Commit | Line | Data |
---|---|---|
09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620 | |
4 | * thermometer driver (as used in the Rebel.com NetWinder) | |
5 | */ | |
1da177e4 | 6 | #include <linux/module.h> |
1da177e4 | 7 | #include <linux/miscdevice.h> |
1da177e4 LT |
8 | #include <linux/delay.h> |
9 | #include <linux/proc_fs.h> | |
9fb8ca5c | 10 | #include <linux/seq_file.h> |
1da177e4 LT |
11 | #include <linux/capability.h> |
12 | #include <linux/init.h> | |
613655fa | 13 | #include <linux/mutex.h> |
1da177e4 | 14 | |
a09e64fb | 15 | #include <mach/hardware.h> |
1da177e4 | 16 | #include <asm/mach-types.h> |
7c0f6ba6 | 17 | #include <linux/uaccess.h> |
1da177e4 LT |
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 | ||
613655fa | 39 | static DEFINE_MUTEX(ds1620_mutex); |
1da177e4 LT |
40 | static const char *fan_state[] = { "off", "on", "on (hardwired)" }; |
41 | ||
42 | /* | |
43 | * Start of NetWinder specifics | |
44 | * Note! We have to hold the gpio lock with IRQs disabled over the | |
45 | * whole of our transaction to the Dallas chip, since there is a | |
46 | * chance that the WaveArtist driver could touch these bits to | |
47 | * enable or disable the speaker. | |
48 | */ | |
1da177e4 LT |
49 | extern unsigned int system_rev; |
50 | ||
51 | static inline void netwinder_ds1620_set_clk(int clk) | |
52 | { | |
70d13e08 | 53 | nw_gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0); |
1da177e4 LT |
54 | } |
55 | ||
56 | static inline void netwinder_ds1620_set_data(int dat) | |
57 | { | |
70d13e08 | 58 | nw_gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0); |
1da177e4 LT |
59 | } |
60 | ||
61 | static inline int netwinder_ds1620_get_data(void) | |
62 | { | |
70d13e08 | 63 | return nw_gpio_read() & GPIO_DATA; |
1da177e4 LT |
64 | } |
65 | ||
66 | static inline void netwinder_ds1620_set_data_dir(int dir) | |
67 | { | |
70d13e08 | 68 | nw_gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0); |
1da177e4 LT |
69 | } |
70 | ||
71 | static inline void netwinder_ds1620_reset(void) | |
72 | { | |
70d13e08 RK |
73 | nw_cpld_modify(CPLD_DS_ENABLE, 0); |
74 | nw_cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE); | |
1da177e4 LT |
75 | } |
76 | ||
77 | static inline void netwinder_lock(unsigned long *flags) | |
78 | { | |
45ef6ac6 | 79 | raw_spin_lock_irqsave(&nw_gpio_lock, *flags); |
1da177e4 LT |
80 | } |
81 | ||
82 | static inline void netwinder_unlock(unsigned long *flags) | |
83 | { | |
45ef6ac6 | 84 | raw_spin_unlock_irqrestore(&nw_gpio_lock, *flags); |
1da177e4 LT |
85 | } |
86 | ||
87 | static inline void netwinder_set_fan(int i) | |
88 | { | |
89 | unsigned long flags; | |
90 | ||
45ef6ac6 | 91 | raw_spin_lock_irqsave(&nw_gpio_lock, flags); |
70d13e08 | 92 | nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0); |
45ef6ac6 | 93 | raw_spin_unlock_irqrestore(&nw_gpio_lock, flags); |
1da177e4 LT |
94 | } |
95 | ||
96 | static inline int netwinder_get_fan(void) | |
97 | { | |
98 | if ((system_rev & 0xf000) == 0x4000) | |
99 | return FAN_ALWAYS_ON; | |
100 | ||
70d13e08 | 101 | return (nw_gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF; |
1da177e4 LT |
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 | ||
080c2226 AB |
214 | static int ds1620_open(struct inode *inode, struct file *file) |
215 | { | |
c5bf68fe | 216 | return stream_open(inode, file); |
080c2226 AB |
217 | } |
218 | ||
1da177e4 LT |
219 | static ssize_t |
220 | ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) | |
221 | { | |
222 | signed int cur_temp; | |
223 | signed char cur_temp_degF; | |
224 | ||
225 | cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1; | |
226 | ||
227 | /* convert to Fahrenheit, as per wdt.c */ | |
228 | cur_temp_degF = (cur_temp * 9) / 5 + 32; | |
229 | ||
230 | if (copy_to_user(buf, &cur_temp_degF, 1)) | |
231 | return -EFAULT; | |
232 | ||
233 | return 1; | |
234 | } | |
235 | ||
236 | static int | |
55929332 | 237 | ds1620_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
238 | { |
239 | struct therm therm; | |
240 | union { | |
241 | struct therm __user *therm; | |
242 | int __user *i; | |
243 | } uarg; | |
244 | int i; | |
245 | ||
246 | uarg.i = (int __user *)arg; | |
247 | ||
248 | switch(cmd) { | |
249 | case CMD_SET_THERMOSTATE: | |
250 | case CMD_SET_THERMOSTATE2: | |
251 | if (!capable(CAP_SYS_ADMIN)) | |
252 | return -EPERM; | |
253 | ||
254 | if (cmd == CMD_SET_THERMOSTATE) { | |
255 | if (get_user(therm.hi, uarg.i)) | |
256 | return -EFAULT; | |
257 | therm.lo = therm.hi - 3; | |
258 | } else { | |
259 | if (copy_from_user(&therm, uarg.therm, sizeof(therm))) | |
260 | return -EFAULT; | |
261 | } | |
262 | ||
263 | therm.lo <<= 1; | |
264 | therm.hi <<= 1; | |
265 | ||
266 | ds1620_write_state(&therm); | |
267 | break; | |
268 | ||
269 | case CMD_GET_THERMOSTATE: | |
270 | case CMD_GET_THERMOSTATE2: | |
271 | ds1620_read_state(&therm); | |
272 | ||
273 | therm.lo >>= 1; | |
274 | therm.hi >>= 1; | |
275 | ||
276 | if (cmd == CMD_GET_THERMOSTATE) { | |
277 | if (put_user(therm.hi, uarg.i)) | |
278 | return -EFAULT; | |
279 | } else { | |
280 | if (copy_to_user(uarg.therm, &therm, sizeof(therm))) | |
281 | return -EFAULT; | |
282 | } | |
283 | break; | |
284 | ||
285 | case CMD_GET_TEMPERATURE: | |
286 | case CMD_GET_TEMPERATURE2: | |
287 | i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
288 | ||
289 | if (cmd == CMD_GET_TEMPERATURE) | |
290 | i >>= 1; | |
291 | ||
292 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
293 | ||
294 | case CMD_GET_STATUS: | |
295 | i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3; | |
296 | ||
297 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
298 | ||
299 | case CMD_GET_FAN: | |
300 | i = netwinder_get_fan(); | |
301 | ||
302 | return put_user(i, uarg.i) ? -EFAULT : 0; | |
303 | ||
304 | case CMD_SET_FAN: | |
305 | if (!capable(CAP_SYS_ADMIN)) | |
306 | return -EPERM; | |
307 | ||
308 | if (get_user(i, uarg.i)) | |
309 | return -EFAULT; | |
310 | ||
311 | netwinder_set_fan(i); | |
312 | break; | |
313 | ||
314 | default: | |
315 | return -ENOIOCTLCMD; | |
316 | } | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
55929332 AB |
321 | static long |
322 | ds1620_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
323 | { | |
324 | int ret; | |
325 | ||
613655fa | 326 | mutex_lock(&ds1620_mutex); |
55929332 | 327 | ret = ds1620_ioctl(file, cmd, arg); |
613655fa | 328 | mutex_unlock(&ds1620_mutex); |
55929332 AB |
329 | |
330 | return ret; | |
331 | } | |
332 | ||
1da177e4 | 333 | #ifdef THERM_USE_PROC |
9fb8ca5c | 334 | static int ds1620_proc_therm_show(struct seq_file *m, void *v) |
1da177e4 LT |
335 | { |
336 | struct therm th; | |
337 | int temp; | |
338 | ||
339 | ds1620_read_state(&th); | |
340 | temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
341 | ||
9fb8ca5c DH |
342 | seq_printf(m, "Thermostat: HI %i.%i, LOW %i.%i; temperature: %i.%i C, fan %s\n", |
343 | th.hi >> 1, th.hi & 1 ? 5 : 0, | |
344 | th.lo >> 1, th.lo & 1 ? 5 : 0, | |
345 | temp >> 1, temp & 1 ? 5 : 0, | |
346 | fan_state[netwinder_get_fan()]); | |
347 | return 0; | |
348 | } | |
1da177e4 LT |
349 | #endif |
350 | ||
62322d25 | 351 | static const struct file_operations ds1620_fops = { |
1da177e4 | 352 | .owner = THIS_MODULE, |
080c2226 | 353 | .open = ds1620_open, |
1da177e4 | 354 | .read = ds1620_read, |
55929332 | 355 | .unlocked_ioctl = ds1620_unlocked_ioctl, |
6038f373 | 356 | .llseek = no_llseek, |
1da177e4 LT |
357 | }; |
358 | ||
359 | static struct miscdevice ds1620_miscdev = { | |
360 | TEMP_MINOR, | |
361 | "temp", | |
362 | &ds1620_fops | |
363 | }; | |
364 | ||
365 | static int __init ds1620_init(void) | |
366 | { | |
367 | int ret; | |
368 | struct therm th, th_start; | |
369 | ||
370 | if (!machine_is_netwinder()) | |
371 | return -ENODEV; | |
372 | ||
373 | ds1620_out(THERM_RESET, 0, 0); | |
374 | ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU); | |
375 | ds1620_out(THERM_START_CONVERT, 0, 0); | |
376 | ||
377 | /* | |
378 | * Trigger the fan to start by setting | |
379 | * temperature high point low. This kicks | |
380 | * the fan into action. | |
381 | */ | |
382 | ds1620_read_state(&th); | |
383 | th_start.lo = 0; | |
384 | th_start.hi = 1; | |
385 | ds1620_write_state(&th_start); | |
386 | ||
387 | msleep(2000); | |
388 | ||
389 | ds1620_write_state(&th); | |
390 | ||
391 | ret = misc_register(&ds1620_miscdev); | |
392 | if (ret < 0) | |
393 | return ret; | |
394 | ||
395 | #ifdef THERM_USE_PROC | |
3f3942ac | 396 | if (!proc_create_single("therm", 0, NULL, ds1620_proc_therm_show)) |
1da177e4 LT |
397 | printk(KERN_ERR "therm: unable to register /proc/therm\n"); |
398 | #endif | |
399 | ||
400 | ds1620_read_state(&th); | |
401 | ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)); | |
402 | ||
403 | printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, " | |
404 | "current %i.%i C, fan %s.\n", | |
405 | th.hi >> 1, th.hi & 1 ? 5 : 0, | |
406 | th.lo >> 1, th.lo & 1 ? 5 : 0, | |
407 | ret >> 1, ret & 1 ? 5 : 0, | |
408 | fan_state[netwinder_get_fan()]); | |
409 | ||
410 | return 0; | |
411 | } | |
412 | ||
413 | static void __exit ds1620_exit(void) | |
414 | { | |
415 | #ifdef THERM_USE_PROC | |
416 | remove_proc_entry("therm", NULL); | |
417 | #endif | |
418 | misc_deregister(&ds1620_miscdev); | |
419 | } | |
420 | ||
421 | module_init(ds1620_init); | |
422 | module_exit(ds1620_exit); | |
423 | ||
424 | MODULE_LICENSE("GPL"); |