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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 <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 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 nonseekable_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 | ||
349 | static int ds1620_proc_therm_open(struct inode *inode, struct file *file) | |
350 | { | |
351 | return single_open(file, ds1620_proc_therm_show, NULL); | |
352 | } | |
353 | ||
354 | static const struct file_operations ds1620_proc_therm_fops = { | |
355 | .open = ds1620_proc_therm_open, | |
356 | .read = seq_read, | |
357 | .llseek = seq_lseek, | |
358 | .release = single_release, | |
359 | }; | |
360 | #endif | |
361 | ||
362 | static const struct file_operations ds1620_fops = { | |
363 | .owner = THIS_MODULE, | |
364 | .open = ds1620_open, | |
365 | .read = ds1620_read, | |
366 | .unlocked_ioctl = ds1620_unlocked_ioctl, | |
367 | .llseek = no_llseek, | |
368 | }; | |
369 | ||
370 | static struct miscdevice ds1620_miscdev = { | |
371 | TEMP_MINOR, | |
372 | "temp", | |
373 | &ds1620_fops | |
374 | }; | |
375 | ||
376 | static int __init ds1620_init(void) | |
377 | { | |
378 | int ret; | |
379 | struct therm th, th_start; | |
380 | ||
381 | if (!machine_is_netwinder()) | |
382 | return -ENODEV; | |
383 | ||
384 | ds1620_out(THERM_RESET, 0, 0); | |
385 | ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); | |
386 | ds1620_out(THERM_START_CONVERT, 0, 0); | |
387 | ||
388 | /* | |
389 | * Trigger the fan to start by setting | |
390 | * temperature high point low. This kicks | |
391 | * the fan into action. | |
392 | */ | |
393 | ds1620_read_state(&th); | |
394 | th_start.lo = 0; | |
395 | th_start.hi = 1; | |
396 | ds1620_write_state(&th_start); | |
397 | ||
398 | msleep(2000); | |
399 | ||
400 | ds1620_write_state(&th); | |
401 | ||
402 | ret = misc_register(&ds1620_miscdev); | |
403 | if (ret < 0) | |
404 | return ret; | |
405 | ||
406 | #ifdef THERM_USE_PROC | |
407 | if (!proc_create("therm", 0, NULL, &ds1620_proc_therm_fops)) | |
408 | printk(KERN_ERR "therm: unable to register /proc/therm\n"); | |
409 | #endif | |
410 | ||
411 | ds1620_read_state(&th); | |
412 | ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
413 | ||
414 | printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, " | |
415 | "current %i.%i C, fan %s.\n", | |
416 | th.hi >> 1, th.hi & 1 ? 5 : 0, | |
417 | th.lo >> 1, th.lo & 1 ? 5 : 0, | |
418 | ret >> 1, ret & 1 ? 5 : 0, | |
419 | fan_state[netwinder_get_fan()]); | |
420 | ||
421 | return 0; | |
422 | } | |
423 | ||
424 | static void __exit ds1620_exit(void) | |
425 | { | |
426 | #ifdef THERM_USE_PROC | |
427 | remove_proc_entry("therm", NULL); | |
428 | #endif | |
429 | misc_deregister(&ds1620_miscdev); | |
430 | } | |
431 | ||
432 | module_init(ds1620_init); | |
433 | module_exit(ds1620_exit); | |
434 | ||
435 | MODULE_LICENSE("GPL"); |