arch/arm/mach-ks8695/gpio.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
  35 /*
  36  * Configure a GPIO line for either GPIO function, or its internal
  37  * function (Interrupt, Timer, etc).
  38  */
  39 static void ks8695_gpio_mode(unsigned int pin, short gpio)
  40 {
  41         unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
  42         unsigned long x, flags;
  43
  44         if (pin > KS8695_GPIO_5)        /* only GPIO 0..5 have internal functions */
  45                 return;
  46
  47         local_irq_save(flags);
  48
  49         x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
  50         if (gpio)                       /* GPIO: set bit to 0 */
  51                 x &= ~enable[pin];
  52         else                            /* Internal function: set bit to 1 */
  53                 x |= enable[pin];
  54         __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPC);
  55
  56         local_irq_restore(flags);
  57 }
  58
  59
  60 static unsigned short gpio_irq[] = { KS8695_IRQ_EXTERN0, KS8695_IRQ_EXTERN1, KS8695_IRQ_EXTERN2, KS8695_IRQ_EXTERN3 };
  61
  62 /*
  63  * Configure GPIO pin as external interrupt source.
  64  */
  65 int ks8695_gpio_interrupt(unsigned int pin, unsigned int type)
  66 {
  67         unsigned long x, flags;
  68
  69         if (pin > KS8695_GPIO_3)        /* only GPIO 0..3 can generate IRQ */
  70                 return -EINVAL;
  71
  72         local_irq_save(flags);
  73
  74         /* set pin as input */
  75         x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
  76         x &= ~IOPM(pin);
  77         __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
  78
  79         local_irq_restore(flags);
  80
  81         /* Set IRQ triggering type */
  82         irq_set_irq_type(gpio_irq[pin], type);
  83
  84         /* enable interrupt mode */
  85         ks8695_gpio_mode(pin, 0);
  86
  87         return 0;
  88 }
  89 EXPORT_SYMBOL(ks8695_gpio_interrupt);
  90
  91
  92
  93 /* .... Generic GPIO interface .............................................. */
  94
  95 /*
  96  * Configure the GPIO line as an input.
  97  */
  98 static int ks8695_gpio_direction_input(struct gpio_chip *gc, unsigned int pin)
  99 {
 100         unsigned long x, flags;
 101
 102         if (pin > KS8695_GPIO_15)
 103                 return -EINVAL;
 104
 105         /* set pin to GPIO mode */
 106         ks8695_gpio_mode(pin, 1);
 107
 108         local_irq_save(flags);
 109
 110         /* set pin as input */
 111         x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
 112         x &= ~IOPM(pin);
 113         __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
 114
 115         local_irq_restore(flags);
 116
 117         return 0;
 118 }
 119
 120
 121 /*
 122  * Configure the GPIO line as an output, with default state.
 123  */
 124 static int ks8695_gpio_direction_output(struct gpio_chip *gc,
 125                                         unsigned int pin, int state)
 126 {
 127         unsigned long x, flags;
 128
 129         if (pin > KS8695_GPIO_15)
 130                 return -EINVAL;
 131
 132         /* set pin to GPIO mode */
 133         ks8695_gpio_mode(pin, 1);
 134
 135         local_irq_save(flags);
 136
 137         /* set line state */
 138         x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
 139         if (state)
 140                 x |= IOPD(pin);
 141         else
 142                 x &= ~IOPD(pin);
 143         __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
 144
 145         /* set pin as output */
 146         x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
 147         x |= IOPM(pin);
 148         __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPM);
 149
 150         local_irq_restore(flags);
 151
 152         return 0;
 153 }
 154
 155
 156 /*
 157  * Set the state of an output GPIO line.
 158  */
 159 static void ks8695_gpio_set_value(struct gpio_chip *gc,
 160                                   unsigned int pin, int state)
 161 {
 162         unsigned long x, flags;
 163
 164         if (pin > KS8695_GPIO_15)
 165                 return;
 166
 167         local_irq_save(flags);
 168
 169         /* set output line state */
 170         x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
 171         if (state)
 172                 x |= IOPD(pin);
 173         else
 174                 x &= ~IOPD(pin);
 175         __raw_writel(x, KS8695_GPIO_VA + KS8695_IOPD);
 176
 177         local_irq_restore(flags);
 178 }
 179
 180
 181 /*
 182  * Read the state of a GPIO line.
 183  */
 184 static int ks8695_gpio_get_value(struct gpio_chip *gc, unsigned int pin)
 185 {
 186         unsigned long x;
 187
 188         if (pin > KS8695_GPIO_15)
 189                 return -EINVAL;
 190
 191         x = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
 192         return (x & IOPD(pin)) != 0;
 193 }
 194
 195
 196 /*
 197  * Map GPIO line to IRQ number.
 198  */
 199 static int ks8695_gpio_to_irq(struct gpio_chip *gc, unsigned int pin)
 200 {
 201         if (pin > KS8695_GPIO_3)        /* only GPIO 0..3 can generate IRQ */
 202                 return -EINVAL;
 203
 204         return gpio_irq[pin];
 205 }
 206
 207 /*
 208  * Map IRQ number to GPIO line.
 209  */
 210 int irq_to_gpio(unsigned int irq)
 211 {
 212         if ((irq < KS8695_IRQ_EXTERN0) || (irq > KS8695_IRQ_EXTERN3))
 213                 return -EINVAL;
 214
 215         return (irq - KS8695_IRQ_EXTERN0);
 216 }
 217 EXPORT_SYMBOL(irq_to_gpio);
 218
 219 /* GPIOLIB interface */
 220
 221 static struct gpio_chip ks8695_gpio_chip = {
 222         .label                  = "KS8695",
 223         .direction_input        = ks8695_gpio_direction_input,
 224         .direction_output       = ks8695_gpio_direction_output,
 225         .get                    = ks8695_gpio_get_value,
 226         .set                    = ks8695_gpio_set_value,
 227         .to_irq                 = ks8695_gpio_to_irq,
 228         .base                   = 0,
 229         .ngpio                  = 16,
 230         .can_sleep              = 0,
 231 };
 232
 233 /* Register the GPIOs */
 234 void ks8695_register_gpios(void)
 235 {
 236         if (gpiochip_add(&ks8695_gpio_chip))
 237                 printk(KERN_ERR "Unable to register core GPIOs\n");
 238 }
 239
 240 /* .... Debug interface ..................................................... */
 241
 242 #ifdef CONFIG_DEBUG_FS
 243
 244 static int ks8695_gpio_show(struct seq_file *s, void *unused)
 245 {
 246         unsigned int enable[] = { IOPC_IOEINT0EN, IOPC_IOEINT1EN, IOPC_IOEINT2EN, IOPC_IOEINT3EN, IOPC_IOTIM0EN, IOPC_IOTIM1EN };
 247         unsigned int intmask[] = { IOPC_IOEINT0TM, IOPC_IOEINT1TM, IOPC_IOEINT2TM, IOPC_IOEINT3TM };
 248         unsigned long mode, ctrl, data;
 249         int i;
 250
 251         mode = __raw_readl(KS8695_GPIO_VA + KS8695_IOPM);
 252         ctrl = __raw_readl(KS8695_GPIO_VA + KS8695_IOPC);
 253         data = __raw_readl(KS8695_GPIO_VA + KS8695_IOPD);
 254
 255         seq_printf(s, "Pin\tI/O\tFunction\tState\n\n");
 256
 257         for (i = KS8695_GPIO_0; i <= KS8695_GPIO_15 ; i++) {
 258                 seq_printf(s, "%i:\t", i);
 259
 260                 seq_printf(s, "%s\t", (mode & IOPM(i)) ? "Output" : "Input");
 261
 262                 if (i <= KS8695_GPIO_3) {
 263                         if (ctrl & enable[i]) {
 264                                 seq_printf(s, "EXT%i ", i);
 265
 266                                 switch ((ctrl & intmask[i]) >> (4 * i)) {
 267                                         case IOPC_TM_LOW:
 268                                                 seq_printf(s, "(Low)");         break;
 269                                         case IOPC_TM_HIGH:
 270                                                 seq_printf(s, "(High)");        break;
 271                                         case IOPC_TM_RISING:
 272                                                 seq_printf(s, "(Rising)");      break;
 273                                         case IOPC_TM_FALLING:
 274                                                 seq_printf(s, "(Falling)");     break;
 275                                         case IOPC_TM_EDGE:
 276                                                 seq_printf(s, "(Edges)");       break;
 277                                 }
 278                         }
 279                         else
 280                                 seq_printf(s, "GPIO\t");
 281                 }
 282                 else if (i <= KS8695_GPIO_5) {
 283                         if (ctrl & enable[i])
 284                                 seq_printf(s, "TOUT%i\t", i - KS8695_GPIO_4);
 285                         else
 286                                 seq_printf(s, "GPIO\t");
 287                 }
 288                 else
 289                         seq_printf(s, "GPIO\t");
 290
 291                 seq_printf(s, "\t");
 292
 293                 seq_printf(s, "%i\n", (data & IOPD(i)) ? 1 : 0);
 294         }
 295         return 0;
 296 }
 297
 298 static int ks8695_gpio_open(struct inode *inode, struct file *file)
 299 {
 300         return single_open(file, ks8695_gpio_show, NULL);
 301 }
 302
 303 static const struct file_operations ks8695_gpio_operations = {
 304         .open           = ks8695_gpio_open,
 305         .read           = seq_read,
 306         .llseek         = seq_lseek,
 307         .release        = single_release,
 308 };
 309
 310 static int __init ks8695_gpio_debugfs_init(void)
 311 {
 312         /* /sys/kernel/debug/ks8695_gpio */
 313         (void) debugfs_create_file("ks8695_gpio", S_IFREG | S_IRUGO, NULL, NULL, &ks8695_gpio_operations);
 314         return 0;
 315 }
 316 postcore_initcall(ks8695_gpio_debugfs_init);
 317
 318 #endif