aboutsummaryrefslogtreecommitdiff
path: root/drivers/mtd/maps/sc520cdp.c
blob: 8fead8e46bce6bad5a72f74c80bda4c592a15cf0 (plain)
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
/* sc520cdp.c -- MTD map driver for AMD SC520 Customer Development Platform
 *
 * Copyright (C) 2001 Sysgo Real-Time Solutions GmbH
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 *
 *
 * The SC520CDP is an evaluation board for the Elan SC520 processor available
 * from AMD. It has two banks of 32-bit Flash ROM, each 8 Megabytes in size,
 * and up to 512 KiB of 8-bit DIL Flash ROM.
 * For details see http://www.amd.com/products/epd/desiging/evalboards/18.elansc520/520_cdp_brief/index.html
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <asm/io.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/concat.h>

/*
** The Embedded Systems BIOS decodes the first FLASH starting at
** 0x8400000. This is a *terrible* place for it because accessing
** the flash at this location causes the A22 address line to be high
** (that's what 0x8400000 binary's ought to be). But this is the highest
** order address line on the raw flash devices themselves!!
** This causes the top HALF of the flash to be accessed first. Beyond
** the physical limits of the flash, the flash chip aliases over (to
** 0x880000 which causes the bottom half to be accessed. This splits the
** flash into two and inverts it! If you then try to access this from another
** program that does NOT do this insanity, then you *will* access the
** first half of the flash, but not find what you expect there. That
** stuff is in the *second* half! Similarly, the address used by the
** BIOS for the second FLASH bank is also quite a bad choice.
** If REPROGRAM_PAR is defined below (the default), then this driver will
** choose more useful addresses for the FLASH banks by reprogramming the
** responsible PARxx registers in the SC520's MMCR region. This will
** cause the settings to be incompatible with the BIOS's settings, which
** shouldn't be a problem since you are running Linux, (i.e. the BIOS is
** not much use anyway). However, if you need to be compatible with
** the BIOS for some reason, just undefine REPROGRAM_PAR.
*/
#define REPROGRAM_PAR



#ifdef REPROGRAM_PAR

/* These are the addresses we want.. */
#define WINDOW_ADDR_0	0x08800000
#define WINDOW_ADDR_1	0x09000000
#define WINDOW_ADDR_2	0x09800000

/* .. and these are the addresses the BIOS gives us */
#define WINDOW_ADDR_0_BIOS	0x08400000
#define WINDOW_ADDR_1_BIOS	0x08c00000
#define WINDOW_ADDR_2_BIOS	0x09400000

#else

#define WINDOW_ADDR_0	0x08400000
#define WINDOW_ADDR_1	0x08C00000
#define WINDOW_ADDR_2	0x09400000

#endif

#define WINDOW_SIZE_0	0x00800000
#define WINDOW_SIZE_1	0x00800000
#define WINDOW_SIZE_2	0x00080000


static struct map_info sc520cdp_map[] = {
	{
		.name = "SC520CDP Flash Bank #0",
		.size = WINDOW_SIZE_0,
		.bankwidth = 4,
		.phys = WINDOW_ADDR_0
	},
	{
		.name = "SC520CDP Flash Bank #1",
		.size = WINDOW_SIZE_1,
		.bankwidth = 4,
		.phys = WINDOW_ADDR_1
	},
	{
		.name = "SC520CDP DIL Flash",
		.size = WINDOW_SIZE_2,
		.bankwidth = 1,
		.phys = WINDOW_ADDR_2
	},
};

#define NUM_FLASH_BANKS	ARRAY_SIZE(sc520cdp_map)

static struct mtd_info *mymtd[NUM_FLASH_BANKS];
static struct mtd_info *merged_mtd;

#ifdef REPROGRAM_PAR

/*
** The SC520 MMCR (memory mapped control register) region resides
** at 0xFFFEF000. The 16 Programmable Address Region (PAR) registers
** are at offset 0x88 in the MMCR:
*/
#define SC520_MMCR_BASE		0xFFFEF000
#define SC520_MMCR_EXTENT	0x1000
#define SC520_PAR(x)		((0x88/sizeof(unsigned long)) + (x))
#define NUM_SC520_PAR		16	/* total number of PAR registers */

/*
** The highest three bits in a PAR register determine what target
** device is controlled by this PAR. Here, only ROMCS? and BOOTCS
** devices are of interest.
*/
#define SC520_PAR_BOOTCS	(0x4<<29)
#define SC520_PAR_ROMCS0	(0x5<<29)
#define SC520_PAR_ROMCS1	(0x6<<29)
#define SC520_PAR_TRGDEV	(0x7<<29)

/*
** Bits 28 thru 26 determine some attributes for the
** region controlled by the PAR. (We only use non-cacheable)
*/
#define SC520_PAR_WRPROT	(1<<26)	/* write protected       */
#define SC520_PAR_NOCACHE	(1<<27)	/* non-cacheable         */
#define SC520_PAR_NOEXEC	(1<<28)	/* code execution denied */


/*
** Bit 25 determines the granularity: 4K or 64K
*/
#define SC520_PAR_PG_SIZ4	(0<<25)
#define SC520_PAR_PG_SIZ64	(1<<25)

/*
** Build a value to be written into a PAR register.
** We only need ROM entries, 64K page size:
*/
#define SC520_PAR_ENTRY(trgdev, address, size) \
	((trgdev) | SC520_PAR_NOCACHE | SC520_PAR_PG_SIZ64 | \
	(address) >> 16 | (((size) >> 16) - 1) << 14)

struct sc520_par_table
{
	unsigned long trgdev;
	unsigned long new_par;
	unsigned long default_address;
};

static const struct sc520_par_table par_table[NUM_FLASH_BANKS] =
{
	{	/* Flash Bank #0: selected by ROMCS0 */
		SC520_PAR_ROMCS0,
		SC520_PAR_ENTRY(SC520_PAR_ROMCS0, WINDOW_ADDR_0, WINDOW_SIZE_0),
		WINDOW_ADDR_0_BIOS
	},
	{	/* Flash Bank #1: selected by ROMCS1 */
		SC520_PAR_ROMCS1,
		SC520_PAR_ENTRY(SC520_PAR_ROMCS1, WINDOW_ADDR_1, WINDOW_SIZE_1),
		WINDOW_ADDR_1_BIOS
	},
	{	/* DIL (BIOS) Flash: selected by BOOTCS */
		SC520_PAR_BOOTCS,
		SC520_PAR_ENTRY(SC520_PAR_BOOTCS, WINDOW_ADDR_2, WINDOW_SIZE_2),
		WINDOW_ADDR_2_BIOS
	}
};


static void sc520cdp_setup_par(void)
{
	volatile unsigned long __iomem *mmcr;
	unsigned long mmcr_val;
	int i, j;

	/* map in SC520's MMCR area */
	mmcr = ioremap_nocache(SC520_MMCR_BASE, SC520_MMCR_EXTENT);
	if(!mmcr) { /* ioremap_nocache failed: skip the PAR reprogramming */
		/* force physical address fields to BIOS defaults: */
		for(i = 0; i < NUM_FLASH_BANKS; i++)
			sc520cdp_map[i].phys = par_table[i].default_address;
		return;
	}

	/*
	** Find the PARxx registers that are responsible for activating
	** ROMCS0, ROMCS1 and BOOTCS. Reprogram each of these with a
	** new value from the table.
	*/
	for(i = 0; i < NUM_FLASH_BANKS; i++) {		/* for each par_table entry  */
		for(j = 0; j < NUM_SC520_PAR; j++) {	/* for each PAR register     */
			mmcr_val = mmcr[SC520_PAR(j)];
			/* if target device field matches, reprogram the PAR */
			if((mmcr_val & SC520_PAR_TRGDEV) == par_table[i].trgdev)
			{
				mmcr[SC520_PAR(j)] = par_table[i].new_par;
				break;
			}
		}
		if(j == NUM_SC520_PAR)
		{	/* no matching PAR found: try default BIOS address */
			printk(KERN_NOTICE "Could not find PAR responsible for %s\n",
				sc520cdp_map[i].name);
			printk(KERN_NOTICE "Trying default address 0x%lx\n",
				par_table[i].default_address);
			sc520cdp_map[i].phys = par_table[i].default_address;
		}
	}
	iounmap(mmcr);
}
#endif


static int __init init_sc520cdp(void)
{
	int i, devices_found = 0;

#ifdef REPROGRAM_PAR
	/* reprogram PAR registers so flash appears at the desired addresses */
	sc520cdp_setup_par();
#endif

	for (i = 0; i < NUM_FLASH_BANKS; i++) {
		printk(KERN_NOTICE "SC520 CDP flash device: 0x%Lx at 0x%Lx\n",
			(unsigned long long)sc520cdp_map[i].size,
			(unsigned long long)sc520cdp_map[i].phys);

		sc520cdp_map[i].virt = ioremap_nocache(sc520cdp_map[i].phys, sc520cdp_map[i].size);

		if (!sc520cdp_map[i].virt) {
			printk("Failed to ioremap_nocache\n");
			return -EIO;
		}

		simple_map_init(&sc520cdp_map[i]);

		mymtd[i] = do_map_probe("cfi_probe", &sc520cdp_map[i]);
		if(!mymtd[i])
			mymtd[i] = do_map_probe("jedec_probe", &sc520cdp_map[i]);
		if(!mymtd[i])
			mymtd[i] = do_map_probe("map_rom", &sc520cdp_map[i]);

		if (mymtd[i]) {
			mymtd[i]->owner = THIS_MODULE;
			++devices_found;
		}
		else {
			iounmap(sc520cdp_map[i].virt);
		}
	}
	if(devices_found >= 2) {
		/* Combine the two flash banks into a single MTD device & register it: */
		merged_mtd = mtd_concat_create(mymtd, 2, "SC520CDP Flash Banks #0 and #1");
		if(merged_mtd)
			mtd_device_register(merged_mtd, NULL, 0);
	}
	if(devices_found == 3) /* register the third (DIL-Flash) device */
		mtd_device_register(mymtd[2], NULL, 0);
	return(devices_found ? 0 : -ENXIO);
}

static void __exit cleanup_sc520cdp(void)
{
	int i;

	if (merged_mtd) {
		mtd_device_unregister(merged_mtd);
		mtd_concat_destroy(merged_mtd);
	}
	if (mymtd[2])
		mtd_device_unregister(mymtd[2]);

	for (i = 0; i < NUM_FLASH_BANKS; i++) {
		if (mymtd[i])
			map_destroy(mymtd[i]);
		if (sc520cdp_map[i].virt) {
			iounmap(sc520cdp_map[i].virt);
			sc520cdp_map[i].virt = NULL;
		}
	}
}

module_init(init_sc520cdp);
module_exit(cleanup_sc520cdp);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sysgo Real-Time Solutions GmbH");
MODULE_DESCRIPTION("MTD map driver for AMD SC520 Customer Development Platform");