[POWERPC] pseries: Constify & voidify get_property()
[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/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
38 static 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  */
47 extern spinlock_t gpio_lock;
48 extern unsigned int system_rev;
49
50 static inline void netwinder_ds1620_set_clk(int clk)
51 {
52         gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
53 }
54
55 static inline void netwinder_ds1620_set_data(int dat)
56 {
57         gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
58 }
59
60 static inline int netwinder_ds1620_get_data(void)
61 {
62         return gpio_read() & GPIO_DATA;
63 }
64
65 static inline void netwinder_ds1620_set_data_dir(int dir)
66 {
67         gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
68 }
69
70 static 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
76 static inline void netwinder_lock(unsigned long *flags)
77 {
78         spin_lock_irqsave(&gpio_lock, *flags);
79 }
80
81 static inline void netwinder_unlock(unsigned long *flags)
82 {
83         spin_unlock_irqrestore(&gpio_lock, *flags);
84 }
85
86 static 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
95 static 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
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
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
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
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
191 static int cvt_9_to_int(unsigned int val)
192 {
193         if (val & 0x100)
194                 val |= 0xfffffe00;
195
196         return val;
197 }
198
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
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
213 static ssize_t
214 ds1620_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
230 static int
231 ds1620_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
316 static int
317 proc_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
336 static struct proc_dir_entry *proc_therm_ds1620;
337 #endif
338
339 static const struct file_operations ds1620_fops = {
340         .owner          = THIS_MODULE,
341         .open           = nonseekable_open,
342         .read           = ds1620_read,
343         .ioctl          = ds1620_ioctl,
344 };
345
346 static struct miscdevice ds1620_miscdev = {
347         TEMP_MINOR,
348         "temp",
349         &ds1620_fops
350 };
351
352 static 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
403 static 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
411 module_init(ds1620_init);
412 module_exit(ds1620_exit);
413
414 MODULE_LICENSE("GPL");