[deliverable/linux.git] / drivers / gpio / gpio-mm-lantiq.c

/*
 *  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.
 *
 *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/gpio.h>
#include <linux/io.h>

#include <lantiq_soc.h>

/*
 * By attaching hardware latches to the EBU it is possible to create output
 * only gpios. This driver configures a special memory address, which when
 * written to outputs 16 bit to the latches.
 */

#define LTQ_EBU_BUSCON	0x1e7ff		/* 16 bit access, slowest timing */
#define LTQ_EBU_WP	0x80000000	/* write protect bit */

/* we keep a shadow value of the last value written to the ebu */
static int ltq_ebu_gpio_shadow = 0x0;
static void __iomem *ltq_ebu_gpio_membase;

static void ltq_ebu_apply(void)
{
	unsigned long flags;

	spin_lock_irqsave(&ebu_lock, flags);
	ltq_ebu_w32(LTQ_EBU_BUSCON, LTQ_EBU_BUSCON1);
	*((__u16 *)ltq_ebu_gpio_membase) = ltq_ebu_gpio_shadow;
	ltq_ebu_w32(LTQ_EBU_BUSCON | LTQ_EBU_WP, LTQ_EBU_BUSCON1);
	spin_unlock_irqrestore(&ebu_lock, flags);
}

static void ltq_ebu_set(struct gpio_chip *chip, unsigned offset, int value)
{
	if (value)
		ltq_ebu_gpio_shadow |= (1 << offset);
	else
		ltq_ebu_gpio_shadow &= ~(1 << offset);
	ltq_ebu_apply();
}

static int ltq_ebu_direction_output(struct gpio_chip *chip, unsigned offset,
	int value)
{
	ltq_ebu_set(chip, offset, value);

	return 0;
}

static struct gpio_chip ltq_ebu_chip = {
	.label = "ltq_ebu",
	.direction_output = ltq_ebu_direction_output,
	.set = ltq_ebu_set,
	.base = 72,
	.ngpio = 16,
	.can_sleep = 1,
	.owner = THIS_MODULE,
};

static int ltq_ebu_probe(struct platform_device *pdev)
{
	int ret = 0;
	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!res) {
		dev_err(&pdev->dev, "failed to get memory resource\n");
		return -ENOENT;
	}

	res = devm_request_mem_region(&pdev->dev, res->start,
		resource_size(res), dev_name(&pdev->dev));
	if (!res) {
		dev_err(&pdev->dev, "failed to request memory resource\n");
		return -EBUSY;
	}

	ltq_ebu_gpio_membase = devm_ioremap_nocache(&pdev->dev, res->start,
		resource_size(res));
	if (!ltq_ebu_gpio_membase) {
		dev_err(&pdev->dev, "Failed to ioremap mem region\n");
		return -ENOMEM;
	}

	/* grab the default shadow value passed form the platform code */
	ltq_ebu_gpio_shadow = (unsigned int) pdev->dev.platform_data;

	/* tell the ebu controller which memory address we will be using */
	ltq_ebu_w32(pdev->resource->start | 0x1, LTQ_EBU_ADDRSEL1);

	/* write protect the region */
	ltq_ebu_w32(LTQ_EBU_BUSCON | LTQ_EBU_WP, LTQ_EBU_BUSCON1);

	ret = gpiochip_add(&ltq_ebu_chip);
	if (!ret)
		ltq_ebu_apply();
	return ret;
}

static struct platform_driver ltq_ebu_driver = {
	.probe = ltq_ebu_probe,
	.driver = {
		.name = "ltq_ebu",
		.owner = THIS_MODULE,
	},
};

static int __init ltq_ebu_init(void)
{
	int ret = platform_driver_register(&ltq_ebu_driver);

	if (ret)
		pr_info("ltq_ebu : Error registering platfom driver!");
	return ret;
}

postcore_initcall(ltq_ebu_init);
Commit	Line	Data
935c500c JC	1	/*
	2	* This program is free software; you can redistribute it and/or modify it
	3	* under the terms of the GNU General Public License version 2 as published
	4	* by the Free Software Foundation.
	5	*
	6	* Copyright (C) 2010 John Crispin <blogic@openwrt.org>
	7	*/
	8
	9	#include <linux/init.h>
4af92e7a	10	#include <linux/export.h>
935c500c JC	11	#include <linux/types.h>
	12	#include <linux/platform_device.h>
	13	#include <linux/mutex.h>
	14	#include <linux/gpio.h>
	15	#include <linux/io.h>
	16
	17	#include <lantiq_soc.h>
	18
	19	/*
	20	* By attaching hardware latches to the EBU it is possible to create output
	21	* only gpios. This driver configures a special memory address, which when
	22	* written to outputs 16 bit to the latches.
	23	*/
	24
	25	#define LTQ_EBU_BUSCON 0x1e7ff /* 16 bit access, slowest timing */
	26	#define LTQ_EBU_WP 0x80000000 /* write protect bit */
	27
	28	/* we keep a shadow value of the last value written to the ebu */
	29	static int ltq_ebu_gpio_shadow = 0x0;
	30	static void __iomem *ltq_ebu_gpio_membase;
	31
	32	static void ltq_ebu_apply(void)
	33	{
	34	unsigned long flags;
	35
	36	spin_lock_irqsave(&ebu_lock, flags);
	37	ltq_ebu_w32(LTQ_EBU_BUSCON, LTQ_EBU_BUSCON1);
	38	((__u16 )ltq_ebu_gpio_membase) = ltq_ebu_gpio_shadow;
	39	ltq_ebu_w32(LTQ_EBU_BUSCON \| LTQ_EBU_WP, LTQ_EBU_BUSCON1);
	40	spin_unlock_irqrestore(&ebu_lock, flags);
	41	}
	42
	43	static void ltq_ebu_set(struct gpio_chip *chip, unsigned offset, int value)
	44	{
	45	if (value)
	46	ltq_ebu_gpio_shadow \|= (1 << offset);
	47	else
	48	ltq_ebu_gpio_shadow &= ~(1 << offset);
	49	ltq_ebu_apply();
	50	}
	51
	52	static int ltq_ebu_direction_output(struct gpio_chip *chip, unsigned offset,
	53	int value)
	54	{
	55	ltq_ebu_set(chip, offset, value);
	56
	57	return 0;
	58	}
	59
	60	static struct gpio_chip ltq_ebu_chip = {
	61	.label = "ltq_ebu",
	62	.direction_output = ltq_ebu_direction_output,
	63	.set = ltq_ebu_set,
	64	.base = 72,
	65	.ngpio = 16,
	66	.can_sleep = 1,
	67	.owner = THIS_MODULE,
	68	};
	69
	70	static int ltq_ebu_probe(struct platform_device *pdev)
	71	{
	72	int ret = 0;
	73	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	74
75	if (!res) {
76	dev_err(&pdev->dev, "failed to get memory resource\n");
77	return -ENOENT;
78	}
79
80	res = devm_request_mem_region(&pdev->dev, res->start,
81	resource_size(res), dev_name(&pdev->dev));
82	if (!res) {
83	dev_err(&pdev->dev, "failed to request memory resource\n");
84	return -EBUSY;
85	}
86
87	ltq_ebu_gpio_membase = devm_ioremap_nocache(&pdev->dev, res->start,
88	resource_size(res));
89	if (!ltq_ebu_gpio_membase) {
90	dev_err(&pdev->dev, "Failed to ioremap mem region\n");
91	return -ENOMEM;
92	}
93
94	/* grab the default shadow value passed form the platform code */
95	ltq_ebu_gpio_shadow = (unsigned int) pdev->dev.platform_data;
96
97	/* tell the ebu controller which memory address we will be using */
98	ltq_ebu_w32(pdev->resource->start \| 0x1, LTQ_EBU_ADDRSEL1);
99
100	/* write protect the region */
101	ltq_ebu_w32(LTQ_EBU_BUSCON \| LTQ_EBU_WP, LTQ_EBU_BUSCON1);
102
103	ret = gpiochip_add(&ltq_ebu_chip);
104	if (!ret)
105	ltq_ebu_apply();
106	return ret;
107	}
108
109	static struct platform_driver ltq_ebu_driver = {
110	.probe = ltq_ebu_probe,
111	.driver = {
112	.name = "ltq_ebu",
113	.owner = THIS_MODULE,
114	},
115	};
116
117	static int __init ltq_ebu_init(void)
118	{
119	int ret = platform_driver_register(&ltq_ebu_driver);
120
121	if (ret)
122	pr_info("ltq_ebu : Error registering platfom driver!");
123	return ret;
124	}
125
126	postcore_initcall(ltq_ebu_init);