1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7  * Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
8  */
9 
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/platform_device.h>
14 #include <linux/mtd/mtd.h>
15 #include <linux/mtd/partitions.h>
16 #include <linux/mtd/physmap.h>
17 #include <linux/ssb/ssb.h>
18 #include <asm/addrspace.h>
19 #include <bcm63xx_board.h>
20 #include <bcm63xx_cpu.h>
21 #include <bcm63xx_regs.h>
22 #include <bcm63xx_io.h>
23 #include <bcm63xx_dev_pci.h>
24 #include <bcm63xx_dev_enet.h>
25 #include <bcm63xx_dev_dsp.h>
26 #include <bcm63xx_dev_pcmcia.h>
27 #include <bcm63xx_dev_uart.h>
28 #include <board_bcm963xx.h>
29 
30 #define PFX	"board_bcm963xx: "
31 
32 static struct bcm963xx_nvram nvram;
33 static unsigned int mac_addr_used;
34 static struct board_info board;
35 
36 /*
37  * known 6338 boards
38  */
39 #ifdef CONFIG_BCM63XX_CPU_6338
40 static struct board_info __initdata board_96338gw = {
41 	.name				= "96338GW",
42 	.expected_cpu_id		= 0x6338,
43 
44 	.has_enet0			= 1,
45 	.enet0 = {
46 		.force_speed_100	= 1,
47 		.force_duplex_full	= 1,
48 	},
49 
50 	.has_ohci0			= 1,
51 
52 	.leds = {
53 		{
54 			.name		= "adsl",
55 			.gpio		= 3,
56 			.active_low	= 1,
57 		},
58 		{
59 			.name		= "ses",
60 			.gpio		= 5,
61 			.active_low	= 1,
62 		},
63 		{
64 			.name		= "ppp-fail",
65 			.gpio		= 4,
66 			.active_low	= 1,
67 		},
68 		{
69 			.name		= "power",
70 			.gpio		= 0,
71 			.active_low	= 1,
72 			.default_trigger = "default-on",
73 		},
74 		{
75 			.name		= "stop",
76 			.gpio		= 1,
77 			.active_low	= 1,
78 		}
79 	},
80 };
81 
82 static struct board_info __initdata board_96338w = {
83 	.name				= "96338W",
84 	.expected_cpu_id		= 0x6338,
85 
86 	.has_enet0			= 1,
87 	.enet0 = {
88 		.force_speed_100	= 1,
89 		.force_duplex_full	= 1,
90 	},
91 
92 	.leds = {
93 		{
94 			.name		= "adsl",
95 			.gpio		= 3,
96 			.active_low	= 1,
97 		},
98 		{
99 			.name		= "ses",
100 			.gpio		= 5,
101 			.active_low	= 1,
102 		},
103 		{
104 			.name		= "ppp-fail",
105 			.gpio		= 4,
106 			.active_low	= 1,
107 		},
108 		{
109 			.name		= "power",
110 			.gpio		= 0,
111 			.active_low	= 1,
112 			.default_trigger = "default-on",
113 		},
114 		{
115 			.name		= "stop",
116 			.gpio		= 1,
117 			.active_low	= 1,
118 		},
119 	},
120 };
121 #endif
122 
123 /*
124  * known 6345 boards
125  */
126 #ifdef CONFIG_BCM63XX_CPU_6345
127 static struct board_info __initdata board_96345gw2 = {
128 	.name				= "96345GW2",
129 	.expected_cpu_id		= 0x6345,
130 };
131 #endif
132 
133 /*
134  * known 6348 boards
135  */
136 #ifdef CONFIG_BCM63XX_CPU_6348
137 static struct board_info __initdata board_96348r = {
138 	.name				= "96348R",
139 	.expected_cpu_id		= 0x6348,
140 
141 	.has_enet0			= 1,
142 	.has_pci			= 1,
143 
144 	.enet0 = {
145 		.has_phy		= 1,
146 		.use_internal_phy	= 1,
147 	},
148 
149 	.leds = {
150 		{
151 			.name		= "adsl-fail",
152 			.gpio		= 2,
153 			.active_low	= 1,
154 		},
155 		{
156 			.name		= "ppp",
157 			.gpio		= 3,
158 			.active_low	= 1,
159 		},
160 		{
161 			.name		= "ppp-fail",
162 			.gpio		= 4,
163 			.active_low	= 1,
164 		},
165 		{
166 			.name		= "power",
167 			.gpio		= 0,
168 			.active_low	= 1,
169 			.default_trigger = "default-on",
170 
171 		},
172 		{
173 			.name		= "stop",
174 			.gpio		= 1,
175 			.active_low	= 1,
176 		},
177 	},
178 };
179 
180 static struct board_info __initdata board_96348gw_10 = {
181 	.name				= "96348GW-10",
182 	.expected_cpu_id		= 0x6348,
183 
184 	.has_enet0			= 1,
185 	.has_enet1			= 1,
186 	.has_pci			= 1,
187 
188 	.enet0 = {
189 		.has_phy		= 1,
190 		.use_internal_phy	= 1,
191 	},
192 	.enet1 = {
193 		.force_speed_100	= 1,
194 		.force_duplex_full	= 1,
195 	},
196 
197 	.has_ohci0			= 1,
198 	.has_pccard			= 1,
199 	.has_ehci0			= 1,
200 
201 	.has_dsp			= 1,
202 	.dsp = {
203 		.gpio_rst		= 6,
204 		.gpio_int		= 34,
205 		.cs			= 2,
206 		.ext_irq		= 2,
207 	},
208 
209 	.leds = {
210 		{
211 			.name		= "adsl-fail",
212 			.gpio		= 2,
213 			.active_low	= 1,
214 		},
215 		{
216 			.name		= "ppp",
217 			.gpio		= 3,
218 			.active_low	= 1,
219 		},
220 		{
221 			.name		= "ppp-fail",
222 			.gpio		= 4,
223 			.active_low	= 1,
224 		},
225 		{
226 			.name		= "power",
227 			.gpio		= 0,
228 			.active_low	= 1,
229 			.default_trigger = "default-on",
230 		},
231 		{
232 			.name		= "stop",
233 			.gpio		= 1,
234 			.active_low	= 1,
235 		},
236 	},
237 };
238 
239 static struct board_info __initdata board_96348gw_11 = {
240 	.name				= "96348GW-11",
241 	.expected_cpu_id		= 0x6348,
242 
243 	.has_enet0			= 1,
244 	.has_enet1			= 1,
245 	.has_pci			= 1,
246 
247 	.enet0 = {
248 		.has_phy		= 1,
249 		.use_internal_phy	= 1,
250 	},
251 
252 	.enet1 = {
253 		.force_speed_100	= 1,
254 		.force_duplex_full	= 1,
255 	},
256 
257 
258 	.has_ohci0 = 1,
259 	.has_pccard = 1,
260 	.has_ehci0 = 1,
261 
262 	.leds = {
263 		{
264 			.name		= "adsl-fail",
265 			.gpio		= 2,
266 			.active_low	= 1,
267 		},
268 		{
269 			.name		= "ppp",
270 			.gpio		= 3,
271 			.active_low	= 1,
272 		},
273 		{
274 			.name		= "ppp-fail",
275 			.gpio		= 4,
276 			.active_low	= 1,
277 		},
278 		{
279 			.name		= "power",
280 			.gpio		= 0,
281 			.active_low	= 1,
282 			.default_trigger = "default-on",
283 		},
284 		{
285 			.name		= "stop",
286 			.gpio		= 1,
287 			.active_low	= 1,
288 		},
289 	},
290 };
291 
292 static struct board_info __initdata board_96348gw = {
293 	.name				= "96348GW",
294 	.expected_cpu_id		= 0x6348,
295 
296 	.has_enet0			= 1,
297 	.has_enet1			= 1,
298 	.has_pci			= 1,
299 
300 	.enet0 = {
301 		.has_phy		= 1,
302 		.use_internal_phy	= 1,
303 	},
304 	.enet1 = {
305 		.force_speed_100	= 1,
306 		.force_duplex_full	= 1,
307 	},
308 
309 	.has_ohci0 = 1,
310 
311 	.has_dsp			= 1,
312 	.dsp = {
313 		.gpio_rst		= 6,
314 		.gpio_int		= 34,
315 		.ext_irq		= 2,
316 		.cs			= 2,
317 	},
318 
319 	.leds = {
320 		{
321 			.name		= "adsl-fail",
322 			.gpio		= 2,
323 			.active_low	= 1,
324 		},
325 		{
326 			.name		= "ppp",
327 			.gpio		= 3,
328 			.active_low	= 1,
329 		},
330 		{
331 			.name		= "ppp-fail",
332 			.gpio		= 4,
333 			.active_low	= 1,
334 		},
335 		{
336 			.name		= "power",
337 			.gpio		= 0,
338 			.active_low	= 1,
339 			.default_trigger = "default-on",
340 		},
341 		{
342 			.name		= "stop",
343 			.gpio		= 1,
344 			.active_low	= 1,
345 		},
346 	},
347 };
348 
349 static struct board_info __initdata board_FAST2404 = {
350         .name                           = "F@ST2404",
351         .expected_cpu_id                = 0x6348,
352 
353         .has_enet0                      = 1,
354         .has_enet1                      = 1,
355         .has_pci                        = 1,
356 
357         .enet0 = {
358                 .has_phy                = 1,
359                 .use_internal_phy       = 1,
360         },
361 
362         .enet1 = {
363                 .force_speed_100        = 1,
364                 .force_duplex_full      = 1,
365         },
366 
367 
368         .has_ohci0 = 1,
369         .has_pccard = 1,
370         .has_ehci0 = 1,
371 };
372 
373 static struct board_info __initdata board_DV201AMR = {
374 	.name				= "DV201AMR",
375 	.expected_cpu_id		= 0x6348,
376 
377 	.has_pci			= 1,
378 	.has_ohci0			= 1,
379 
380 	.has_enet0			= 1,
381 	.has_enet1			= 1,
382 	.enet0 = {
383 		.has_phy		= 1,
384 		.use_internal_phy	= 1,
385 	},
386 	.enet1 = {
387 		.force_speed_100	= 1,
388 		.force_duplex_full	= 1,
389 	},
390 };
391 
392 static struct board_info __initdata board_96348gw_a = {
393 	.name				= "96348GW-A",
394 	.expected_cpu_id		= 0x6348,
395 
396 	.has_enet0			= 1,
397 	.has_enet1			= 1,
398 	.has_pci			= 1,
399 
400 	.enet0 = {
401 		.has_phy		= 1,
402 		.use_internal_phy	= 1,
403 	},
404 	.enet1 = {
405 		.force_speed_100	= 1,
406 		.force_duplex_full	= 1,
407 	},
408 
409 	.has_ohci0 = 1,
410 };
411 #endif
412 
413 /*
414  * known 6358 boards
415  */
416 #ifdef CONFIG_BCM63XX_CPU_6358
417 static struct board_info __initdata board_96358vw = {
418 	.name				= "96358VW",
419 	.expected_cpu_id		= 0x6358,
420 
421 	.has_enet0			= 1,
422 	.has_enet1			= 1,
423 	.has_pci			= 1,
424 
425 	.enet0 = {
426 		.has_phy		= 1,
427 		.use_internal_phy	= 1,
428 	},
429 
430 	.enet1 = {
431 		.force_speed_100	= 1,
432 		.force_duplex_full	= 1,
433 	},
434 
435 
436 	.has_ohci0 = 1,
437 	.has_pccard = 1,
438 	.has_ehci0 = 1,
439 
440 	.leds = {
441 		{
442 			.name		= "adsl-fail",
443 			.gpio		= 15,
444 			.active_low	= 1,
445 		},
446 		{
447 			.name		= "ppp",
448 			.gpio		= 22,
449 			.active_low	= 1,
450 		},
451 		{
452 			.name		= "ppp-fail",
453 			.gpio		= 23,
454 			.active_low	= 1,
455 		},
456 		{
457 			.name		= "power",
458 			.gpio		= 4,
459 			.default_trigger = "default-on",
460 		},
461 		{
462 			.name		= "stop",
463 			.gpio		= 5,
464 		},
465 	},
466 };
467 
468 static struct board_info __initdata board_96358vw2 = {
469 	.name				= "96358VW2",
470 	.expected_cpu_id		= 0x6358,
471 
472 	.has_enet0			= 1,
473 	.has_enet1			= 1,
474 	.has_pci			= 1,
475 
476 	.enet0 = {
477 		.has_phy		= 1,
478 		.use_internal_phy	= 1,
479 	},
480 
481 	.enet1 = {
482 		.force_speed_100	= 1,
483 		.force_duplex_full	= 1,
484 	},
485 
486 
487 	.has_ohci0 = 1,
488 	.has_pccard = 1,
489 	.has_ehci0 = 1,
490 
491 	.leds = {
492 		{
493 			.name		= "adsl",
494 			.gpio		= 22,
495 			.active_low	= 1,
496 		},
497 		{
498 			.name		= "ppp-fail",
499 			.gpio		= 23,
500 		},
501 		{
502 			.name		= "power",
503 			.gpio		= 5,
504 			.active_low	= 1,
505 			.default_trigger = "default-on",
506 		},
507 		{
508 			.name		= "stop",
509 			.gpio		= 4,
510 			.active_low	= 1,
511 		},
512 	},
513 };
514 
515 static struct board_info __initdata board_AGPFS0 = {
516 	.name                           = "AGPF-S0",
517 	.expected_cpu_id                = 0x6358,
518 
519 	.has_enet0                      = 1,
520 	.has_enet1                      = 1,
521 	.has_pci                        = 1,
522 
523 	.enet0 = {
524 		.has_phy                = 1,
525 		.use_internal_phy       = 1,
526 	},
527 
528 	.enet1 = {
529 		.force_speed_100        = 1,
530 		.force_duplex_full      = 1,
531 	},
532 
533 	.has_ohci0 = 1,
534 	.has_ehci0 = 1,
535 };
536 #endif
537 
538 /*
539  * all boards
540  */
541 static const struct board_info __initdata *bcm963xx_boards[] = {
542 #ifdef CONFIG_BCM63XX_CPU_6338
543 	&board_96338gw,
544 	&board_96338w,
545 #endif
546 #ifdef CONFIG_BCM63XX_CPU_6345
547 	&board_96345gw2,
548 #endif
549 #ifdef CONFIG_BCM63XX_CPU_6348
550 	&board_96348r,
551 	&board_96348gw,
552 	&board_96348gw_10,
553 	&board_96348gw_11,
554 	&board_FAST2404,
555 	&board_DV201AMR,
556 	&board_96348gw_a,
557 #endif
558 
559 #ifdef CONFIG_BCM63XX_CPU_6358
560 	&board_96358vw,
561 	&board_96358vw2,
562 	&board_AGPFS0,
563 #endif
564 };
565 
566 /*
567  * early init callback, read nvram data from flash and checksum it
568  */
569 void __init board_prom_init(void)
570 {
571 	unsigned int check_len, i;
572 	u8 *boot_addr, *cfe, *p;
573 	char cfe_version[32];
574 	u32 val;
575 
576 	/* read base address of boot chip select (0)
577 	 * 6345 does not have MPI but boots from standard
578 	 * MIPS Flash address */
579 	if (BCMCPU_IS_6345())
580 		val = 0x1fc00000;
581 	else {
582 		val = bcm_mpi_readl(MPI_CSBASE_REG(0));
583 		val &= MPI_CSBASE_BASE_MASK;
584 	}
585 	boot_addr = (u8 *)KSEG1ADDR(val);
586 
587 	/* dump cfe version */
588 	cfe = boot_addr + BCM963XX_CFE_VERSION_OFFSET;
589 	if (!memcmp(cfe, "cfe-v", 5))
590 		snprintf(cfe_version, sizeof(cfe_version), "%u.%u.%u-%u.%u",
591 			 cfe[5], cfe[6], cfe[7], cfe[8], cfe[9]);
592 	else
593 		strcpy(cfe_version, "unknown");
594 	printk(KERN_INFO PFX "CFE version: %s\n", cfe_version);
595 
596 	/* extract nvram data */
597 	memcpy(&nvram, boot_addr + BCM963XX_NVRAM_OFFSET, sizeof(nvram));
598 
599 	/* check checksum before using data */
600 	if (nvram.version <= 4)
601 		check_len = offsetof(struct bcm963xx_nvram, checksum_old);
602 	else
603 		check_len = sizeof(nvram);
604 	val = 0;
605 	p = (u8 *)&nvram;
606 	while (check_len--)
607 		val += *p;
608 	if (val) {
609 		printk(KERN_ERR PFX "invalid nvram checksum\n");
610 		return;
611 	}
612 
613 	/* find board by name */
614 	for (i = 0; i < ARRAY_SIZE(bcm963xx_boards); i++) {
615 		if (strncmp(nvram.name, bcm963xx_boards[i]->name,
616 			    sizeof(nvram.name)))
617 			continue;
618 		/* copy, board desc array is marked initdata */
619 		memcpy(&board, bcm963xx_boards[i], sizeof(board));
620 		break;
621 	}
622 
623 	/* bail out if board is not found, will complain later */
624 	if (!board.name[0]) {
625 		char name[17];
626 		memcpy(name, nvram.name, 16);
627 		name[16] = 0;
628 		printk(KERN_ERR PFX "unknown bcm963xx board: %s\n",
629 		       name);
630 		return;
631 	}
632 
633 	/* setup pin multiplexing depending on board enabled device,
634 	 * this has to be done this early since PCI init is done
635 	 * inside arch_initcall */
636 	val = 0;
637 
638 #ifdef CONFIG_PCI
639 	if (board.has_pci) {
640 		bcm63xx_pci_enabled = 1;
641 		if (BCMCPU_IS_6348())
642 			val |= GPIO_MODE_6348_G2_PCI;
643 	}
644 #endif
645 
646 	if (board.has_pccard) {
647 		if (BCMCPU_IS_6348())
648 			val |= GPIO_MODE_6348_G1_MII_PCCARD;
649 	}
650 
651 	if (board.has_enet0 && !board.enet0.use_internal_phy) {
652 		if (BCMCPU_IS_6348())
653 			val |= GPIO_MODE_6348_G3_EXT_MII |
654 				GPIO_MODE_6348_G0_EXT_MII;
655 	}
656 
657 	if (board.has_enet1 && !board.enet1.use_internal_phy) {
658 		if (BCMCPU_IS_6348())
659 			val |= GPIO_MODE_6348_G3_EXT_MII |
660 				GPIO_MODE_6348_G0_EXT_MII;
661 	}
662 
663 	bcm_gpio_writel(val, GPIO_MODE_REG);
664 }
665 
666 /*
667  * second stage init callback, good time to panic if we couldn't
668  * identify on which board we're running since early printk is working
669  */
670 void __init board_setup(void)
671 {
672 	if (!board.name[0])
673 		panic("unable to detect bcm963xx board");
674 	printk(KERN_INFO PFX "board name: %s\n", board.name);
675 
676 	/* make sure we're running on expected cpu */
677 	if (bcm63xx_get_cpu_id() != board.expected_cpu_id)
678 		panic("unexpected CPU for bcm963xx board");
679 }
680 
681 /*
682  * return board name for /proc/cpuinfo
683  */
684 const char *board_get_name(void)
685 {
686 	return board.name;
687 }
688 
689 /*
690  * register & return a new board mac address
691  */
692 static int board_get_mac_address(u8 *mac)
693 {
694 	u8 *p;
695 	int count;
696 
697 	if (mac_addr_used >= nvram.mac_addr_count) {
698 		printk(KERN_ERR PFX "not enough mac address\n");
699 		return -ENODEV;
700 	}
701 
702 	memcpy(mac, nvram.mac_addr_base, ETH_ALEN);
703 	p = mac + ETH_ALEN - 1;
704 	count = mac_addr_used;
705 
706 	while (count--) {
707 		do {
708 			(*p)++;
709 			if (*p != 0)
710 				break;
711 			p--;
712 		} while (p != mac);
713 	}
714 
715 	if (p == mac) {
716 		printk(KERN_ERR PFX "unable to fetch mac address\n");
717 		return -ENODEV;
718 	}
719 
720 	mac_addr_used++;
721 	return 0;
722 }
723 
724 static struct mtd_partition mtd_partitions[] = {
725 	{
726 		.name		= "cfe",
727 		.offset		= 0x0,
728 		.size		= 0x40000,
729 	}
730 };
731 
732 static struct physmap_flash_data flash_data = {
733 	.width			= 2,
734 	.nr_parts		= ARRAY_SIZE(mtd_partitions),
735 	.parts			= mtd_partitions,
736 };
737 
738 static struct resource mtd_resources[] = {
739 	{
740 		.start		= 0,	/* filled at runtime */
741 		.end		= 0,	/* filled at runtime */
742 		.flags		= IORESOURCE_MEM,
743 	}
744 };
745 
746 static struct platform_device mtd_dev = {
747 	.name			= "physmap-flash",
748 	.resource		= mtd_resources,
749 	.num_resources		= ARRAY_SIZE(mtd_resources),
750 	.dev			= {
751 		.platform_data	= &flash_data,
752 	},
753 };
754 
755 /*
756  * Register a sane SPROMv2 to make the on-board
757  * bcm4318 WLAN work
758  */
759 #ifdef CONFIG_SSB_PCIHOST
760 static struct ssb_sprom bcm63xx_sprom = {
761 	.revision		= 0x02,
762 	.board_rev		= 0x17,
763 	.country_code		= 0x0,
764 	.ant_available_bg 	= 0x3,
765 	.pa0b0			= 0x15ae,
766 	.pa0b1			= 0xfa85,
767 	.pa0b2			= 0xfe8d,
768 	.pa1b0			= 0xffff,
769 	.pa1b1			= 0xffff,
770 	.pa1b2			= 0xffff,
771 	.gpio0			= 0xff,
772 	.gpio1			= 0xff,
773 	.gpio2			= 0xff,
774 	.gpio3			= 0xff,
775 	.maxpwr_bg		= 0x004c,
776 	.itssi_bg		= 0x00,
777 	.boardflags_lo		= 0x2848,
778 	.boardflags_hi		= 0x0000,
779 };
780 #endif
781 
782 static struct gpio_led_platform_data bcm63xx_led_data;
783 
784 static struct platform_device bcm63xx_gpio_leds = {
785 	.name			= "leds-gpio",
786 	.id			= 0,
787 	.dev.platform_data	= &bcm63xx_led_data,
788 };
789 
790 /*
791  * third stage init callback, register all board devices.
792  */
793 int __init board_register_devices(void)
794 {
795 	u32 val;
796 
797 	bcm63xx_uart_register();
798 
799 	if (board.has_pccard)
800 		bcm63xx_pcmcia_register();
801 
802 	if (board.has_enet0 &&
803 	    !board_get_mac_address(board.enet0.mac_addr))
804 		bcm63xx_enet_register(0, &board.enet0);
805 
806 	if (board.has_enet1 &&
807 	    !board_get_mac_address(board.enet1.mac_addr))
808 		bcm63xx_enet_register(1, &board.enet1);
809 
810 	if (board.has_dsp)
811 		bcm63xx_dsp_register(&board.dsp);
812 
813 	/* Generate MAC address for WLAN and
814 	 * register our SPROM */
815 #ifdef CONFIG_SSB_PCIHOST
816 	if (!board_get_mac_address(bcm63xx_sprom.il0mac)) {
817 		memcpy(bcm63xx_sprom.et0mac, bcm63xx_sprom.il0mac, ETH_ALEN);
818 		memcpy(bcm63xx_sprom.et1mac, bcm63xx_sprom.il0mac, ETH_ALEN);
819 		if (ssb_arch_set_fallback_sprom(&bcm63xx_sprom) < 0)
820 			printk(KERN_ERR "failed to register fallback SPROM\n");
821 	}
822 #endif
823 
824 	/* read base address of boot chip select (0) */
825 	if (BCMCPU_IS_6345())
826 		val = 0x1fc00000;
827 	else {
828 		val = bcm_mpi_readl(MPI_CSBASE_REG(0));
829 		val &= MPI_CSBASE_BASE_MASK;
830 	}
831 	mtd_resources[0].start = val;
832 	mtd_resources[0].end = 0x1FFFFFFF;
833 
834 	platform_device_register(&mtd_dev);
835 
836 	bcm63xx_led_data.num_leds = ARRAY_SIZE(board.leds);
837 	bcm63xx_led_data.leds = board.leds;
838 
839 	platform_device_register(&bcm63xx_gpio_leds);
840 
841 	return 0;
842 }
843 
844