Commit | Line | Data |
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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 | */ | |
1da177e4 | 5 | #include <linux/module.h> |
1da177e4 | 6 | #include <linux/miscdevice.h> |
1da177e4 LT |
7 | #include <linux/delay.h> |
8 | #include <linux/proc_fs.h> | |
9 | #include <linux/capability.h> | |
10 | #include <linux/init.h> | |
11 | ||
12 | #include <asm/hardware.h> | |
13 | #include <asm/mach-types.h> | |
14 | #include <asm/uaccess.h> | |
15 | #include <asm/therm.h> | |
16 | ||
17 | #ifdef CONFIG_PROC_FS | |
18 | /* define for /proc interface */ | |
19 | #define THERM_USE_PROC | |
20 | #endif | |
21 | ||
22 | /* Definitions for DS1620 chip */ | |
23 | #define THERM_START_CONVERT 0xee | |
24 | #define THERM_RESET 0xaf | |
25 | #define THERM_READ_CONFIG 0xac | |
26 | #define THERM_READ_TEMP 0xaa | |
27 | #define THERM_READ_TL 0xa2 | |
28 | #define THERM_READ_TH 0xa1 | |
29 | #define THERM_WRITE_CONFIG 0x0c | |
30 | #define THERM_WRITE_TL 0x02 | |
31 | #define THERM_WRITE_TH 0x01 | |
32 | ||
33 | #define CFG_CPU 2 | |
34 | #define CFG_1SHOT 1 | |
35 | ||
36 | static const char *fan_state[] = { "off", "on", "on (hardwired)" }; | |
37 | ||
38 | /* | |
39 | * Start of NetWinder specifics | |
40 | * Note! We have to hold the gpio lock with IRQs disabled over the | |
41 | * whole of our transaction to the Dallas chip, since there is a | |
42 | * chance that the WaveArtist driver could touch these bits to | |
43 | * enable or disable the speaker. | |
44 | */ | |
45 | extern spinlock_t gpio_lock; | |
46 | extern unsigned int system_rev; | |
47 | ||
48 | static inline void netwinder_ds1620_set_clk(int clk) | |
49 | { | |
50 | gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0); | |
51 | } | |
52 | ||
53 | static inline void netwinder_ds1620_set_data(int dat) | |
54 | { | |
55 | gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0); | |
56 | } | |
57 | ||
58 | static inline int netwinder_ds1620_get_data(void) | |
59 | { | |
60 | return gpio_read() & GPIO_DATA; | |
61 | } | |
62 | ||
63 | static inline void netwinder_ds1620_set_data_dir(int dir) | |
64 | { | |
65 | gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0); | |
66 | } | |
67 | ||
68 | static inline void netwinder_ds1620_reset(void) | |
69 | { | |
70 | cpld_modify(CPLD_DS_ENABLE, 0); | |
71 | cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE); | |
72 | } | |
73 | ||
74 | static inline void netwinder_lock(unsigned long *flags) | |
75 | { | |
76 | spin_lock_irqsave(&gpio_lock, *flags); | |
77 | } | |
78 | ||
79 | static inline void netwinder_unlock(unsigned long *flags) | |
80 | { | |
81 | spin_unlock_irqrestore(&gpio_lock, *flags); | |
82 | } | |
83 | ||
84 | static inline void netwinder_set_fan(int i) | |
85 | { | |
86 | unsigned long flags; | |
87 | ||
88 | spin_lock_irqsave(&gpio_lock, flags); | |
89 | gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0); | |
90 | spin_unlock_irqrestore(&gpio_lock, flags); | |
91 | } | |
92 | ||
93 | static inline int netwinder_get_fan(void) | |
94 | { | |
95 | if ((system_rev & 0xf000) == 0x4000) | |
96 | return FAN_ALWAYS_ON; | |
97 | ||
98 | return (gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF; | |
99 | } | |
100 | ||
101 | /* | |
102 | * End of NetWinder specifics | |
103 | */ | |
104 | ||
105 | static void ds1620_send_bits(int nr, int value) | |
106 | { | |
107 | int i; | |
108 | ||
109 | for (i = 0; i < nr; i++) { | |
110 | netwinder_ds1620_set_data(value & 1); | |
111 | netwinder_ds1620_set_clk(0); | |
112 | udelay(1); | |
113 | netwinder_ds1620_set_clk(1); | |
114 | udelay(1); | |
115 | ||
116 | value >>= 1; | |
117 | } | |
118 | } | |
119 | ||
120 | static unsigned int ds1620_recv_bits(int nr) | |
121 | { | |
122 | unsigned int value = 0, mask = 1; | |
123 | int i; | |
124 | ||
125 | netwinder_ds1620_set_data(0); | |
126 | ||
127 | for (i = 0; i < nr; i++) { | |
128 | netwinder_ds1620_set_clk(0); | |
129 | udelay(1); | |
130 | ||
131 | if (netwinder_ds1620_get_data()) | |
132 | value |= mask; | |
133 | ||
134 | mask <<= 1; | |
135 | ||
136 | netwinder_ds1620_set_clk(1); | |
137 | udelay(1); | |
138 | } | |
139 | ||
140 | return value; | |
141 | } | |
142 | ||
143 | static void ds1620_out(int cmd, int bits, int value) | |
144 | { | |
145 | unsigned long flags; | |
146 | ||
147 | netwinder_lock(&flags); | |
148 | netwinder_ds1620_set_clk(1); | |
149 | netwinder_ds1620_set_data_dir(0); | |
150 | netwinder_ds1620_reset(); | |
151 | ||
152 | udelay(1); | |
153 | ||
154 | ds1620_send_bits(8, cmd); | |
155 | if (bits) | |
156 | ds1620_send_bits(bits, value); | |
157 | ||
158 | udelay(1); | |
159 | ||
160 | netwinder_ds1620_reset(); | |
161 | netwinder_unlock(&flags); | |
162 | ||
d8eddb62 | 163 | msleep(20); |
1da177e4 LT |
164 | } |
165 | ||
166 | static unsigned int ds1620_in(int cmd, int bits) | |
167 | { | |
168 | unsigned long flags; | |
169 | unsigned int value; | |
170 | ||
171 | netwinder_lock(&flags); | |
172 | netwinder_ds1620_set_clk(1); | |
173 | netwinder_ds1620_set_data_dir(0); | |
174 | netwinder_ds1620_reset(); | |
175 | ||
176 | udelay(1); | |
177 | ||
178 | ds1620_send_bits(8, cmd); | |
179 | ||
180 | netwinder_ds1620_set_data_dir(1); | |
181 | value = ds1620_recv_bits(bits); | |
182 | ||
183 | netwinder_ds1620_reset(); | |
184 | netwinder_unlock(&flags); | |
185 | ||
186 | return value; | |
187 | } | |
188 | ||
189 | static int cvt_9_to_int(unsigned int val) | |
190 | { | |
191 | if (val & 0x100) | |
192 | val |= 0xfffffe00; | |
193 | ||
194 | return val; | |
195 | } | |
196 | ||
197 | static void ds1620_write_state(struct therm *therm) | |
198 | { | |
199 | ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); | |
200 | ds1620_out(THERM_WRITE_TL, 9, therm->lo); | |
201 | ds1620_out(THERM_WRITE_TH, 9, therm->hi); | |
202 | ds1620_out(THERM_START_CONVERT, 0, 0); | |
203 | } | |
204 | ||
205 | static void ds1620_read_state(struct therm *therm) | |
206 | { | |
207 | therm->lo = cvt_9_to_int(ds1620_in(THERM_READ_TL, 9)); | |
208 | therm->hi = cvt_9_to_int(ds1620_in(THERM_READ_TH, 9)); | |
209 | } | |
210 | ||
211 | static ssize_t | |
212 | ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) | |
213 | { | |
214 | signed int cur_temp; | |
215 | signed char cur_temp_degF; | |
216 | ||
217 | cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1; | |
218 | ||
219 | /* convert to Fahrenheit, as per wdt.c */ | |
220 | cur_temp_degF = (cur_temp * 9) / 5 + 32; | |
221 | ||
222 | if (copy_to_user(buf, &cur_temp_degF, 1)) | |
223 | return -EFAULT; | |
224 | ||
225 | return 1; | |
226 | } | |
227 | ||
228 | static int | |
229 | ds1620_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) | |
230 | { | |
231 | struct therm therm; | |
232 | union { | |
233 | struct therm __user *therm; | |
234 | int __user *i; | |
235 | } uarg; | |
236 | int i; | |
237 | ||
238 | uarg.i = (int __user *)arg; | |
239 | ||
240 | switch(cmd) { | |
241 | case CMD_SET_THERMOSTATE: | |
242 | case CMD_SET_THERMOSTATE2: | |
243 | if (!capable(CAP_SYS_ADMIN)) | |
244 | return -EPERM; | |
245 | ||
246 | if (cmd == CMD_SET_THERMOSTATE) { | |
247 | if (get_user(therm.hi, uarg.i)) | |
248 | return -EFAULT; | |
249 | therm.lo = therm.hi - 3; | |
250 | } else { | |
251 | if (copy_from_user(&therm, uarg.therm, sizeof(therm))) | |
252 | return -EFAULT; | |
253 | } | |
254 | ||
255 | therm.lo <<= 1; | |
256 | therm.hi <<= 1; | |
257 | ||
258 | ds1620_write_state(&therm); | |
259 | break; | |
260 | ||
261 | case CMD_GET_THERMOSTATE: | |
262 | case CMD_GET_THERMOSTATE2: | |
263 | ds1620_read_state(&therm); | |
264 | ||
265 | therm.lo >>= 1; | |
266 | therm.hi >>= 1; | |
267 | ||
268 | if (cmd == CMD_GET_THERMOSTATE) { | |
269 | if (put_user(therm.hi, uarg.i)) | |
270 | return -EFAULT; | |
271 | } else { | |
272 | if (copy_to_user(uarg.therm, &therm, sizeof(therm))) | |
273 | return -EFAULT; | |
274 | } | |
275 | break; | |
276 | ||
277 | case CMD_GET_TEMPERATURE: | |
278 | case CMD_GET_TEMPERATURE2: | |
279 | i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
280 | ||
281 | if (cmd == CMD_GET_TEMPERATURE) | |
282 | i >>= 1; | |
283 | ||
284 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
285 | ||
286 | case CMD_GET_STATUS: | |
287 | i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3; | |
288 | ||
289 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
290 | ||
291 | case CMD_GET_FAN: | |
292 | i = netwinder_get_fan(); | |
293 | ||
294 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
295 | ||
296 | case CMD_SET_FAN: | |
297 | if (!capable(CAP_SYS_ADMIN)) | |
298 | return -EPERM; | |
299 | ||
300 | if (get_user(i, uarg.i)) | |
301 | return -EFAULT; | |
302 | ||
303 | netwinder_set_fan(i); | |
304 | break; | |
305 | ||
306 | default: | |
307 | return -ENOIOCTLCMD; | |
308 | } | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
313 | #ifdef THERM_USE_PROC | |
314 | static int | |
315 | proc_therm_ds1620_read(char *buf, char **start, off_t offset, | |
316 | int len, int *eof, void *unused) | |
317 | { | |
318 | struct therm th; | |
319 | int temp; | |
320 | ||
321 | ds1620_read_state(&th); | |
322 | temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
323 | ||
324 | len = sprintf(buf, "Thermostat: HI %i.%i, LOW %i.%i; " | |
325 | "temperature: %i.%i C, fan %s\n", | |
326 | th.hi >> 1, th.hi & 1 ? 5 : 0, | |
327 | th.lo >> 1, th.lo & 1 ? 5 : 0, | |
328 | temp >> 1, temp & 1 ? 5 : 0, | |
329 | fan_state[netwinder_get_fan()]); | |
330 | ||
331 | return len; | |
332 | } | |
333 | ||
334 | static struct proc_dir_entry *proc_therm_ds1620; | |
335 | #endif | |
336 | ||
62322d25 | 337 | static const struct file_operations ds1620_fops = { |
1da177e4 LT |
338 | .owner = THIS_MODULE, |
339 | .open = nonseekable_open, | |
340 | .read = ds1620_read, | |
341 | .ioctl = ds1620_ioctl, | |
342 | }; | |
343 | ||
344 | static struct miscdevice ds1620_miscdev = { | |
345 | TEMP_MINOR, | |
346 | "temp", | |
347 | &ds1620_fops | |
348 | }; | |
349 | ||
350 | static int __init ds1620_init(void) | |
351 | { | |
352 | int ret; | |
353 | struct therm th, th_start; | |
354 | ||
355 | if (!machine_is_netwinder()) | |
356 | return -ENODEV; | |
357 | ||
358 | ds1620_out(THERM_RESET, 0, 0); | |
359 | ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); | |
360 | ds1620_out(THERM_START_CONVERT, 0, 0); | |
361 | ||
362 | /* | |
363 | * Trigger the fan to start by setting | |
364 | * temperature high point low. This kicks | |
365 | * the fan into action. | |
366 | */ | |
367 | ds1620_read_state(&th); | |
368 | th_start.lo = 0; | |
369 | th_start.hi = 1; | |
370 | ds1620_write_state(&th_start); | |
371 | ||
372 | msleep(2000); | |
373 | ||
374 | ds1620_write_state(&th); | |
375 | ||
376 | ret = misc_register(&ds1620_miscdev); | |
377 | if (ret < 0) | |
378 | return ret; | |
379 | ||
380 | #ifdef THERM_USE_PROC | |
381 | proc_therm_ds1620 = create_proc_entry("therm", 0, NULL); | |
382 | if (proc_therm_ds1620) | |
383 | proc_therm_ds1620->read_proc = proc_therm_ds1620_read; | |
384 | else | |
385 | printk(KERN_ERR "therm: unable to register /proc/therm\n"); | |
386 | #endif | |
387 | ||
388 | ds1620_read_state(&th); | |
389 | ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
390 | ||
391 | printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, " | |
392 | "current %i.%i C, fan %s.\n", | |
393 | th.hi >> 1, th.hi & 1 ? 5 : 0, | |
394 | th.lo >> 1, th.lo & 1 ? 5 : 0, | |
395 | ret >> 1, ret & 1 ? 5 : 0, | |
396 | fan_state[netwinder_get_fan()]); | |
397 | ||
398 | return 0; | |
399 | } | |
400 | ||
401 | static void __exit ds1620_exit(void) | |
402 | { | |
403 | #ifdef THERM_USE_PROC | |
404 | remove_proc_entry("therm", NULL); | |
405 | #endif | |
406 | misc_deregister(&ds1620_miscdev); | |
407 | } | |
408 | ||
409 | module_init(ds1620_init); | |
410 | module_exit(ds1620_exit); | |
411 | ||
412 | MODULE_LICENSE("GPL"); |