aboutsummaryrefslogtreecommitdiffstats
path: root/arch/ppc64/kernel/pmac_nvram.c
blob: 11586d535f8103096ecf92fc4f491c7c70dabdf2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
/*
 *  arch/ppc/platforms/pmac_nvram.c
 *
 *  Copyright (C) 2002 Benjamin Herrenschmidt (benh@kernel.crashing.org)
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 *  Todo: - add support for the OF persistent properties
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/bootmem.h>
#include <linux/completion.h>
#include <linux/spinlock.h>
#include <asm/sections.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/nvram.h>

#define DEBUG

#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif

#define NVRAM_SIZE		0x2000	/* 8kB of non-volatile RAM */

#define CORE99_SIGNATURE	0x5a
#define CORE99_ADLER_START	0x14

/* On Core99, nvram is either a sharp, a micron or an AMD flash */
#define SM_FLASH_STATUS_DONE	0x80
#define SM_FLASH_STATUS_ERR	0x38

#define SM_FLASH_CMD_ERASE_CONFIRM	0xd0
#define SM_FLASH_CMD_ERASE_SETUP	0x20
#define SM_FLASH_CMD_RESET		0xff
#define SM_FLASH_CMD_WRITE_SETUP	0x40
#define SM_FLASH_CMD_CLEAR_STATUS	0x50
#define SM_FLASH_CMD_READ_STATUS	0x70

/* CHRP NVRAM header */
struct chrp_header {
  u8		signature;
  u8		cksum;
  u16		len;
  char          name[12];
  u8		data[0];
};

struct core99_header {
  struct chrp_header	hdr;
  u32			adler;
  u32			generation;
  u32			reserved[2];
};

/*
 * Read and write the non-volatile RAM on PowerMacs and CHRP machines.
 */
static volatile unsigned char *nvram_data;
static int core99_bank = 0;
// XXX Turn that into a sem
static DEFINE_SPINLOCK(nv_lock);

extern int system_running;

static int (*core99_write_bank)(int bank, u8* datas);
static int (*core99_erase_bank)(int bank);

static char *nvram_image;


static ssize_t core99_nvram_read(char *buf, size_t count, loff_t *index)
{
	int i;

	if (nvram_image == NULL)
		return -ENODEV;
	if (*index > NVRAM_SIZE)
		return 0;

	i = *index;
	if (i + count > NVRAM_SIZE)
		count = NVRAM_SIZE - i;

	memcpy(buf, &nvram_image[i], count);
	*index = i + count;
	return count;
}

static ssize_t core99_nvram_write(char *buf, size_t count, loff_t *index)
{
	int i;

	if (nvram_image == NULL)
		return -ENODEV;
	if (*index > NVRAM_SIZE)
		return 0;

	i = *index;
	if (i + count > NVRAM_SIZE)
		count = NVRAM_SIZE - i;

	memcpy(&nvram_image[i], buf, count);
	*index = i + count;
	return count;
}

static ssize_t core99_nvram_size(void)
{
	if (nvram_image == NULL)
		return -ENODEV;
	return NVRAM_SIZE;
}

static u8 chrp_checksum(struct chrp_header* hdr)
{
	u8 *ptr;
	u16 sum = hdr->signature;
	for (ptr = (u8 *)&hdr->len; ptr < hdr->data; ptr++)
		sum += *ptr;
	while (sum > 0xFF)
		sum = (sum & 0xFF) + (sum>>8);
	return sum;
}

static u32 core99_calc_adler(u8 *buffer)
{
	int cnt;
	u32 low, high;

   	buffer += CORE99_ADLER_START;
	low = 1;
	high = 0;
	for (cnt=0; cnt<(NVRAM_SIZE-CORE99_ADLER_START); cnt++) {
		if ((cnt % 5000) == 0) {
			high  %= 65521UL;
			high %= 65521UL;
		}
		low += buffer[cnt];
		high += low;
	}
	low  %= 65521UL;
	high %= 65521UL;

	return (high << 16) | low;
}

static u32 core99_check(u8* datas)
{
	struct core99_header* hdr99 = (struct core99_header*)datas;

	if (hdr99->hdr.signature != CORE99_SIGNATURE) {
		DBG("Invalid signature\n");
		return 0;
	}
	if (hdr99->hdr.cksum != chrp_checksum(&hdr99->hdr)) {
		DBG("Invalid checksum\n");
		return 0;
	}
	if (hdr99->adler != core99_calc_adler(datas)) {
		DBG("Invalid adler\n");
		return 0;
	}
	return hdr99->generation;
}

static int sm_erase_bank(int bank)
{
	int stat, i;
	unsigned long timeout;

	u8* base = (u8 *)nvram_data + core99_bank*NVRAM_SIZE;

       	DBG("nvram: Sharp/Micron Erasing bank %d...\n", bank);

	out_8(base, SM_FLASH_CMD_ERASE_SETUP);
	out_8(base, SM_FLASH_CMD_ERASE_CONFIRM);
	timeout = 0;
	do {
		if (++timeout > 1000000) {
			printk(KERN_ERR "nvram: Sharp/Miron flash erase timeout !\n");
			break;
		}
		out_8(base, SM_FLASH_CMD_READ_STATUS);
		stat = in_8(base);
	} while (!(stat & SM_FLASH_STATUS_DONE));

	out_8(base, SM_FLASH_CMD_CLEAR_STATUS);
	out_8(base, SM_FLASH_CMD_RESET);

	for (i=0; i<NVRAM_SIZE; i++)
		if (base[i] != 0xff) {
			printk(KERN_ERR "nvram: Sharp/Micron flash erase failed !\n");
			return -ENXIO;
		}
	return 0;
}

static int sm_write_bank(int bank, u8* datas)
{
	int i, stat = 0;
	unsigned long timeout;

	u8* base = (u8 *)nvram_data + core99_bank*NVRAM_SIZE;

       	DBG("nvram: Sharp/Micron Writing bank %d...\n", bank);

	for (i=0; i<NVRAM_SIZE; i++) {
		out_8(base+i, SM_FLASH_CMD_WRITE_SETUP);
		udelay(1);
		out_8(base+i, datas[i]);
		timeout = 0;
		do {
			if (++timeout > 1000000) {
				printk(KERN_ERR "nvram: Sharp/Micron flash write timeout !\n");
				break;
			}
			out_8(base, SM_FLASH_CMD_READ_STATUS);
			stat = in_8(base);
		} while (!(stat & SM_FLASH_STATUS_DONE));
		if (!(stat & SM_FLASH_STATUS_DONE))
			break;
	}
	out_8(base, SM_FLASH_CMD_CLEAR_STATUS);
	out_8(base, SM_FLASH_CMD_RESET);
	for (i=0; i<NVRAM_SIZE; i++)
		if (base[i] != datas[i]) {
			printk(KERN_ERR "nvram: Sharp/Micron flash write failed !\n");
			return -ENXIO;
		}
	return 0;
}

static int amd_erase_bank(int bank)
{
	int i, stat = 0;
	unsigned long timeout;

	u8* base = (u8 *)nvram_data + core99_bank*NVRAM_SIZE;

       	DBG("nvram: AMD Erasing bank %d...\n", bank);

	/* Unlock 1 */
	out_8(base+0x555, 0xaa);
	udelay(1);
	/* Unlock 2 */
	out_8(base+0x2aa, 0x55);
	udelay(1);

	/* Sector-Erase */
	out_8(base+0x555, 0x80);
	udelay(1);
	out_8(base+0x555, 0xaa);
	udelay(1);
	out_8(base+0x2aa, 0x55);
	udelay(1);
	out_8(base, 0x30);
	udelay(1);

	timeout = 0;
	do {
		if (++timeout > 1000000) {
			printk(KERN_ERR "nvram: AMD flash erase timeout !\n");
			break;
		}
		stat = in_8(base) ^ in_8(base);
	} while (stat != 0);
	
	/* Reset */
	out_8(base, 0xf0);
	udelay(1);
	
	for (i=0; i<NVRAM_SIZE; i++)
		if (base[i] != 0xff) {
			printk(KERN_ERR "nvram: AMD flash erase failed !\n");
			return -ENXIO;
		}
	return 0;
}

static int amd_write_bank(int bank, u8* datas)
{
	int i, stat = 0;
	unsigned long timeout;

	u8* base = (u8 *)nvram_data + core99_bank*NVRAM_SIZE;

       	DBG("nvram: AMD Writing bank %d...\n", bank);

	for (i=0; i<NVRAM_SIZE; i++) {
		/* Unlock 1 */
		out_8(base+0x555, 0xaa);
		udelay(1);
		/* Unlock 2 */
		out_8(base+0x2aa, 0x55);
		udelay(1);

		/* Write single word */
		out_8(base+0x555, 0xa0);
		udelay(1);
		out_8(base+i, datas[i]);
		
		timeout = 0;
		do {
			if (++timeout > 1000000) {
				printk(KERN_ERR "nvram: AMD flash write timeout !\n");
				break;
			}
			stat = in_8(base) ^ in_8(base);
		} while (stat != 0);
		if (stat != 0)
			break;
	}

	/* Reset */
	out_8(base, 0xf0);
	udelay(1);

	for (i=0; i<NVRAM_SIZE; i++)
		if (base[i] != datas[i]) {
			printk(KERN_ERR "nvram: AMD flash write failed !\n");
			return -ENXIO;
		}
	return 0;
}


static int core99_nvram_sync(void)
{
	struct core99_header* hdr99;
	unsigned long flags;

	spin_lock_irqsave(&nv_lock, flags);
	if (!memcmp(nvram_image, (u8*)nvram_data + core99_bank*NVRAM_SIZE,
		NVRAM_SIZE))
		goto bail;

	DBG("Updating nvram...\n");

	hdr99 = (struct core99_header*)nvram_image;
	hdr99->generation++;
	hdr99->hdr.signature = CORE99_SIGNATURE;
	hdr99->hdr.cksum = chrp_checksum(&hdr99->hdr);
	hdr99->adler = core99_calc_adler(nvram_image);
	core99_bank = core99_bank ? 0 : 1;
	if (core99_erase_bank)
		if (core99_erase_bank(core99_bank)) {
			printk("nvram: Error erasing bank %d\n", core99_bank);
			goto bail;
		}
	if (core99_write_bank)
		if (core99_write_bank(core99_bank, nvram_image))
			printk("nvram: Error writing bank %d\n", core99_bank);
 bail:
	spin_unlock_irqrestore(&nv_lock, flags);

	return 0;
}

int __init pmac_nvram_init(void)
{
	struct device_node *dp;
	u32 gen_bank0, gen_bank1;
	int i;

	dp = find_devices("nvram");
	if (dp == NULL) {
		printk(KERN_ERR "Can't find NVRAM device\n");
		return -ENODEV;
	}
	if (!device_is_compatible(dp, "nvram,flash")) {
		printk(KERN_ERR "Incompatible type of NVRAM\n");
		return -ENXIO;
	}

	nvram_image = alloc_bootmem(NVRAM_SIZE);
	if (nvram_image == NULL) {
		printk(KERN_ERR "nvram: can't allocate ram image\n");
		return -ENOMEM;
	}
	nvram_data = ioremap(dp->addrs[0].address, NVRAM_SIZE*2);
	
	DBG("nvram: Checking bank 0...\n");

	gen_bank0 = core99_check((u8 *)nvram_data);
	gen_bank1 = core99_check((u8 *)nvram_data + NVRAM_SIZE);
	core99_bank = (gen_bank0 < gen_bank1) ? 1 : 0;

	DBG("nvram: gen0=%d, gen1=%d\n", gen_bank0, gen_bank1);
	DBG("nvram: Active bank is: %d\n", core99_bank);

	for (i=0; i<NVRAM_SIZE; i++)
		nvram_image[i] = nvram_data[i + core99_bank*NVRAM_SIZE];

	ppc_md.nvram_read	= core99_nvram_read;
	ppc_md.nvram_write	= core99_nvram_write;
	ppc_md.nvram_size	= core99_nvram_size;
	ppc_md.nvram_sync	= core99_nvram_sync;
	
	/* 
	 * Maybe we could be smarter here though making an exclusive list
	 * of known flash chips is a bit nasty as older OF didn't provide us
	 * with a useful "compatible" entry. A solution would be to really
	 * identify the chip using flash id commands and base ourselves on
	 * a list of known chips IDs
	 */
	if (device_is_compatible(dp, "amd-0137")) {
		core99_erase_bank = amd_erase_bank;
		core99_write_bank = amd_write_bank;
	} else {
		core99_erase_bank = sm_erase_bank;
		core99_write_bank = sm_write_bank;
	}

	return 0;
}

int pmac_get_partition(int partition)
{
	struct nvram_partition *part;
	const char *name;
	int sig;

	switch(partition) {
	case pmac_nvram_OF:
		name = "common";
		sig = NVRAM_SIG_SYS;
		break;
	case pmac_nvram_XPRAM:
		name = "APL,MacOS75";
		sig = NVRAM_SIG_OS;
		break;
	case pmac_nvram_NR:
	default:
		/* Oldworld stuff */
		return -ENODEV;
	}

	part = nvram_find_partition(sig, name);
	if (part == NULL)
		return 0;

	return part->index;
}

u8 pmac_xpram_read(int xpaddr)
{
	int offset = pmac_get_partition(pmac_nvram_XPRAM);
	loff_t index;
	u8 buf;
	ssize_t count;

	if (offset < 0 || xpaddr < 0 || xpaddr > 0x100)
		return 0xff;
	index = offset + xpaddr;

	count = ppc_md.nvram_read(&buf, 1, &index);
	if (count != 1)
		return 0xff;
	return buf;
}

void pmac_xpram_write(int xpaddr, u8 data)
{
	int offset = pmac_get_partition(pmac_nvram_XPRAM);
	loff_t index;
	u8 buf;

	if (offset < 0 || xpaddr < 0 || xpaddr > 0x100)
		return;
	index = offset + xpaddr;
	buf = data;

	ppc_md.nvram_write(&buf, 1, &index);
}

EXPORT_SYMBOL(pmac_get_partition);
EXPORT_SYMBOL(pmac_xpram_read);
EXPORT_SYMBOL(pmac_xpram_write);