managed functions by the
	 * UART driver we can also use managed functions here.
	 */
	p = pcim_iomap(pcidev, 0, 0);
	if (!p)
		return -ENOMEM;

	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 = &pcidev->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 = 16;
	exar_gpio->regs = p;
	exar_gpio->index = index;

	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 <[email protected]>");
MODULE_LICENSE("GPL");
Commit	Line	Data
6596e59e SM	1	/*
	2	* GPIO driver for Exar XR17V35X chip
	3	*
	4	* Copyright (C) 2015 Sudip Mukherjee <[email protected]>
	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];
	34	};
	35
	36	static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
	37	unsigned int offset)
	38	{
	39	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	40	int temp;
	41
	42	mutex_lock(&exar_gpio->lock);
	43	temp = readb(exar_gpio->regs + reg);
	44	temp &= ~BIT(offset);
	45	if (val)
	46	temp \|= BIT(offset);
	47	writeb(temp, exar_gpio->regs + reg);
	48	mutex_unlock(&exar_gpio->lock);
	49	}
	50
	51	static int exar_set_direction(struct gpio_chip *chip, int direction,
	52	unsigned int offset)
	53	{
	54	unsigned int bank = offset / 8;
	55	unsigned int addr;
	56
	57	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
	58	exar_update(chip, addr, direction, offset % 8);
	59	return 0;
	60	}
	61
6596e59e SM	62	static int exar_get(struct gpio_chip *chip, unsigned int reg)
	63	{
	64	struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
	65	int value;
	66
	67	mutex_lock(&exar_gpio->lock);
	68	value = readb(exar_gpio->regs + reg);
	69	mutex_unlock(&exar_gpio->lock);
	70
7f45a875	71	return value;
6596e59e SM	72	}
	73
	74	static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
	75	{
	76	unsigned int bank = offset / 8;
	77	unsigned int addr;
	78	int val;
	79
	80	addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
7f45a875	81	val = exar_get(chip, addr) & BIT(offset % 8);
6596e59e SM	82
	83	return !!val;
	84	}
	85
	86	static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
	87	{
	88	unsigned int bank = offset / 8;
	89	unsigned int addr;
	90	int val;
	91
7f45a875 JK	92	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
7f45a875 JK	93	val = exar_get(chip, addr) & BIT(offset % 8);
6596e59e SM	94
	95	return !!val;
	96	}
	97
	98	static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
	99	int value)
	100	{
	101	unsigned int bank = offset / 8;
	102	unsigned int addr;
	103
	104	addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
	105	exar_update(chip, addr, value, offset % 8);
	106	}
	107
eddeae07 AL	108	static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
	109	int value)
	110	{
	111	exar_set_value(chip, offset, value);
	112	return exar_set_direction(chip, 0, offset);
	113	}
	114
	115	static int exar_direction_input(struct gpio_chip *chip, unsigned int offset)
	116	{
	117	return exar_set_direction(chip, 1, offset);
	118	}
	119
6596e59e SM	120	static int gpio_exar_probe(struct platform_device *pdev)
6596e59e SM	121	{
d3936d74	122	struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent);
6596e59e SM	123	struct exar_gpio_chip *exar_gpio;
	124	void __iomem *p;
	125	int index, ret;
	126
6596e59e SM	127	/*
	128	* Map the pci device to get the register addresses.
	129	* We will need to read and write those registers to control
	130	* the GPIO pins.
	131	* Using managed functions will save us from unmaping on exit.
	132	* As the device is enabled using managed functions by the
	133	* UART driver we can also use managed functions here.
	134	*/
	135	p = pcim_iomap(pcidev, 0, 0);
	136	if (!p)
	137	return -ENOMEM;
	138
5dab5872	139	exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL);
6596e59e SM	140	if (!exar_gpio)
	141	return -ENOMEM;
	142
	143	mutex_init(&exar_gpio->lock);
	144
	145	index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
	146
	147	sprintf(exar_gpio->name, "exar_gpio%d", index);
	148	exar_gpio->gpio_chip.label = exar_gpio->name;
	149	exar_gpio->gpio_chip.parent = &pcidev->dev;
	150	exar_gpio->gpio_chip.direction_output = exar_direction_output;
	151	exar_gpio->gpio_chip.direction_input = exar_direction_input;
	152	exar_gpio->gpio_chip.get_direction = exar_get_direction;
	153	exar_gpio->gpio_chip.get = exar_get_value;
	154	exar_gpio->gpio_chip.set = exar_set_value;
	155	exar_gpio->gpio_chip.base = -1;
	156	exar_gpio->gpio_chip.ngpio = 16;
	157	exar_gpio->regs = p;
	158	exar_gpio->index = index;
	159
5dab5872	160	ret = devm_gpiochip_add_data(&pdev->dev,
6596e59e SM	161	&exar_gpio->gpio_chip, exar_gpio);
	162	if (ret)
	163	goto err_destroy;
	164
	165	platform_set_drvdata(pdev, exar_gpio);
	166
	167	return 0;
	168
	169	err_destroy:
	170	ida_simple_remove(&ida_index, index);
	171	mutex_destroy(&exar_gpio->lock);
	172	return ret;
	173	}
	174
	175	static int gpio_exar_remove(struct platform_device *pdev)
	176	{
	177	struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev);
	178
	179	ida_simple_remove(&ida_index, exar_gpio->index);
	180	mutex_destroy(&exar_gpio->lock);
	181
	182	return 0;
	183	}
	184
	185	static struct platform_driver gpio_exar_driver = {
	186	.probe = gpio_exar_probe,
	187	.remove = gpio_exar_remove,
	188	.driver = {
	189	.name = DRIVER_NAME,
	190	},
	191	};
	192
	193	module_platform_driver(gpio_exar_driver);
	194
	195	MODULE_ALIAS("platform:" DRIVER_NAME);
	196	MODULE_DESCRIPTION("Exar GPIO driver");
	197	MODULE_AUTHOR("Sudip Mukherjee <[email protected]>");
	198	MODULE_LICENSE("GPL");