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