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/driver.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 /* GPIOLIB interface */
 209
 210 static 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 */
 223 void 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
 233 static 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
 285 static int ks8695_gpio_open(struct inode *inode, struct file *file)
 286 {
 287         return single_open(file, ks8695_gpio_show, NULL);
 288 }
 289
 290 static 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
 297 static 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 }
 303 postcore_initcall(ks8695_gpio_debugfs_init);
 304
 305 #endif