aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mtd/maps/ixp4xx.c
blob: 7b0515297411fc092a3793222f95dd11c9adb6a8 (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
/*
 * drivers/mtd/maps/ixp4xx.c
 *
 * MTD Map file for IXP4XX based systems. Please do not make per-board
 * changes in here. If your board needs special setup, do it in your
 * platform level code in arch/arm/mach-ixp4xx/board-setup.c
 *
 * Original Author: Intel Corporation
 * Maintainer: Deepak Saxena <dsaxena@mvista.com>
 *
 * Copyright (C) 2002 Intel Corporation
 * Copyright (C) 2003-2004 MontaVista Software, Inc.
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/platform_device.h>

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

#include <asm/io.h>
#include <asm/mach/flash.h>

#include <linux/reboot.h>

/*
 * Read/write a 16 bit word from flash address 'addr'.
 *
 * When the cpu is in little-endian mode it swizzles the address lines
 * ('address coherency') so we need to undo the swizzling to ensure commands
 * and the like end up on the correct flash address.
 *
 * To further complicate matters, due to the way the expansion bus controller
 * handles 32 bit reads, the byte stream ABCD is stored on the flash as:
 *     D15    D0
 *     +---+---+
 *     | A | B | 0
 *     +---+---+
 *     | C | D | 2
 *     +---+---+
 * This means that on LE systems each 16 bit word must be swapped. Note that
 * this requires CONFIG_MTD_CFI_BE_BYTE_SWAP to be enabled to 'unswap' the CFI
 * data and other flash commands which are always in D7-D0.
 */
#ifndef __ARMEB__
#ifndef CONFIG_MTD_CFI_BE_BYTE_SWAP
#  error CONFIG_MTD_CFI_BE_BYTE_SWAP required
#endif

static inline u16 flash_read16(void __iomem *addr)
{
	return be16_to_cpu(__raw_readw((void __iomem *)((unsigned long)addr ^ 0x2)));
}

static inline void flash_write16(u16 d, void __iomem *addr)
{
	__raw_writew(cpu_to_be16(d), (void __iomem *)((unsigned long)addr ^ 0x2));
}

#define	BYTE0(h)	((h) & 0xFF)
#define	BYTE1(h)	(((h) >> 8) & 0xFF)

#else

static inline u16 flash_read16(const void __iomem *addr)
{
	return __raw_readw(addr);
}

static inline void flash_write16(u16 d, void __iomem *addr)
{
	__raw_writew(d, addr);
}

#define	BYTE0(h)	(((h) >> 8) & 0xFF)
#define	BYTE1(h)	((h) & 0xFF)
#endif

static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
{
	map_word val;
	val.x[0] = flash_read16(map->virt + ofs);
	return val;
}

/*
 * The IXP4xx expansion bus only allows 16-bit wide acceses
 * when attached to a 16-bit wide device (such as the 28F128J3A),
 * so we can't just memcpy_fromio().
 */
static void ixp4xx_copy_from(struct map_info *map, void *to,
			     unsigned long from, ssize_t len)
{
	u8 *dest = (u8 *) to;
	void __iomem *src = map->virt + from;

	if (len <= 0)
		return;

	if (from & 1) {
		*dest++ = BYTE1(flash_read16(src));
                src++;
		--len;
	}

	while (len >= 2) {
		u16 data = flash_read16(src);
		*dest++ = BYTE0(data);
		*dest++ = BYTE1(data);
		src += 2;
		len -= 2;
        }

	if (len > 0)
		*dest++ = BYTE0(flash_read16(src));
}

/*
 * Unaligned writes are ignored, causing the 8-bit
 * probe to fail and proceed to the 16-bit probe (which succeeds).
 */
static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
{
	if (!(adr & 1))
		flash_write16(d.x[0], map->virt + adr);
}

/*
 * Fast write16 function without the probing check above
 */
static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
{
	flash_write16(d.x[0], map->virt + adr);
}

struct ixp4xx_flash_info {
	struct mtd_info *mtd;
	struct map_info map;
	struct mtd_partition *partitions;
	struct resource *res;
};

static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };

static int ixp4xx_flash_remove(struct platform_device *dev)
{
	struct flash_platform_data *plat = dev->dev.platform_data;
	struct ixp4xx_flash_info *info = platform_get_drvdata(dev);

	platform_set_drvdata(dev, NULL);

	if(!info)
		return 0;

	if (info->mtd) {
		del_mtd_partitions(info->mtd);
		map_destroy(info->mtd);
	}
	if (info->map.virt)
		iounmap(info->map.virt);

	kfree(info->partitions);

	if (info->res) {
		release_resource(info->res);
		kfree(info->res);
	}

	if (plat->exit)
		plat->exit();

	return 0;
}

static int ixp4xx_flash_probe(struct platform_device *dev)
{
	struct flash_platform_data *plat = dev->dev.platform_data;
	struct ixp4xx_flash_info *info;
	int err = -1;

	if (!plat)
		return -ENODEV;

	if (plat->init) {
		err = plat->init();
		if (err)
			return err;
	}

	info = kmalloc(sizeof(struct ixp4xx_flash_info), GFP_KERNEL);
	if(!info) {
		err = -ENOMEM;
		goto Error;
	}
	memset(info, 0, sizeof(struct ixp4xx_flash_info));

	platform_set_drvdata(dev, info);

	/*
	 * Tell the MTD layer we're not 1:1 mapped so that it does
	 * not attempt to do a direct access on us.
	 */
	info->map.phys = NO_XIP;
	info->map.size = resource_size(dev->resource);

	/*
	 * We only support 16-bit accesses for now. If and when
	 * any board use 8-bit access, we'll fixup the driver to
	 * handle that.
	 */
	info->map.bankwidth = 2;
	info->map.name = dev_name(&dev->dev);
	info->map.read = ixp4xx_read16,
	info->map.write = ixp4xx_probe_write16,
	info->map.copy_from = ixp4xx_copy_from,

	info->res = request_mem_region(dev->resource->start,
			resource_size(dev->resource),
			"IXP4XXFlash");
	if (!info->res) {
		printk(KERN_ERR "IXP4XXFlash: Could not reserve memory region\n");
		err = -ENOMEM;
		goto Error;
	}

	info->map.virt = ioremap(dev->resource->start,
				 resource_size(dev->resource));
	if (!info->map.virt) {
		printk(KERN_ERR "IXP4XXFlash: Failed to ioremap region\n");
		err = -EIO;
		goto Error;
	}

	info->mtd = do_map_probe(plat->map_name, &info->map);
	if (!info->mtd) {
		printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
		err = -ENXIO;
		goto Error;
	}
	info->mtd->owner = THIS_MODULE;

	/* Use the fast version */
	info->map.write = ixp4xx_write16,

	err = parse_mtd_partitions(info->mtd, probes, &info->partitions, dev->resource->start);
	if (err > 0) {
		err = add_mtd_partitions(info->mtd, info->partitions, err);
		if(err)
			printk(KERN_ERR "Could not parse partitions\n");
	}

	if (err)
		goto Error;

	return 0;

Error:
	ixp4xx_flash_remove(dev);
	return err;
}

static struct platform_driver ixp4xx_flash_driver = {
	.probe		= ixp4xx_flash_probe,
	.remove		= ixp4xx_flash_remove,
	.driver		= {
		.name	= "IXP4XX-Flash",
		.owner	= THIS_MODULE,
	},
};

static int __init ixp4xx_flash_init(void)
{
	return platform_driver_register(&ixp4xx_flash_driver);
}

static void __exit ixp4xx_flash_exit(void)
{
	platform_driver_unregister(&ixp4xx_flash_driver);
}


module_init(ixp4xx_flash_init);
module_exit(ixp4xx_flash_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems");
MODULE_AUTHOR("Deepak Saxena");
MODULE_ALIAS("platform:IXP4XX-Flash");