1 /* 2 * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620 3 * thermometer driver (as used in the Rebel.com NetWinder) 4 */ 5 #include <linux/module.h> 6 #include <linux/sched.h> 7 #include <linux/miscdevice.h> 8 #include <linux/smp_lock.h> 9 #include <linux/delay.h> 10 #include <linux/proc_fs.h> 11 #include <linux/capability.h> 12 #include <linux/init.h> 13 14 #include <asm/hardware.h> 15 #include <asm/mach-types.h> 16 #include <asm/uaccess.h> 17 #include <asm/therm.h> 18 19 #ifdef CONFIG_PROC_FS 20 /* define for /proc interface */ 21 #define THERM_USE_PROC 22 #endif 23 24 /* Definitions for DS1620 chip */ 25 #define THERM_START_CONVERT 0xee 26 #define THERM_RESET 0xaf 27 #define THERM_READ_CONFIG 0xac 28 #define THERM_READ_TEMP 0xaa 29 #define THERM_READ_TL 0xa2 30 #define THERM_READ_TH 0xa1 31 #define THERM_WRITE_CONFIG 0x0c 32 #define THERM_WRITE_TL 0x02 33 #define THERM_WRITE_TH 0x01 34 35 #define CFG_CPU 2 36 #define CFG_1SHOT 1 37 38 static const char *fan_state[] = { "off", "on", "on (hardwired)" }; 39 40 /* 41 * Start of NetWinder specifics 42 * Note! We have to hold the gpio lock with IRQs disabled over the 43 * whole of our transaction to the Dallas chip, since there is a 44 * chance that the WaveArtist driver could touch these bits to 45 * enable or disable the speaker. 46 */ 47 extern spinlock_t gpio_lock; 48 extern unsigned int system_rev; 49 50 static inline void netwinder_ds1620_set_clk(int clk) 51 { 52 gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0); 53 } 54 55 static inline void netwinder_ds1620_set_data(int dat) 56 { 57 gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0); 58 } 59 60 static inline int netwinder_ds1620_get_data(void) 61 { 62 return gpio_read() & GPIO_DATA; 63 } 64 65 static inline void netwinder_ds1620_set_data_dir(int dir) 66 { 67 gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0); 68 } 69 70 static inline void netwinder_ds1620_reset(void) 71 { 72 cpld_modify(CPLD_DS_ENABLE, 0); 73 cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE); 74 } 75 76 static inline void netwinder_lock(unsigned long *flags) 77 { 78 spin_lock_irqsave(&gpio_lock, *flags); 79 } 80 81 static inline void netwinder_unlock(unsigned long *flags) 82 { 83 spin_unlock_irqrestore(&gpio_lock, *flags); 84 } 85 86 static inline void netwinder_set_fan(int i) 87 { 88 unsigned long flags; 89 90 spin_lock_irqsave(&gpio_lock, flags); 91 gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0); 92 spin_unlock_irqrestore(&gpio_lock, flags); 93 } 94 95 static inline int netwinder_get_fan(void) 96 { 97 if ((system_rev & 0xf000) == 0x4000) 98 return FAN_ALWAYS_ON; 99 100 return (gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF; 101 } 102 103 /* 104 * End of NetWinder specifics 105 */ 106 107 static void ds1620_send_bits(int nr, int value) 108 { 109 int i; 110 111 for (i = 0; i < nr; i++) { 112 netwinder_ds1620_set_data(value & 1); 113 netwinder_ds1620_set_clk(0); 114 udelay(1); 115 netwinder_ds1620_set_clk(1); 116 udelay(1); 117 118 value >>= 1; 119 } 120 } 121 122 static unsigned int ds1620_recv_bits(int nr) 123 { 124 unsigned int value = 0, mask = 1; 125 int i; 126 127 netwinder_ds1620_set_data(0); 128 129 for (i = 0; i < nr; i++) { 130 netwinder_ds1620_set_clk(0); 131 udelay(1); 132 133 if (netwinder_ds1620_get_data()) 134 value |= mask; 135 136 mask <<= 1; 137 138 netwinder_ds1620_set_clk(1); 139 udelay(1); 140 } 141 142 return value; 143 } 144 145 static void ds1620_out(int cmd, int bits, int value) 146 { 147 unsigned long flags; 148 149 netwinder_lock(&flags); 150 netwinder_ds1620_set_clk(1); 151 netwinder_ds1620_set_data_dir(0); 152 netwinder_ds1620_reset(); 153 154 udelay(1); 155 156 ds1620_send_bits(8, cmd); 157 if (bits) 158 ds1620_send_bits(bits, value); 159 160 udelay(1); 161 162 netwinder_ds1620_reset(); 163 netwinder_unlock(&flags); 164 165 msleep(20); 166 } 167 168 static unsigned int ds1620_in(int cmd, int bits) 169 { 170 unsigned long flags; 171 unsigned int value; 172 173 netwinder_lock(&flags); 174 netwinder_ds1620_set_clk(1); 175 netwinder_ds1620_set_data_dir(0); 176 netwinder_ds1620_reset(); 177 178 udelay(1); 179 180 ds1620_send_bits(8, cmd); 181 182 netwinder_ds1620_set_data_dir(1); 183 value = ds1620_recv_bits(bits); 184 185 netwinder_ds1620_reset(); 186 netwinder_unlock(&flags); 187 188 return value; 189 } 190 191 static int cvt_9_to_int(unsigned int val) 192 { 193 if (val & 0x100) 194 val |= 0xfffffe00; 195 196 return val; 197 } 198 199 static void ds1620_write_state(struct therm *therm) 200 { 201 ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); 202 ds1620_out(THERM_WRITE_TL, 9, therm->lo); 203 ds1620_out(THERM_WRITE_TH, 9, therm->hi); 204 ds1620_out(THERM_START_CONVERT, 0, 0); 205 } 206 207 static void ds1620_read_state(struct therm *therm) 208 { 209 therm->lo = cvt_9_to_int(ds1620_in(THERM_READ_TL, 9)); 210 therm->hi = cvt_9_to_int(ds1620_in(THERM_READ_TH, 9)); 211 } 212 213 static ssize_t 214 ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) 215 { 216 signed int cur_temp; 217 signed char cur_temp_degF; 218 219 cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1; 220 221 /* convert to Fahrenheit, as per wdt.c */ 222 cur_temp_degF = (cur_temp * 9) / 5 + 32; 223 224 if (copy_to_user(buf, &cur_temp_degF, 1)) 225 return -EFAULT; 226 227 return 1; 228 } 229 230 static int 231 ds1620_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) 232 { 233 struct therm therm; 234 union { 235 struct therm __user *therm; 236 int __user *i; 237 } uarg; 238 int i; 239 240 uarg.i = (int __user *)arg; 241 242 switch(cmd) { 243 case CMD_SET_THERMOSTATE: 244 case CMD_SET_THERMOSTATE2: 245 if (!capable(CAP_SYS_ADMIN)) 246 return -EPERM; 247 248 if (cmd == CMD_SET_THERMOSTATE) { 249 if (get_user(therm.hi, uarg.i)) 250 return -EFAULT; 251 therm.lo = therm.hi - 3; 252 } else { 253 if (copy_from_user(&therm, uarg.therm, sizeof(therm))) 254 return -EFAULT; 255 } 256 257 therm.lo <<= 1; 258 therm.hi <<= 1; 259 260 ds1620_write_state(&therm); 261 break; 262 263 case CMD_GET_THERMOSTATE: 264 case CMD_GET_THERMOSTATE2: 265 ds1620_read_state(&therm); 266 267 therm.lo >>= 1; 268 therm.hi >>= 1; 269 270 if (cmd == CMD_GET_THERMOSTATE) { 271 if (put_user(therm.hi, uarg.i)) 272 return -EFAULT; 273 } else { 274 if (copy_to_user(uarg.therm, &therm, sizeof(therm))) 275 return -EFAULT; 276 } 277 break; 278 279 case CMD_GET_TEMPERATURE: 280 case CMD_GET_TEMPERATURE2: 281 i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); 282 283 if (cmd == CMD_GET_TEMPERATURE) 284 i >>= 1; 285 286 return put_user(i, uarg.i) ? -EFAULT : 0; 287 288 case CMD_GET_STATUS: 289 i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3; 290 291 return put_user(i, uarg.i) ? -EFAULT : 0; 292 293 case CMD_GET_FAN: 294 i = netwinder_get_fan(); 295 296 return put_user(i, uarg.i) ? -EFAULT : 0; 297 298 case CMD_SET_FAN: 299 if (!capable(CAP_SYS_ADMIN)) 300 return -EPERM; 301 302 if (get_user(i, uarg.i)) 303 return -EFAULT; 304 305 netwinder_set_fan(i); 306 break; 307 308 default: 309 return -ENOIOCTLCMD; 310 } 311 312 return 0; 313 } 314 315 #ifdef THERM_USE_PROC 316 static int 317 proc_therm_ds1620_read(char *buf, char **start, off_t offset, 318 int len, int *eof, void *unused) 319 { 320 struct therm th; 321 int temp; 322 323 ds1620_read_state(&th); 324 temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); 325 326 len = sprintf(buf, "Thermostat: HI %i.%i, LOW %i.%i; " 327 "temperature: %i.%i C, fan %s\n", 328 th.hi >> 1, th.hi & 1 ? 5 : 0, 329 th.lo >> 1, th.lo & 1 ? 5 : 0, 330 temp >> 1, temp & 1 ? 5 : 0, 331 fan_state[netwinder_get_fan()]); 332 333 return len; 334 } 335 336 static struct proc_dir_entry *proc_therm_ds1620; 337 #endif 338 339 static const struct file_operations ds1620_fops = { 340 .owner = THIS_MODULE, 341 .open = nonseekable_open, 342 .read = ds1620_read, 343 .ioctl = ds1620_ioctl, 344 }; 345 346 static struct miscdevice ds1620_miscdev = { 347 TEMP_MINOR, 348 "temp", 349 &ds1620_fops 350 }; 351 352 static int __init ds1620_init(void) 353 { 354 int ret; 355 struct therm th, th_start; 356 357 if (!machine_is_netwinder()) 358 return -ENODEV; 359 360 ds1620_out(THERM_RESET, 0, 0); 361 ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); 362 ds1620_out(THERM_START_CONVERT, 0, 0); 363 364 /* 365 * Trigger the fan to start by setting 366 * temperature high point low. This kicks 367 * the fan into action. 368 */ 369 ds1620_read_state(&th); 370 th_start.lo = 0; 371 th_start.hi = 1; 372 ds1620_write_state(&th_start); 373 374 msleep(2000); 375 376 ds1620_write_state(&th); 377 378 ret = misc_register(&ds1620_miscdev); 379 if (ret < 0) 380 return ret; 381 382 #ifdef THERM_USE_PROC 383 proc_therm_ds1620 = create_proc_entry("therm", 0, NULL); 384 if (proc_therm_ds1620) 385 proc_therm_ds1620->read_proc = proc_therm_ds1620_read; 386 else 387 printk(KERN_ERR "therm: unable to register /proc/therm\n"); 388 #endif 389 390 ds1620_read_state(&th); 391 ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); 392 393 printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, " 394 "current %i.%i C, fan %s.\n", 395 th.hi >> 1, th.hi & 1 ? 5 : 0, 396 th.lo >> 1, th.lo & 1 ? 5 : 0, 397 ret >> 1, ret & 1 ? 5 : 0, 398 fan_state[netwinder_get_fan()]); 399 400 return 0; 401 } 402 403 static void __exit ds1620_exit(void) 404 { 405 #ifdef THERM_USE_PROC 406 remove_proc_entry("therm", NULL); 407 #endif 408 misc_deregister(&ds1620_miscdev); 409 } 410 411 module_init(ds1620_init); 412 module_exit(ds1620_exit); 413 414 MODULE_LICENSE("GPL"); 415