1 /*
2  * Samsung Laptop driver
3  *
4  * Copyright (C) 2009,2011 Greg Kroah-Hartman (gregkh@suse.de)
5  * Copyright (C) 2009,2011 Novell Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published by
9  * the Free Software Foundation.
10  *
11  */
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/delay.h>
18 #include <linux/pci.h>
19 #include <linux/backlight.h>
20 #include <linux/fb.h>
21 #include <linux/dmi.h>
22 #include <linux/platform_device.h>
23 #include <linux/rfkill.h>
24 
25 /*
26  * This driver is needed because a number of Samsung laptops do not hook
27  * their control settings through ACPI.  So we have to poke around in the
28  * BIOS to do things like brightness values, and "special" key controls.
29  */
30 
31 /*
32  * We have 0 - 8 as valid brightness levels.  The specs say that level 0 should
33  * be reserved by the BIOS (which really doesn't make much sense), we tell
34  * userspace that the value is 0 - 7 and then just tell the hardware 1 - 8
35  */
36 #define MAX_BRIGHT	0x07
37 
38 
39 #define SABI_IFACE_MAIN			0x00
40 #define SABI_IFACE_SUB			0x02
41 #define SABI_IFACE_COMPLETE		0x04
42 #define SABI_IFACE_DATA			0x05
43 
44 /* Structure to get data back to the calling function */
45 struct sabi_retval {
46 	u8 retval[20];
47 };
48 
49 struct sabi_header_offsets {
50 	u8 port;
51 	u8 re_mem;
52 	u8 iface_func;
53 	u8 en_mem;
54 	u8 data_offset;
55 	u8 data_segment;
56 };
57 
58 struct sabi_commands {
59 	/*
60 	 * Brightness is 0 - 8, as described above.
61 	 * Value 0 is for the BIOS to use
62 	 */
63 	u8 get_brightness;
64 	u8 set_brightness;
65 
66 	/*
67 	 * first byte:
68 	 * 0x00 - wireless is off
69 	 * 0x01 - wireless is on
70 	 * second byte:
71 	 * 0x02 - 3G is off
72 	 * 0x03 - 3G is on
73 	 * TODO, verify 3G is correct, that doesn't seem right...
74 	 */
75 	u8 get_wireless_button;
76 	u8 set_wireless_button;
77 
78 	/* 0 is off, 1 is on */
79 	u8 get_backlight;
80 	u8 set_backlight;
81 
82 	/*
83 	 * 0x80 or 0x00 - no action
84 	 * 0x81 - recovery key pressed
85 	 */
86 	u8 get_recovery_mode;
87 	u8 set_recovery_mode;
88 
89 	/*
90 	 * on seclinux: 0 is low, 1 is high,
91 	 * on swsmi: 0 is normal, 1 is silent, 2 is turbo
92 	 */
93 	u8 get_performance_level;
94 	u8 set_performance_level;
95 
96 	/*
97 	 * Tell the BIOS that Linux is running on this machine.
98 	 * 81 is on, 80 is off
99 	 */
100 	u8 set_linux;
101 };
102 
103 struct sabi_performance_level {
104 	const char *name;
105 	u8 value;
106 };
107 
108 struct sabi_config {
109 	const char *test_string;
110 	u16 main_function;
111 	const struct sabi_header_offsets header_offsets;
112 	const struct sabi_commands commands;
113 	const struct sabi_performance_level performance_levels[4];
114 	u8 min_brightness;
115 	u8 max_brightness;
116 };
117 
118 static const struct sabi_config sabi_configs[] = {
119 	{
120 		.test_string = "SECLINUX",
121 
122 		.main_function = 0x4c49,
123 
124 		.header_offsets = {
125 			.port = 0x00,
126 			.re_mem = 0x02,
127 			.iface_func = 0x03,
128 			.en_mem = 0x04,
129 			.data_offset = 0x05,
130 			.data_segment = 0x07,
131 		},
132 
133 		.commands = {
134 			.get_brightness = 0x00,
135 			.set_brightness = 0x01,
136 
137 			.get_wireless_button = 0x02,
138 			.set_wireless_button = 0x03,
139 
140 			.get_backlight = 0x04,
141 			.set_backlight = 0x05,
142 
143 			.get_recovery_mode = 0x06,
144 			.set_recovery_mode = 0x07,
145 
146 			.get_performance_level = 0x08,
147 			.set_performance_level = 0x09,
148 
149 			.set_linux = 0x0a,
150 		},
151 
152 		.performance_levels = {
153 			{
154 				.name = "silent",
155 				.value = 0,
156 			},
157 			{
158 				.name = "normal",
159 				.value = 1,
160 			},
161 			{ },
162 		},
163 		.min_brightness = 1,
164 		.max_brightness = 8,
165 	},
166 	{
167 		.test_string = "SwSmi@",
168 
169 		.main_function = 0x5843,
170 
171 		.header_offsets = {
172 			.port = 0x00,
173 			.re_mem = 0x04,
174 			.iface_func = 0x02,
175 			.en_mem = 0x03,
176 			.data_offset = 0x05,
177 			.data_segment = 0x07,
178 		},
179 
180 		.commands = {
181 			.get_brightness = 0x10,
182 			.set_brightness = 0x11,
183 
184 			.get_wireless_button = 0x12,
185 			.set_wireless_button = 0x13,
186 
187 			.get_backlight = 0x2d,
188 			.set_backlight = 0x2e,
189 
190 			.get_recovery_mode = 0xff,
191 			.set_recovery_mode = 0xff,
192 
193 			.get_performance_level = 0x31,
194 			.set_performance_level = 0x32,
195 
196 			.set_linux = 0xff,
197 		},
198 
199 		.performance_levels = {
200 			{
201 				.name = "normal",
202 				.value = 0,
203 			},
204 			{
205 				.name = "silent",
206 				.value = 1,
207 			},
208 			{
209 				.name = "overclock",
210 				.value = 2,
211 			},
212 			{ },
213 		},
214 		.min_brightness = 0,
215 		.max_brightness = 8,
216 	},
217 	{ },
218 };
219 
220 static const struct sabi_config *sabi_config;
221 
222 static void __iomem *sabi;
223 static void __iomem *sabi_iface;
224 static void __iomem *f0000_segment;
225 static struct backlight_device *backlight_device;
226 static struct mutex sabi_mutex;
227 static struct platform_device *sdev;
228 static struct rfkill *rfk;
229 
230 static int force;
231 module_param(force, bool, 0);
232 MODULE_PARM_DESC(force,
233 		"Disable the DMI check and forces the driver to be loaded");
234 
235 static int debug;
236 module_param(debug, bool, S_IRUGO | S_IWUSR);
237 MODULE_PARM_DESC(debug, "Debug enabled or not");
238 
239 static int sabi_get_command(u8 command, struct sabi_retval *sretval)
240 {
241 	int retval = 0;
242 	u16 port = readw(sabi + sabi_config->header_offsets.port);
243 	u8 complete, iface_data;
244 
245 	mutex_lock(&sabi_mutex);
246 
247 	/* enable memory to be able to write to it */
248 	outb(readb(sabi + sabi_config->header_offsets.en_mem), port);
249 
250 	/* write out the command */
251 	writew(sabi_config->main_function, sabi_iface + SABI_IFACE_MAIN);
252 	writew(command, sabi_iface + SABI_IFACE_SUB);
253 	writeb(0, sabi_iface + SABI_IFACE_COMPLETE);
254 	outb(readb(sabi + sabi_config->header_offsets.iface_func), port);
255 
256 	/* write protect memory to make it safe */
257 	outb(readb(sabi + sabi_config->header_offsets.re_mem), port);
258 
259 	/* see if the command actually succeeded */
260 	complete = readb(sabi_iface + SABI_IFACE_COMPLETE);
261 	iface_data = readb(sabi_iface + SABI_IFACE_DATA);
262 	if (complete != 0xaa || iface_data == 0xff) {
263 		pr_warn("SABI get command 0x%02x failed with completion flag 0x%02x and data 0x%02x\n",
264 		        command, complete, iface_data);
265 		retval = -EINVAL;
266 		goto exit;
267 	}
268 	/*
269 	 * Save off the data into a structure so the caller use it.
270 	 * Right now we only want the first 4 bytes,
271 	 * There are commands that need more, but not for the ones we
272 	 * currently care about.
273 	 */
274 	sretval->retval[0] = readb(sabi_iface + SABI_IFACE_DATA);
275 	sretval->retval[1] = readb(sabi_iface + SABI_IFACE_DATA + 1);
276 	sretval->retval[2] = readb(sabi_iface + SABI_IFACE_DATA + 2);
277 	sretval->retval[3] = readb(sabi_iface + SABI_IFACE_DATA + 3);
278 
279 exit:
280 	mutex_unlock(&sabi_mutex);
281 	return retval;
282 
283 }
284 
285 static int sabi_set_command(u8 command, u8 data)
286 {
287 	int retval = 0;
288 	u16 port = readw(sabi + sabi_config->header_offsets.port);
289 	u8 complete, iface_data;
290 
291 	mutex_lock(&sabi_mutex);
292 
293 	/* enable memory to be able to write to it */
294 	outb(readb(sabi + sabi_config->header_offsets.en_mem), port);
295 
296 	/* write out the command */
297 	writew(sabi_config->main_function, sabi_iface + SABI_IFACE_MAIN);
298 	writew(command, sabi_iface + SABI_IFACE_SUB);
299 	writeb(0, sabi_iface + SABI_IFACE_COMPLETE);
300 	writeb(data, sabi_iface + SABI_IFACE_DATA);
301 	outb(readb(sabi + sabi_config->header_offsets.iface_func), port);
302 
303 	/* write protect memory to make it safe */
304 	outb(readb(sabi + sabi_config->header_offsets.re_mem), port);
305 
306 	/* see if the command actually succeeded */
307 	complete = readb(sabi_iface + SABI_IFACE_COMPLETE);
308 	iface_data = readb(sabi_iface + SABI_IFACE_DATA);
309 	if (complete != 0xaa || iface_data == 0xff) {
310 		pr_warn("SABI set command 0x%02x failed with completion flag 0x%02x and data 0x%02x\n",
311 		       command, complete, iface_data);
312 		retval = -EINVAL;
313 	}
314 
315 	mutex_unlock(&sabi_mutex);
316 	return retval;
317 }
318 
319 static void test_backlight(void)
320 {
321 	struct sabi_retval sretval;
322 
323 	sabi_get_command(sabi_config->commands.get_backlight, &sretval);
324 	printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
325 
326 	sabi_set_command(sabi_config->commands.set_backlight, 0);
327 	printk(KERN_DEBUG "backlight should be off\n");
328 
329 	sabi_get_command(sabi_config->commands.get_backlight, &sretval);
330 	printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
331 
332 	msleep(1000);
333 
334 	sabi_set_command(sabi_config->commands.set_backlight, 1);
335 	printk(KERN_DEBUG "backlight should be on\n");
336 
337 	sabi_get_command(sabi_config->commands.get_backlight, &sretval);
338 	printk(KERN_DEBUG "backlight = 0x%02x\n", sretval.retval[0]);
339 }
340 
341 static void test_wireless(void)
342 {
343 	struct sabi_retval sretval;
344 
345 	sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
346 	printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
347 
348 	sabi_set_command(sabi_config->commands.set_wireless_button, 0);
349 	printk(KERN_DEBUG "wireless led should be off\n");
350 
351 	sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
352 	printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
353 
354 	msleep(1000);
355 
356 	sabi_set_command(sabi_config->commands.set_wireless_button, 1);
357 	printk(KERN_DEBUG "wireless led should be on\n");
358 
359 	sabi_get_command(sabi_config->commands.get_wireless_button, &sretval);
360 	printk(KERN_DEBUG "wireless led = 0x%02x\n", sretval.retval[0]);
361 }
362 
363 static u8 read_brightness(void)
364 {
365 	struct sabi_retval sretval;
366 	int user_brightness = 0;
367 	int retval;
368 
369 	retval = sabi_get_command(sabi_config->commands.get_brightness,
370 				  &sretval);
371 	if (!retval) {
372 		user_brightness = sretval.retval[0];
373 		if (user_brightness != 0)
374 			user_brightness -= sabi_config->min_brightness;
375 	}
376 	return user_brightness;
377 }
378 
379 static void set_brightness(u8 user_brightness)
380 {
381 	u8 user_level = user_brightness - sabi_config->min_brightness;
382 
383 	sabi_set_command(sabi_config->commands.set_brightness, user_level);
384 }
385 
386 static int get_brightness(struct backlight_device *bd)
387 {
388 	return (int)read_brightness();
389 }
390 
391 static int update_status(struct backlight_device *bd)
392 {
393 	set_brightness(bd->props.brightness);
394 
395 	if (bd->props.power == FB_BLANK_UNBLANK)
396 		sabi_set_command(sabi_config->commands.set_backlight, 1);
397 	else
398 		sabi_set_command(sabi_config->commands.set_backlight, 0);
399 	return 0;
400 }
401 
402 static const struct backlight_ops backlight_ops = {
403 	.get_brightness	= get_brightness,
404 	.update_status	= update_status,
405 };
406 
407 static int rfkill_set(void *data, bool blocked)
408 {
409 	/* Do something with blocked...*/
410 	/*
411 	 * blocked == false is on
412 	 * blocked == true is off
413 	 */
414 	if (blocked)
415 		sabi_set_command(sabi_config->commands.set_wireless_button, 0);
416 	else
417 		sabi_set_command(sabi_config->commands.set_wireless_button, 1);
418 
419 	return 0;
420 }
421 
422 static struct rfkill_ops rfkill_ops = {
423 	.set_block = rfkill_set,
424 };
425 
426 static int init_wireless(struct platform_device *sdev)
427 {
428 	int retval;
429 
430 	rfk = rfkill_alloc("samsung-wifi", &sdev->dev, RFKILL_TYPE_WLAN,
431 			   &rfkill_ops, NULL);
432 	if (!rfk)
433 		return -ENOMEM;
434 
435 	retval = rfkill_register(rfk);
436 	if (retval) {
437 		rfkill_destroy(rfk);
438 		return -ENODEV;
439 	}
440 
441 	return 0;
442 }
443 
444 static void destroy_wireless(void)
445 {
446 	rfkill_unregister(rfk);
447 	rfkill_destroy(rfk);
448 }
449 
450 static ssize_t get_performance_level(struct device *dev,
451 				     struct device_attribute *attr, char *buf)
452 {
453 	struct sabi_retval sretval;
454 	int retval;
455 	int i;
456 
457 	/* Read the state */
458 	retval = sabi_get_command(sabi_config->commands.get_performance_level,
459 				  &sretval);
460 	if (retval)
461 		return retval;
462 
463 	/* The logic is backwards, yeah, lots of fun... */
464 	for (i = 0; sabi_config->performance_levels[i].name; ++i) {
465 		if (sretval.retval[0] == sabi_config->performance_levels[i].value)
466 			return sprintf(buf, "%s\n", sabi_config->performance_levels[i].name);
467 	}
468 	return sprintf(buf, "%s\n", "unknown");
469 }
470 
471 static ssize_t set_performance_level(struct device *dev,
472 				struct device_attribute *attr, const char *buf,
473 				size_t count)
474 {
475 	if (count >= 1) {
476 		int i;
477 		for (i = 0; sabi_config->performance_levels[i].name; ++i) {
478 			const struct sabi_performance_level *level =
479 				&sabi_config->performance_levels[i];
480 			if (!strncasecmp(level->name, buf, strlen(level->name))) {
481 				sabi_set_command(sabi_config->commands.set_performance_level,
482 						 level->value);
483 				break;
484 			}
485 		}
486 		if (!sabi_config->performance_levels[i].name)
487 			return -EINVAL;
488 	}
489 	return count;
490 }
491 static DEVICE_ATTR(performance_level, S_IWUSR | S_IRUGO,
492 		   get_performance_level, set_performance_level);
493 
494 
495 static int __init dmi_check_cb(const struct dmi_system_id *id)
496 {
497 	pr_info("found laptop model '%s'\n",
498 		id->ident);
499 	return 1;
500 }
501 
502 static struct dmi_system_id __initdata samsung_dmi_table[] = {
503 	{
504 		.ident = "N128",
505 		.matches = {
506 			DMI_MATCH(DMI_SYS_VENDOR,
507 					"SAMSUNG ELECTRONICS CO., LTD."),
508 			DMI_MATCH(DMI_PRODUCT_NAME, "N128"),
509 			DMI_MATCH(DMI_BOARD_NAME, "N128"),
510 		},
511 		.callback = dmi_check_cb,
512 	},
513 	{
514 		.ident = "N130",
515 		.matches = {
516 			DMI_MATCH(DMI_SYS_VENDOR,
517 					"SAMSUNG ELECTRONICS CO., LTD."),
518 			DMI_MATCH(DMI_PRODUCT_NAME, "N130"),
519 			DMI_MATCH(DMI_BOARD_NAME, "N130"),
520 		},
521 		.callback = dmi_check_cb,
522 	},
523 	{
524 		.ident = "N510",
525 		.matches = {
526 			DMI_MATCH(DMI_SYS_VENDOR,
527 					"SAMSUNG ELECTRONICS CO., LTD."),
528 			DMI_MATCH(DMI_PRODUCT_NAME, "N510"),
529 			DMI_MATCH(DMI_BOARD_NAME, "N510"),
530 		},
531 		.callback = dmi_check_cb,
532 	},
533 	{
534 		.ident = "X125",
535 		.matches = {
536 			DMI_MATCH(DMI_SYS_VENDOR,
537 					"SAMSUNG ELECTRONICS CO., LTD."),
538 			DMI_MATCH(DMI_PRODUCT_NAME, "X125"),
539 			DMI_MATCH(DMI_BOARD_NAME, "X125"),
540 		},
541 		.callback = dmi_check_cb,
542 	},
543 	{
544 		.ident = "X120/X170",
545 		.matches = {
546 			DMI_MATCH(DMI_SYS_VENDOR,
547 					"SAMSUNG ELECTRONICS CO., LTD."),
548 			DMI_MATCH(DMI_PRODUCT_NAME, "X120/X170"),
549 			DMI_MATCH(DMI_BOARD_NAME, "X120/X170"),
550 		},
551 		.callback = dmi_check_cb,
552 	},
553 	{
554 		.ident = "NC10",
555 		.matches = {
556 			DMI_MATCH(DMI_SYS_VENDOR,
557 					"SAMSUNG ELECTRONICS CO., LTD."),
558 			DMI_MATCH(DMI_PRODUCT_NAME, "NC10"),
559 			DMI_MATCH(DMI_BOARD_NAME, "NC10"),
560 		},
561 		.callback = dmi_check_cb,
562 	},
563 		{
564 		.ident = "NP-Q45",
565 		.matches = {
566 			DMI_MATCH(DMI_SYS_VENDOR,
567 					"SAMSUNG ELECTRONICS CO., LTD."),
568 			DMI_MATCH(DMI_PRODUCT_NAME, "SQ45S70S"),
569 			DMI_MATCH(DMI_BOARD_NAME, "SQ45S70S"),
570 		},
571 		.callback = dmi_check_cb,
572 		},
573 	{
574 		.ident = "X360",
575 		.matches = {
576 			DMI_MATCH(DMI_SYS_VENDOR,
577 					"SAMSUNG ELECTRONICS CO., LTD."),
578 			DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
579 			DMI_MATCH(DMI_BOARD_NAME, "X360"),
580 		},
581 		.callback = dmi_check_cb,
582 	},
583 	{
584 		.ident = "R410 Plus",
585 		.matches = {
586 			DMI_MATCH(DMI_SYS_VENDOR,
587 					"SAMSUNG ELECTRONICS CO., LTD."),
588 			DMI_MATCH(DMI_PRODUCT_NAME, "R410P"),
589 			DMI_MATCH(DMI_BOARD_NAME, "R460"),
590 		},
591 		.callback = dmi_check_cb,
592 	},
593 	{
594 		.ident = "R518",
595 		.matches = {
596 			DMI_MATCH(DMI_SYS_VENDOR,
597 					"SAMSUNG ELECTRONICS CO., LTD."),
598 			DMI_MATCH(DMI_PRODUCT_NAME, "R518"),
599 			DMI_MATCH(DMI_BOARD_NAME, "R518"),
600 		},
601 		.callback = dmi_check_cb,
602 	},
603 	{
604 		.ident = "R519/R719",
605 		.matches = {
606 			DMI_MATCH(DMI_SYS_VENDOR,
607 					"SAMSUNG ELECTRONICS CO., LTD."),
608 			DMI_MATCH(DMI_PRODUCT_NAME, "R519/R719"),
609 			DMI_MATCH(DMI_BOARD_NAME, "R519/R719"),
610 		},
611 		.callback = dmi_check_cb,
612 	},
613 	{
614 		.ident = "N150/N210/N220",
615 		.matches = {
616 			DMI_MATCH(DMI_SYS_VENDOR,
617 					"SAMSUNG ELECTRONICS CO., LTD."),
618 			DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220"),
619 			DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220"),
620 		},
621 		.callback = dmi_check_cb,
622 	},
623 	{
624 		.ident = "N150/N210/N220/N230",
625 		.matches = {
626 			DMI_MATCH(DMI_SYS_VENDOR,
627 					"SAMSUNG ELECTRONICS CO., LTD."),
628 			DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220/N230"),
629 			DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220/N230"),
630 		},
631 		.callback = dmi_check_cb,
632 	},
633 	{
634 		.ident = "N150P/N210P/N220P",
635 		.matches = {
636 			DMI_MATCH(DMI_SYS_VENDOR,
637 					"SAMSUNG ELECTRONICS CO., LTD."),
638 			DMI_MATCH(DMI_PRODUCT_NAME, "N150P/N210P/N220P"),
639 			DMI_MATCH(DMI_BOARD_NAME, "N150P/N210P/N220P"),
640 		},
641 		.callback = dmi_check_cb,
642 	},
643 	{
644 		.ident = "R530/R730",
645 		.matches = {
646 		      DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
647 		      DMI_MATCH(DMI_PRODUCT_NAME, "R530/R730"),
648 		      DMI_MATCH(DMI_BOARD_NAME, "R530/R730"),
649 		},
650 		.callback = dmi_check_cb,
651 	},
652 	{
653 		.ident = "NF110/NF210/NF310",
654 		.matches = {
655 			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
656 			DMI_MATCH(DMI_PRODUCT_NAME, "NF110/NF210/NF310"),
657 			DMI_MATCH(DMI_BOARD_NAME, "NF110/NF210/NF310"),
658 		},
659 		.callback = dmi_check_cb,
660 	},
661 	{
662 		.ident = "N145P/N250P/N260P",
663 		.matches = {
664 			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
665 			DMI_MATCH(DMI_PRODUCT_NAME, "N145P/N250P/N260P"),
666 			DMI_MATCH(DMI_BOARD_NAME, "N145P/N250P/N260P"),
667 		},
668 		.callback = dmi_check_cb,
669 	},
670 	{
671 		.ident = "R70/R71",
672 		.matches = {
673 			DMI_MATCH(DMI_SYS_VENDOR,
674 					"SAMSUNG ELECTRONICS CO., LTD."),
675 			DMI_MATCH(DMI_PRODUCT_NAME, "R70/R71"),
676 			DMI_MATCH(DMI_BOARD_NAME, "R70/R71"),
677 		},
678 		.callback = dmi_check_cb,
679 	},
680 	{
681 		.ident = "P460",
682 		.matches = {
683 			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
684 			DMI_MATCH(DMI_PRODUCT_NAME, "P460"),
685 			DMI_MATCH(DMI_BOARD_NAME, "P460"),
686 		},
687 		.callback = dmi_check_cb,
688 	},
689 	{ },
690 };
691 MODULE_DEVICE_TABLE(dmi, samsung_dmi_table);
692 
693 static int find_signature(void __iomem *memcheck, const char *testStr)
694 {
695 	int i = 0;
696 	int loca;
697 
698 	for (loca = 0; loca < 0xffff; loca++) {
699 		char temp = readb(memcheck + loca);
700 
701 		if (temp == testStr[i]) {
702 			if (i == strlen(testStr)-1)
703 				break;
704 			++i;
705 		} else {
706 			i = 0;
707 		}
708 	}
709 	return loca;
710 }
711 
712 static int __init samsung_init(void)
713 {
714 	struct backlight_properties props;
715 	struct sabi_retval sretval;
716 	unsigned int ifaceP;
717 	int i;
718 	int loca;
719 	int retval;
720 
721 	mutex_init(&sabi_mutex);
722 
723 	if (!force && !dmi_check_system(samsung_dmi_table))
724 		return -ENODEV;
725 
726 	f0000_segment = ioremap_nocache(0xf0000, 0xffff);
727 	if (!f0000_segment) {
728 		pr_err("Can't map the segment at 0xf0000\n");
729 		return -EINVAL;
730 	}
731 
732 	/* Try to find one of the signatures in memory to find the header */
733 	for (i = 0; sabi_configs[i].test_string != 0; ++i) {
734 		sabi_config = &sabi_configs[i];
735 		loca = find_signature(f0000_segment, sabi_config->test_string);
736 		if (loca != 0xffff)
737 			break;
738 	}
739 
740 	if (loca == 0xffff) {
741 		pr_err("This computer does not support SABI\n");
742 		goto error_no_signature;
743 	}
744 
745 	/* point to the SMI port Number */
746 	loca += 1;
747 	sabi = (f0000_segment + loca);
748 
749 	if (debug) {
750 		printk(KERN_DEBUG "This computer supports SABI==%x\n",
751 			loca + 0xf0000 - 6);
752 		printk(KERN_DEBUG "SABI header:\n");
753 		printk(KERN_DEBUG " SMI Port Number = 0x%04x\n",
754 			readw(sabi + sabi_config->header_offsets.port));
755 		printk(KERN_DEBUG " SMI Interface Function = 0x%02x\n",
756 			readb(sabi + sabi_config->header_offsets.iface_func));
757 		printk(KERN_DEBUG " SMI enable memory buffer = 0x%02x\n",
758 			readb(sabi + sabi_config->header_offsets.en_mem));
759 		printk(KERN_DEBUG " SMI restore memory buffer = 0x%02x\n",
760 			readb(sabi + sabi_config->header_offsets.re_mem));
761 		printk(KERN_DEBUG " SABI data offset = 0x%04x\n",
762 			readw(sabi + sabi_config->header_offsets.data_offset));
763 		printk(KERN_DEBUG " SABI data segment = 0x%04x\n",
764 			readw(sabi + sabi_config->header_offsets.data_segment));
765 	}
766 
767 	/* Get a pointer to the SABI Interface */
768 	ifaceP = (readw(sabi + sabi_config->header_offsets.data_segment) & 0x0ffff) << 4;
769 	ifaceP += readw(sabi + sabi_config->header_offsets.data_offset) & 0x0ffff;
770 	sabi_iface = ioremap_nocache(ifaceP, 16);
771 	if (!sabi_iface) {
772 		pr_err("Can't remap %x\n", ifaceP);
773 		goto exit;
774 	}
775 	if (debug) {
776 		printk(KERN_DEBUG "ifaceP = 0x%08x\n", ifaceP);
777 		printk(KERN_DEBUG "sabi_iface = %p\n", sabi_iface);
778 
779 		test_backlight();
780 		test_wireless();
781 
782 		retval = sabi_get_command(sabi_config->commands.get_brightness,
783 					  &sretval);
784 		printk(KERN_DEBUG "brightness = 0x%02x\n", sretval.retval[0]);
785 	}
786 
787 	/* Turn on "Linux" mode in the BIOS */
788 	if (sabi_config->commands.set_linux != 0xff) {
789 		retval = sabi_set_command(sabi_config->commands.set_linux,
790 					  0x81);
791 		if (retval) {
792 			pr_warn("Linux mode was not set!\n");
793 			goto error_no_platform;
794 		}
795 	}
796 
797 	/* knock up a platform device to hang stuff off of */
798 	sdev = platform_device_register_simple("samsung", -1, NULL, 0);
799 	if (IS_ERR(sdev))
800 		goto error_no_platform;
801 
802 	/* create a backlight device to talk to this one */
803 	memset(&props, 0, sizeof(struct backlight_properties));
804 	props.type = BACKLIGHT_PLATFORM;
805 	props.max_brightness = sabi_config->max_brightness;
806 	backlight_device = backlight_device_register("samsung", &sdev->dev,
807 						     NULL, &backlight_ops,
808 						     &props);
809 	if (IS_ERR(backlight_device))
810 		goto error_no_backlight;
811 
812 	backlight_device->props.brightness = read_brightness();
813 	backlight_device->props.power = FB_BLANK_UNBLANK;
814 	backlight_update_status(backlight_device);
815 
816 	retval = init_wireless(sdev);
817 	if (retval)
818 		goto error_no_rfk;
819 
820 	retval = device_create_file(&sdev->dev, &dev_attr_performance_level);
821 	if (retval)
822 		goto error_file_create;
823 
824 exit:
825 	return 0;
826 
827 error_file_create:
828 	destroy_wireless();
829 
830 error_no_rfk:
831 	backlight_device_unregister(backlight_device);
832 
833 error_no_backlight:
834 	platform_device_unregister(sdev);
835 
836 error_no_platform:
837 	iounmap(sabi_iface);
838 
839 error_no_signature:
840 	iounmap(f0000_segment);
841 	return -EINVAL;
842 }
843 
844 static void __exit samsung_exit(void)
845 {
846 	/* Turn off "Linux" mode in the BIOS */
847 	if (sabi_config->commands.set_linux != 0xff)
848 		sabi_set_command(sabi_config->commands.set_linux, 0x80);
849 
850 	device_remove_file(&sdev->dev, &dev_attr_performance_level);
851 	backlight_device_unregister(backlight_device);
852 	destroy_wireless();
853 	iounmap(sabi_iface);
854 	iounmap(f0000_segment);
855 	platform_device_unregister(sdev);
856 }
857 
858 module_init(samsung_init);
859 module_exit(samsung_exit);
860 
861 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@suse.de>");
862 MODULE_DESCRIPTION("Samsung Backlight driver");
863 MODULE_LICENSE("GPL");
864