[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / gpio / gpio-xilinx.c

/*
 * Xilinx gpio driver
 *
 * Copyright 2008 Xilinx, Inc.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/init.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/slab.h>

/* Register Offset Definitions */
#define XGPIO_DATA_OFFSET   (0x0)	/* Data register  */
#define XGPIO_TRI_OFFSET    (0x4)	/* I/O direction register  */

struct xgpio_instance {
	struct of_mm_gpio_chip mmchip;
	u32 gpio_state;		/* GPIO state shadow register */
	u32 gpio_dir;		/* GPIO direction shadow register */
	spinlock_t gpio_lock;	/* Lock used for synchronization */
};

/**
 * xgpio_get - Read the specified signal of the GPIO device.
 * @gc:     Pointer to gpio_chip device structure.
 * @gpio:   GPIO signal number.
 *
 * This function reads the specified signal of the GPIO device. It returns 0 if
 * the signal clear, 1 if signal is set or negative value on error.
 */
static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
{
	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	return (in_be32(mm_gc->regs + XGPIO_DATA_OFFSET) >> gpio) & 1;
}

/**
 * xgpio_set - Write the specified signal of the GPIO device.
 * @gc:     Pointer to gpio_chip device structure.
 * @gpio:   GPIO signal number.
 * @val:    Value to be written to specified signal.
 *
 * This function writes the specified value in to the specified signal of the
 * GPIO device.
 */
static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
	unsigned long flags;
	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
	struct xgpio_instance *chip =
	    container_of(mm_gc, struct xgpio_instance, mmchip);

	spin_lock_irqsave(&chip->gpio_lock, flags);

	/* Write to GPIO signal and set its direction to output */
	if (val)
		chip->gpio_state |= 1 << gpio;
	else
		chip->gpio_state &= ~(1 << gpio);
	out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);

	spin_unlock_irqrestore(&chip->gpio_lock, flags);
}

/**
 * xgpio_dir_in - Set the direction of the specified GPIO signal as input.
 * @gc:     Pointer to gpio_chip device structure.
 * @gpio:   GPIO signal number.
 *
 * This function sets the direction of specified GPIO signal as input.
 * It returns 0 if direction of GPIO signals is set as input otherwise it
 * returns negative error value.
 */
static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
	unsigned long flags;
	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
	struct xgpio_instance *chip =
	    container_of(mm_gc, struct xgpio_instance, mmchip);

	spin_lock_irqsave(&chip->gpio_lock, flags);

	/* Set the GPIO bit in shadow register and set direction as input */
	chip->gpio_dir |= (1 << gpio);
	out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);

	spin_unlock_irqrestore(&chip->gpio_lock, flags);

	return 0;
}

/**
 * xgpio_dir_out - Set the direction of the specified GPIO signal as output.
 * @gc:     Pointer to gpio_chip device structure.
 * @gpio:   GPIO signal number.
 * @val:    Value to be written to specified signal.
 *
 * This function sets the direction of specified GPIO signal as output. If all
 * GPIO signals of GPIO chip is configured as input then it returns
 * error otherwise it returns 0.
 */
static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
	unsigned long flags;
	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
	struct xgpio_instance *chip =
	    container_of(mm_gc, struct xgpio_instance, mmchip);

	spin_lock_irqsave(&chip->gpio_lock, flags);

	/* Write state of GPIO signal */
	if (val)
		chip->gpio_state |= 1 << gpio;
	else
		chip->gpio_state &= ~(1 << gpio);
	out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);

	/* Clear the GPIO bit in shadow register and set direction as output */
	chip->gpio_dir &= (~(1 << gpio));
	out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);

	spin_unlock_irqrestore(&chip->gpio_lock, flags);

	return 0;
}

/**
 * xgpio_save_regs - Set initial values of GPIO pins
 * @mm_gc: pointer to memory mapped GPIO chip structure
 */
static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
{
	struct xgpio_instance *chip =
	    container_of(mm_gc, struct xgpio_instance, mmchip);

	out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
	out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
}

/**
 * xgpio_of_probe - Probe method for the GPIO device.
 * @np: pointer to device tree node
 *
 * This function probes the GPIO device in the device tree. It initializes the
 * driver data structure. It returns 0, if the driver is bound to the GPIO
 * device, or a negative value if there is an error.
 */
static int xgpio_of_probe(struct device_node *np)
{
	struct xgpio_instance *chip;
	int status = 0;
	const u32 *tree_info;

	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	/* Update GPIO state shadow register with default value */
	tree_info = of_get_property(np, "xlnx,dout-default", NULL);
	if (tree_info)
		chip->gpio_state = be32_to_cpup(tree_info);

	/* Update GPIO direction shadow register with default value */
	chip->gpio_dir = 0xFFFFFFFF; /* By default, all pins are inputs */
	tree_info = of_get_property(np, "xlnx,tri-default", NULL);
	if (tree_info)
		chip->gpio_dir = be32_to_cpup(tree_info);

	/* Check device node and parent device node for device width */
	chip->mmchip.gc.ngpio = 32; /* By default assume full GPIO controller */
	tree_info = of_get_property(np, "xlnx,gpio-width", NULL);
	if (!tree_info)
		tree_info = of_get_property(np->parent,
					    "xlnx,gpio-width", NULL);
	if (tree_info)
		chip->mmchip.gc.ngpio = be32_to_cpup(tree_info);

	spin_lock_init(&chip->gpio_lock);

	chip->mmchip.gc.direction_input = xgpio_dir_in;
	chip->mmchip.gc.direction_output = xgpio_dir_out;
	chip->mmchip.gc.get = xgpio_get;
	chip->mmchip.gc.set = xgpio_set;

	chip->mmchip.save_regs = xgpio_save_regs;

	/* Call the OF gpio helper to setup and register the GPIO device */
	status = of_mm_gpiochip_add(np, &chip->mmchip);
	if (status) {
		kfree(chip);
		pr_err("%s: error in probe function with status %d\n",
		       np->full_name, status);
		return status;
	}
	return 0;
}

static struct of_device_id xgpio_of_match[] = {
	{ .compatible = "xlnx,xps-gpio-1.00.a", },
	{ /* end of list */ },
};

static int __init xgpio_init(void)
{
	struct device_node *np;

	for_each_matching_node(np, xgpio_of_match)
		xgpio_of_probe(np);

	return 0;
}

/* Make sure we get initialized before anyone else tries to use us */
subsys_initcall(xgpio_init);
/* No exit call at the moment as we cannot unregister of GPIO chips */

MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx GPIO driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
0bcb6069 JL	1	/*
	2	* Xilinx gpio driver
	3	*
	4	* Copyright 2008 Xilinx, Inc.
	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
	8	* as published by the Free Software Foundation.
	9	*
	10	* You should have received a copy of the GNU General Public License
	11	* along with this program; if not, write to the Free Software
	12	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	13	*/
	14
	15	#include <linux/init.h>
	16	#include <linux/errno.h>
bb207ef1	17	#include <linux/module.h>
0bcb6069 JL	18	#include <linux/of_device.h>
	19	#include <linux/of_platform.h>
	20	#include <linux/of_gpio.h>
	21	#include <linux/io.h>
	22	#include <linux/gpio.h>
5a0e3ad6	23	#include <linux/slab.h>
0bcb6069 JL	24
	25	/* Register Offset Definitions */
	26	#define XGPIO_DATA_OFFSET (0x0) /* Data register */
	27	#define XGPIO_TRI_OFFSET (0x4) /* I/O direction register */
	28
	29	struct xgpio_instance {
	30	struct of_mm_gpio_chip mmchip;
	31	u32 gpio_state; /* GPIO state shadow register */
	32	u32 gpio_dir; /* GPIO direction shadow register */
	33	spinlock_t gpio_lock; /* Lock used for synchronization */
	34	};
	35
	36	/**
	37	* xgpio_get - Read the specified signal of the GPIO device.
	38	* @gc: Pointer to gpio_chip device structure.
	39	* @gpio: GPIO signal number.
	40	*
	41	* This function reads the specified signal of the GPIO device. It returns 0 if
	42	* the signal clear, 1 if signal is set or negative value on error.
	43	*/
	44	static int xgpio_get(struct gpio_chip *gc, unsigned int gpio)
	45	{
	46	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
	47
	48	return (in_be32(mm_gc->regs + XGPIO_DATA_OFFSET) >> gpio) & 1;
	49	}
	50
	51	/**
	52	* xgpio_set - Write the specified signal of the GPIO device.
	53	* @gc: Pointer to gpio_chip device structure.
	54	* @gpio: GPIO signal number.
	55	* @val: Value to be written to specified signal.
	56	*
	57	* This function writes the specified value in to the specified signal of the
	58	* GPIO device.
	59	*/
	60	static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
	61	{
	62	unsigned long flags;
	63	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
	64	struct xgpio_instance *chip =
	65	container_of(mm_gc, struct xgpio_instance, mmchip);
	66
	67	spin_lock_irqsave(&chip->gpio_lock, flags);
	68
	69	/* Write to GPIO signal and set its direction to output */
	70	if (val)
	71	chip->gpio_state \|= 1 << gpio;
	72	else
	73	chip->gpio_state &= ~(1 << gpio);
	74	out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
	75
	76	spin_unlock_irqrestore(&chip->gpio_lock, flags);
	77	}
	78
	79	/**
	80	* xgpio_dir_in - Set the direction of the specified GPIO signal as input.
	81	* @gc: Pointer to gpio_chip device structure.
	82	* @gpio: GPIO signal number.
	83	*
	84	* This function sets the direction of specified GPIO signal as input.
	85	* It returns 0 if direction of GPIO signals is set as input otherwise it
	86	* returns negative error value.
	87	*/
88	static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
89	{
90	unsigned long flags;
91	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
92	struct xgpio_instance *chip =
93	container_of(mm_gc, struct xgpio_instance, mmchip);
94
95	spin_lock_irqsave(&chip->gpio_lock, flags);
96
97	/* Set the GPIO bit in shadow register and set direction as input */
98	chip->gpio_dir \|= (1 << gpio);
99	out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
100
101	spin_unlock_irqrestore(&chip->gpio_lock, flags);
102
103	return 0;
104	}
105
106	/**
107	* xgpio_dir_out - Set the direction of the specified GPIO signal as output.
108	* @gc: Pointer to gpio_chip device structure.
109	* @gpio: GPIO signal number.
110	* @val: Value to be written to specified signal.
111	*
112	* This function sets the direction of specified GPIO signal as output. If all
113	* GPIO signals of GPIO chip is configured as input then it returns
114	* error otherwise it returns 0.
115	*/
116	static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
117	{
118	unsigned long flags;
119	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
120	struct xgpio_instance *chip =
121	container_of(mm_gc, struct xgpio_instance, mmchip);
122
123	spin_lock_irqsave(&chip->gpio_lock, flags);
124
125	/* Write state of GPIO signal */
126	if (val)
127	chip->gpio_state \|= 1 << gpio;
128	else
129	chip->gpio_state &= ~(1 << gpio);
130	out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
131
132	/* Clear the GPIO bit in shadow register and set direction as output */
133	chip->gpio_dir &= (~(1 << gpio));
134	out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
135
136	spin_unlock_irqrestore(&chip->gpio_lock, flags);
137
138	return 0;
139	}
140
141	/**
142	* xgpio_save_regs - Set initial values of GPIO pins
143	* @mm_gc: pointer to memory mapped GPIO chip structure
144	*/
145	static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
146	{
147	struct xgpio_instance *chip =
148	container_of(mm_gc, struct xgpio_instance, mmchip);
149
150	out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
151	out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
152	}
153
154	/**
155	* xgpio_of_probe - Probe method for the GPIO device.
156	* @np: pointer to device tree node
157	*
158	* This function probes the GPIO device in the device tree. It initializes the
159	* driver data structure. It returns 0, if the driver is bound to the GPIO
160	* device, or a negative value if there is an error.
161	*/
3836309d	162	static int xgpio_of_probe(struct device_node *np)
0bcb6069 JL	163	{
0bcb6069 JL	164	struct xgpio_instance *chip;
0bcb6069 JL	165	int status = 0;
	166	const u32 *tree_info;
	167
	168	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	169	if (!chip)
	170	return -ENOMEM;
0bcb6069 JL	171
	172	/* Update GPIO state shadow register with default value */
	173	tree_info = of_get_property(np, "xlnx,dout-default", NULL);
	174	if (tree_info)
a04e78b8	175	chip->gpio_state = be32_to_cpup(tree_info);
0bcb6069 JL	176
	177	/* Update GPIO direction shadow register with default value */
	178	chip->gpio_dir = 0xFFFFFFFF; /* By default, all pins are inputs */
	179	tree_info = of_get_property(np, "xlnx,tri-default", NULL);
	180	if (tree_info)
a04e78b8	181	chip->gpio_dir = be32_to_cpup(tree_info);
0bcb6069 JL	182
0bcb6069 JL	183	/* Check device node and parent device node for device width */
a19e3da5	184	chip->mmchip.gc.ngpio = 32; /* By default assume full GPIO controller */
0bcb6069 JL	185	tree_info = of_get_property(np, "xlnx,gpio-width", NULL);
	186	if (!tree_info)
	187	tree_info = of_get_property(np->parent,
	188	"xlnx,gpio-width", NULL);
	189	if (tree_info)
a04e78b8	190	chip->mmchip.gc.ngpio = be32_to_cpup(tree_info);
0bcb6069 JL	191
	192	spin_lock_init(&chip->gpio_lock);
	193
a19e3da5 AV	194	chip->mmchip.gc.direction_input = xgpio_dir_in;
	195	chip->mmchip.gc.direction_output = xgpio_dir_out;
	196	chip->mmchip.gc.get = xgpio_get;
	197	chip->mmchip.gc.set = xgpio_set;
0bcb6069 JL	198
	199	chip->mmchip.save_regs = xgpio_save_regs;
	200
	201	/* Call the OF gpio helper to setup and register the GPIO device */
	202	status = of_mm_gpiochip_add(np, &chip->mmchip);
	203	if (status) {
	204	kfree(chip);
	205	pr_err("%s: error in probe function with status %d\n",
	206	np->full_name, status);
	207	return status;
	208	}
0bcb6069 JL	209	return 0;
	210	}
	211
aeca8ad1	212	static struct of_device_id xgpio_of_match[] = {
0bcb6069 JL	213	{ .compatible = "xlnx,xps-gpio-1.00.a", },
	214	{ /* end of list */ },
	215	};
	216
	217	static int __init xgpio_init(void)
	218	{
	219	struct device_node *np;
	220
	221	for_each_matching_node(np, xgpio_of_match)
	222	xgpio_of_probe(np);
	223
	224	return 0;
	225	}
	226
	227	/* Make sure we get initialized before anyone else tries to use us */
	228	subsys_initcall(xgpio_init);
	229	/* No exit call at the moment as we cannot unregister of GPIO chips */
	230
	231	MODULE_AUTHOR("Xilinx, Inc.");
	232	MODULE_DESCRIPTION("Xilinx GPIO driver");
	233	MODULE_LICENSE("GPL");