Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[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/module.h>
6 #include <linux/miscdevice.h>
7 #include <linux/delay.h>
8 #include <linux/proc_fs.h>
9 #include <linux/capability.h>
10 #include <linux/init.h>
11
12 #include <asm/hardware.h>
13 #include <asm/mach-types.h>
14 #include <asm/uaccess.h>
15 #include <asm/therm.h>
16
17 #ifdef CONFIG_PROC_FS
18 /* define for /proc interface */
19 #define THERM_USE_PROC
20 #endif
21
22 /* Definitions for DS1620 chip */
23 #define THERM_START_CONVERT     0xee
24 #define THERM_RESET             0xaf
25 #define THERM_READ_CONFIG       0xac
26 #define THERM_READ_TEMP         0xaa
27 #define THERM_READ_TL           0xa2
28 #define THERM_READ_TH           0xa1
29 #define THERM_WRITE_CONFIG      0x0c
30 #define THERM_WRITE_TL          0x02
31 #define THERM_WRITE_TH          0x01
32
33 #define CFG_CPU                 2
34 #define CFG_1SHOT               1
35
36 static const char *fan_state[] = { "off", "on", "on (hardwired)" };
37
38 /*
39  * Start of NetWinder specifics
40  *  Note!  We have to hold the gpio lock with IRQs disabled over the
41  *  whole of our transaction to the Dallas chip, since there is a
42  *  chance that the WaveArtist driver could touch these bits to
43  *  enable or disable the speaker.
44  */
45 extern spinlock_t gpio_lock;
46 extern unsigned int system_rev;
47
48 static inline void netwinder_ds1620_set_clk(int clk)
49 {
50         gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
51 }
52
53 static inline void netwinder_ds1620_set_data(int dat)
54 {
55         gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
56 }
57
58 static inline int netwinder_ds1620_get_data(void)
59 {
60         return gpio_read() & GPIO_DATA;
61 }
62
63 static inline void netwinder_ds1620_set_data_dir(int dir)
64 {
65         gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
66 }
67
68 static inline void netwinder_ds1620_reset(void)
69 {
70         cpld_modify(CPLD_DS_ENABLE, 0);
71         cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
72 }
73
74 static inline void netwinder_lock(unsigned long *flags)
75 {
76         spin_lock_irqsave(&gpio_lock, *flags);
77 }
78
79 static inline void netwinder_unlock(unsigned long *flags)
80 {
81         spin_unlock_irqrestore(&gpio_lock, *flags);
82 }
83
84 static inline void netwinder_set_fan(int i)
85 {
86         unsigned long flags;
87
88         spin_lock_irqsave(&gpio_lock, flags);
89         gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
90         spin_unlock_irqrestore(&gpio_lock, flags);
91 }
92
93 static inline int netwinder_get_fan(void)
94 {
95         if ((system_rev & 0xf000) == 0x4000)
96                 return FAN_ALWAYS_ON;
97
98         return (gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF;
99 }
100
101 /*
102  * End of NetWinder specifics
103  */
104
105 static void ds1620_send_bits(int nr, int value)
106 {
107         int i;
108
109         for (i = 0; i < nr; i++) {
110                 netwinder_ds1620_set_data(value & 1);
111                 netwinder_ds1620_set_clk(0);
112                 udelay(1);
113                 netwinder_ds1620_set_clk(1);
114                 udelay(1);
115
116                 value >>= 1;
117         }
118 }
119
120 static unsigned int ds1620_recv_bits(int nr)
121 {
122         unsigned int value = 0, mask = 1;
123         int i;
124
125         netwinder_ds1620_set_data(0);
126
127         for (i = 0; i < nr; i++) {
128                 netwinder_ds1620_set_clk(0);
129                 udelay(1);
130
131                 if (netwinder_ds1620_get_data())
132                         value |= mask;
133
134                 mask <<= 1;
135
136                 netwinder_ds1620_set_clk(1);
137                 udelay(1);
138         }
139
140         return value;
141 }
142
143 static void ds1620_out(int cmd, int bits, int value)
144 {
145         unsigned long flags;
146
147         netwinder_lock(&flags);
148         netwinder_ds1620_set_clk(1);
149         netwinder_ds1620_set_data_dir(0);
150         netwinder_ds1620_reset();
151
152         udelay(1);
153
154         ds1620_send_bits(8, cmd);
155         if (bits)
156                 ds1620_send_bits(bits, value);
157
158         udelay(1);
159
160         netwinder_ds1620_reset();
161         netwinder_unlock(&flags);
162
163         msleep(20);
164 }
165
166 static unsigned int ds1620_in(int cmd, int bits)
167 {
168         unsigned long flags;
169         unsigned int value;
170
171         netwinder_lock(&flags);
172         netwinder_ds1620_set_clk(1);
173         netwinder_ds1620_set_data_dir(0);
174         netwinder_ds1620_reset();
175
176         udelay(1);
177
178         ds1620_send_bits(8, cmd);
179
180         netwinder_ds1620_set_data_dir(1);
181         value = ds1620_recv_bits(bits);
182
183         netwinder_ds1620_reset();
184         netwinder_unlock(&flags);
185
186         return value;
187 }
188
189 static int cvt_9_to_int(unsigned int val)
190 {
191         if (val & 0x100)
192                 val |= 0xfffffe00;
193
194         return val;
195 }
196
197 static void ds1620_write_state(struct therm *therm)
198 {
199         ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
200         ds1620_out(THERM_WRITE_TL, 9, therm->lo);
201         ds1620_out(THERM_WRITE_TH, 9, therm->hi);
202         ds1620_out(THERM_START_CONVERT, 0, 0);
203 }
204
205 static void ds1620_read_state(struct therm *therm)
206 {
207         therm->lo = cvt_9_to_int(ds1620_in(THERM_READ_TL, 9));
208         therm->hi = cvt_9_to_int(ds1620_in(THERM_READ_TH, 9));
209 }
210
211 static ssize_t
212 ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
213 {
214         signed int cur_temp;
215         signed char cur_temp_degF;
216
217         cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1;
218
219         /* convert to Fahrenheit, as per wdt.c */
220         cur_temp_degF = (cur_temp * 9) / 5 + 32;
221
222         if (copy_to_user(buf, &cur_temp_degF, 1))
223                 return -EFAULT;
224
225         return 1;
226 }
227
228 static int
229 ds1620_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
230 {
231         struct therm therm;
232         union {
233                 struct therm __user *therm;
234                 int __user *i;
235         } uarg;
236         int i;
237
238         uarg.i = (int __user *)arg;
239
240         switch(cmd) {
241         case CMD_SET_THERMOSTATE:
242         case CMD_SET_THERMOSTATE2:
243                 if (!capable(CAP_SYS_ADMIN))
244                         return -EPERM;
245
246                 if (cmd == CMD_SET_THERMOSTATE) {
247                         if (get_user(therm.hi, uarg.i))
248                                 return -EFAULT;
249                         therm.lo = therm.hi - 3;
250                 } else {
251                         if (copy_from_user(&therm, uarg.therm, sizeof(therm)))
252                                 return -EFAULT;
253                 }
254
255                 therm.lo <<= 1;
256                 therm.hi <<= 1;
257
258                 ds1620_write_state(&therm);
259                 break;
260
261         case CMD_GET_THERMOSTATE:
262         case CMD_GET_THERMOSTATE2:
263                 ds1620_read_state(&therm);
264
265                 therm.lo >>= 1;
266                 therm.hi >>= 1;
267
268                 if (cmd == CMD_GET_THERMOSTATE) {
269                         if (put_user(therm.hi, uarg.i))
270                                 return -EFAULT;
271                 } else {
272                         if (copy_to_user(uarg.therm, &therm, sizeof(therm)))
273                                 return -EFAULT;
274                 }
275                 break;
276
277         case CMD_GET_TEMPERATURE:
278         case CMD_GET_TEMPERATURE2:
279                 i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
280
281                 if (cmd == CMD_GET_TEMPERATURE)
282                         i >>= 1;
283
284                 return put_user(i, uarg.i) ? -EFAULT : 0;
285
286         case CMD_GET_STATUS:
287                 i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3;
288
289                 return put_user(i, uarg.i) ? -EFAULT : 0;
290
291         case CMD_GET_FAN:
292                 i = netwinder_get_fan();
293
294                 return put_user(i, uarg.i) ? -EFAULT : 0;
295
296         case CMD_SET_FAN:
297                 if (!capable(CAP_SYS_ADMIN))
298                         return -EPERM;
299
300                 if (get_user(i, uarg.i))
301                         return -EFAULT;
302
303                 netwinder_set_fan(i);
304                 break;
305                 
306         default:
307                 return -ENOIOCTLCMD;
308         }
309
310         return 0;
311 }
312
313 #ifdef THERM_USE_PROC
314 static int
315 proc_therm_ds1620_read(char *buf, char **start, off_t offset,
316                        int len, int *eof, void *unused)
317 {
318         struct therm th;
319         int temp;
320
321         ds1620_read_state(&th);
322         temp =  cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
323
324         len = sprintf(buf, "Thermostat: HI %i.%i, LOW %i.%i; "
325                       "temperature: %i.%i C, fan %s\n",
326                       th.hi >> 1, th.hi & 1 ? 5 : 0,
327                       th.lo >> 1, th.lo & 1 ? 5 : 0,
328                       temp  >> 1, temp  & 1 ? 5 : 0,
329                       fan_state[netwinder_get_fan()]);
330
331         return len;
332 }
333
334 static struct proc_dir_entry *proc_therm_ds1620;
335 #endif
336
337 static const struct file_operations ds1620_fops = {
338         .owner          = THIS_MODULE,
339         .open           = nonseekable_open,
340         .read           = ds1620_read,
341         .ioctl          = ds1620_ioctl,
342 };
343
344 static struct miscdevice ds1620_miscdev = {
345         TEMP_MINOR,
346         "temp",
347         &ds1620_fops
348 };
349
350 static int __init ds1620_init(void)
351 {
352         int ret;
353         struct therm th, th_start;
354
355         if (!machine_is_netwinder())
356                 return -ENODEV;
357
358         ds1620_out(THERM_RESET, 0, 0);
359         ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
360         ds1620_out(THERM_START_CONVERT, 0, 0);
361
362         /*
363          * Trigger the fan to start by setting
364          * temperature high point low.  This kicks
365          * the fan into action.
366          */
367         ds1620_read_state(&th);
368         th_start.lo = 0;
369         th_start.hi = 1;
370         ds1620_write_state(&th_start);
371
372         msleep(2000);
373
374         ds1620_write_state(&th);
375
376         ret = misc_register(&ds1620_miscdev);
377         if (ret < 0)
378                 return ret;
379
380 #ifdef THERM_USE_PROC
381         proc_therm_ds1620 = create_proc_entry("therm", 0, NULL);
382         if (proc_therm_ds1620)
383                 proc_therm_ds1620->read_proc = proc_therm_ds1620_read;
384         else
385                 printk(KERN_ERR "therm: unable to register /proc/therm\n");
386 #endif
387
388         ds1620_read_state(&th);
389         ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
390
391         printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, "
392                "current %i.%i C, fan %s.\n",
393                th.hi >> 1, th.hi & 1 ? 5 : 0,
394                th.lo >> 1, th.lo & 1 ? 5 : 0,
395                ret   >> 1, ret   & 1 ? 5 : 0,
396                fan_state[netwinder_get_fan()]);
397
398         return 0;
399 }
400
401 static void __exit ds1620_exit(void)
402 {
403 #ifdef THERM_USE_PROC
404         remove_proc_entry("therm", NULL);
405 #endif
406         misc_deregister(&ds1620_miscdev);
407 }
408
409 module_init(ds1620_init);
410 module_exit(ds1620_exit);
411
412 MODULE_LICENSE("GPL");