1 /*
2 * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620
3 * thermometer driver (as used in the Rebel.com NetWinder)
4 */
5 #include <linux/module.h>
6 #include <linux/miscdevice.h>
7 #include <linux/delay.h>
8 #include <linux/proc_fs.h>
9 #include <linux/seq_file.h>
10 #include <linux/capability.h>
11 #include <linux/init.h>
12 #include <linux/mutex.h>
13
14 #include <mach/hardware.h>
15 #include <asm/mach-types.h>
16 #include <linux/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
38 static DEFINE_MUTEX(ds1620_mutex);
39 static 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 */
48 extern unsigned int system_rev;
49
netwinder_ds1620_set_clk(int clk)50 static inline void netwinder_ds1620_set_clk(int clk)
51 {
52 nw_gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
53 }
54
netwinder_ds1620_set_data(int dat)55 static inline void netwinder_ds1620_set_data(int dat)
56 {
57 nw_gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
58 }
59
netwinder_ds1620_get_data(void)60 static inline int netwinder_ds1620_get_data(void)
61 {
62 return nw_gpio_read() & GPIO_DATA;
63 }
64
netwinder_ds1620_set_data_dir(int dir)65 static inline void netwinder_ds1620_set_data_dir(int dir)
66 {
67 nw_gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
68 }
69
netwinder_ds1620_reset(void)70 static inline void netwinder_ds1620_reset(void)
71 {
72 nw_cpld_modify(CPLD_DS_ENABLE, 0);
73 nw_cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
74 }
75
netwinder_lock(unsigned long * flags)76 static inline void netwinder_lock(unsigned long *flags)
77 {
78 raw_spin_lock_irqsave(&nw_gpio_lock, *flags);
79 }
80
netwinder_unlock(unsigned long * flags)81 static inline void netwinder_unlock(unsigned long *flags)
82 {
83 raw_spin_unlock_irqrestore(&nw_gpio_lock, *flags);
84 }
85
netwinder_set_fan(int i)86 static inline void netwinder_set_fan(int i)
87 {
88 unsigned long flags;
89
90 raw_spin_lock_irqsave(&nw_gpio_lock, flags);
91 nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
92 raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
93 }
94
netwinder_get_fan(void)95 static inline int netwinder_get_fan(void)
96 {
97 if ((system_rev & 0xf000) == 0x4000)
98 return FAN_ALWAYS_ON;
99
100 return (nw_gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF;
101 }
102
103 /*
104 * End of NetWinder specifics
105 */
106
ds1620_send_bits(int nr,int value)107 static 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
ds1620_recv_bits(int nr)122 static 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
ds1620_out(int cmd,int bits,int value)145 static 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
165 msleep(20);
166 }
167
ds1620_in(int cmd,int bits)168 static 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
cvt_9_to_int(unsigned int val)191 static int cvt_9_to_int(unsigned int val)
192 {
193 if (val & 0x100)
194 val |= 0xfffffe00;
195
196 return val;
197 }
198
ds1620_write_state(struct therm * therm)199 static 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
ds1620_read_state(struct therm * therm)207 static 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
ds1620_open(struct inode * inode,struct file * file)213 static int ds1620_open(struct inode *inode, struct file *file)
214 {
215 return nonseekable_open(inode, file);
216 }
217
218 static ssize_t
ds1620_read(struct file * file,char __user * buf,size_t count,loff_t * ptr)219 ds1620_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
235 static int
ds1620_ioctl(struct file * file,unsigned int cmd,unsigned long arg)236 ds1620_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
237 {
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
320 static long
ds1620_unlocked_ioctl(struct file * file,unsigned int cmd,unsigned long arg)321 ds1620_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
322 {
323 int ret;
324
325 mutex_lock(&ds1620_mutex);
326 ret = ds1620_ioctl(file, cmd, arg);
327 mutex_unlock(&ds1620_mutex);
328
329 return ret;
330 }
331
332 #ifdef THERM_USE_PROC
ds1620_proc_therm_show(struct seq_file * m,void * v)333 static int ds1620_proc_therm_show(struct seq_file *m, void *v)
334 {
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
341 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;
347 }
348 #endif
349
350 static const struct file_operations ds1620_fops = {
351 .owner = THIS_MODULE,
352 .open = ds1620_open,
353 .read = ds1620_read,
354 .unlocked_ioctl = ds1620_unlocked_ioctl,
355 .llseek = no_llseek,
356 };
357
358 static struct miscdevice ds1620_miscdev = {
359 TEMP_MINOR,
360 "temp",
361 &ds1620_fops
362 };
363
ds1620_init(void)364 static int __init ds1620_init(void)
365 {
366 int ret;
367 struct therm th, th_start;
368
369 if (!machine_is_netwinder())
370 return -ENODEV;
371
372 ds1620_out(THERM_RESET, 0, 0);
373 ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
374 ds1620_out(THERM_START_CONVERT, 0, 0);
375
376 /*
377 * Trigger the fan to start by setting
378 * temperature high point low. This kicks
379 * the fan into action.
380 */
381 ds1620_read_state(&th);
382 th_start.lo = 0;
383 th_start.hi = 1;
384 ds1620_write_state(&th_start);
385
386 msleep(2000);
387
388 ds1620_write_state(&th);
389
390 ret = misc_register(&ds1620_miscdev);
391 if (ret < 0)
392 return ret;
393
394 #ifdef THERM_USE_PROC
395 if (!proc_create_single("therm", 0, NULL, ds1620_proc_therm_show))
396 printk(KERN_ERR "therm: unable to register /proc/therm\n");
397 #endif
398
399 ds1620_read_state(&th);
400 ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
401
402 printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, "
403 "current %i.%i C, fan %s.\n",
404 th.hi >> 1, th.hi & 1 ? 5 : 0,
405 th.lo >> 1, th.lo & 1 ? 5 : 0,
406 ret >> 1, ret & 1 ? 5 : 0,
407 fan_state[netwinder_get_fan()]);
408
409 return 0;
410 }
411
ds1620_exit(void)412 static void __exit ds1620_exit(void)
413 {
414 #ifdef THERM_USE_PROC
415 remove_proc_entry("therm", NULL);
416 #endif
417 misc_deregister(&ds1620_miscdev);
418 }
419
420 module_init(ds1620_init);
421 module_exit(ds1620_exit);
422
423 MODULE_LICENSE("GPL");
424
