Merge master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb
[linux-2.6] / drivers / char / ds1620.c
1 /*
2  * linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620
3  *   thermometer driver (as used in the Rebel.com NetWinder)
4  */
5 #include <linux/config.h>
6 #include <linux/module.h>
7 #include <linux/sched.h>
8 #include <linux/miscdevice.h>
9 #include <linux/smp_lock.h>
10 #include <linux/delay.h>
11 #include <linux/proc_fs.h>
12 #include <linux/capability.h>
13 #include <linux/init.h>
14
15 #include <asm/hardware.h>
16 #include <asm/mach-types.h>
17 #include <asm/uaccess.h>
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
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 spinlock_t gpio_lock;
49 extern unsigned int system_rev;
50
51 static inline void netwinder_ds1620_set_clk(int clk)
52 {
53         gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
54 }
55
56 static inline void netwinder_ds1620_set_data(int dat)
57 {
58         gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
59 }
60
61 static inline int netwinder_ds1620_get_data(void)
62 {
63         return gpio_read() & GPIO_DATA;
64 }
65
66 static inline void netwinder_ds1620_set_data_dir(int dir)
67 {
68         gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
69 }
70
71 static inline void netwinder_ds1620_reset(void)
72 {
73         cpld_modify(CPLD_DS_ENABLE, 0);
74         cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
75 }
76
77 static inline void netwinder_lock(unsigned long *flags)
78 {
79         spin_lock_irqsave(&gpio_lock, *flags);
80 }
81
82 static inline void netwinder_unlock(unsigned long *flags)
83 {
84         spin_unlock_irqrestore(&gpio_lock, *flags);
85 }
86
87 static inline void netwinder_set_fan(int i)
88 {
89         unsigned long flags;
90
91         spin_lock_irqsave(&gpio_lock, flags);
92         gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
93         spin_unlock_irqrestore(&gpio_lock, flags);
94 }
95
96 static inline int netwinder_get_fan(void)
97 {
98         if ((system_rev & 0xf000) == 0x4000)
99                 return FAN_ALWAYS_ON;
100
101         return (gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF;
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
166         msleep(20);
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
214 static ssize_t
215 ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
216 {
217         signed int cur_temp;
218         signed char cur_temp_degF;
219
220         cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1;
221
222         /* convert to Fahrenheit, as per wdt.c */
223         cur_temp_degF = (cur_temp * 9) / 5 + 32;
224
225         if (copy_to_user(buf, &cur_temp_degF, 1))
226                 return -EFAULT;
227
228         return 1;
229 }
230
231 static int
232 ds1620_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
233 {
234         struct therm therm;
235         union {
236                 struct therm __user *therm;
237                 int __user *i;
238         } uarg;
239         int i;
240
241         uarg.i = (int __user *)arg;
242
243         switch(cmd) {
244         case CMD_SET_THERMOSTATE:
245         case CMD_SET_THERMOSTATE2:
246                 if (!capable(CAP_SYS_ADMIN))
247                         return -EPERM;
248
249                 if (cmd == CMD_SET_THERMOSTATE) {
250                         if (get_user(therm.hi, uarg.i))
251                                 return -EFAULT;
252                         therm.lo = therm.hi - 3;
253                 } else {
254                         if (copy_from_user(&therm, uarg.therm, sizeof(therm)))
255                                 return -EFAULT;
256                 }
257
258                 therm.lo <<= 1;
259                 therm.hi <<= 1;
260
261                 ds1620_write_state(&therm);
262                 break;
263
264         case CMD_GET_THERMOSTATE:
265         case CMD_GET_THERMOSTATE2:
266                 ds1620_read_state(&therm);
267
268                 therm.lo >>= 1;
269                 therm.hi >>= 1;
270
271                 if (cmd == CMD_GET_THERMOSTATE) {
272                         if (put_user(therm.hi, uarg.i))
273                                 return -EFAULT;
274                 } else {
275                         if (copy_to_user(uarg.therm, &therm, sizeof(therm)))
276                                 return -EFAULT;
277                 }
278                 break;
279
280         case CMD_GET_TEMPERATURE:
281         case CMD_GET_TEMPERATURE2:
282                 i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
283
284                 if (cmd == CMD_GET_TEMPERATURE)
285                         i >>= 1;
286
287                 return put_user(i, uarg.i) ? -EFAULT : 0;
288
289         case CMD_GET_STATUS:
290                 i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3;
291
292                 return put_user(i, uarg.i) ? -EFAULT : 0;
293
294         case CMD_GET_FAN:
295                 i = netwinder_get_fan();
296
297                 return put_user(i, uarg.i) ? -EFAULT : 0;
298
299         case CMD_SET_FAN:
300                 if (!capable(CAP_SYS_ADMIN))
301                         return -EPERM;
302
303                 if (get_user(i, uarg.i))
304                         return -EFAULT;
305
306                 netwinder_set_fan(i);
307                 break;
308                 
309         default:
310                 return -ENOIOCTLCMD;
311         }
312
313         return 0;
314 }
315
316 #ifdef THERM_USE_PROC
317 static int
318 proc_therm_ds1620_read(char *buf, char **start, off_t offset,
319                        int len, int *eof, void *unused)
320 {
321         struct therm th;
322         int temp;
323
324         ds1620_read_state(&th);
325         temp =  cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
326
327         len = sprintf(buf, "Thermostat: HI %i.%i, LOW %i.%i; "
328                       "temperature: %i.%i C, fan %s\n",
329                       th.hi >> 1, th.hi & 1 ? 5 : 0,
330                       th.lo >> 1, th.lo & 1 ? 5 : 0,
331                       temp  >> 1, temp  & 1 ? 5 : 0,
332                       fan_state[netwinder_get_fan()]);
333
334         return len;
335 }
336
337 static struct proc_dir_entry *proc_therm_ds1620;
338 #endif
339
340 static struct file_operations ds1620_fops = {
341         .owner          = THIS_MODULE,
342         .open           = nonseekable_open,
343         .read           = ds1620_read,
344         .ioctl          = ds1620_ioctl,
345 };
346
347 static struct miscdevice ds1620_miscdev = {
348         TEMP_MINOR,
349         "temp",
350         &ds1620_fops
351 };
352
353 static int __init ds1620_init(void)
354 {
355         int ret;
356         struct therm th, th_start;
357
358         if (!machine_is_netwinder())
359                 return -ENODEV;
360
361         ds1620_out(THERM_RESET, 0, 0);
362         ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
363         ds1620_out(THERM_START_CONVERT, 0, 0);
364
365         /*
366          * Trigger the fan to start by setting
367          * temperature high point low.  This kicks
368          * the fan into action.
369          */
370         ds1620_read_state(&th);
371         th_start.lo = 0;
372         th_start.hi = 1;
373         ds1620_write_state(&th_start);
374
375         msleep(2000);
376
377         ds1620_write_state(&th);
378
379         ret = misc_register(&ds1620_miscdev);
380         if (ret < 0)
381                 return ret;
382
383 #ifdef THERM_USE_PROC
384         proc_therm_ds1620 = create_proc_entry("therm", 0, NULL);
385         if (proc_therm_ds1620)
386                 proc_therm_ds1620->read_proc = proc_therm_ds1620_read;
387         else
388                 printk(KERN_ERR "therm: unable to register /proc/therm\n");
389 #endif
390
391         ds1620_read_state(&th);
392         ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
393
394         printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, "
395                "current %i.%i C, fan %s.\n",
396                th.hi >> 1, th.hi & 1 ? 5 : 0,
397                th.lo >> 1, th.lo & 1 ? 5 : 0,
398                ret   >> 1, ret   & 1 ? 5 : 0,
399                fan_state[netwinder_get_fan()]);
400
401         return 0;
402 }
403
404 static void __exit ds1620_exit(void)
405 {
406 #ifdef THERM_USE_PROC
407         remove_proc_entry("therm", NULL);
408 #endif
409         misc_deregister(&ds1620_miscdev);
410 }
411
412 module_init(ds1620_init);
413 module_exit(ds1620_exit);
414
415 MODULE_LICENSE("GPL");