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/drivers/gpio/gpio-ks8695.c

http://github.com/mirrors/linux
C | 305 lines | 182 code | 67 blank | 56 comment | 20 complexity | a0c099b972957e0931fd09c6855143e2 MD5 | raw file
  1/*
  2 * arch/arm/mach-ks8695/gpio.c
  3 *
  4 * Copyright (C) 2006 Andrew Victor
  5 * Updated to GPIOLIB, Copyright 2008 Simtec Electronics
  6 *                     Daniel Silverstone <dsilvers@simtec.co.uk>
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License version 2 as
 10 * published by the Free Software Foundation.
 11 *
 12 * This program is distributed in the hope that it will be useful,
 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 * GNU General Public License for more details.
 16 *
 17 * You should have received a copy of the GNU General Public License
 18 * along with this program; if not, write to the Free Software
 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 20 */
 21#include <linux/gpio.h>
 22#include <linux/kernel.h>
 23#include <linux/mm.h>
 24#include <linux/init.h>
 25#include <linux/debugfs.h>
 26#include <linux/seq_file.h>
 27#include <linux/module.h>
 28#include <linux/io.h>
 29
 30#include <mach/hardware.h>
 31#include <asm/mach/irq.h>
 32
 33#include <mach/regs-gpio.h>
 34#include <mach/gpio-ks8695.h>
 35
 36/*
 37 * Configure a GPIO line for either GPIO function, or its internal
 38 * function (Interrupt, Timer, etc).
 39 */
 40static void ks8695_gpio_mode(unsigned int pin, short gpio)
 41{
 42	unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
 43	unsigned long x, flags;
 44
 45	if (pin > KS8695_GPIO_5)	/* only GPIO 0..5 have internal functions */
 46		return;
 47
 48	local_irq_save(flags);
 49
 50	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
 51	if (gpio)			/* GPIO: set bit to 0 */
 52		x &= ~enable[pin];
 53	else				/* Internal function: set bit to 1 */
 54		x |= enable[pin];
 55	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPC);
 56
 57	local_irq_restore(flags);
 58}
 59
 60
 61static unsigned short gpio_irq[] = { KS8695_IRQ_EXTERN0, KS8695_IRQ_EXTERN1, KS8695_IRQ_EXTERN2, KS8695_IRQ_EXTERN3 };
 62
 63/*
 64 * Configure GPIO pin as external interrupt source.
 65 */
 66int ks8695_gpio_interrupt(unsigned int pin, unsigned int type)
 67{
 68	unsigned long x, flags;
 69
 70	if (pin > KS8695_GPIO_3)	/* only GPIO 0..3 can generate IRQ */
 71		return -EINVAL;
 72
 73	local_irq_save(flags);
 74
 75	/* set pin as input */
 76	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
 77	x &= ~IOPM(pin);
 78	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
 79
 80	local_irq_restore(flags);
 81
 82	/* Set IRQ triggering type */
 83	irq_set_irq_type(gpio_irq[pin], type);
 84
 85	/* enable interrupt mode */
 86	ks8695_gpio_mode(pin, 0);
 87
 88	return 0;
 89}
 90EXPORT_SYMBOL(ks8695_gpio_interrupt);
 91
 92
 93
 94/* .... Generic GPIO interface .............................................. */
 95
 96/*
 97 * Configure the GPIO line as an input.
 98 */
 99static int ks8695_gpio_direction_input(struct gpio_chip *gc, unsigned int pin)
100{
101	unsigned long x, flags;
102
103	if (pin > KS8695_GPIO_15)
104		return -EINVAL;
105
106	/* set pin to GPIO mode */
107	ks8695_gpio_mode(pin, 1);
108
109	local_irq_save(flags);
110
111	/* set pin as input */
112	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
113	x &= ~IOPM(pin);
114	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
115
116	local_irq_restore(flags);
117
118	return 0;
119}
120
121
122/*
123 * Configure the GPIO line as an output, with default state.
124 */
125static int ks8695_gpio_direction_output(struct gpio_chip *gc,
126					unsigned int pin, int state)
127{
128	unsigned long x, flags;
129
130	if (pin > KS8695_GPIO_15)
131		return -EINVAL;
132
133	/* set pin to GPIO mode */
134	ks8695_gpio_mode(pin, 1);
135
136	local_irq_save(flags);
137
138	/* set line state */
139	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
140	if (state)
141		x |= IOPD(pin);
142	else
143		x &= ~IOPD(pin);
144	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
145
146	/* set pin as output */
147	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
148	x |= IOPM(pin);
149	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
150
151	local_irq_restore(flags);
152
153	return 0;
154}
155
156
157/*
158 * Set the state of an output GPIO line.
159 */
160static void ks8695_gpio_set_value(struct gpio_chip *gc,
161				  unsigned int pin, int state)
162{
163	unsigned long x, flags;
164
165	if (pin > KS8695_GPIO_15)
166		return;
167
168	local_irq_save(flags);
169
170	/* set output line state */
171	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
172	if (state)
173		x |= IOPD(pin);
174	else
175		x &= ~IOPD(pin);
176	__raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
177
178	local_irq_restore(flags);
179}
180
181
182/*
183 * Read the state of a GPIO line.
184 */
185static int ks8695_gpio_get_value(struct gpio_chip *gc, unsigned int pin)
186{
187	unsigned long x;
188
189	if (pin > KS8695_GPIO_15)
190		return -EINVAL;
191
192	x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
193	return (x & IOPD(pin)) != 0;
194}
195
196
197/*
198 * Map GPIO line to IRQ number.
199 */
200static int ks8695_gpio_to_irq(struct gpio_chip *gc, unsigned int pin)
201{
202	if (pin > KS8695_GPIO_3)	/* only GPIO 0..3 can generate IRQ */
203		return -EINVAL;
204
205	return gpio_irq[pin];
206}
207
208/* GPIOLIB interface */
209
210static struct gpio_chip ks8695_gpio_chip = {
211	.label			= "KS8695",
212	.direction_input	= ks8695_gpio_direction_input,
213	.direction_output	= ks8695_gpio_direction_output,
214	.get			= ks8695_gpio_get_value,
215	.set			= ks8695_gpio_set_value,
216	.to_irq			= ks8695_gpio_to_irq,
217	.base			= 0,
218	.ngpio			= 16,
219	.can_sleep		= false,
220};
221
222/* Register the GPIOs */
223void ks8695_register_gpios(void)
224{
225	if (gpiochip_add_data(&ks8695_gpio_chip, NULL))
226		printk(KERN_ERR "Unable to register core GPIOs\n");
227}
228
229/* .... Debug interface ..................................................... */
230
231#ifdef CONFIG_DEBUG_FS
232
233static int ks8695_gpio_show(struct seq_file *s, void *unused)
234{
235	unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
236	unsigned int intmask[] = { IOPC_IOEINT0TM, IOPC_IOEINT1TM, IOPC_IOEINT2TM, IOPC_IOEINT3TM };
237	unsigned long mode, ctrl, data;
238	int i;
239
240	mode = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
241	ctrl = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
242	data = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
243
244	seq_printf(s, "Pin\tI/O\tFunction\tState\n\n");
245
246	for (i = KS8695_GPIO_0; i <= KS8695_GPIO_15 ; i++) {
247		seq_printf(s, "%i:\t", i);
248
249		seq_printf(s, "%s\t", (mode & IOPM(i)) ? "Output" : "Input");
250
251		if (i <= KS8695_GPIO_3) {
252			if (ctrl & enable[i]) {
253				seq_printf(s, "EXT%i ", i);
254
255				switch ((ctrl & intmask[i]) >> (4 * i)) {
256				case IOPC_TM_LOW:
257					seq_printf(s, "(Low)");		break;
258				case IOPC_TM_HIGH:
259					seq_printf(s, "(High)");	break;
260				case IOPC_TM_RISING:
261					seq_printf(s, "(Rising)");	break;
262				case IOPC_TM_FALLING:
263					seq_printf(s, "(Falling)");	break;
264				case IOPC_TM_EDGE:
265					seq_printf(s, "(Edges)");	break;
266				}
267			} else
268				seq_printf(s, "GPIO\t");
269		} else if (i <= KS8695_GPIO_5) {
270			if (ctrl & enable[i])
271				seq_printf(s, "TOUT%i\t", i - KS8695_GPIO_4);
272			else
273				seq_printf(s, "GPIO\t");
274		} else {
275			seq_printf(s, "GPIO\t");
276		}
277
278		seq_printf(s, "\t");
279
280		seq_printf(s, "%i\n", (data & IOPD(i)) ? 1 : 0);
281	}
282	return 0;
283}
284
285static int ks8695_gpio_open(struct inode *inode, struct file *file)
286{
287	return single_open(file, ks8695_gpio_show, NULL);
288}
289
290static const struct file_operations ks8695_gpio_operations = {
291	.open		= ks8695_gpio_open,
292	.read		= seq_read,
293	.llseek		= seq_lseek,
294	.release	= single_release,
295};
296
297static int __init ks8695_gpio_debugfs_init(void)
298{
299	/* /sys/kernel/debug/ks8695_gpio */
300	(void) debugfs_create_file("ks8695_gpio", S_IFREG | S_IRUGO, NULL, NULL, &ks8695_gpio_operations);
301	return 0;
302}
303postcore_initcall(ks8695_gpio_debugfs_init);
304
305#endif