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 #include <linux/uaccess.h>
  25
  26 #include <asm/io.h>
  27 #include <asm/reboot.h>
  28 #include <asm/vr41xx/giu.h>
  29 #include <asm/vr41xx/tb0219.h>
  30
  31 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
  32 MODULE_DESCRIPTION("TANBAC TB0219 base board driver");
  33 MODULE_LICENSE("GPL");
  34
  35 static int major;       /* default is dynamic major device number */
  36 module_param(major, int, 0);
  37 MODULE_PARM_DESC(major, "Major device number");
  38
  39 static void (*old_machine_restart)(char *command);
  40 static void __iomem *tb0219_base;
  41 static DEFINE_SPINLOCK(tb0219_lock);
  42
  43 #define tb0219_read(offset)             readw(tb0219_base + (offset))
  44 #define tb0219_write(offset, value)     writew((value), tb0219_base + (offset))
  45
  46 #define TB0219_START    0x0a000000UL
  47 #define TB0219_SIZE     0x20UL
  48
  49 #define TB0219_LED                      0x00
  50 #define TB0219_GPIO_INPUT               0x02
  51 #define TB0219_GPIO_OUTPUT              0x04
  52 #define TB0219_DIP_SWITCH               0x06
  53 #define TB0219_MISC                     0x08
  54 #define TB0219_RESET                    0x0e
  55 #define TB0219_PCI_SLOT1_IRQ_STATUS     0x10
  56 #define TB0219_PCI_SLOT2_IRQ_STATUS     0x12
  57 #define TB0219_PCI_SLOT3_IRQ_STATUS     0x14
  58
  59 typedef enum {
  60         TYPE_LED,
  61         TYPE_GPIO_OUTPUT,
  62 } tb0219_type_t;
  63
  64 /*
  65  * Minor device number
  66  *       0 = 7 segment LED
  67  *
  68  *      16 = GPIO IN 0
  69  *      17 = GPIO IN 1
  70  *      18 = GPIO IN 2
  71  *      19 = GPIO IN 3
  72  *      20 = GPIO IN 4
  73  *      21 = GPIO IN 5
  74  *      22 = GPIO IN 6
  75  *      23 = GPIO IN 7
  76  *
  77  *      32 = GPIO OUT 0
  78  *      33 = GPIO OUT 1
  79  *      34 = GPIO OUT 2
  80  *      35 = GPIO OUT 3
  81  *      36 = GPIO OUT 4
  82  *      37 = GPIO OUT 5
  83  *      38 = GPIO OUT 6
  84  *      39 = GPIO OUT 7
  85  *
  86  *      48 = DIP switch 1
  87  *      49 = DIP switch 2
  88  *      50 = DIP switch 3
  89  *      51 = DIP switch 4
  90  *      52 = DIP switch 5
  91  *      53 = DIP switch 6
  92  *      54 = DIP switch 7
  93  *      55 = DIP switch 8
  94  */
  95
  96 static inline char get_led(void)
  97 {
  98         return (char)tb0219_read(TB0219_LED);
  99 }
 100
 101 static inline char get_gpio_input_pin(unsigned int pin)
 102 {
 103         uint16_t values;
 104
 105         values = tb0219_read(TB0219_GPIO_INPUT);
 106         if (values & (1 << pin))
 107                 return '1';
 108
 109         return '0';
 110 }
 111
 112 static inline char get_gpio_output_pin(unsigned int pin)
 113 {
 114         uint16_t values;
 115
 116         values = tb0219_read(TB0219_GPIO_OUTPUT);
 117         if (values & (1 << pin))
 118                 return '1';
 119
 120         return '0';
 121 }
 122
 123 static inline char get_dip_switch(unsigned int pin)
 124 {
 125         uint16_t values;
 126
 127         values = tb0219_read(TB0219_DIP_SWITCH);
 128         if (values & (1 << pin))
 129                 return '1';
 130
 131         return '0';
 132 }
 133
 134 static inline int set_led(char command)
 135 {
 136         tb0219_write(TB0219_LED, command);
 137
 138         return 0;
 139 }
 140
 141 static inline int set_gpio_output_pin(unsigned int pin, char command)
 142 {
 143         unsigned long flags;
 144         uint16_t value;
 145
 146         if (command != '0' && command != '1')
 147                 return -EINVAL;
 148
 149         spin_lock_irqsave(&tb0219_lock, flags);
 150         value = tb0219_read(TB0219_GPIO_OUTPUT);
 151         if (command == '0')
 152                 value &= ~(1 << pin);
 153         else
 154                 value |= 1 << pin;
 155         tb0219_write(TB0219_GPIO_OUTPUT, value);
 156         spin_unlock_irqrestore(&tb0219_lock, flags);
 157
 158         return 0;
 159
 160 }
 161
 162 static ssize_t tanbac_tb0219_read(struct file *file, char __user *buf, size_t len,
 163                                   loff_t *ppos)
 164 {
 165         unsigned int minor;
 166         char value;
 167
 168         minor = iminor(file_inode(file));
 169         switch (minor) {
 170         case 0:
 171                 value = get_led();
 172                 break;
 173         case 16 ... 23:
 174                 value = get_gpio_input_pin(minor - 16);
 175                 break;
 176         case 32 ... 39:
 177                 value = get_gpio_output_pin(minor - 32);
 178                 break;
 179         case 48 ... 55:
 180                 value = get_dip_switch(minor - 48);
 181                 break;
 182         default:
 183                 return -EBADF;
 184         }
 185
 186         if (len <= 0)
 187                 return -EFAULT;
 188
 189         if (put_user(value, buf))
 190                 return -EFAULT;
 191
 192         return 1;
 193 }
 194
 195 static ssize_t tanbac_tb0219_write(struct file *file, const char __user *data,
 196                                    size_t len, loff_t *ppos)
 197 {
 198         unsigned int minor;
 199         tb0219_type_t type;
 200         size_t i;
 201         int retval = 0;
 202         char c;
 203
 204         minor = iminor(file_inode(file));
 205         switch (minor) {
 206         case 0:
 207                 type = TYPE_LED;
 208                 break;
 209         case 32 ... 39:
 210                 type = TYPE_GPIO_OUTPUT;
 211                 break;
 212         default:
 213                 return -EBADF;
 214         }
 215
 216         for (i = 0; i < len; i++) {
 217                 if (get_user(c, data + i))
 218                         return -EFAULT;
 219
 220                 switch (type) {
 221                 case TYPE_LED:
 222                         retval = set_led(c);
 223                         break;
 224                 case TYPE_GPIO_OUTPUT:
 225                         retval = set_gpio_output_pin(minor - 32, c);
 226                         break;
 227                 }
 228
 229                 if (retval < 0)
 230                         break;
 231         }
 232
 233         return i;
 234 }
 235
 236 static int tanbac_tb0219_open(struct inode *inode, struct file *file)
 237 {
 238         unsigned int minor;
 239
 240         minor = iminor(inode);
 241         switch (minor) {
 242         case 0:
 243         case 16 ... 23:
 244         case 32 ... 39:
 245         case 48 ... 55:
 246                 return nonseekable_open(inode, file);
 247         default:
 248                 break;
 249         }
 250
 251         return -EBADF;
 252 }
 253
 254 static int tanbac_tb0219_release(struct inode *inode, struct file *file)
 255 {
 256         return 0;
 257 }
 258
 259 static const struct file_operations tb0219_fops = {
 260         .owner          = THIS_MODULE,
 261         .read           = tanbac_tb0219_read,
 262         .write          = tanbac_tb0219_write,
 263         .open           = tanbac_tb0219_open,
 264         .release        = tanbac_tb0219_release,
 265         .llseek         = no_llseek,
 266 };
 267
 268 static void tb0219_restart(char *command)
 269 {
 270         tb0219_write(TB0219_RESET, 0);
 271 }
 272
 273 static void tb0219_pci_irq_init(void)
 274 {
 275         /* PCI Slot 1 */
 276         vr41xx_set_irq_trigger(TB0219_PCI_SLOT1_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
 277         vr41xx_set_irq_level(TB0219_PCI_SLOT1_PIN, IRQ_LEVEL_LOW);
 278
 279         /* PCI Slot 2 */
 280         vr41xx_set_irq_trigger(TB0219_PCI_SLOT2_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
 281         vr41xx_set_irq_level(TB0219_PCI_SLOT2_PIN, IRQ_LEVEL_LOW);
 282
 283         /* PCI Slot 3 */
 284         vr41xx_set_irq_trigger(TB0219_PCI_SLOT3_PIN, IRQ_TRIGGER_LEVEL, IRQ_SIGNAL_THROUGH);
 285         vr41xx_set_irq_level(TB0219_PCI_SLOT3_PIN, IRQ_LEVEL_LOW);
 286 }
 287
 288 static int tb0219_probe(struct platform_device *dev)
 289 {
 290         int retval;
 291
 292         if (request_mem_region(TB0219_START, TB0219_SIZE, "TB0219") == NULL)
 293                 return -EBUSY;
 294
 295         tb0219_base = ioremap(TB0219_START, TB0219_SIZE);
 296         if (tb0219_base == NULL) {
 297                 release_mem_region(TB0219_START, TB0219_SIZE);
 298                 return -ENOMEM;
 299         }
 300
 301         retval = register_chrdev(major, "TB0219", &tb0219_fops);
 302         if (retval < 0) {
 303                 iounmap(tb0219_base);
 304                 tb0219_base = NULL;
 305                 release_mem_region(TB0219_START, TB0219_SIZE);
 306                 return retval;
 307         }
 308
 309         old_machine_restart = _machine_restart;
 310         _machine_restart = tb0219_restart;
 311
 312         tb0219_pci_irq_init();
 313
 314         if (major == 0) {
 315                 major = retval;
 316                 printk(KERN_INFO "TB0219: major number %d\n", major);
 317         }
 318
 319         return 0;
 320 }
 321
 322 static int tb0219_remove(struct platform_device *dev)
 323 {
 324         _machine_restart = old_machine_restart;
 325
 326         iounmap(tb0219_base);
 327         tb0219_base = NULL;
 328
 329         release_mem_region(TB0219_START, TB0219_SIZE);
 330
 331         return 0;
 332 }
 333
 334 static struct platform_device *tb0219_platform_device;
 335
 336 static struct platform_driver tb0219_device_driver = {
 337         .probe          = tb0219_probe,
 338         .remove         = tb0219_remove,
 339         .driver         = {
 340                 .name   = "TB0219",
 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);