aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mtd/maps/dc21285.c
blob: 701620b6baede850569e5516a1d2683a86323d6f (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
/*
 * MTD map driver for flash on the DC21285 (the StrongARM-110 companion chip)
 *
 * (C) 2000  Nicolas Pitre <nico@cam.org>
 *
 * This code is GPL
 *
 * $Id: dc21285.c,v 1.24 2005/11/07 11:14:26 gleixner Exp $
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>

#include <asm/io.h>
#include <asm/hardware/dec21285.h>
#include <asm/mach-types.h>


static struct mtd_info *dc21285_mtd;

#ifdef CONFIG_ARCH_NETWINDER
/*
 * This is really ugly, but it seams to be the only
 * realiable way to do it, as the cpld state machine
 * is unpredictible. So we have a 25us penalty per
 * write access.
 */
static void nw_en_write(void)
{
	extern spinlock_t gpio_lock;
	unsigned long flags;

	/*
	 * we want to write a bit pattern XXX1 to Xilinx to enable
	 * the write gate, which will be open for about the next 2ms.
	 */
	spin_lock_irqsave(&gpio_lock, flags);
	cpld_modify(1, 1);
	spin_unlock_irqrestore(&gpio_lock, flags);

	/*
	 * let the ISA bus to catch on...
	 */
	udelay(25);
}
#else
#define nw_en_write() do { } while (0)
#endif

static map_word dc21285_read8(struct map_info *map, unsigned long ofs)
{
	map_word val;
	val.x[0] = *(uint8_t*)(map->virt + ofs);
	return val;
}

static map_word dc21285_read16(struct map_info *map, unsigned long ofs)
{
	map_word val;
	val.x[0] = *(uint16_t*)(map->virt + ofs);
	return val;
}

static map_word dc21285_read32(struct map_info *map, unsigned long ofs)
{
	map_word val;
	val.x[0] = *(uint32_t*)(map->virt + ofs);
	return val;
}

static void dc21285_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
{
	memcpy(to, (void*)(map->virt + from), len);
}

static void dc21285_write8(struct map_info *map, const map_word d, unsigned long adr)
{
	if (machine_is_netwinder())
		nw_en_write();
	*CSR_ROMWRITEREG = adr & 3;
	adr &= ~3;
	*(uint8_t*)(map->virt + adr) = d.x[0];
}

static void dc21285_write16(struct map_info *map, const map_word d, unsigned long adr)
{
	if (machine_is_netwinder())
		nw_en_write();
	*CSR_ROMWRITEREG = adr & 3;
	adr &= ~3;
	*(uint16_t*)(map->virt + adr) = d.x[0];
}

static void dc21285_write32(struct map_info *map, const map_word d, unsigned long adr)
{
	if (machine_is_netwinder())
		nw_en_write();
	*(uint32_t*)(map->virt + adr) = d.x[0];
}

static void dc21285_copy_to_32(struct map_info *map, unsigned long to, const void *from, ssize_t len)
{
	while (len > 0) {
		map_word d;
		d.x[0] = *((uint32_t*)from)++;
		dc21285_write32(map, d, to);
		to += 4;
		len -= 4;
	}
}

static void dc21285_copy_to_16(struct map_info *map, unsigned long to, const void *from, ssize_t len)
{
	while (len > 0) {
		map_word d;
		d.x[0] = *((uint16_t*)from)++;
		dc21285_write16(map, d, to);
		to += 2;
		len -= 2;
	}
}

static void dc21285_copy_to_8(struct map_info *map, unsigned long to, const void *from, ssize_t len)
{
	map_word d;
	d.x[0] = *((uint8_t*)from)++;
	dc21285_write8(map, d, to);
	to++;
	len--;
}

static struct map_info dc21285_map = {
	.name = "DC21285 flash",
	.phys = NO_XIP,
	.size = 16*1024*1024,
	.copy_from = dc21285_copy_from,
};


/* Partition stuff */
#ifdef CONFIG_MTD_PARTITIONS
static struct mtd_partition *dc21285_parts;
static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
#endif

static int __init init_dc21285(void)
{

#ifdef CONFIG_MTD_PARTITIONS
	int nrparts;
#endif

	/* Determine bankwidth */
	switch (*CSR_SA110_CNTL & (3<<14)) {
		case SA110_CNTL_ROMWIDTH_8:
			dc21285_map.bankwidth = 1;
			dc21285_map.read = dc21285_read8;
			dc21285_map.write = dc21285_write8;
			dc21285_map.copy_to = dc21285_copy_to_8;
			break;
		case SA110_CNTL_ROMWIDTH_16:
			dc21285_map.bankwidth = 2;
			dc21285_map.read = dc21285_read16;
			dc21285_map.write = dc21285_write16;
			dc21285_map.copy_to = dc21285_copy_to_16;
			break;
		case SA110_CNTL_ROMWIDTH_32:
			dc21285_map.bankwidth = 4;
			dc21285_map.read = dc21285_read32;
			dc21285_map.write = dc21285_write32;
			dc21285_map.copy_to = dc21285_copy_to_32;
			break;
		default:
			printk (KERN_ERR "DC21285 flash: undefined bankwidth\n");
			return -ENXIO;
	}
	printk (KERN_NOTICE "DC21285 flash support (%d-bit bankwidth)\n",
		dc21285_map.bankwidth*8);

	/* Let's map the flash area */
	dc21285_map.virt = ioremap(DC21285_FLASH, 16*1024*1024);
	if (!dc21285_map.virt) {
		printk("Failed to ioremap\n");
		return -EIO;
	}

	if (machine_is_ebsa285()) {
		dc21285_mtd = do_map_probe("cfi_probe", &dc21285_map);
	} else {
		dc21285_mtd = do_map_probe("jedec_probe", &dc21285_map);
	}

	if (!dc21285_mtd) {
		iounmap(dc21285_map.virt);
		return -ENXIO;
	}

	dc21285_mtd->owner = THIS_MODULE;

#ifdef CONFIG_MTD_PARTITIONS
	nrparts = parse_mtd_partitions(dc21285_mtd, probes, &dc21285_parts, 0);
	if (nrparts > 0)
		add_mtd_partitions(dc21285_mtd, dc21285_parts, nrparts);
	else
#endif
		add_mtd_device(dc21285_mtd);

	if(machine_is_ebsa285()) {
		/*
		 * Flash timing is determined with bits 19-16 of the
		 * CSR_SA110_CNTL.  The value is the number of wait cycles, or
		 * 0 for 16 cycles (the default).  Cycles are 20 ns.
		 * Here we use 7 for 140 ns flash chips.
		 */
		/* access time */
		*CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x000f0000) | (7 << 16));
		/* burst time */
		*CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x00f00000) | (7 << 20));
		/* tristate time */
		*CSR_SA110_CNTL = ((*CSR_SA110_CNTL & ~0x0f000000) | (7 << 24));
	}

	return 0;
}

static void __exit cleanup_dc21285(void)
{
#ifdef CONFIG_MTD_PARTITIONS
	if (dc21285_parts) {
		del_mtd_partitions(dc21285_mtd);
		kfree(dc21285_parts);
	} else
#endif
		del_mtd_device(dc21285_mtd);

	map_destroy(dc21285_mtd);
	iounmap(dc21285_map.virt);
}

module_init(init_dc21285);
module_exit(cleanup_dc21285);


MODULE_LICENSE("GPL");
MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");
MODULE_DESCRIPTION("MTD map driver for DC21285 boards");