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/miscdevice.h> 7 #include <linux/delay.h> 8 #include <linux/proc_fs.h> 9 #include <linux/seq_file.h> 10 #include <linux/capability.h> 11 #include <linux/init.h> 12 #include <linux/mutex.h> 13 14 #include <mach/hardware.h> 15 #include <asm/mach-types.h> 16 #include <linux/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 DEFINE_MUTEX(ds1620_mutex); 39 static const char *fan_state[] = { "off", "on", "on (hardwired)" }; 40 41 /* 42 * Start of NetWinder specifics 43 * Note! We have to hold the gpio lock with IRQs disabled over the 44 * whole of our transaction to the Dallas chip, since there is a 45 * chance that the WaveArtist driver could touch these bits to 46 * enable or disable the speaker. 47 */ 48 extern unsigned int system_rev; 49 50 static inline void netwinder_ds1620_set_clk(int clk) 51 { 52 nw_gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0); 53 } 54 55 static inline void netwinder_ds1620_set_data(int dat) 56 { 57 nw_gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0); 58 } 59 60 static inline int netwinder_ds1620_get_data(void) 61 { 62 return nw_gpio_read() & GPIO_DATA; 63 } 64 65 static inline void netwinder_ds1620_set_data_dir(int dir) 66 { 67 nw_gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0); 68 } 69 70 static inline void netwinder_ds1620_reset(void) 71 { 72 nw_cpld_modify(CPLD_DS_ENABLE, 0); 73 nw_cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE); 74 } 75 76 static inline void netwinder_lock(unsigned long *flags) 77 { 78 raw_spin_lock_irqsave(&nw_gpio_lock, *flags); 79 } 80 81 static inline void netwinder_unlock(unsigned long *flags) 82 { 83 raw_spin_unlock_irqrestore(&nw_gpio_lock, *flags); 84 } 85 86 static inline void netwinder_set_fan(int i) 87 { 88 unsigned long flags; 89 90 raw_spin_lock_irqsave(&nw_gpio_lock, flags); 91 nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0); 92 raw_spin_unlock_irqrestore(&nw_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 (nw_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 int ds1620_open(struct inode *inode, struct file *file) 214 { 215 return stream_open(inode, file); 216 } 217 218 static ssize_t 219 ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) 220 { 221 signed int cur_temp; 222 signed char cur_temp_degF; 223 224 cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1; 225 226 /* convert to Fahrenheit, as per wdt.c */ 227 cur_temp_degF = (cur_temp * 9) / 5 + 32; 228 229 if (copy_to_user(buf, &cur_temp_degF, 1)) 230 return -EFAULT; 231 232 return 1; 233 } 234 235 static int 236 ds1620_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 237 { 238 struct therm therm; 239 union { 240 struct therm __user *therm; 241 int __user *i; 242 } uarg; 243 int i; 244 245 uarg.i = (int __user *)arg; 246 247 switch(cmd) { 248 case CMD_SET_THERMOSTATE: 249 case CMD_SET_THERMOSTATE2: 250 if (!capable(CAP_SYS_ADMIN)) 251 return -EPERM; 252 253 if (cmd == CMD_SET_THERMOSTATE) { 254 if (get_user(therm.hi, uarg.i)) 255 return -EFAULT; 256 therm.lo = therm.hi - 3; 257 } else { 258 if (copy_from_user(&therm, uarg.therm, sizeof(therm))) 259 return -EFAULT; 260 } 261 262 therm.lo <<= 1; 263 therm.hi <<= 1; 264 265 ds1620_write_state(&therm); 266 break; 267 268 case CMD_GET_THERMOSTATE: 269 case CMD_GET_THERMOSTATE2: 270 ds1620_read_state(&therm); 271 272 therm.lo >>= 1; 273 therm.hi >>= 1; 274 275 if (cmd == CMD_GET_THERMOSTATE) { 276 if (put_user(therm.hi, uarg.i)) 277 return -EFAULT; 278 } else { 279 if (copy_to_user(uarg.therm, &therm, sizeof(therm))) 280 return -EFAULT; 281 } 282 break; 283 284 case CMD_GET_TEMPERATURE: 285 case CMD_GET_TEMPERATURE2: 286 i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); 287 288 if (cmd == CMD_GET_TEMPERATURE) 289 i >>= 1; 290 291 return put_user(i, uarg.i) ? -EFAULT : 0; 292 293 case CMD_GET_STATUS: 294 i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3; 295 296 return put_user(i, uarg.i) ? -EFAULT : 0; 297 298 case CMD_GET_FAN: 299 i = netwinder_get_fan(); 300 301 return put_user(i, uarg.i) ? -EFAULT : 0; 302 303 case CMD_SET_FAN: 304 if (!capable(CAP_SYS_ADMIN)) 305 return -EPERM; 306 307 if (get_user(i, uarg.i)) 308 return -EFAULT; 309 310 netwinder_set_fan(i); 311 break; 312 313 default: 314 return -ENOIOCTLCMD; 315 } 316 317 return 0; 318 } 319 320 static long 321 ds1620_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 322 { 323 int ret; 324 325 mutex_lock(&ds1620_mutex); 326 ret = ds1620_ioctl(file, cmd, arg); 327 mutex_unlock(&ds1620_mutex); 328 329 return ret; 330 } 331 332 #ifdef THERM_USE_PROC 333 static int ds1620_proc_therm_show(struct seq_file *m, void *v) 334 { 335 struct therm th; 336 int temp; 337 338 ds1620_read_state(&th); 339 temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); 340 341 seq_printf(m, "Thermostat: HI %i.%i, LOW %i.%i; temperature: %i.%i C, fan %s\n", 342 th.hi >> 1, th.hi & 1 ? 5 : 0, 343 th.lo >> 1, th.lo & 1 ? 5 : 0, 344 temp >> 1, temp & 1 ? 5 : 0, 345 fan_state[netwinder_get_fan()]); 346 return 0; 347 } 348 #endif 349 350 static const struct file_operations ds1620_fops = { 351 .owner = THIS_MODULE, 352 .open = ds1620_open, 353 .read = ds1620_read, 354 .unlocked_ioctl = ds1620_unlocked_ioctl, 355 .llseek = no_llseek, 356 }; 357 358 static struct miscdevice ds1620_miscdev = { 359 TEMP_MINOR, 360 "temp", 361 &ds1620_fops 362 }; 363 364 static int __init ds1620_init(void) 365 { 366 int ret; 367 struct therm th, th_start; 368 369 if (!machine_is_netwinder()) 370 return -ENODEV; 371 372 ds1620_out(THERM_RESET, 0, 0); 373 ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); 374 ds1620_out(THERM_START_CONVERT, 0, 0); 375 376 /* 377 * Trigger the fan to start by setting 378 * temperature high point low. This kicks 379 * the fan into action. 380 */ 381 ds1620_read_state(&th); 382 th_start.lo = 0; 383 th_start.hi = 1; 384 ds1620_write_state(&th_start); 385 386 msleep(2000); 387 388 ds1620_write_state(&th); 389 390 ret = misc_register(&ds1620_miscdev); 391 if (ret < 0) 392 return ret; 393 394 #ifdef THERM_USE_PROC 395 if (!proc_create_single("therm", 0, NULL, ds1620_proc_therm_show)) 396 printk(KERN_ERR "therm: unable to register /proc/therm\n"); 397 #endif 398 399 ds1620_read_state(&th); 400 ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); 401 402 printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, " 403 "current %i.%i C, fan %s.\n", 404 th.hi >> 1, th.hi & 1 ? 5 : 0, 405 th.lo >> 1, th.lo & 1 ? 5 : 0, 406 ret >> 1, ret & 1 ? 5 : 0, 407 fan_state[netwinder_get_fan()]); 408 409 return 0; 410 } 411 412 static void __exit ds1620_exit(void) 413 { 414 #ifdef THERM_USE_PROC 415 remove_proc_entry("therm", NULL); 416 #endif 417 misc_deregister(&ds1620_miscdev); 418 } 419 420 module_init(ds1620_init); 421 module_exit(ds1620_exit); 422 423 MODULE_LICENSE("GPL"); 424