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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>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006#include <linux/miscdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <linux/delay.h>
8#include <linux/proc_fs.h>
David Howells9fb8ca52013-04-10 16:48:39 +01009#include <linux/seq_file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/capability.h>
11#include <linux/init.h>
Arnd Bergmann613655f2010-06-02 14:28:52 +020012#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
Russell Kinga09e64f2008-08-05 16:14:15 +010014#include <mach/hardware.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <asm/mach-types.h>
Linus Torvalds7c0f6ba2016-12-24 11:46:01 -080016#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#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
Arnd Bergmann613655f2010-06-02 14:28:52 +020038static DEFINE_MUTEX(ds1620_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039static 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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070048extern unsigned int system_rev;
49
50static inline void netwinder_ds1620_set_clk(int clk)
51{
Russell King70d13e02008-12-06 08:25:16 +000052 nw_gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053}
54
55static inline void netwinder_ds1620_set_data(int dat)
56{
Russell King70d13e02008-12-06 08:25:16 +000057 nw_gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058}
59
60static inline int netwinder_ds1620_get_data(void)
61{
Russell King70d13e02008-12-06 08:25:16 +000062 return nw_gpio_read() & GPIO_DATA;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063}
64
65static inline void netwinder_ds1620_set_data_dir(int dir)
66{
Russell King70d13e02008-12-06 08:25:16 +000067 nw_gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068}
69
70static inline void netwinder_ds1620_reset(void)
71{
Russell King70d13e02008-12-06 08:25:16 +000072 nw_cpld_modify(CPLD_DS_ENABLE, 0);
73 nw_cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074}
75
76static inline void netwinder_lock(unsigned long *flags)
77{
Arnd Bergmann45ef6ac2012-08-05 14:59:12 +000078 raw_spin_lock_irqsave(&nw_gpio_lock, *flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079}
80
81static inline void netwinder_unlock(unsigned long *flags)
82{
Arnd Bergmann45ef6ac2012-08-05 14:59:12 +000083 raw_spin_unlock_irqrestore(&nw_gpio_lock, *flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084}
85
86static inline void netwinder_set_fan(int i)
87{
88 unsigned long flags;
89
Arnd Bergmann45ef6ac2012-08-05 14:59:12 +000090 raw_spin_lock_irqsave(&nw_gpio_lock, flags);
Russell King70d13e02008-12-06 08:25:16 +000091 nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
Arnd Bergmann45ef6ac2012-08-05 14:59:12 +000092 raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093}
94
95static inline int netwinder_get_fan(void)
96{
97 if ((system_rev & 0xf000) == 0x4000)
98 return FAN_ALWAYS_ON;
99
Russell King70d13e02008-12-06 08:25:16 +0000100 return (nw_gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101}
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
Arnd Bergmann080c2222008-05-20 19:15:50 +0200213static int ds1620_open(struct inode *inode, struct file *file)
214{
Arnd Bergmann080c2222008-05-20 19:15:50 +0200215 return nonseekable_open(inode, file);
216}
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218static ssize_t
219ds1620_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
235static int
Arnd Bergmann55929332010-04-27 00:24:05 +0200236ds1620_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237{
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
Arnd Bergmann55929332010-04-27 00:24:05 +0200320static long
321ds1620_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
322{
323 int ret;
324
Arnd Bergmann613655f2010-06-02 14:28:52 +0200325 mutex_lock(&ds1620_mutex);
Arnd Bergmann55929332010-04-27 00:24:05 +0200326 ret = ds1620_ioctl(file, cmd, arg);
Arnd Bergmann613655f2010-06-02 14:28:52 +0200327 mutex_unlock(&ds1620_mutex);
Arnd Bergmann55929332010-04-27 00:24:05 +0200328
329 return ret;
330}
331
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332#ifdef THERM_USE_PROC
David Howells9fb8ca52013-04-10 16:48:39 +0100333static int ds1620_proc_therm_show(struct seq_file *m, void *v)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334{
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
David Howells9fb8ca52013-04-10 16:48:39 +0100341 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347}
348
David Howells9fb8ca52013-04-10 16:48:39 +0100349static int ds1620_proc_therm_open(struct inode *inode, struct file *file)
350{
351 return single_open(file, ds1620_proc_therm_show, NULL);
352}
353
354static const struct file_operations ds1620_proc_therm_fops = {
355 .open = ds1620_proc_therm_open,
356 .read = seq_read,
357 .llseek = seq_lseek,
Al Viro7485e162013-05-05 00:11:29 -0400358 .release = single_release,
David Howells9fb8ca52013-04-10 16:48:39 +0100359};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360#endif
361
Arjan van de Ven62322d22006-07-03 00:24:21 -0700362static const struct file_operations ds1620_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 .owner = THIS_MODULE,
Arnd Bergmann080c2222008-05-20 19:15:50 +0200364 .open = ds1620_open,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 .read = ds1620_read,
Arnd Bergmann55929332010-04-27 00:24:05 +0200366 .unlocked_ioctl = ds1620_unlocked_ioctl,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200367 .llseek = no_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368};
369
370static struct miscdevice ds1620_miscdev = {
371 TEMP_MINOR,
372 "temp",
373 &ds1620_fops
374};
375
376static 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
David Howells9fb8ca52013-04-10 16:48:39 +0100407 if (!proc_create("therm", 0, NULL, &ds1620_proc_therm_fops))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 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
424static 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
432module_init(ds1620_init);
433module_exit(ds1620_exit);
434
435MODULE_LICENSE("GPL");