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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620
3 * thermometer driver (as used in the Rebel.com NetWinder)
4 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/module.h>
6#include <linux/sched.h>
7#include <linux/miscdevice.h>
8#include <linux/smp_lock.h>
9#include <linux/delay.h>
10#include <linux/proc_fs.h>
11#include <linux/capability.h>
12#include <linux/init.h>
13
14#include <asm/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
38static const char *fan_state[] = { "off", "on", "on (hardwired)" };
39
40/*
41 * Start of NetWinder specifics
42 * Note! We have to hold the gpio lock with IRQs disabled over the
43 * whole of our transaction to the Dallas chip, since there is a
44 * chance that the WaveArtist driver could touch these bits to
45 * enable or disable the speaker.
46 */
47extern spinlock_t gpio_lock;
48extern unsigned int system_rev;
49
50static inline void netwinder_ds1620_set_clk(int clk)
51{
52 gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
53}
54
55static inline void netwinder_ds1620_set_data(int dat)
56{
57 gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
58}
59
60static inline int netwinder_ds1620_get_data(void)
61{
62 return gpio_read() & GPIO_DATA;
63}
64
65static inline void netwinder_ds1620_set_data_dir(int dir)
66{
67 gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
68}
69
70static inline void netwinder_ds1620_reset(void)
71{
72 cpld_modify(CPLD_DS_ENABLE, 0);
73 cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
74}
75
76static inline void netwinder_lock(unsigned long *flags)
77{
78 spin_lock_irqsave(&gpio_lock, *flags);
79}
80
81static inline void netwinder_unlock(unsigned long *flags)
82{
83 spin_unlock_irqrestore(&gpio_lock, *flags);
84}
85
86static inline void netwinder_set_fan(int i)
87{
88 unsigned long flags;
89
90 spin_lock_irqsave(&gpio_lock, flags);
91 gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
92 spin_unlock_irqrestore(&gpio_lock, flags);
93}
94
95static inline int netwinder_get_fan(void)
96{
97 if ((system_rev & 0xf000) == 0x4000)
98 return FAN_ALWAYS_ON;
99
100 return (gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF;
101}
102
103/*
104 * End of NetWinder specifics
105 */
106
107static 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
122static 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
145static 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
Domen Puncerd8eddb62005-06-25 14:58:41 -0700165 msleep(20);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166}
167
168static 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
191static int cvt_9_to_int(unsigned int val)
192{
193 if (val & 0x100)
194 val |= 0xfffffe00;
195
196 return val;
197}
198
199static 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
207static 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
213static ssize_t
214ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
215{
216 signed int cur_temp;
217 signed char cur_temp_degF;
218
219 cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1;
220
221 /* convert to Fahrenheit, as per wdt.c */
222 cur_temp_degF = (cur_temp * 9) / 5 + 32;
223
224 if (copy_to_user(buf, &cur_temp_degF, 1))
225 return -EFAULT;
226
227 return 1;
228}
229
230static int
231ds1620_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
232{
233 struct therm therm;
234 union {
235 struct therm __user *therm;
236 int __user *i;
237 } uarg;
238 int i;
239
240 uarg.i = (int __user *)arg;
241
242 switch(cmd) {
243 case CMD_SET_THERMOSTATE:
244 case CMD_SET_THERMOSTATE2:
245 if (!capable(CAP_SYS_ADMIN))
246 return -EPERM;
247
248 if (cmd == CMD_SET_THERMOSTATE) {
249 if (get_user(therm.hi, uarg.i))
250 return -EFAULT;
251 therm.lo = therm.hi - 3;
252 } else {
253 if (copy_from_user(&therm, uarg.therm, sizeof(therm)))
254 return -EFAULT;
255 }
256
257 therm.lo <<= 1;
258 therm.hi <<= 1;
259
260 ds1620_write_state(&therm);
261 break;
262
263 case CMD_GET_THERMOSTATE:
264 case CMD_GET_THERMOSTATE2:
265 ds1620_read_state(&therm);
266
267 therm.lo >>= 1;
268 therm.hi >>= 1;
269
270 if (cmd == CMD_GET_THERMOSTATE) {
271 if (put_user(therm.hi, uarg.i))
272 return -EFAULT;
273 } else {
274 if (copy_to_user(uarg.therm, &therm, sizeof(therm)))
275 return -EFAULT;
276 }
277 break;
278
279 case CMD_GET_TEMPERATURE:
280 case CMD_GET_TEMPERATURE2:
281 i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
282
283 if (cmd == CMD_GET_TEMPERATURE)
284 i >>= 1;
285
286 return put_user(i, uarg.i) ? -EFAULT : 0;
287
288 case CMD_GET_STATUS:
289 i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3;
290
291 return put_user(i, uarg.i) ? -EFAULT : 0;
292
293 case CMD_GET_FAN:
294 i = netwinder_get_fan();
295
296 return put_user(i, uarg.i) ? -EFAULT : 0;
297
298 case CMD_SET_FAN:
299 if (!capable(CAP_SYS_ADMIN))
300 return -EPERM;
301
302 if (get_user(i, uarg.i))
303 return -EFAULT;
304
305 netwinder_set_fan(i);
306 break;
307
308 default:
309 return -ENOIOCTLCMD;
310 }
311
312 return 0;
313}
314
315#ifdef THERM_USE_PROC
316static int
317proc_therm_ds1620_read(char *buf, char **start, off_t offset,
318 int len, int *eof, void *unused)
319{
320 struct therm th;
321 int temp;
322
323 ds1620_read_state(&th);
324 temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
325
326 len = sprintf(buf, "Thermostat: HI %i.%i, LOW %i.%i; "
327 "temperature: %i.%i C, fan %s\n",
328 th.hi >> 1, th.hi & 1 ? 5 : 0,
329 th.lo >> 1, th.lo & 1 ? 5 : 0,
330 temp >> 1, temp & 1 ? 5 : 0,
331 fan_state[netwinder_get_fan()]);
332
333 return len;
334}
335
336static struct proc_dir_entry *proc_therm_ds1620;
337#endif
338
Arjan van de Ven62322d22006-07-03 00:24:21 -0700339static const struct file_operations ds1620_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 .owner = THIS_MODULE,
341 .open = nonseekable_open,
342 .read = ds1620_read,
343 .ioctl = ds1620_ioctl,
344};
345
346static struct miscdevice ds1620_miscdev = {
347 TEMP_MINOR,
348 "temp",
349 &ds1620_fops
350};
351
352static int __init ds1620_init(void)
353{
354 int ret;
355 struct therm th, th_start;
356
357 if (!machine_is_netwinder())
358 return -ENODEV;
359
360 ds1620_out(THERM_RESET, 0, 0);
361 ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
362 ds1620_out(THERM_START_CONVERT, 0, 0);
363
364 /*
365 * Trigger the fan to start by setting
366 * temperature high point low. This kicks
367 * the fan into action.
368 */
369 ds1620_read_state(&th);
370 th_start.lo = 0;
371 th_start.hi = 1;
372 ds1620_write_state(&th_start);
373
374 msleep(2000);
375
376 ds1620_write_state(&th);
377
378 ret = misc_register(&ds1620_miscdev);
379 if (ret < 0)
380 return ret;
381
382#ifdef THERM_USE_PROC
383 proc_therm_ds1620 = create_proc_entry("therm", 0, NULL);
384 if (proc_therm_ds1620)
385 proc_therm_ds1620->read_proc = proc_therm_ds1620_read;
386 else
387 printk(KERN_ERR "therm: unable to register /proc/therm\n");
388#endif
389
390 ds1620_read_state(&th);
391 ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
392
393 printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, "
394 "current %i.%i C, fan %s.\n",
395 th.hi >> 1, th.hi & 1 ? 5 : 0,
396 th.lo >> 1, th.lo & 1 ? 5 : 0,
397 ret >> 1, ret & 1 ? 5 : 0,
398 fan_state[netwinder_get_fan()]);
399
400 return 0;
401}
402
403static void __exit ds1620_exit(void)
404{
405#ifdef THERM_USE_PROC
406 remove_proc_entry("therm", NULL);
407#endif
408 misc_deregister(&ds1620_miscdev);
409}
410
411module_init(ds1620_init);
412module_exit(ds1620_exit);
413
414MODULE_LICENSE("GPL");