ACPI: drivers/acpi: elide a non-zero test on a result that is never 0
[linux/fpc-iii.git] / drivers / acpi / toshiba_acpi.c
blob0a43c8e0eff323fe55f29846695c71e750ffedf3
1 /*
2 * toshiba_acpi.c - Toshiba Laptop ACPI Extras
5 * Copyright (C) 2002-2004 John Belmonte
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * The devolpment page for this driver is located at
23 * http://memebeam.org/toys/ToshibaAcpiDriver.
25 * Credits:
26 * Jonathan A. Buzzard - Toshiba HCI info, and critical tips on reverse
27 * engineering the Windows drivers
28 * Yasushi Nagato - changes for linux kernel 2.4 -> 2.5
29 * Rob Miller - TV out and hotkeys help
32 * TODO
36 #define TOSHIBA_ACPI_VERSION "0.18"
37 #define PROC_INTERFACE_VERSION 1
39 #include <linux/kernel.h>
40 #include <linux/module.h>
41 #include <linux/init.h>
42 #include <linux/types.h>
43 #include <linux/proc_fs.h>
44 #include <linux/backlight.h>
46 #include <asm/uaccess.h>
48 #include <acpi/acpi_drivers.h>
50 MODULE_AUTHOR("John Belmonte");
51 MODULE_DESCRIPTION("Toshiba Laptop ACPI Extras Driver");
52 MODULE_LICENSE("GPL");
54 #define MY_LOGPREFIX "toshiba_acpi: "
55 #define MY_ERR KERN_ERR MY_LOGPREFIX
56 #define MY_NOTICE KERN_NOTICE MY_LOGPREFIX
57 #define MY_INFO KERN_INFO MY_LOGPREFIX
59 /* Toshiba ACPI method paths */
60 #define METHOD_LCD_BRIGHTNESS "\\_SB_.PCI0.VGA_.LCD_._BCM"
61 #define METHOD_HCI_1 "\\_SB_.VALD.GHCI"
62 #define METHOD_HCI_2 "\\_SB_.VALZ.GHCI"
63 #define METHOD_VIDEO_OUT "\\_SB_.VALX.DSSX"
65 /* Toshiba HCI interface definitions
67 * HCI is Toshiba's "Hardware Control Interface" which is supposed to
68 * be uniform across all their models. Ideally we would just call
69 * dedicated ACPI methods instead of using this primitive interface.
70 * However the ACPI methods seem to be incomplete in some areas (for
71 * example they allow setting, but not reading, the LCD brightness value),
72 * so this is still useful.
75 #define HCI_WORDS 6
77 /* operations */
78 #define HCI_SET 0xff00
79 #define HCI_GET 0xfe00
81 /* return codes */
82 #define HCI_SUCCESS 0x0000
83 #define HCI_FAILURE 0x1000
84 #define HCI_NOT_SUPPORTED 0x8000
85 #define HCI_EMPTY 0x8c00
87 /* registers */
88 #define HCI_FAN 0x0004
89 #define HCI_SYSTEM_EVENT 0x0016
90 #define HCI_VIDEO_OUT 0x001c
91 #define HCI_HOTKEY_EVENT 0x001e
92 #define HCI_LCD_BRIGHTNESS 0x002a
94 /* field definitions */
95 #define HCI_LCD_BRIGHTNESS_BITS 3
96 #define HCI_LCD_BRIGHTNESS_SHIFT (16-HCI_LCD_BRIGHTNESS_BITS)
97 #define HCI_LCD_BRIGHTNESS_LEVELS (1 << HCI_LCD_BRIGHTNESS_BITS)
98 #define HCI_VIDEO_OUT_LCD 0x1
99 #define HCI_VIDEO_OUT_CRT 0x2
100 #define HCI_VIDEO_OUT_TV 0x4
102 static const struct acpi_device_id toshiba_device_ids[] = {
103 {"TOS6200", 0},
104 {"TOS1900", 0},
105 {"", 0},
107 MODULE_DEVICE_TABLE(acpi, toshiba_device_ids);
109 /* utility
112 static __inline__ void _set_bit(u32 * word, u32 mask, int value)
114 *word = (*word & ~mask) | (mask * value);
117 /* acpi interface wrappers
120 static int is_valid_acpi_path(const char *methodName)
122 acpi_handle handle;
123 acpi_status status;
125 status = acpi_get_handle(NULL, (char *)methodName, &handle);
126 return !ACPI_FAILURE(status);
129 static int write_acpi_int(const char *methodName, int val)
131 struct acpi_object_list params;
132 union acpi_object in_objs[1];
133 acpi_status status;
135 params.count = ARRAY_SIZE(in_objs);
136 params.pointer = in_objs;
137 in_objs[0].type = ACPI_TYPE_INTEGER;
138 in_objs[0].integer.value = val;
140 status = acpi_evaluate_object(NULL, (char *)methodName, &params, NULL);
141 return (status == AE_OK);
144 #if 0
145 static int read_acpi_int(const char *methodName, int *pVal)
147 struct acpi_buffer results;
148 union acpi_object out_objs[1];
149 acpi_status status;
151 results.length = sizeof(out_objs);
152 results.pointer = out_objs;
154 status = acpi_evaluate_object(0, (char *)methodName, 0, &results);
155 *pVal = out_objs[0].integer.value;
157 return (status == AE_OK) && (out_objs[0].type == ACPI_TYPE_INTEGER);
159 #endif
161 static const char *method_hci /*= 0*/ ;
163 /* Perform a raw HCI call. Here we don't care about input or output buffer
164 * format.
166 static acpi_status hci_raw(const u32 in[HCI_WORDS], u32 out[HCI_WORDS])
168 struct acpi_object_list params;
169 union acpi_object in_objs[HCI_WORDS];
170 struct acpi_buffer results;
171 union acpi_object out_objs[HCI_WORDS + 1];
172 acpi_status status;
173 int i;
175 params.count = HCI_WORDS;
176 params.pointer = in_objs;
177 for (i = 0; i < HCI_WORDS; ++i) {
178 in_objs[i].type = ACPI_TYPE_INTEGER;
179 in_objs[i].integer.value = in[i];
182 results.length = sizeof(out_objs);
183 results.pointer = out_objs;
185 status = acpi_evaluate_object(NULL, (char *)method_hci, &params,
186 &results);
187 if ((status == AE_OK) && (out_objs->package.count <= HCI_WORDS)) {
188 for (i = 0; i < out_objs->package.count; ++i) {
189 out[i] = out_objs->package.elements[i].integer.value;
193 return status;
196 /* common hci tasks (get or set one value)
198 * In addition to the ACPI status, the HCI system returns a result which
199 * may be useful (such as "not supported").
202 static acpi_status hci_write1(u32 reg, u32 in1, u32 * result)
204 u32 in[HCI_WORDS] = { HCI_SET, reg, in1, 0, 0, 0 };
205 u32 out[HCI_WORDS];
206 acpi_status status = hci_raw(in, out);
207 *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
208 return status;
211 static acpi_status hci_read1(u32 reg, u32 * out1, u32 * result)
213 u32 in[HCI_WORDS] = { HCI_GET, reg, 0, 0, 0, 0 };
214 u32 out[HCI_WORDS];
215 acpi_status status = hci_raw(in, out);
216 *out1 = out[2];
217 *result = (status == AE_OK) ? out[0] : HCI_FAILURE;
218 return status;
221 static struct proc_dir_entry *toshiba_proc_dir /*= 0*/ ;
222 static struct backlight_device *toshiba_backlight_device;
223 static int force_fan;
224 static int last_key_event;
225 static int key_event_valid;
227 typedef struct _ProcItem {
228 const char *name;
229 char *(*read_func) (char *);
230 unsigned long (*write_func) (const char *, unsigned long);
231 } ProcItem;
233 /* proc file handlers
236 static int
237 dispatch_read(char *page, char **start, off_t off, int count, int *eof,
238 ProcItem * item)
240 char *p = page;
241 int len;
243 if (off == 0)
244 p = item->read_func(p);
246 /* ISSUE: I don't understand this code */
247 len = (p - page);
248 if (len <= off + count)
249 *eof = 1;
250 *start = page + off;
251 len -= off;
252 if (len > count)
253 len = count;
254 if (len < 0)
255 len = 0;
256 return len;
259 static int
260 dispatch_write(struct file *file, const char __user * buffer,
261 unsigned long count, ProcItem * item)
263 int result;
264 char *tmp_buffer;
266 /* Arg buffer points to userspace memory, which can't be accessed
267 * directly. Since we're making a copy, zero-terminate the
268 * destination so that sscanf can be used on it safely.
270 tmp_buffer = kmalloc(count + 1, GFP_KERNEL);
271 if (!tmp_buffer)
272 return -ENOMEM;
274 if (copy_from_user(tmp_buffer, buffer, count)) {
275 result = -EFAULT;
276 } else {
277 tmp_buffer[count] = 0;
278 result = item->write_func(tmp_buffer, count);
280 kfree(tmp_buffer);
281 return result;
284 static int get_lcd(struct backlight_device *bd)
286 u32 hci_result;
287 u32 value;
289 hci_read1(HCI_LCD_BRIGHTNESS, &value, &hci_result);
290 if (hci_result == HCI_SUCCESS) {
291 return (value >> HCI_LCD_BRIGHTNESS_SHIFT);
292 } else
293 return -EFAULT;
296 static char *read_lcd(char *p)
298 int value = get_lcd(NULL);
300 if (value >= 0) {
301 p += sprintf(p, "brightness: %d\n", value);
302 p += sprintf(p, "brightness_levels: %d\n",
303 HCI_LCD_BRIGHTNESS_LEVELS);
304 } else {
305 printk(MY_ERR "Error reading LCD brightness\n");
308 return p;
311 static int set_lcd(int value)
313 u32 hci_result;
315 value = value << HCI_LCD_BRIGHTNESS_SHIFT;
316 hci_write1(HCI_LCD_BRIGHTNESS, value, &hci_result);
317 if (hci_result != HCI_SUCCESS)
318 return -EFAULT;
320 return 0;
323 static int set_lcd_status(struct backlight_device *bd)
325 return set_lcd(bd->props.brightness);
328 static unsigned long write_lcd(const char *buffer, unsigned long count)
330 int value;
331 int ret;
333 if (sscanf(buffer, " brightness : %i", &value) == 1 &&
334 value >= 0 && value < HCI_LCD_BRIGHTNESS_LEVELS) {
335 ret = set_lcd(value);
336 if (ret == 0)
337 ret = count;
338 } else {
339 ret = -EINVAL;
341 return ret;
344 static char *read_video(char *p)
346 u32 hci_result;
347 u32 value;
349 hci_read1(HCI_VIDEO_OUT, &value, &hci_result);
350 if (hci_result == HCI_SUCCESS) {
351 int is_lcd = (value & HCI_VIDEO_OUT_LCD) ? 1 : 0;
352 int is_crt = (value & HCI_VIDEO_OUT_CRT) ? 1 : 0;
353 int is_tv = (value & HCI_VIDEO_OUT_TV) ? 1 : 0;
354 p += sprintf(p, "lcd_out: %d\n", is_lcd);
355 p += sprintf(p, "crt_out: %d\n", is_crt);
356 p += sprintf(p, "tv_out: %d\n", is_tv);
357 } else {
358 printk(MY_ERR "Error reading video out status\n");
361 return p;
364 static unsigned long write_video(const char *buffer, unsigned long count)
366 int value;
367 int remain = count;
368 int lcd_out = -1;
369 int crt_out = -1;
370 int tv_out = -1;
371 u32 hci_result;
372 u32 video_out;
374 /* scan expression. Multiple expressions may be delimited with ;
376 * NOTE: to keep scanning simple, invalid fields are ignored
378 while (remain) {
379 if (sscanf(buffer, " lcd_out : %i", &value) == 1)
380 lcd_out = value & 1;
381 else if (sscanf(buffer, " crt_out : %i", &value) == 1)
382 crt_out = value & 1;
383 else if (sscanf(buffer, " tv_out : %i", &value) == 1)
384 tv_out = value & 1;
385 /* advance to one character past the next ; */
386 do {
387 ++buffer;
388 --remain;
390 while (remain && *(buffer - 1) != ';');
393 hci_read1(HCI_VIDEO_OUT, &video_out, &hci_result);
394 if (hci_result == HCI_SUCCESS) {
395 int new_video_out = video_out;
396 if (lcd_out != -1)
397 _set_bit(&new_video_out, HCI_VIDEO_OUT_LCD, lcd_out);
398 if (crt_out != -1)
399 _set_bit(&new_video_out, HCI_VIDEO_OUT_CRT, crt_out);
400 if (tv_out != -1)
401 _set_bit(&new_video_out, HCI_VIDEO_OUT_TV, tv_out);
402 /* To avoid unnecessary video disruption, only write the new
403 * video setting if something changed. */
404 if (new_video_out != video_out)
405 write_acpi_int(METHOD_VIDEO_OUT, new_video_out);
406 } else {
407 return -EFAULT;
410 return count;
413 static char *read_fan(char *p)
415 u32 hci_result;
416 u32 value;
418 hci_read1(HCI_FAN, &value, &hci_result);
419 if (hci_result == HCI_SUCCESS) {
420 p += sprintf(p, "running: %d\n", (value > 0));
421 p += sprintf(p, "force_on: %d\n", force_fan);
422 } else {
423 printk(MY_ERR "Error reading fan status\n");
426 return p;
429 static unsigned long write_fan(const char *buffer, unsigned long count)
431 int value;
432 u32 hci_result;
434 if (sscanf(buffer, " force_on : %i", &value) == 1 &&
435 value >= 0 && value <= 1) {
436 hci_write1(HCI_FAN, value, &hci_result);
437 if (hci_result != HCI_SUCCESS)
438 return -EFAULT;
439 else
440 force_fan = value;
441 } else {
442 return -EINVAL;
445 return count;
448 static char *read_keys(char *p)
450 u32 hci_result;
451 u32 value;
453 if (!key_event_valid) {
454 hci_read1(HCI_SYSTEM_EVENT, &value, &hci_result);
455 if (hci_result == HCI_SUCCESS) {
456 key_event_valid = 1;
457 last_key_event = value;
458 } else if (hci_result == HCI_EMPTY) {
459 /* better luck next time */
460 } else if (hci_result == HCI_NOT_SUPPORTED) {
461 /* This is a workaround for an unresolved issue on
462 * some machines where system events sporadically
463 * become disabled. */
464 hci_write1(HCI_SYSTEM_EVENT, 1, &hci_result);
465 printk(MY_NOTICE "Re-enabled hotkeys\n");
466 } else {
467 printk(MY_ERR "Error reading hotkey status\n");
468 goto end;
472 p += sprintf(p, "hotkey_ready: %d\n", key_event_valid);
473 p += sprintf(p, "hotkey: 0x%04x\n", last_key_event);
475 end:
476 return p;
479 static unsigned long write_keys(const char *buffer, unsigned long count)
481 int value;
483 if (sscanf(buffer, " hotkey_ready : %i", &value) == 1 && value == 0) {
484 key_event_valid = 0;
485 } else {
486 return -EINVAL;
489 return count;
492 static char *read_version(char *p)
494 p += sprintf(p, "driver: %s\n", TOSHIBA_ACPI_VERSION);
495 p += sprintf(p, "proc_interface: %d\n",
496 PROC_INTERFACE_VERSION);
497 return p;
500 /* proc and module init
503 #define PROC_TOSHIBA "toshiba"
505 static ProcItem proc_items[] = {
506 {"lcd", read_lcd, write_lcd},
507 {"video", read_video, write_video},
508 {"fan", read_fan, write_fan},
509 {"keys", read_keys, write_keys},
510 {"version", read_version, NULL},
511 {NULL}
514 static acpi_status __init add_device(void)
516 struct proc_dir_entry *proc;
517 ProcItem *item;
519 for (item = proc_items; item->name; ++item) {
520 proc = create_proc_read_entry(item->name,
521 S_IFREG | S_IRUGO | S_IWUSR,
522 toshiba_proc_dir,
523 (read_proc_t *) dispatch_read,
524 item);
525 if (proc)
526 proc->owner = THIS_MODULE;
527 if (proc && item->write_func)
528 proc->write_proc = (write_proc_t *) dispatch_write;
531 return AE_OK;
534 static acpi_status remove_device(void)
536 ProcItem *item;
538 for (item = proc_items; item->name; ++item)
539 remove_proc_entry(item->name, toshiba_proc_dir);
540 return AE_OK;
543 static struct backlight_ops toshiba_backlight_data = {
544 .get_brightness = get_lcd,
545 .update_status = set_lcd_status,
548 static void toshiba_acpi_exit(void)
550 if (toshiba_backlight_device)
551 backlight_device_unregister(toshiba_backlight_device);
553 remove_device();
555 if (toshiba_proc_dir)
556 remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
558 return;
561 static int __init toshiba_acpi_init(void)
563 acpi_status status = AE_OK;
564 u32 hci_result;
566 if (acpi_disabled)
567 return -ENODEV;
569 /* simple device detection: look for HCI method */
570 if (is_valid_acpi_path(METHOD_HCI_1))
571 method_hci = METHOD_HCI_1;
572 else if (is_valid_acpi_path(METHOD_HCI_2))
573 method_hci = METHOD_HCI_2;
574 else
575 return -ENODEV;
577 printk(MY_INFO "Toshiba Laptop ACPI Extras version %s\n",
578 TOSHIBA_ACPI_VERSION);
579 printk(MY_INFO " HCI method: %s\n", method_hci);
581 force_fan = 0;
582 key_event_valid = 0;
584 /* enable event fifo */
585 hci_write1(HCI_SYSTEM_EVENT, 1, &hci_result);
587 toshiba_proc_dir = proc_mkdir(PROC_TOSHIBA, acpi_root_dir);
588 if (!toshiba_proc_dir) {
589 status = AE_ERROR;
590 } else {
591 toshiba_proc_dir->owner = THIS_MODULE;
592 status = add_device();
593 if (ACPI_FAILURE(status))
594 remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
597 toshiba_backlight_device = backlight_device_register("toshiba",NULL,
598 NULL,
599 &toshiba_backlight_data);
600 if (IS_ERR(toshiba_backlight_device)) {
601 int ret = PTR_ERR(toshiba_backlight_device);
603 printk(KERN_ERR "Could not register toshiba backlight device\n");
604 toshiba_backlight_device = NULL;
605 toshiba_acpi_exit();
606 return ret;
608 toshiba_backlight_device->props.max_brightness = HCI_LCD_BRIGHTNESS_LEVELS - 1;
610 return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
613 module_init(toshiba_acpi_init);
614 module_exit(toshiba_acpi_exit);