[linux.git] / drivers / gpio / gpio-vx855.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 <[email protected]>
 * 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/slab.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),
};

module_platform_driver(vx855gpio_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <[email protected]>");
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 <[email protected]>
	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>
c5e7043e	29	#include <linux/slab.h>
99ea2626 DD	30	#include <linux/device.h>
	31	#include <linux/platform_device.h>
	32	#include <linux/pci.h>
	33	#include <linux/io.h>
	34
	35	#define MODULE_NAME "vx855_gpio"
	36
	37	/* The VX855 south bridge has the following GPIO pins:
	38	* GPI 0...13 General Purpose Input
	39	* GPO 0...12 General Purpose Output
	40	* GPIO 0...14 General Purpose I/O (Open-Drain)
	41	*/
	42
	43	#define NR_VX855_GPI 14
	44	#define NR_VX855_GPO 13
	45	#define NR_VX855_GPIO 15
	46
	47	#define NR_VX855_GPInO (NR_VX855_GPI + NR_VX855_GPO)
	48	#define NR_VX855_GP (NR_VX855_GPI + NR_VX855_GPO + NR_VX855_GPIO)
	49
	50	struct vx855_gpio {
	51	struct gpio_chip gpio;
	52	spinlock_t lock;
	53	u32 io_gpi;
	54	u32 io_gpo;
	55	bool gpi_reserved;
	56	bool gpo_reserved;
	57	};
	58
	59	/* resolve a GPIx into the corresponding bit position */
	60	static inline u_int32_t gpi_i_bit(int i)
	61	{
	62	if (i < 10)
	63	return 1 << i;
	64	else
	65	return 1 << (i + 14);
	66	}
	67
	68	static inline u_int32_t gpo_o_bit(int i)
	69	{
	70	if (i < 11)
	71	return 1 << i;
	72	else
	73	return 1 << (i + 14);
	74	}
	75
	76	static inline u_int32_t gpio_i_bit(int i)
	77	{
	78	if (i < 14)
	79	return 1 << (i + 10);
	80	else
	81	return 1 << (i + 14);
	82	}
	83
	84	static inline u_int32_t gpio_o_bit(int i)
	85	{
	86	if (i < 14)
	87	return 1 << (i + 11);
	88	else
	89	return 1 << (i + 13);
	90	}
	91
	92	/* Mapping betwee numeric GPIO ID and the actual GPIO hardware numbering:
	93	* 0..13 GPI 0..13
94	* 14..26 GPO 0..12
95	* 27..41 GPIO 0..14
96	*/
97
98	static int vx855gpio_direction_input(struct gpio_chip *gpio,
99	unsigned int nr)
100	{
101	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
102	unsigned long flags;
103	u_int32_t reg_out;
104
105	/* Real GPI bits are always in input direction */
106	if (nr < NR_VX855_GPI)
107	return 0;
108
109	/* Real GPO bits cannot be put in output direction */
110	if (nr < NR_VX855_GPInO)
111	return -EINVAL;
112
113	/* Open Drain GPIO have to be set to one */
114	spin_lock_irqsave(&vg->lock, flags);
115	reg_out = inl(vg->io_gpo);
116	reg_out \|= gpio_o_bit(nr - NR_VX855_GPInO);
117	outl(reg_out, vg->io_gpo);
118	spin_unlock_irqrestore(&vg->lock, flags);
119
120	return 0;
121	}
122
123	static int vx855gpio_get(struct gpio_chip *gpio, unsigned int nr)
124	{
125	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
126	u_int32_t reg_in;
127	int ret = 0;
128
129	if (nr < NR_VX855_GPI) {
130	reg_in = inl(vg->io_gpi);
131	if (reg_in & gpi_i_bit(nr))
132	ret = 1;
133	} else if (nr < NR_VX855_GPInO) {
134	/* GPO don't have an input bit, we need to read it
135	* back from the output register */
136	reg_in = inl(vg->io_gpo);
137	if (reg_in & gpo_o_bit(nr - NR_VX855_GPI))
138	ret = 1;
139	} else {
140	reg_in = inl(vg->io_gpi);
141	if (reg_in & gpio_i_bit(nr - NR_VX855_GPInO))
142	ret = 1;
143	}
144
145	return ret;
146	}
147
148	static void vx855gpio_set(struct gpio_chip *gpio, unsigned int nr,
149	int val)
150	{
151	struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio);
152	unsigned long flags;
153	u_int32_t reg_out;
154
155	/* True GPI cannot be switched to output mode */
156	if (nr < NR_VX855_GPI)
157	return;
158
159	spin_lock_irqsave(&vg->lock, flags);
160	reg_out = inl(vg->io_gpo);
161	if (nr < NR_VX855_GPInO) {
162	if (val)
163	reg_out \|= gpo_o_bit(nr - NR_VX855_GPI);
164	else
165	reg_out &= ~gpo_o_bit(nr - NR_VX855_GPI);
166	} else {
167	if (val)
168	reg_out \|= gpio_o_bit(nr - NR_VX855_GPInO);
169	else
170	reg_out &= ~gpio_o_bit(nr - NR_VX855_GPInO);
171	}
172	outl(reg_out, vg->io_gpo);
173	spin_unlock_irqrestore(&vg->lock, flags);
174	}
175
176	static int vx855gpio_direction_output(struct gpio_chip *gpio,
177	unsigned int nr, int val)
178	{
179	/* True GPI cannot be switched to output mode */
180	if (nr < NR_VX855_GPI)
181	return -EINVAL;
182
183	/* True GPO don't need to be switched to output mode,
184	* and GPIO are open-drain, i.e. also need no switching,
185	* so all we do is set the level */
186	vx855gpio_set(gpio, nr, val);
187
188	return 0;
189	}
190
191	static const char *vx855gpio_names[NR_VX855_GP] = {
192	"VX855_GPI0", "VX855_GPI1", "VX855_GPI2", "VX855_GPI3", "VX855_GPI4",
193	"VX855_GPI5", "VX855_GPI6", "VX855_GPI7", "VX855_GPI8", "VX855_GPI9",
194	"VX855_GPI10", "VX855_GPI11", "VX855_GPI12", "VX855_GPI13",
195	"VX855_GPO0", "VX855_GPO1", "VX855_GPO2", "VX855_GPO3", "VX855_GPO4",
196	"VX855_GPO5", "VX855_GPO6", "VX855_GPO7", "VX855_GPO8", "VX855_GPO9",
197	"VX855_GPO10", "VX855_GPO11", "VX855_GPO12",
198	"VX855_GPIO0", "VX855_GPIO1", "VX855_GPIO2", "VX855_GPIO3",
199	"VX855_GPIO4", "VX855_GPIO5", "VX855_GPIO6", "VX855_GPIO7",
200	"VX855_GPIO8", "VX855_GPIO9", "VX855_GPIO10", "VX855_GPIO11",
201	"VX855_GPIO12", "VX855_GPIO13", "VX855_GPIO14"
202	};
203
204	static void vx855gpio_gpio_setup(struct vx855_gpio *vg)
205	{
206	struct gpio_chip *c = &vg->gpio;
207
208	c->label = "VX855 South Bridge";
209	c->owner = THIS_MODULE;
210	c->direction_input = vx855gpio_direction_input;
211	c->direction_output = vx855gpio_direction_output;
212	c->get = vx855gpio_get;
213	c->set = vx855gpio_set;
214	c->dbg_show = NULL;
215	c->base = 0;
216	c->ngpio = NR_VX855_GP;
217	c->can_sleep = 0;
218	c->names = vx855gpio_names;
219	}
220
221	/* This platform device is ordinarily registered by the vx855 mfd driver */
222	static __devinit int vx855gpio_probe(struct platform_device *pdev)
223	{
224	struct resource *res_gpi;
225	struct resource *res_gpo;
226	struct vx855_gpio *vg;
227	int ret;
228
229	res_gpi = platform_get_resource(pdev, IORESOURCE_IO, 0);
230	res_gpo = platform_get_resource(pdev, IORESOURCE_IO, 1);
231	if (!res_gpi \|\| !res_gpo)
232	return -EBUSY;
233
234	vg = kzalloc(sizeof(*vg), GFP_KERNEL);
235	if (!vg)
236	return -ENOMEM;
237
238	platform_set_drvdata(pdev, vg);
239
240	dev_info(&pdev->dev, "found VX855 GPIO controller\n");
241	vg->io_gpi = res_gpi->start;
242	vg->io_gpo = res_gpo->start;
243	spin_lock_init(&vg->lock);
244
245	/*
246	* A single byte is used to control various GPIO ports on the VX855,
247	* and in the case of the OLPC XO-1.5, some of those ports are used
248	* for switches that are interpreted and exposed through ACPI. ACPI
249	* will have reserved the region, so our own reservation will not
250	* succeed. Ignore and continue.
251	*/
252
253	if (!request_region(res_gpi->start, resource_size(res_gpi),
254	MODULE_NAME "_gpi"))
255	dev_warn(&pdev->dev,
256	"GPI I/O resource busy, probably claimed by ACPI\n");
257	else
258	vg->gpi_reserved = true;
259
260	if (!request_region(res_gpo->start, resource_size(res_gpo),
261	MODULE_NAME "_gpo"))
262	dev_warn(&pdev->dev,
263	"GPO I/O resource busy, probably claimed by ACPI\n");
264	else
265	vg->gpo_reserved = true;
266
267	vx855gpio_gpio_setup(vg);
268
269	ret = gpiochip_add(&vg->gpio);
270	if (ret) {
271	dev_err(&pdev->dev, "failed to register GPIOs\n");
272	goto out_release;
273	}
274
275	return 0;
276
277	out_release:
278	if (vg->gpi_reserved)
279	release_region(res_gpi->start, resource_size(res_gpi));
280	if (vg->gpo_reserved)
281	release_region(res_gpi->start, resource_size(res_gpo));
282	platform_set_drvdata(pdev, NULL);
283	kfree(vg);
284	return ret;
285	}
286
287	static int __devexit vx855gpio_remove(struct platform_device *pdev)
288	{
289	struct vx855_gpio *vg = platform_get_drvdata(pdev);
290	struct resource *res;
291
292	if (gpiochip_remove(&vg->gpio))
293	dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
294
295	if (vg->gpi_reserved) {
296	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
297	release_region(res->start, resource_size(res));
298	}
299	if (vg->gpo_reserved) {
300	res = platform_get_resource(pdev, IORESOURCE_IO, 1);
301	release_region(res->start, resource_size(res));
302	}
303
304	platform_set_drvdata(pdev, NULL);
305	kfree(vg);
306	return 0;
307	}
308
309	static struct platform_driver vx855gpio_driver = {
310	.driver = {
311	.name = MODULE_NAME,
312	.owner = THIS_MODULE,
313	},
314	.probe = vx855gpio_probe,
315	.remove = __devexit_p(vx855gpio_remove),
316	};
317
6f61415e	318	module_platform_driver(vx855gpio_driver);
99ea2626 DD	319
	320	MODULE_LICENSE("GPL");
	321	MODULE_AUTHOR("Harald Welte <[email protected]>");
	322	MODULE_DESCRIPTION("GPIO driver for the VIA VX855 chipset");
	323	MODULE_ALIAS("platform:vx855_gpio");