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  */
  40 static 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
  61 static 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  */
  66 int 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 }
  90 EXPORT_SYMBOL(ks8695_gpio_interrupt);
  91
  92
  93
  94 /* .... Generic GPIO interface .............................................. */
  95
  96 /*
  97  * Configure the GPIO line as an input.
  98  */
  99 static 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  */
 125 static 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  */
 160 static 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  */
 185 static 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  */
 200 static 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  */
 211 int 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 }
 218 EXPORT_SYMBOL(irq_to_gpio);
 219
 220 /* GPIOLIB interface */
 221
 222 static 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 */
 235 void 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
 245 static 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
 299 static int ks8695_gpio_open(struct inode *inode, struct file *file)
 300 {
 301         return single_open(file, ks8695_gpio_show, NULL);
 302 }
 303
 304 static 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
 311 static 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 }
 317 postcore_initcall(ks8695_gpio_debugfs_init);
 318
 319 #endif