drivers/char/tb0219.c

   1 /*
   2  *  Driver for TANBAC TB0219 base board.
   3  *
   4  *  Copyright (C) 2005  Yoichi Yuasa <yuasa@linux-mips.org>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #include <linux/platform_device.h>
  21 #include <linux/fs.h>
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24
  25 #include <asm/io.h>
  26 #include <asm/reboot.h>
  27 #include <asm/vr41xx/giu.h>
  28 #include <asm/vr41xx/tb0219.h>
  29
  30 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
  31 MODULE_DESCRIPTION("TANBAC TB0219 base board driver");
  32 MODULE_LICENSE("GPL");
  33
  34 static int major;       /* default is dynamic major device number */
  35 module_param(major, int, 0);
  36 MODULE_PARM_DESC(major, "Major device number");
  37
  38 static void (*old_machine_restart)(char *command);
  39 static void __iomem *tb0219_base;
  40 static DEFINE_SPINLOCK(tb0219_lock);
  41
  42 #define tb0219_read(offset)             readw(tb0219_base + (offset))
  43 #define tb0219_write(offset, value)     writew((value), tb0219_base + (offset))
  44
  45 #define TB0219_START    0x0a000000UL
  46 #define TB0219_SIZE     0x20UL
  47
  48 #define TB0219_LED                      0x00
  49 #define TB0219_GPIO_INPUT               0x02
  50 #define TB0219_GPIO_OUTPUT              0x04
  51 #define TB0219_DIP_SWITCH               0x06
  52 #define TB0219_MISC                     0x08
  53 #define TB0219_RESET                    0x0e
  54 #define TB0219_PCI_SLOT1_IRQ_STATUS     0x10
  55 #define TB0219_PCI_SLOT2_IRQ_STATUS     0x12
  56 #define TB0219_PCI_SLOT3_IRQ_STATUS     0x14
  57
  58 typedef enum {
  59         TYPE_LED,
  60         TYPE_GPIO_OUTPUT,
  61 } tb0219_type_t;
  62
  63 /*
  64  * Minor device number
  65  *       0 = 7 segment LED
  66  *
  67  *      16 = GPIO IN 0
  68  *      17 = GPIO IN 1
  69  *      18 = GPIO IN 2
  70  *      19 = GPIO IN 3
  71  *      20 = GPIO IN 4
  72  *      21 = GPIO IN 5
  73  *      22 = GPIO IN 6
  74  *      23 = GPIO IN 7
  75  *
  76  *      32 = GPIO OUT 0
  77  *      33 = GPIO OUT 1
  78  *      34 = GPIO OUT 2
  79  *      35 = GPIO OUT 3
  80  *      36 = GPIO OUT 4
  81  *      37 = GPIO OUT 5
  82  *      38 = GPIO OUT 6
  83  *      39 = GPIO OUT 7
  84  *
  85  *      48 = DIP switch 1
  86  *      49 = DIP switch 2
  87  *      50 = DIP switch 3
  88  *      51 = DIP switch 4
  89  *      52 = DIP switch 5
  90  *      53 = DIP switch 6
  91  *      54 = DIP switch 7
  92  *      55 = DIP switch 8
  93  */
  94
  95 static inline char get_led(void)
  96 {
  97         return (char)tb0219_read(TB0219_LED);
  98 }
  99
 100 static inline char get_gpio_input_pin(unsigned int pin)
 101 {
 102         uint16_t values;
 103
 104         values = tb0219_read(TB0219_GPIO_INPUT);
 105         if (values & (1 << pin))
 106                 return '1';
 107
 108         return '0';
 109 }
 110
 111 static inline char get_gpio_output_pin(unsigned int pin)
 112 {
 113         uint16_t values;
 114
 115         values = tb0219_read(TB0219_GPIO_OUTPUT);
 116         if (values & (1 << pin))
 117                 return '1';
 118
 119         return '0';
 120 }
 121
 122 static inline char get_dip_switch(unsigned int pin)
 123 {
 124         uint16_t values;
 125
 126         values = tb0219_read(TB0219_DIP_SWITCH);
 127         if (values & (1 << pin))
 128                 return '1';
 129
 130         return '0';
 131 }
 132
 133 static inline int set_led(char command)
 134 {
 135         tb0219_write(TB0219_LED, command);
 136
 137         return 0;
 138 }
 139
 140 static inline int set_gpio_output_pin(unsigned int pin, char command)
 141 {
 142         unsigned long flags;
 143         uint16_t value;
 144
 145         if (command != '0' && command != '1')
 146                 return -EINVAL;
 147
 148         spin_lock_irqsave(&tb0219_lock, flags);
 149         value = tb0219_read(TB0219_GPIO_OUTPUT);
 150         if (command == '0')
 151                 value &= ~(1 << pin);
 152         else
 153                 value |= 1 << pin;
 154         tb0219_write(TB0219_GPIO_OUTPUT, value);
 155         spin_unlock_irqrestore(&tb0219_lock, flags);
 156
 157         return 0;
 158
 159 }
 160
 161 static ssize_t tanbac_tb0219_read(struct file *file, char __user *buf, size_t len,
 162                                   loff_t *ppos)
 163 {
 164         unsigned int minor;
 165         char value;
 166
 167         minor = iminor(file->f_path.dentry->d_inode);
 168         switch (minor) {
 169         case 0:
 170                 value = get_led();
 171                 break;
 172         case 16 ... 23:
 173                 value = get_gpio_input_pin(minor - 16);
 174                 break;
 175         case 32 ... 39:
 176                 value = get_gpio_output_pin(minor - 32);
 177                 break;
 178         case 48 ... 55:
 179                 value = get_dip_switch(minor - 48);
 180                 break;
 181         default:
 182                 return -EBADF;
 183         }
 184
 185         if (len <= 0)
 186                 return -EFAULT;
 187
 188         if (put_user(value, buf))
 189                 return -EFAULT;
 190
 191         return 1;
 192 }
 193
 194 static ssize_t tanbac_tb0219_write(struct file *file, const char __user *data,
 195                                    size_t len, loff_t *ppos)
 196 {
 197         unsigned int minor;
 198         tb0219_type_t type;
 199         size_t i;
 200         int retval = 0;
 201         char c;
 202
 203         minor = iminor(file->f_path.dentry->d_inode);
 204         switch (minor) {
 205         case 0:
 206                 type = TYPE_LED;
 207                 break;
 208         case 32 ... 39:
 209                 type = TYPE_GPIO_OUTPUT;
 210                 break;
 211         default:
 212                 return -EBADF;
 213         }
 214
 215         for (i = 0; i < len; i++) {
 216                 if (get_user(c, data + i))
 217                         return -EFAULT;
 218
 219                 switch (type) {
 220                 case TYPE_LED:
 221                         retval = set_led(c);
 222                         break;
 223                 case TYPE_GPIO_OUTPUT:
 224                         retval = set_gpio_output_pin(minor - 32, c);
 225                         break;
 226                 }
 227
 228                 if (retval < 0)
 229                         break;
 230         }
 231
 232         return i;
 233 }
 234
 235 static int tanbac_tb0219_open(struct inode *inode, struct file *file)
 236 {
 237         unsigned int minor;
 238
 239         minor = iminor(inode);
 240         switch (minor) {
 241         case 0:
 242         case 16 ... 23:
 243         case 32 ... 39:
 244         case 48 ... 55:
 245                 return nonseekable_open(inode, file);
 246         default:
 247                 break;
 248         }
 249
 250         return -EBADF;
 251 }
 252
 253 static int tanbac_tb0219_release(struct inode *inode, struct file *file)
 254 {
 255         return 0;
 256 }
 257
 258 static const struct file_operations tb0219_fops = {
 259         .owner          = THIS_MODULE,
 260         .read           = tanbac_tb0219_read,
 261         .write          = tanbac_tb0219_write,
 262         .open           = tanbac_tb0219_open,
 263         .release        = tanbac_tb0219_release,
 264         .llseek         = no_llseek,
 265 };
 266
 267 static void tb0219_restart(char *command)
 268 {
 269         tb0219_write(TB0219_RESET, 0);
 270 }
 271
 272 static void tb0219_pci_irq_init(void)
 273 {
 274         /* PCI Slot 1 */
 275         vr41xx_set_irq_trigger(TB0219_PCI_SLOT1_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
 276         vr41xx_set_irq_level(TB0219_PCI_SLOT1_PIN, IRQ_LEVEL_LOW);
 277
 278         /* PCI Slot 2 */
 279         vr41xx_set_irq_trigger(TB0219_PCI_SLOT2_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
 280         vr41xx_set_irq_level(TB0219_PCI_SLOT2_PIN, IRQ_LEVEL_LOW);
 281
 282         /* PCI Slot 3 */
 283         vr41xx_set_irq_trigger(TB0219_PCI_SLOT3_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
 284         vr41xx_set_irq_level(TB0219_PCI_SLOT3_PIN, IRQ_LEVEL_LOW);
 285 }
 286
 287 static int tb0219_probe(struct platform_device *dev)
 288 {
 289         int retval;
 290
 291         if (request_mem_region(TB0219_START, TB0219_SIZE, "TB0219") == NULL)
 292                 return -EBUSY;
 293
 294         tb0219_base = ioremap(TB0219_START, TB0219_SIZE);
 295         if (tb0219_base == NULL) {
 296                 release_mem_region(TB0219_START, TB0219_SIZE);
 297                 return -ENOMEM;
 298         }
 299
 300         retval = register_chrdev(major, "TB0219", &tb0219_fops);
 301         if (retval < 0) {
 302                 iounmap(tb0219_base);
 303                 tb0219_base = NULL;
 304                 release_mem_region(TB0219_START, TB0219_SIZE);
 305                 return retval;
 306         }
 307
 308         old_machine_restart = _machine_restart;
 309         _machine_restart = tb0219_restart;
 310
 311         tb0219_pci_irq_init();
 312
 313         if (major == 0) {
 314                 major = retval;
 315                 printk(KERN_INFO "TB0219: major number %d\n", major);
 316         }
 317
 318         return 0;
 319 }
 320
 321 static int tb0219_remove(struct platform_device *dev)
 322 {
 323         _machine_restart = old_machine_restart;
 324
 325         iounmap(tb0219_base);
 326         tb0219_base = NULL;
 327
 328         release_mem_region(TB0219_START, TB0219_SIZE);
 329
 330         return 0;
 331 }
 332
 333 static struct platform_device *tb0219_platform_device;
 334
 335 static struct platform_driver tb0219_device_driver = {
 336         .probe          = tb0219_probe,
 337         .remove         = tb0219_remove,
 338         .driver         = {
 339                 .name   = "TB0219",
 340                 .owner  = THIS_MODULE,
 341         },
 342 };
 343
 344 static int __init tanbac_tb0219_init(void)
 345 {
 346         int retval;
 347
 348         tb0219_platform_device = platform_device_alloc("TB0219", -1);
 349         if (!tb0219_platform_device)
 350                 return -ENOMEM;
 351
 352         retval = platform_device_add(tb0219_platform_device);
 353         if (retval < 0) {
 354                 platform_device_put(tb0219_platform_device);
 355                 return retval;
 356         }
 357
 358         retval = platform_driver_register(&tb0219_device_driver);
 359         if (retval < 0)
 360                 platform_device_unregister(tb0219_platform_device);
 361
 362         return retval;
 363 }
 364
 365 static void __exit tanbac_tb0219_exit(void)
 366 {
 367         platform_driver_unregister(&tb0219_device_driver);
 368         platform_device_unregister(tb0219_platform_device);
 369 }
 370
 371 module_init(tanbac_tb0219_init);
 372 module_exit(tanbac_tb0219_exit);