1 /*
2  *  Copyright (C) 2002 Benjamin Herrenschmidt (benh@kernel.crashing.org)
3  *
4  *  This program is free software; you can redistribute it and/or
5  *  modify it under the terms of the GNU General Public License
6  *  as published by the Free Software Foundation; either version
7  *  2 of the License, or (at your option) any later version.
8  *
9  *  Todo: - add support for the OF persistent properties
10  */
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/stddef.h>
14 #include <linux/string.h>
15 #include <linux/nvram.h>
16 #include <linux/init.h>
17 #include <linux/delay.h>
18 #include <linux/errno.h>
19 #include <linux/adb.h>
20 #include <linux/pmu.h>
21 #include <linux/bootmem.h>
22 #include <linux/completion.h>
23 #include <linux/spinlock.h>
24 #include <asm/sections.h>
25 #include <asm/io.h>
26 #include <asm/system.h>
27 #include <asm/prom.h>
28 #include <asm/machdep.h>
29 #include <asm/nvram.h>
30 
31 #include "pmac.h"
32 
33 #define DEBUG
34 
35 #ifdef DEBUG
36 #define DBG(x...) printk(x)
37 #else
38 #define DBG(x...)
39 #endif
40 
41 #define NVRAM_SIZE		0x2000	/* 8kB of non-volatile RAM */
42 
43 #define CORE99_SIGNATURE	0x5a
44 #define CORE99_ADLER_START	0x14
45 
46 /* On Core99, nvram is either a sharp, a micron or an AMD flash */
47 #define SM_FLASH_STATUS_DONE	0x80
48 #define SM_FLASH_STATUS_ERR	0x38
49 
50 #define SM_FLASH_CMD_ERASE_CONFIRM	0xd0
51 #define SM_FLASH_CMD_ERASE_SETUP	0x20
52 #define SM_FLASH_CMD_RESET		0xff
53 #define SM_FLASH_CMD_WRITE_SETUP	0x40
54 #define SM_FLASH_CMD_CLEAR_STATUS	0x50
55 #define SM_FLASH_CMD_READ_STATUS	0x70
56 
57 /* CHRP NVRAM header */
58 struct chrp_header {
59   u8		signature;
60   u8		cksum;
61   u16		len;
62   char          name[12];
63   u8		data[0];
64 };
65 
66 struct core99_header {
67   struct chrp_header	hdr;
68   u32			adler;
69   u32			generation;
70   u32			reserved[2];
71 };
72 
73 /*
74  * Read and write the non-volatile RAM on PowerMacs and CHRP machines.
75  */
76 static int nvram_naddrs;
77 static volatile unsigned char __iomem *nvram_data;
78 static int is_core_99;
79 static int core99_bank = 0;
80 static int nvram_partitions[3];
81 // XXX Turn that into a sem
82 static DEFINE_RAW_SPINLOCK(nv_lock);
83 
84 static int (*core99_write_bank)(int bank, u8* datas);
85 static int (*core99_erase_bank)(int bank);
86 
87 static char *nvram_image;
88 
89 
90 static unsigned char core99_nvram_read_byte(int addr)
91 {
92 	if (nvram_image == NULL)
93 		return 0xff;
94 	return nvram_image[addr];
95 }
96 
97 static void core99_nvram_write_byte(int addr, unsigned char val)
98 {
99 	if (nvram_image == NULL)
100 		return;
101 	nvram_image[addr] = val;
102 }
103 
104 static ssize_t core99_nvram_read(char *buf, size_t count, loff_t *index)
105 {
106 	int i;
107 
108 	if (nvram_image == NULL)
109 		return -ENODEV;
110 	if (*index > NVRAM_SIZE)
111 		return 0;
112 
113 	i = *index;
114 	if (i + count > NVRAM_SIZE)
115 		count = NVRAM_SIZE - i;
116 
117 	memcpy(buf, &nvram_image[i], count);
118 	*index = i + count;
119 	return count;
120 }
121 
122 static ssize_t core99_nvram_write(char *buf, size_t count, loff_t *index)
123 {
124 	int i;
125 
126 	if (nvram_image == NULL)
127 		return -ENODEV;
128 	if (*index > NVRAM_SIZE)
129 		return 0;
130 
131 	i = *index;
132 	if (i + count > NVRAM_SIZE)
133 		count = NVRAM_SIZE - i;
134 
135 	memcpy(&nvram_image[i], buf, count);
136 	*index = i + count;
137 	return count;
138 }
139 
140 static ssize_t core99_nvram_size(void)
141 {
142 	if (nvram_image == NULL)
143 		return -ENODEV;
144 	return NVRAM_SIZE;
145 }
146 
147 #ifdef CONFIG_PPC32
148 static volatile unsigned char __iomem *nvram_addr;
149 static int nvram_mult;
150 
151 static unsigned char direct_nvram_read_byte(int addr)
152 {
153 	return in_8(&nvram_data[(addr & (NVRAM_SIZE - 1)) * nvram_mult]);
154 }
155 
156 static void direct_nvram_write_byte(int addr, unsigned char val)
157 {
158 	out_8(&nvram_data[(addr & (NVRAM_SIZE - 1)) * nvram_mult], val);
159 }
160 
161 
162 static unsigned char indirect_nvram_read_byte(int addr)
163 {
164 	unsigned char val;
165 	unsigned long flags;
166 
167 	raw_spin_lock_irqsave(&nv_lock, flags);
168 	out_8(nvram_addr, addr >> 5);
169 	val = in_8(&nvram_data[(addr & 0x1f) << 4]);
170 	raw_spin_unlock_irqrestore(&nv_lock, flags);
171 
172 	return val;
173 }
174 
175 static void indirect_nvram_write_byte(int addr, unsigned char val)
176 {
177 	unsigned long flags;
178 
179 	raw_spin_lock_irqsave(&nv_lock, flags);
180 	out_8(nvram_addr, addr >> 5);
181 	out_8(&nvram_data[(addr & 0x1f) << 4], val);
182 	raw_spin_unlock_irqrestore(&nv_lock, flags);
183 }
184 
185 
186 #ifdef CONFIG_ADB_PMU
187 
188 static void pmu_nvram_complete(struct adb_request *req)
189 {
190 	if (req->arg)
191 		complete((struct completion *)req->arg);
192 }
193 
194 static unsigned char pmu_nvram_read_byte(int addr)
195 {
196 	struct adb_request req;
197 	DECLARE_COMPLETION_ONSTACK(req_complete);
198 
199 	req.arg = system_state == SYSTEM_RUNNING ? &req_complete : NULL;
200 	if (pmu_request(&req, pmu_nvram_complete, 3, PMU_READ_NVRAM,
201 			(addr >> 8) & 0xff, addr & 0xff))
202 		return 0xff;
203 	if (system_state == SYSTEM_RUNNING)
204 		wait_for_completion(&req_complete);
205 	while (!req.complete)
206 		pmu_poll();
207 	return req.reply[0];
208 }
209 
210 static void pmu_nvram_write_byte(int addr, unsigned char val)
211 {
212 	struct adb_request req;
213 	DECLARE_COMPLETION_ONSTACK(req_complete);
214 
215 	req.arg = system_state == SYSTEM_RUNNING ? &req_complete : NULL;
216 	if (pmu_request(&req, pmu_nvram_complete, 4, PMU_WRITE_NVRAM,
217 			(addr >> 8) & 0xff, addr & 0xff, val))
218 		return;
219 	if (system_state == SYSTEM_RUNNING)
220 		wait_for_completion(&req_complete);
221 	while (!req.complete)
222 		pmu_poll();
223 }
224 
225 #endif /* CONFIG_ADB_PMU */
226 #endif /* CONFIG_PPC32 */
227 
228 static u8 chrp_checksum(struct chrp_header* hdr)
229 {
230 	u8 *ptr;
231 	u16 sum = hdr->signature;
232 	for (ptr = (u8 *)&hdr->len; ptr < hdr->data; ptr++)
233 		sum += *ptr;
234 	while (sum > 0xFF)
235 		sum = (sum & 0xFF) + (sum>>8);
236 	return sum;
237 }
238 
239 static u32 core99_calc_adler(u8 *buffer)
240 {
241 	int cnt;
242 	u32 low, high;
243 
244    	buffer += CORE99_ADLER_START;
245 	low = 1;
246 	high = 0;
247 	for (cnt=0; cnt<(NVRAM_SIZE-CORE99_ADLER_START); cnt++) {
248 		if ((cnt % 5000) == 0) {
249 			high  %= 65521UL;
250 			high %= 65521UL;
251 		}
252 		low += buffer[cnt];
253 		high += low;
254 	}
255 	low  %= 65521UL;
256 	high %= 65521UL;
257 
258 	return (high << 16) | low;
259 }
260 
261 static u32 core99_check(u8* datas)
262 {
263 	struct core99_header* hdr99 = (struct core99_header*)datas;
264 
265 	if (hdr99->hdr.signature != CORE99_SIGNATURE) {
266 		DBG("Invalid signature\n");
267 		return 0;
268 	}
269 	if (hdr99->hdr.cksum != chrp_checksum(&hdr99->hdr)) {
270 		DBG("Invalid checksum\n");
271 		return 0;
272 	}
273 	if (hdr99->adler != core99_calc_adler(datas)) {
274 		DBG("Invalid adler\n");
275 		return 0;
276 	}
277 	return hdr99->generation;
278 }
279 
280 static int sm_erase_bank(int bank)
281 {
282 	int stat, i;
283 	unsigned long timeout;
284 
285 	u8 __iomem *base = (u8 __iomem *)nvram_data + core99_bank*NVRAM_SIZE;
286 
287        	DBG("nvram: Sharp/Micron Erasing bank %d...\n", bank);
288 
289 	out_8(base, SM_FLASH_CMD_ERASE_SETUP);
290 	out_8(base, SM_FLASH_CMD_ERASE_CONFIRM);
291 	timeout = 0;
292 	do {
293 		if (++timeout > 1000000) {
294 			printk(KERN_ERR "nvram: Sharp/Micron flash erase timeout !\n");
295 			break;
296 		}
297 		out_8(base, SM_FLASH_CMD_READ_STATUS);
298 		stat = in_8(base);
299 	} while (!(stat & SM_FLASH_STATUS_DONE));
300 
301 	out_8(base, SM_FLASH_CMD_CLEAR_STATUS);
302 	out_8(base, SM_FLASH_CMD_RESET);
303 
304 	for (i=0; i<NVRAM_SIZE; i++)
305 		if (base[i] != 0xff) {
306 			printk(KERN_ERR "nvram: Sharp/Micron flash erase failed !\n");
307 			return -ENXIO;
308 		}
309 	return 0;
310 }
311 
312 static int sm_write_bank(int bank, u8* datas)
313 {
314 	int i, stat = 0;
315 	unsigned long timeout;
316 
317 	u8 __iomem *base = (u8 __iomem *)nvram_data + core99_bank*NVRAM_SIZE;
318 
319        	DBG("nvram: Sharp/Micron Writing bank %d...\n", bank);
320 
321 	for (i=0; i<NVRAM_SIZE; i++) {
322 		out_8(base+i, SM_FLASH_CMD_WRITE_SETUP);
323 		udelay(1);
324 		out_8(base+i, datas[i]);
325 		timeout = 0;
326 		do {
327 			if (++timeout > 1000000) {
328 				printk(KERN_ERR "nvram: Sharp/Micron flash write timeout !\n");
329 				break;
330 			}
331 			out_8(base, SM_FLASH_CMD_READ_STATUS);
332 			stat = in_8(base);
333 		} while (!(stat & SM_FLASH_STATUS_DONE));
334 		if (!(stat & SM_FLASH_STATUS_DONE))
335 			break;
336 	}
337 	out_8(base, SM_FLASH_CMD_CLEAR_STATUS);
338 	out_8(base, SM_FLASH_CMD_RESET);
339 	for (i=0; i<NVRAM_SIZE; i++)
340 		if (base[i] != datas[i]) {
341 			printk(KERN_ERR "nvram: Sharp/Micron flash write failed !\n");
342 			return -ENXIO;
343 		}
344 	return 0;
345 }
346 
347 static int amd_erase_bank(int bank)
348 {
349 	int i, stat = 0;
350 	unsigned long timeout;
351 
352 	u8 __iomem *base = (u8 __iomem *)nvram_data + core99_bank*NVRAM_SIZE;
353 
354        	DBG("nvram: AMD Erasing bank %d...\n", bank);
355 
356 	/* Unlock 1 */
357 	out_8(base+0x555, 0xaa);
358 	udelay(1);
359 	/* Unlock 2 */
360 	out_8(base+0x2aa, 0x55);
361 	udelay(1);
362 
363 	/* Sector-Erase */
364 	out_8(base+0x555, 0x80);
365 	udelay(1);
366 	out_8(base+0x555, 0xaa);
367 	udelay(1);
368 	out_8(base+0x2aa, 0x55);
369 	udelay(1);
370 	out_8(base, 0x30);
371 	udelay(1);
372 
373 	timeout = 0;
374 	do {
375 		if (++timeout > 1000000) {
376 			printk(KERN_ERR "nvram: AMD flash erase timeout !\n");
377 			break;
378 		}
379 		stat = in_8(base) ^ in_8(base);
380 	} while (stat != 0);
381 
382 	/* Reset */
383 	out_8(base, 0xf0);
384 	udelay(1);
385 
386 	for (i=0; i<NVRAM_SIZE; i++)
387 		if (base[i] != 0xff) {
388 			printk(KERN_ERR "nvram: AMD flash erase failed !\n");
389 			return -ENXIO;
390 		}
391 	return 0;
392 }
393 
394 static int amd_write_bank(int bank, u8* datas)
395 {
396 	int i, stat = 0;
397 	unsigned long timeout;
398 
399 	u8 __iomem *base = (u8 __iomem *)nvram_data + core99_bank*NVRAM_SIZE;
400 
401        	DBG("nvram: AMD Writing bank %d...\n", bank);
402 
403 	for (i=0; i<NVRAM_SIZE; i++) {
404 		/* Unlock 1 */
405 		out_8(base+0x555, 0xaa);
406 		udelay(1);
407 		/* Unlock 2 */
408 		out_8(base+0x2aa, 0x55);
409 		udelay(1);
410 
411 		/* Write single word */
412 		out_8(base+0x555, 0xa0);
413 		udelay(1);
414 		out_8(base+i, datas[i]);
415 
416 		timeout = 0;
417 		do {
418 			if (++timeout > 1000000) {
419 				printk(KERN_ERR "nvram: AMD flash write timeout !\n");
420 				break;
421 			}
422 			stat = in_8(base) ^ in_8(base);
423 		} while (stat != 0);
424 		if (stat != 0)
425 			break;
426 	}
427 
428 	/* Reset */
429 	out_8(base, 0xf0);
430 	udelay(1);
431 
432 	for (i=0; i<NVRAM_SIZE; i++)
433 		if (base[i] != datas[i]) {
434 			printk(KERN_ERR "nvram: AMD flash write failed !\n");
435 			return -ENXIO;
436 		}
437 	return 0;
438 }
439 
440 static void __init lookup_partitions(void)
441 {
442 	u8 buffer[17];
443 	int i, offset;
444 	struct chrp_header* hdr;
445 
446 	if (pmac_newworld) {
447 		nvram_partitions[pmac_nvram_OF] = -1;
448 		nvram_partitions[pmac_nvram_XPRAM] = -1;
449 		nvram_partitions[pmac_nvram_NR] = -1;
450 		hdr = (struct chrp_header *)buffer;
451 
452 		offset = 0;
453 		buffer[16] = 0;
454 		do {
455 			for (i=0;i<16;i++)
456 				buffer[i] = ppc_md.nvram_read_val(offset+i);
457 			if (!strcmp(hdr->name, "common"))
458 				nvram_partitions[pmac_nvram_OF] = offset + 0x10;
459 			if (!strcmp(hdr->name, "APL,MacOS75")) {
460 				nvram_partitions[pmac_nvram_XPRAM] = offset + 0x10;
461 				nvram_partitions[pmac_nvram_NR] = offset + 0x110;
462 			}
463 			offset += (hdr->len * 0x10);
464 		} while(offset < NVRAM_SIZE);
465 	} else {
466 		nvram_partitions[pmac_nvram_OF] = 0x1800;
467 		nvram_partitions[pmac_nvram_XPRAM] = 0x1300;
468 		nvram_partitions[pmac_nvram_NR] = 0x1400;
469 	}
470 	DBG("nvram: OF partition at 0x%x\n", nvram_partitions[pmac_nvram_OF]);
471 	DBG("nvram: XP partition at 0x%x\n", nvram_partitions[pmac_nvram_XPRAM]);
472 	DBG("nvram: NR partition at 0x%x\n", nvram_partitions[pmac_nvram_NR]);
473 }
474 
475 static void core99_nvram_sync(void)
476 {
477 	struct core99_header* hdr99;
478 	unsigned long flags;
479 
480 	if (!is_core_99 || !nvram_data || !nvram_image)
481 		return;
482 
483 	raw_spin_lock_irqsave(&nv_lock, flags);
484 	if (!memcmp(nvram_image, (u8*)nvram_data + core99_bank*NVRAM_SIZE,
485 		NVRAM_SIZE))
486 		goto bail;
487 
488 	DBG("Updating nvram...\n");
489 
490 	hdr99 = (struct core99_header*)nvram_image;
491 	hdr99->generation++;
492 	hdr99->hdr.signature = CORE99_SIGNATURE;
493 	hdr99->hdr.cksum = chrp_checksum(&hdr99->hdr);
494 	hdr99->adler = core99_calc_adler(nvram_image);
495 	core99_bank = core99_bank ? 0 : 1;
496 	if (core99_erase_bank)
497 		if (core99_erase_bank(core99_bank)) {
498 			printk("nvram: Error erasing bank %d\n", core99_bank);
499 			goto bail;
500 		}
501 	if (core99_write_bank)
502 		if (core99_write_bank(core99_bank, nvram_image))
503 			printk("nvram: Error writing bank %d\n", core99_bank);
504  bail:
505 	raw_spin_unlock_irqrestore(&nv_lock, flags);
506 
507 #ifdef DEBUG
508        	mdelay(2000);
509 #endif
510 }
511 
512 static int __init core99_nvram_setup(struct device_node *dp, unsigned long addr)
513 {
514 	int i;
515 	u32 gen_bank0, gen_bank1;
516 
517 	if (nvram_naddrs < 1) {
518 		printk(KERN_ERR "nvram: no address\n");
519 		return -EINVAL;
520 	}
521 	nvram_image = alloc_bootmem(NVRAM_SIZE);
522 	if (nvram_image == NULL) {
523 		printk(KERN_ERR "nvram: can't allocate ram image\n");
524 		return -ENOMEM;
525 	}
526 	nvram_data = ioremap(addr, NVRAM_SIZE*2);
527 	nvram_naddrs = 1; /* Make sure we get the correct case */
528 
529 	DBG("nvram: Checking bank 0...\n");
530 
531 	gen_bank0 = core99_check((u8 *)nvram_data);
532 	gen_bank1 = core99_check((u8 *)nvram_data + NVRAM_SIZE);
533 	core99_bank = (gen_bank0 < gen_bank1) ? 1 : 0;
534 
535 	DBG("nvram: gen0=%d, gen1=%d\n", gen_bank0, gen_bank1);
536 	DBG("nvram: Active bank is: %d\n", core99_bank);
537 
538 	for (i=0; i<NVRAM_SIZE; i++)
539 		nvram_image[i] = nvram_data[i + core99_bank*NVRAM_SIZE];
540 
541 	ppc_md.nvram_read_val	= core99_nvram_read_byte;
542 	ppc_md.nvram_write_val	= core99_nvram_write_byte;
543 	ppc_md.nvram_read	= core99_nvram_read;
544 	ppc_md.nvram_write	= core99_nvram_write;
545 	ppc_md.nvram_size	= core99_nvram_size;
546 	ppc_md.nvram_sync	= core99_nvram_sync;
547 	ppc_md.machine_shutdown	= core99_nvram_sync;
548 	/*
549 	 * Maybe we could be smarter here though making an exclusive list
550 	 * of known flash chips is a bit nasty as older OF didn't provide us
551 	 * with a useful "compatible" entry. A solution would be to really
552 	 * identify the chip using flash id commands and base ourselves on
553 	 * a list of known chips IDs
554 	 */
555 	if (of_device_is_compatible(dp, "amd-0137")) {
556 		core99_erase_bank = amd_erase_bank;
557 		core99_write_bank = amd_write_bank;
558 	} else {
559 		core99_erase_bank = sm_erase_bank;
560 		core99_write_bank = sm_write_bank;
561 	}
562 	return 0;
563 }
564 
565 int __init pmac_nvram_init(void)
566 {
567 	struct device_node *dp;
568 	struct resource r1, r2;
569 	unsigned int s1 = 0, s2 = 0;
570 	int err = 0;
571 
572 	nvram_naddrs = 0;
573 
574 	dp = of_find_node_by_name(NULL, "nvram");
575 	if (dp == NULL) {
576 		printk(KERN_ERR "Can't find NVRAM device\n");
577 		return -ENODEV;
578 	}
579 
580 	/* Try to obtain an address */
581 	if (of_address_to_resource(dp, 0, &r1) == 0) {
582 		nvram_naddrs = 1;
583 		s1 = (r1.end - r1.start) + 1;
584 		if (of_address_to_resource(dp, 1, &r2) == 0) {
585 			nvram_naddrs = 2;
586 			s2 = (r2.end - r2.start) + 1;
587 		}
588 	}
589 
590 	is_core_99 = of_device_is_compatible(dp, "nvram,flash");
591 	if (is_core_99) {
592 		err = core99_nvram_setup(dp, r1.start);
593 		goto bail;
594 	}
595 
596 #ifdef CONFIG_PPC32
597 	if (machine_is(chrp) && nvram_naddrs == 1) {
598 		nvram_data = ioremap(r1.start, s1);
599 		nvram_mult = 1;
600 		ppc_md.nvram_read_val	= direct_nvram_read_byte;
601 		ppc_md.nvram_write_val	= direct_nvram_write_byte;
602 	} else if (nvram_naddrs == 1) {
603 		nvram_data = ioremap(r1.start, s1);
604 		nvram_mult = (s1 + NVRAM_SIZE - 1) / NVRAM_SIZE;
605 		ppc_md.nvram_read_val	= direct_nvram_read_byte;
606 		ppc_md.nvram_write_val	= direct_nvram_write_byte;
607 	} else if (nvram_naddrs == 2) {
608 		nvram_addr = ioremap(r1.start, s1);
609 		nvram_data = ioremap(r2.start, s2);
610 		ppc_md.nvram_read_val	= indirect_nvram_read_byte;
611 		ppc_md.nvram_write_val	= indirect_nvram_write_byte;
612 	} else if (nvram_naddrs == 0 && sys_ctrler == SYS_CTRLER_PMU) {
613 #ifdef CONFIG_ADB_PMU
614 		nvram_naddrs = -1;
615 		ppc_md.nvram_read_val	= pmu_nvram_read_byte;
616 		ppc_md.nvram_write_val	= pmu_nvram_write_byte;
617 #endif /* CONFIG_ADB_PMU */
618 	} else {
619 		printk(KERN_ERR "Incompatible type of NVRAM\n");
620 		err = -ENXIO;
621 	}
622 #endif /* CONFIG_PPC32 */
623 bail:
624 	of_node_put(dp);
625 	if (err == 0)
626 		lookup_partitions();
627 	return err;
628 }
629 
630 int pmac_get_partition(int partition)
631 {
632 	return nvram_partitions[partition];
633 }
634 
635 u8 pmac_xpram_read(int xpaddr)
636 {
637 	int offset = pmac_get_partition(pmac_nvram_XPRAM);
638 
639 	if (offset < 0 || xpaddr < 0 || xpaddr > 0x100)
640 		return 0xff;
641 
642 	return ppc_md.nvram_read_val(xpaddr + offset);
643 }
644 
645 void pmac_xpram_write(int xpaddr, u8 data)
646 {
647 	int offset = pmac_get_partition(pmac_nvram_XPRAM);
648 
649 	if (offset < 0 || xpaddr < 0 || xpaddr > 0x100)
650 		return;
651 
652 	ppc_md.nvram_write_val(xpaddr + offset, data);
653 }
654 
655 EXPORT_SYMBOL(pmac_get_partition);
656 EXPORT_SYMBOL(pmac_xpram_read);
657 EXPORT_SYMBOL(pmac_xpram_write);
658