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1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620 | |
3 | * thermometer driver (as used in the Rebel.com NetWinder) | |
4 | */ | |
5 | #include <linux/config.h> | |
6 | #include <linux/module.h> | |
7 | #include <linux/sched.h> | |
8 | #include <linux/miscdevice.h> | |
9 | #include <linux/smp_lock.h> | |
10 | #include <linux/delay.h> | |
11 | #include <linux/proc_fs.h> | |
12 | #include <linux/capability.h> | |
13 | #include <linux/init.h> | |
14 | ||
15 | #include <asm/hardware.h> | |
16 | #include <asm/mach-types.h> | |
17 | #include <asm/uaccess.h> | |
18 | #include <asm/therm.h> | |
19 | ||
20 | #ifdef CONFIG_PROC_FS | |
21 | /* define for /proc interface */ | |
22 | #define THERM_USE_PROC | |
23 | #endif | |
24 | ||
25 | /* Definitions for DS1620 chip */ | |
26 | #define THERM_START_CONVERT 0xee | |
27 | #define THERM_RESET 0xaf | |
28 | #define THERM_READ_CONFIG 0xac | |
29 | #define THERM_READ_TEMP 0xaa | |
30 | #define THERM_READ_TL 0xa2 | |
31 | #define THERM_READ_TH 0xa1 | |
32 | #define THERM_WRITE_CONFIG 0x0c | |
33 | #define THERM_WRITE_TL 0x02 | |
34 | #define THERM_WRITE_TH 0x01 | |
35 | ||
36 | #define CFG_CPU 2 | |
37 | #define CFG_1SHOT 1 | |
38 | ||
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 spinlock_t gpio_lock; | |
49 | extern unsigned int system_rev; | |
50 | ||
51 | static inline void netwinder_ds1620_set_clk(int clk) | |
52 | { | |
53 | gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0); | |
54 | } | |
55 | ||
56 | static inline void netwinder_ds1620_set_data(int dat) | |
57 | { | |
58 | gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0); | |
59 | } | |
60 | ||
61 | static inline int netwinder_ds1620_get_data(void) | |
62 | { | |
63 | return gpio_read() & GPIO_DATA; | |
64 | } | |
65 | ||
66 | static inline void netwinder_ds1620_set_data_dir(int dir) | |
67 | { | |
68 | gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0); | |
69 | } | |
70 | ||
71 | static inline void netwinder_ds1620_reset(void) | |
72 | { | |
73 | cpld_modify(CPLD_DS_ENABLE, 0); | |
74 | cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE); | |
75 | } | |
76 | ||
77 | static inline void netwinder_lock(unsigned long *flags) | |
78 | { | |
79 | spin_lock_irqsave(&gpio_lock, *flags); | |
80 | } | |
81 | ||
82 | static inline void netwinder_unlock(unsigned long *flags) | |
83 | { | |
84 | spin_unlock_irqrestore(&gpio_lock, *flags); | |
85 | } | |
86 | ||
87 | static inline void netwinder_set_fan(int i) | |
88 | { | |
89 | unsigned long flags; | |
90 | ||
91 | spin_lock_irqsave(&gpio_lock, flags); | |
92 | gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0); | |
93 | spin_unlock_irqrestore(&gpio_lock, flags); | |
94 | } | |
95 | ||
96 | static inline int netwinder_get_fan(void) | |
97 | { | |
98 | if ((system_rev & 0xf000) == 0x4000) | |
99 | return FAN_ALWAYS_ON; | |
100 | ||
101 | return (gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF; | |
102 | } | |
103 | ||
104 | /* | |
105 | * End of NetWinder specifics | |
106 | */ | |
107 | ||
108 | static void ds1620_send_bits(int nr, int value) | |
109 | { | |
110 | int i; | |
111 | ||
112 | for (i = 0; i < nr; i++) { | |
113 | netwinder_ds1620_set_data(value & 1); | |
114 | netwinder_ds1620_set_clk(0); | |
115 | udelay(1); | |
116 | netwinder_ds1620_set_clk(1); | |
117 | udelay(1); | |
118 | ||
119 | value >>= 1; | |
120 | } | |
121 | } | |
122 | ||
123 | static unsigned int ds1620_recv_bits(int nr) | |
124 | { | |
125 | unsigned int value = 0, mask = 1; | |
126 | int i; | |
127 | ||
128 | netwinder_ds1620_set_data(0); | |
129 | ||
130 | for (i = 0; i < nr; i++) { | |
131 | netwinder_ds1620_set_clk(0); | |
132 | udelay(1); | |
133 | ||
134 | if (netwinder_ds1620_get_data()) | |
135 | value |= mask; | |
136 | ||
137 | mask <<= 1; | |
138 | ||
139 | netwinder_ds1620_set_clk(1); | |
140 | udelay(1); | |
141 | } | |
142 | ||
143 | return value; | |
144 | } | |
145 | ||
146 | static void ds1620_out(int cmd, int bits, int value) | |
147 | { | |
148 | unsigned long flags; | |
149 | ||
150 | netwinder_lock(&flags); | |
151 | netwinder_ds1620_set_clk(1); | |
152 | netwinder_ds1620_set_data_dir(0); | |
153 | netwinder_ds1620_reset(); | |
154 | ||
155 | udelay(1); | |
156 | ||
157 | ds1620_send_bits(8, cmd); | |
158 | if (bits) | |
159 | ds1620_send_bits(bits, value); | |
160 | ||
161 | udelay(1); | |
162 | ||
163 | netwinder_ds1620_reset(); | |
164 | netwinder_unlock(&flags); | |
165 | ||
d8eddb62 | 166 | msleep(20); |
1da177e4 LT |
167 | } |
168 | ||
169 | static unsigned int ds1620_in(int cmd, int bits) | |
170 | { | |
171 | unsigned long flags; | |
172 | unsigned int value; | |
173 | ||
174 | netwinder_lock(&flags); | |
175 | netwinder_ds1620_set_clk(1); | |
176 | netwinder_ds1620_set_data_dir(0); | |
177 | netwinder_ds1620_reset(); | |
178 | ||
179 | udelay(1); | |
180 | ||
181 | ds1620_send_bits(8, cmd); | |
182 | ||
183 | netwinder_ds1620_set_data_dir(1); | |
184 | value = ds1620_recv_bits(bits); | |
185 | ||
186 | netwinder_ds1620_reset(); | |
187 | netwinder_unlock(&flags); | |
188 | ||
189 | return value; | |
190 | } | |
191 | ||
192 | static int cvt_9_to_int(unsigned int val) | |
193 | { | |
194 | if (val & 0x100) | |
195 | val |= 0xfffffe00; | |
196 | ||
197 | return val; | |
198 | } | |
199 | ||
200 | static void ds1620_write_state(struct therm *therm) | |
201 | { | |
202 | ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); | |
203 | ds1620_out(THERM_WRITE_TL, 9, therm->lo); | |
204 | ds1620_out(THERM_WRITE_TH, 9, therm->hi); | |
205 | ds1620_out(THERM_START_CONVERT, 0, 0); | |
206 | } | |
207 | ||
208 | static void ds1620_read_state(struct therm *therm) | |
209 | { | |
210 | therm->lo = cvt_9_to_int(ds1620_in(THERM_READ_TL, 9)); | |
211 | therm->hi = cvt_9_to_int(ds1620_in(THERM_READ_TH, 9)); | |
212 | } | |
213 | ||
214 | static ssize_t | |
215 | ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) | |
216 | { | |
217 | signed int cur_temp; | |
218 | signed char cur_temp_degF; | |
219 | ||
220 | cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1; | |
221 | ||
222 | /* convert to Fahrenheit, as per wdt.c */ | |
223 | cur_temp_degF = (cur_temp * 9) / 5 + 32; | |
224 | ||
225 | if (copy_to_user(buf, &cur_temp_degF, 1)) | |
226 | return -EFAULT; | |
227 | ||
228 | return 1; | |
229 | } | |
230 | ||
231 | static int | |
232 | ds1620_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | |
233 | { | |
234 | struct therm therm; | |
235 | union { | |
236 | struct therm __user *therm; | |
237 | int __user *i; | |
238 | } uarg; | |
239 | int i; | |
240 | ||
241 | uarg.i = (int __user *)arg; | |
242 | ||
243 | switch(cmd) { | |
244 | case CMD_SET_THERMOSTATE: | |
245 | case CMD_SET_THERMOSTATE2: | |
246 | if (!capable(CAP_SYS_ADMIN)) | |
247 | return -EPERM; | |
248 | ||
249 | if (cmd == CMD_SET_THERMOSTATE) { | |
250 | if (get_user(therm.hi, uarg.i)) | |
251 | return -EFAULT; | |
252 | therm.lo = therm.hi - 3; | |
253 | } else { | |
254 | if (copy_from_user(&therm, uarg.therm, sizeof(therm))) | |
255 | return -EFAULT; | |
256 | } | |
257 | ||
258 | therm.lo <<= 1; | |
259 | therm.hi <<= 1; | |
260 | ||
261 | ds1620_write_state(&therm); | |
262 | break; | |
263 | ||
264 | case CMD_GET_THERMOSTATE: | |
265 | case CMD_GET_THERMOSTATE2: | |
266 | ds1620_read_state(&therm); | |
267 | ||
268 | therm.lo >>= 1; | |
269 | therm.hi >>= 1; | |
270 | ||
271 | if (cmd == CMD_GET_THERMOSTATE) { | |
272 | if (put_user(therm.hi, uarg.i)) | |
273 | return -EFAULT; | |
274 | } else { | |
275 | if (copy_to_user(uarg.therm, &therm, sizeof(therm))) | |
276 | return -EFAULT; | |
277 | } | |
278 | break; | |
279 | ||
280 | case CMD_GET_TEMPERATURE: | |
281 | case CMD_GET_TEMPERATURE2: | |
282 | i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
283 | ||
284 | if (cmd == CMD_GET_TEMPERATURE) | |
285 | i >>= 1; | |
286 | ||
287 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
288 | ||
289 | case CMD_GET_STATUS: | |
290 | i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3; | |
291 | ||
292 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
293 | ||
294 | case CMD_GET_FAN: | |
295 | i = netwinder_get_fan(); | |
296 | ||
297 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
298 | ||
299 | case CMD_SET_FAN: | |
300 | if (!capable(CAP_SYS_ADMIN)) | |
301 | return -EPERM; | |
302 | ||
303 | if (get_user(i, uarg.i)) | |
304 | return -EFAULT; | |
305 | ||
306 | netwinder_set_fan(i); | |
307 | break; | |
308 | ||
309 | default: | |
310 | return -ENOIOCTLCMD; | |
311 | } | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
316 | #ifdef THERM_USE_PROC | |
317 | static int | |
318 | proc_therm_ds1620_read(char *buf, char **start, off_t offset, | |
319 | int len, int *eof, void *unused) | |
320 | { | |
321 | struct therm th; | |
322 | int temp; | |
323 | ||
324 | ds1620_read_state(&th); | |
325 | temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
326 | ||
327 | len = sprintf(buf, "Thermostat: HI %i.%i, LOW %i.%i; " | |
328 | "temperature: %i.%i C, fan %s\n", | |
329 | th.hi >> 1, th.hi & 1 ? 5 : 0, | |
330 | th.lo >> 1, th.lo & 1 ? 5 : 0, | |
331 | temp >> 1, temp & 1 ? 5 : 0, | |
332 | fan_state[netwinder_get_fan()]); | |
333 | ||
334 | return len; | |
335 | } | |
336 | ||
337 | static struct proc_dir_entry *proc_therm_ds1620; | |
338 | #endif | |
339 | ||
340 | static struct file_operations ds1620_fops = { | |
341 | .owner = THIS_MODULE, | |
342 | .open = nonseekable_open, | |
343 | .read = ds1620_read, | |
344 | .ioctl = ds1620_ioctl, | |
345 | }; | |
346 | ||
347 | static struct miscdevice ds1620_miscdev = { | |
348 | TEMP_MINOR, | |
349 | "temp", | |
350 | &ds1620_fops | |
351 | }; | |
352 | ||
353 | static int __init ds1620_init(void) | |
354 | { | |
355 | int ret; | |
356 | struct therm th, th_start; | |
357 | ||
358 | if (!machine_is_netwinder()) | |
359 | return -ENODEV; | |
360 | ||
361 | ds1620_out(THERM_RESET, 0, 0); | |
362 | ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); | |
363 | ds1620_out(THERM_START_CONVERT, 0, 0); | |
364 | ||
365 | /* | |
366 | * Trigger the fan to start by setting | |
367 | * temperature high point low. This kicks | |
368 | * the fan into action. | |
369 | */ | |
370 | ds1620_read_state(&th); | |
371 | th_start.lo = 0; | |
372 | th_start.hi = 1; | |
373 | ds1620_write_state(&th_start); | |
374 | ||
375 | msleep(2000); | |
376 | ||
377 | ds1620_write_state(&th); | |
378 | ||
379 | ret = misc_register(&ds1620_miscdev); | |
380 | if (ret < 0) | |
381 | return ret; | |
382 | ||
383 | #ifdef THERM_USE_PROC | |
384 | proc_therm_ds1620 = create_proc_entry("therm", 0, NULL); | |
385 | if (proc_therm_ds1620) | |
386 | proc_therm_ds1620->read_proc = proc_therm_ds1620_read; | |
387 | else | |
388 | printk(KERN_ERR "therm: unable to register /proc/therm\n"); | |
389 | #endif | |
390 | ||
391 | ds1620_read_state(&th); | |
392 | ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
393 | ||
394 | printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, " | |
395 | "current %i.%i C, fan %s.\n", | |
396 | th.hi >> 1, th.hi & 1 ? 5 : 0, | |
397 | th.lo >> 1, th.lo & 1 ? 5 : 0, | |
398 | ret >> 1, ret & 1 ? 5 : 0, | |
399 | fan_state[netwinder_get_fan()]); | |
400 | ||
401 | return 0; | |
402 | } | |
403 | ||
404 | static void __exit ds1620_exit(void) | |
405 | { | |
406 | #ifdef THERM_USE_PROC | |
407 | remove_proc_entry("therm", NULL); | |
408 | #endif | |
409 | misc_deregister(&ds1620_miscdev); | |
410 | } | |
411 | ||
412 | module_init(ds1620_init); | |
413 | module_exit(ds1620_exit); | |
414 | ||
415 | MODULE_LICENSE("GPL"); |