[net-next-2.6.git] / drivers / gpio / vx855_gpio.c

/*
 * Linux GPIOlib driver for the VIA VX855 integrated southbridge GPIO
 *
 * Copyright (C) 2009 VIA Technologies, Inc.
 * Copyright (C) 2010 One Laptop per Child
 * Author: Harald Welte <HaraldWelte@viatech.com>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/pci.h>
#include <linux/io.h>

#define MODULE_NAME "vx855_gpio"

/* The VX855 south bridge has the following GPIO pins:
 *	GPI 0...13	General Purpose Input
 *	GPO 0...12	General Purpose Output
 *	GPIO 0...14	General Purpose I/O (Open-Drain)
 */

#define NR_VX855_GPI	14
#define NR_VX855_GPO	13
#define NR_VX855_GPIO	15

#define NR_VX855_GPInO	(NR_VX855_GPI + NR_VX855_GPO)
#define NR_VX855_GP	(NR_VX855_GPI + NR_VX855_GPO + NR_VX855_GPIO)

struct vx855_gpio {
	struct gpio_chip gpio;
	spinlock_t lock;
	u32 io_gpi;
	u32 io_gpo;
	bool gpi_reserved;
	bool gpo_reserved;
};

/* resolve a GPIx into the corresponding bit position */
static inline u_int32_t gpi_i_bit(int i)
{
	if (i < 10)
		return 1 << i;
	else
		return 1 << (i + 14);
}

static inline u_int32_t gpo_o_bit(int i)
{
	if (i < 11)
		return 1 << i;
	else
		return 1 << (i + 14);
}

static inline u_int32_t gpio_i_bit(int i)
{
	if (i < 14)
		return 1 << (i + 10);
	else
		return 1 << (i + 14);
}

static inline u_int32_t gpio_o_bit(int i)
{
	if (i < 14)
		return 1 << (i + 11);
	else
		return 1 << (i + 13);
}

/* Mapping betwee numeric GPIO ID and the actual GPIO hardware numbering:
 * 0..13	GPI 0..13
 * 14..26	GPO 0..12
 * 27..41	GPIO 0..14
 */

static int vx855gpio_direction_input(struct gpio_chip *gpio,
				     unsigned int nr)
{
	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
	unsigned long flags;
	u_int32_t reg_out;

	/* Real GPI bits are always in input direction */
	if (nr < NR_VX855_GPI)
		return 0;

	/* Real GPO bits cannot be put in output direction */
	if (nr < NR_VX855_GPInO)
		return -EINVAL;

	/* Open Drain GPIO have to be set to one */
	spin_lock_irqsave(&vg->lock, flags);
	reg_out = inl(vg->io_gpo);
	reg_out |= gpio_o_bit(nr - NR_VX855_GPInO);
	outl(reg_out, vg->io_gpo);
	spin_unlock_irqrestore(&vg->lock, flags);

	return 0;
}

static int vx855gpio_get(struct gpio_chip *gpio, unsigned int nr)
{
	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
	u_int32_t reg_in;
	int ret = 0;

	if (nr < NR_VX855_GPI) {
		reg_in = inl(vg->io_gpi);
		if (reg_in & gpi_i_bit(nr))
			ret = 1;
	} else if (nr < NR_VX855_GPInO) {
		/* GPO don't have an input bit, we need to read it
		 * back from the output register */
		reg_in = inl(vg->io_gpo);
		if (reg_in & gpo_o_bit(nr - NR_VX855_GPI))
			ret = 1;
	} else {
		reg_in = inl(vg->io_gpi);
		if (reg_in & gpio_i_bit(nr - NR_VX855_GPInO))
			ret = 1;
	}

	return ret;
}

static void vx855gpio_set(struct gpio_chip *gpio, unsigned int nr,
			  int val)
{
	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
	unsigned long flags;
	u_int32_t reg_out;

	/* True GPI cannot be switched to output mode */
	if (nr < NR_VX855_GPI)
		return;

	spin_lock_irqsave(&vg->lock, flags);
	reg_out = inl(vg->io_gpo);
	if (nr < NR_VX855_GPInO) {
		if (val)
			reg_out |= gpo_o_bit(nr - NR_VX855_GPI);
		else
			reg_out &= ~gpo_o_bit(nr - NR_VX855_GPI);
	} else {
		if (val)
			reg_out |= gpio_o_bit(nr - NR_VX855_GPInO);
		else
			reg_out &= ~gpio_o_bit(nr - NR_VX855_GPInO);
	}
	outl(reg_out, vg->io_gpo);
	spin_unlock_irqrestore(&vg->lock, flags);
}

static int vx855gpio_direction_output(struct gpio_chip *gpio,
				      unsigned int nr, int val)
{
	/* True GPI cannot be switched to output mode */
	if (nr < NR_VX855_GPI)
		return -EINVAL;

	/* True GPO don't need to be switched to output mode,
	 * and GPIO are open-drain, i.e. also need no switching,
	 * so all we do is set the level */
	vx855gpio_set(gpio, nr, val);

	return 0;
}

static const char *vx855gpio_names[NR_VX855_GP] = {
	"VX855_GPI0", "VX855_GPI1", "VX855_GPI2", "VX855_GPI3", "VX855_GPI4",
	"VX855_GPI5", "VX855_GPI6", "VX855_GPI7", "VX855_GPI8", "VX855_GPI9",
	"VX855_GPI10", "VX855_GPI11", "VX855_GPI12", "VX855_GPI13",
	"VX855_GPO0", "VX855_GPO1", "VX855_GPO2", "VX855_GPO3", "VX855_GPO4",
	"VX855_GPO5", "VX855_GPO6", "VX855_GPO7", "VX855_GPO8", "VX855_GPO9",
	"VX855_GPO10", "VX855_GPO11", "VX855_GPO12",
	"VX855_GPIO0", "VX855_GPIO1", "VX855_GPIO2", "VX855_GPIO3",
	"VX855_GPIO4", "VX855_GPIO5", "VX855_GPIO6", "VX855_GPIO7",
	"VX855_GPIO8", "VX855_GPIO9", "VX855_GPIO10", "VX855_GPIO11",
	"VX855_GPIO12", "VX855_GPIO13", "VX855_GPIO14"
};

static void vx855gpio_gpio_setup(struct vx855_gpio *vg)
{
	struct gpio_chip *c = &vg->gpio;

	c->label = "VX855 South Bridge";
	c->owner = THIS_MODULE;
	c->direction_input = vx855gpio_direction_input;
	c->direction_output = vx855gpio_direction_output;
	c->get = vx855gpio_get;
	c->set = vx855gpio_set;
	c->dbg_show = NULL;
	c->base = 0;
	c->ngpio = NR_VX855_GP;
	c->can_sleep = 0;
	c->names = vx855gpio_names;
}

/* This platform device is ordinarily registered by the vx855 mfd driver */
static __devinit int vx855gpio_probe(struct platform_device *pdev)
{
	struct resource *res_gpi;
	struct resource *res_gpo;
	struct vx855_gpio *vg;
	int ret;

	res_gpi = platform_get_resource(pdev, IORESOURCE_IO, 0);
	res_gpo = platform_get_resource(pdev, IORESOURCE_IO, 1);
	if (!res_gpi || !res_gpo)
		return -EBUSY;

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

	platform_set_drvdata(pdev, vg);

	dev_info(&pdev->dev, "found VX855 GPIO controller\n");
	vg->io_gpi = res_gpi->start;
	vg->io_gpo = res_gpo->start;
	spin_lock_init(&vg->lock);

	/*
	 * A single byte is used to control various GPIO ports on the VX855,
	 * and in the case of the OLPC XO-1.5, some of those ports are used
	 * for switches that are interpreted and exposed through ACPI. ACPI
	 * will have reserved the region, so our own reservation will not
	 * succeed. Ignore and continue.
	 */

	if (!request_region(res_gpi->start, resource_size(res_gpi),
			MODULE_NAME "_gpi"))
		dev_warn(&pdev->dev,
			"GPI I/O resource busy, probably claimed by ACPI\n");
	else
		vg->gpi_reserved = true;

	if (!request_region(res_gpo->start, resource_size(res_gpo),
			MODULE_NAME "_gpo"))
		dev_warn(&pdev->dev,
			"GPO I/O resource busy, probably claimed by ACPI\n");
	else
		vg->gpo_reserved = true;

	vx855gpio_gpio_setup(vg);

	ret = gpiochip_add(&vg->gpio);
	if (ret) {
		dev_err(&pdev->dev, "failed to register GPIOs\n");
		goto out_release;
	}

	return 0;

out_release:
	if (vg->gpi_reserved)
		release_region(res_gpi->start, resource_size(res_gpi));
	if (vg->gpo_reserved)
		release_region(res_gpi->start, resource_size(res_gpo));
	platform_set_drvdata(pdev, NULL);
	kfree(vg);
	return ret;
}

static int __devexit vx855gpio_remove(struct platform_device *pdev)
{
	struct vx855_gpio *vg = platform_get_drvdata(pdev);
	struct resource *res;

	if (gpiochip_remove(&vg->gpio))
		dev_err(&pdev->dev, "unable to remove gpio_chip?\n");

	if (vg->gpi_reserved) {
		res = platform_get_resource(pdev, IORESOURCE_IO, 0);
		release_region(res->start, resource_size(res));
	}
	if (vg->gpo_reserved) {
		res = platform_get_resource(pdev, IORESOURCE_IO, 1);
		release_region(res->start, resource_size(res));
	}

	platform_set_drvdata(pdev, NULL);
	kfree(vg);
	return 0;
}

static struct platform_driver vx855gpio_driver = {
	.driver = {
		.name	= MODULE_NAME,
		.owner	= THIS_MODULE,
	},
	.probe		= vx855gpio_probe,
	.remove		= __devexit_p(vx855gpio_remove),
};

static int vx855gpio_init(void)
{
	return platform_driver_register(&vx855gpio_driver);
}
module_init(vx855gpio_init);

static void vx855gpio_exit(void)
{
	platform_driver_unregister(&vx855gpio_driver);
}
module_exit(vx855gpio_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
MODULE_DESCRIPTION("GPIO driver for the VIA VX855 chipset");
MODULE_ALIAS("platform:vx855_gpio");
Commit	Line	Data
99ea2626 DD	1	/*
	2	* Linux GPIOlib driver for the VIA VX855 integrated southbridge GPIO
	3	*
	4	* Copyright (C) 2009 VIA Technologies, Inc.
	5	* Copyright (C) 2010 One Laptop per Child
	6	* Author: Harald Welte <HaraldWelte@viatech.com>
	7	* All rights reserved.
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License as
	11	* published by the Free Software Foundation; either version 2 of
	12	* the License, or (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	22	* MA 02111-1307 USA
	23	*
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/module.h>
	28	#include <linux/gpio.h>
	29	#include <linux/device.h>
	30	#include <linux/platform_device.h>
	31	#include <linux/pci.h>
	32	#include <linux/io.h>
	33
	34	#define MODULE_NAME "vx855_gpio"
	35
	36	/* The VX855 south bridge has the following GPIO pins:
	37	* GPI 0...13 General Purpose Input
	38	* GPO 0...12 General Purpose Output
	39	* GPIO 0...14 General Purpose I/O (Open-Drain)
	40	*/
	41
	42	#define NR_VX855_GPI 14
	43	#define NR_VX855_GPO 13
	44	#define NR_VX855_GPIO 15
	45
	46	#define NR_VX855_GPInO (NR_VX855_GPI + NR_VX855_GPO)
	47	#define NR_VX855_GP (NR_VX855_GPI + NR_VX855_GPO + NR_VX855_GPIO)
	48
	49	struct vx855_gpio {
	50	struct gpio_chip gpio;
	51	spinlock_t lock;
	52	u32 io_gpi;
	53	u32 io_gpo;
	54	bool gpi_reserved;
	55	bool gpo_reserved;
	56	};
	57
	58	/* resolve a GPIx into the corresponding bit position */
	59	static inline u_int32_t gpi_i_bit(int i)
	60	{
	61	if (i < 10)
	62	return 1 << i;
	63	else
	64	return 1 << (i + 14);
65	}
66
67	static inline u_int32_t gpo_o_bit(int i)
68	{
69	if (i < 11)
70	return 1 << i;
71	else
72	return 1 << (i + 14);
73	}
74
75	static inline u_int32_t gpio_i_bit(int i)
76	{
77	if (i < 14)
78	return 1 << (i + 10);
79	else
80	return 1 << (i + 14);
81	}
82
83	static inline u_int32_t gpio_o_bit(int i)
84	{
85	if (i < 14)
86	return 1 << (i + 11);
87	else
88	return 1 << (i + 13);
89	}
90
91	/* Mapping betwee numeric GPIO ID and the actual GPIO hardware numbering:
92	* 0..13 GPI 0..13
93	* 14..26 GPO 0..12
94	* 27..41 GPIO 0..14
95	*/
96
97	static int vx855gpio_direction_input(struct gpio_chip *gpio,
98	unsigned int nr)
99	{
100	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
101	unsigned long flags;
102	u_int32_t reg_out;
103
104	/* Real GPI bits are always in input direction */
105	if (nr < NR_VX855_GPI)
106	return 0;
107
108	/* Real GPO bits cannot be put in output direction */
109	if (nr < NR_VX855_GPInO)
110	return -EINVAL;
111
112	/* Open Drain GPIO have to be set to one */
113	spin_lock_irqsave(&vg->lock, flags);
114	reg_out = inl(vg->io_gpo);
115	reg_out \|= gpio_o_bit(nr - NR_VX855_GPInO);
116	outl(reg_out, vg->io_gpo);
117	spin_unlock_irqrestore(&vg->lock, flags);
118
119	return 0;
120	}
121
122	static int vx855gpio_get(struct gpio_chip *gpio, unsigned int nr)
123	{
124	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
125	u_int32_t reg_in;
126	int ret = 0;
127
128	if (nr < NR_VX855_GPI) {
129	reg_in = inl(vg->io_gpi);
130	if (reg_in & gpi_i_bit(nr))
131	ret = 1;
132	} else if (nr < NR_VX855_GPInO) {
133	/* GPO don't have an input bit, we need to read it
134	* back from the output register */
135	reg_in = inl(vg->io_gpo);
136	if (reg_in & gpo_o_bit(nr - NR_VX855_GPI))
137	ret = 1;
138	} else {
139	reg_in = inl(vg->io_gpi);
140	if (reg_in & gpio_i_bit(nr - NR_VX855_GPInO))
141	ret = 1;
142	}
143
144	return ret;
145	}
146
147	static void vx855gpio_set(struct gpio_chip *gpio, unsigned int nr,
148	int val)
149	{
150	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
151	unsigned long flags;
152	u_int32_t reg_out;
153
154	/* True GPI cannot be switched to output mode */
155	if (nr < NR_VX855_GPI)
156	return;
157
158	spin_lock_irqsave(&vg->lock, flags);
159	reg_out = inl(vg->io_gpo);
160	if (nr < NR_VX855_GPInO) {
161	if (val)
162	reg_out \|= gpo_o_bit(nr - NR_VX855_GPI);
163	else
164	reg_out &= ~gpo_o_bit(nr - NR_VX855_GPI);
165	} else {
166	if (val)
167	reg_out \|= gpio_o_bit(nr - NR_VX855_GPInO);
168	else
169	reg_out &= ~gpio_o_bit(nr - NR_VX855_GPInO);
170	}
171	outl(reg_out, vg->io_gpo);
172	spin_unlock_irqrestore(&vg->lock, flags);
173	}
174
175	static int vx855gpio_direction_output(struct gpio_chip *gpio,
176	unsigned int nr, int val)
177	{
178	/* True GPI cannot be switched to output mode */
179	if (nr < NR_VX855_GPI)
180	return -EINVAL;
181
182	/* True GPO don't need to be switched to output mode,
183	* and GPIO are open-drain, i.e. also need no switching,
184	* so all we do is set the level */
185	vx855gpio_set(gpio, nr, val);
186
187	return 0;
188	}
189
190	static const char *vx855gpio_names[NR_VX855_GP] = {
191	"VX855_GPI0", "VX855_GPI1", "VX855_GPI2", "VX855_GPI3", "VX855_GPI4",
192	"VX855_GPI5", "VX855_GPI6", "VX855_GPI7", "VX855_GPI8", "VX855_GPI9",
193	"VX855_GPI10", "VX855_GPI11", "VX855_GPI12", "VX855_GPI13",
194	"VX855_GPO0", "VX855_GPO1", "VX855_GPO2", "VX855_GPO3", "VX855_GPO4",
195	"VX855_GPO5", "VX855_GPO6", "VX855_GPO7", "VX855_GPO8", "VX855_GPO9",
196	"VX855_GPO10", "VX855_GPO11", "VX855_GPO12",
197	"VX855_GPIO0", "VX855_GPIO1", "VX855_GPIO2", "VX855_GPIO3",
198	"VX855_GPIO4", "VX855_GPIO5", "VX855_GPIO6", "VX855_GPIO7",
199	"VX855_GPIO8", "VX855_GPIO9", "VX855_GPIO10", "VX855_GPIO11",
200	"VX855_GPIO12", "VX855_GPIO13", "VX855_GPIO14"
201	};
202
203	static void vx855gpio_gpio_setup(struct vx855_gpio *vg)
204	{
205	struct gpio_chip *c = &vg->gpio;
206
207	c->label = "VX855 South Bridge";
208	c->owner = THIS_MODULE;
209	c->direction_input = vx855gpio_direction_input;
210	c->direction_output = vx855gpio_direction_output;
211	c->get = vx855gpio_get;
212	c->set = vx855gpio_set;
213	c->dbg_show = NULL;
214	c->base = 0;
215	c->ngpio = NR_VX855_GP;
216	c->can_sleep = 0;
217	c->names = vx855gpio_names;
218	}
219
220	/* This platform device is ordinarily registered by the vx855 mfd driver */
221	static __devinit int vx855gpio_probe(struct platform_device *pdev)
222	{
223	struct resource *res_gpi;
224	struct resource *res_gpo;
225	struct vx855_gpio *vg;
226	int ret;
227
228	res_gpi = platform_get_resource(pdev, IORESOURCE_IO, 0);
229	res_gpo = platform_get_resource(pdev, IORESOURCE_IO, 1);
230	if (!res_gpi \|\| !res_gpo)
231	return -EBUSY;
232
233	vg = kzalloc(sizeof(*vg), GFP_KERNEL);
234	if (!vg)
235	return -ENOMEM;
236
237	platform_set_drvdata(pdev, vg);
238
239	dev_info(&pdev->dev, "found VX855 GPIO controller\n");
240	vg->io_gpi = res_gpi->start;
241	vg->io_gpo = res_gpo->start;
242	spin_lock_init(&vg->lock);
243
244	/*
245	* A single byte is used to control various GPIO ports on the VX855,
246	* and in the case of the OLPC XO-1.5, some of those ports are used
247	* for switches that are interpreted and exposed through ACPI. ACPI
248	* will have reserved the region, so our own reservation will not
249	* succeed. Ignore and continue.
250	*/
251
252	if (!request_region(res_gpi->start, resource_size(res_gpi),
253	MODULE_NAME "_gpi"))
254	dev_warn(&pdev->dev,
255	"GPI I/O resource busy, probably claimed by ACPI\n");
256	else
257	vg->gpi_reserved = true;
258
259	if (!request_region(res_gpo->start, resource_size(res_gpo),
260	MODULE_NAME "_gpo"))
261	dev_warn(&pdev->dev,
262	"GPO I/O resource busy, probably claimed by ACPI\n");
263	else
264	vg->gpo_reserved = true;
265
266	vx855gpio_gpio_setup(vg);
267
268	ret = gpiochip_add(&vg->gpio);
269	if (ret) {
270	dev_err(&pdev->dev, "failed to register GPIOs\n");
271	goto out_release;
272	}
273
274	return 0;
275
276	out_release:
277	if (vg->gpi_reserved)
278	release_region(res_gpi->start, resource_size(res_gpi));
279	if (vg->gpo_reserved)
280	release_region(res_gpi->start, resource_size(res_gpo));
281	platform_set_drvdata(pdev, NULL);
282	kfree(vg);
283	return ret;
284	}
285
286	static int __devexit vx855gpio_remove(struct platform_device *pdev)
287	{
288	struct vx855_gpio *vg = platform_get_drvdata(pdev);
289	struct resource *res;
290
291	if (gpiochip_remove(&vg->gpio))
292	dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
293
294	if (vg->gpi_reserved) {
295	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
296	release_region(res->start, resource_size(res));
297	}
298	if (vg->gpo_reserved) {
299	res = platform_get_resource(pdev, IORESOURCE_IO, 1);
300	release_region(res->start, resource_size(res));
301	}
302
303	platform_set_drvdata(pdev, NULL);
304	kfree(vg);
305	return 0;
306	}
307
308	static struct platform_driver vx855gpio_driver = {
309	.driver = {
310	.name = MODULE_NAME,
311	.owner = THIS_MODULE,
312	},
313	.probe = vx855gpio_probe,
314	.remove = __devexit_p(vx855gpio_remove),
315	};
316
317	static int vx855gpio_init(void)
318	{
319	return platform_driver_register(&vx855gpio_driver);
320	}
321	module_init(vx855gpio_init);
322
323	static void vx855gpio_exit(void)
324	{
325	platform_driver_unregister(&vx855gpio_driver);
326	}
327	module_exit(vx855gpio_exit);
328
329	MODULE_LICENSE("GPL");
330	MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
331	MODULE_DESCRIPTION("GPIO driver for the VIA VX855 chipset");
332	MODULE_ALIAS("platform:vx855_gpio");