Root/drivers/gpio/gpio-ks8695.c

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/*
209 * Map IRQ number to GPIO line.
210 */
211int irq_to_gpio(unsigned int irq)
212{
213    if ((irq < KS8695_IRQ_EXTERN0) || (irq > KS8695_IRQ_EXTERN3))
214        return -EINVAL;
215
216    return (irq - KS8695_IRQ_EXTERN0);
217}
218EXPORT_SYMBOL(irq_to_gpio);
219
220/* GPIOLIB interface */
221
222static struct gpio_chip ks8695_gpio_chip = {
223    .label = "KS8695",
224    .direction_input = ks8695_gpio_direction_input,
225    .direction_output = ks8695_gpio_direction_output,
226    .get = ks8695_gpio_get_value,
227    .set = ks8695_gpio_set_value,
228    .to_irq = ks8695_gpio_to_irq,
229    .base = 0,
230    .ngpio = 16,
231    .can_sleep = 0,
232};
233
234/* Register the GPIOs */
235void ks8695_register_gpios(void)
236{
237    if (gpiochip_add(&ks8695_gpio_chip))
238        printk(KERN_ERR "Unable to register core GPIOs\n");
239}
240
241/* .... Debug interface ..................................................... */
242
243#ifdef CONFIG_DEBUG_FS
244
245static int ks8695_gpio_show(struct seq_file *s, void *unused)
246{
247    unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
248    unsigned int intmask[] = { IOPC_IOEINT0TM, IOPC_IOEINT1TM, IOPC_IOEINT2TM, IOPC_IOEINT3TM };
249    unsigned long mode, ctrl, data;
250    int i;
251
252    mode = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
253    ctrl = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
254    data = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
255
256    seq_printf(s, "Pin\tI/O\tFunction\tState\n\n");
257
258    for (i = KS8695_GPIO_0; i <= KS8695_GPIO_15 ; i++) {
259        seq_printf(s, "%i:\t", i);
260
261        seq_printf(s, "%s\t", (mode & IOPM(i)) ? "Output" : "Input");
262
263        if (i <= KS8695_GPIO_3) {
264            if (ctrl & enable[i]) {
265                seq_printf(s, "EXT%i ", i);
266
267                switch ((ctrl & intmask[i]) >> (4 * i)) {
268                    case IOPC_TM_LOW:
269                        seq_printf(s, "(Low)"); break;
270                    case IOPC_TM_HIGH:
271                        seq_printf(s, "(High)"); break;
272                    case IOPC_TM_RISING:
273                        seq_printf(s, "(Rising)"); break;
274                    case IOPC_TM_FALLING:
275                        seq_printf(s, "(Falling)"); break;
276                    case IOPC_TM_EDGE:
277                        seq_printf(s, "(Edges)"); break;
278                }
279            }
280            else
281                seq_printf(s, "GPIO\t");
282        }
283        else if (i <= KS8695_GPIO_5) {
284            if (ctrl & enable[i])
285                seq_printf(s, "TOUT%i\t", i - KS8695_GPIO_4);
286            else
287                seq_printf(s, "GPIO\t");
288        }
289        else
290            seq_printf(s, "GPIO\t");
291
292        seq_printf(s, "\t");
293
294        seq_printf(s, "%i\n", (data & IOPD(i)) ? 1 : 0);
295    }
296    return 0;
297}
298
299static int ks8695_gpio_open(struct inode *inode, struct file *file)
300{
301    return single_open(file, ks8695_gpio_show, NULL);
302}
303
304static const struct file_operations ks8695_gpio_operations = {
305    .open = ks8695_gpio_open,
306    .read = seq_read,
307    .llseek = seq_lseek,
308    .release = single_release,
309};
310
311static int __init ks8695_gpio_debugfs_init(void)
312{
313    /* /sys/kernel/debug/ks8695_gpio */
314    (void) debugfs_create_file("ks8695_gpio", S_IFREG | S_IRUGO, NULL, NULL, &ks8695_gpio_operations);
315    return 0;
316}
317postcore_initcall(ks8695_gpio_debugfs_init);
318
319#endif
320

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