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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/mtd/maps/
1/*
2 * drivers/mtd/maps/ixp2000.c
3 *
4 * Mapping for the Intel XScale IXP2000 based systems
5 *
6 * Copyright (C) 2002 Intel Corp.
7 * Copyright (C) 2003-2004 MontaVista Software, Inc.
8 *
9 * Original Author: Naeem M Afzal <naeem.m.afzal@intel.com>
10 * Maintainer: Deepak Saxena <dsaxena@plexity.net>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 *
16 */
17
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/string.h>
23#include <linux/slab.h>
24#include <linux/ioport.h>
25#include <linux/device.h>
26#include <linux/platform_device.h>
27
28#include <linux/mtd/mtd.h>
29#include <linux/mtd/map.h>
30#include <linux/mtd/partitions.h>
31
32#include <asm/io.h>
33#include <mach/hardware.h>
34#include <asm/mach/flash.h>
35
36#include <linux/reboot.h>
37
38struct ixp2000_flash_info {
39	struct		mtd_info *mtd;
40	struct		map_info map;
41	struct		mtd_partition *partitions;
42	struct		resource *res;
43};
44
45static inline unsigned long flash_bank_setup(struct map_info *map, unsigned long ofs)
46{
47	unsigned long (*set_bank)(unsigned long) =
48		(unsigned long(*)(unsigned long))map->map_priv_2;
49
50	return (set_bank ? set_bank(ofs) : ofs);
51}
52
53#ifdef __ARMEB__
54/*
55 * Rev A0 and A1 of IXP2400 silicon have a broken addressing unit which
56 * causes the lower address bits to be XORed with 0x11 on 8 bit accesses
57 * and XORed with 0x10 on 16 bit accesses. See the spec update, erratum 44.
58 */
59static int erratum44_workaround = 0;
60
61static inline unsigned long address_fix8_write(unsigned long addr)
62{
63	if (erratum44_workaround) {
64		return (addr ^ 3);
65	}
66	return addr;
67}
68#else
69
70#define address_fix8_write(x)	(x)
71#endif
72
73static map_word ixp2000_flash_read8(struct map_info *map, unsigned long ofs)
74{
75	map_word val;
76
77	val.x[0] =  *((u8 *)(map->map_priv_1 + flash_bank_setup(map, ofs)));
78	return val;
79}
80
81/*
82 * We can't use the standard memcpy due to the broken SlowPort
83 * address translation on rev A0 and A1 silicon and the fact that
84 * we have banked flash.
85 */
86static void ixp2000_flash_copy_from(struct map_info *map, void *to,
87			      unsigned long from, ssize_t len)
88{
89	from = flash_bank_setup(map, from);
90	while(len--)
91		*(__u8 *) to++ = *(__u8 *)(map->map_priv_1 + from++);
92}
93
94static void ixp2000_flash_write8(struct map_info *map, map_word d, unsigned long ofs)
95{
96	*(__u8 *) (address_fix8_write(map->map_priv_1 +
97				      flash_bank_setup(map, ofs))) = d.x[0];
98}
99
100static void ixp2000_flash_copy_to(struct map_info *map, unsigned long to,
101			    const void *from, ssize_t len)
102{
103	to = flash_bank_setup(map, to);
104	while(len--) {
105		unsigned long tmp = address_fix8_write(map->map_priv_1 + to++);
106		*(__u8 *)(tmp) = *(__u8 *)(from++);
107	}
108}
109
110
111static int ixp2000_flash_remove(struct platform_device *dev)
112{
113	struct flash_platform_data *plat = dev->dev.platform_data;
114	struct ixp2000_flash_info *info = platform_get_drvdata(dev);
115
116	platform_set_drvdata(dev, NULL);
117
118	if(!info)
119		return 0;
120
121	if (info->mtd) {
122		del_mtd_partitions(info->mtd);
123		map_destroy(info->mtd);
124	}
125	if (info->map.map_priv_1)
126		iounmap((void *) info->map.map_priv_1);
127
128	kfree(info->partitions);
129
130	if (info->res) {
131		release_resource(info->res);
132		kfree(info->res);
133	}
134
135	if (plat->exit)
136		plat->exit();
137
138	return 0;
139}
140
141
142static int ixp2000_flash_probe(struct platform_device *dev)
143{
144	static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
145	struct ixp2000_flash_data *ixp_data = dev->dev.platform_data;
146	struct flash_platform_data *plat;
147	struct ixp2000_flash_info *info;
148	unsigned long window_size;
149	int err = -1;
150
151	if (!ixp_data)
152		return -ENODEV;
153
154	plat = ixp_data->platform_data;
155	if (!plat)
156		return -ENODEV;
157
158	window_size = dev->resource->end - dev->resource->start + 1;
159	dev_info(&dev->dev, "Probe of IXP2000 flash(%d banks x %dMiB)\n",
160		 ixp_data->nr_banks, ((u32)window_size >> 20));
161
162	if (plat->width != 1) {
163		dev_err(&dev->dev, "IXP2000 MTD map only supports 8-bit mode, asking for %d\n",
164			plat->width * 8);
165		return -EIO;
166	}
167
168	info = kzalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
169	if(!info) {
170		err = -ENOMEM;
171		goto Error;
172	}
173
174	platform_set_drvdata(dev, info);
175
176	/*
177	 * Tell the MTD layer we're not 1:1 mapped so that it does
178	 * not attempt to do a direct access on us.
179	 */
180	info->map.phys = NO_XIP;
181
182	info->map.size = ixp_data->nr_banks * window_size;
183	info->map.bankwidth = 1;
184
185	/*
186 	 * map_priv_2 is used to store a ptr to the bank_setup routine
187 	 */
188	info->map.map_priv_2 = (unsigned long) ixp_data->bank_setup;
189
190	info->map.name = dev_name(&dev->dev);
191	info->map.read = ixp2000_flash_read8;
192	info->map.write = ixp2000_flash_write8;
193	info->map.copy_from = ixp2000_flash_copy_from;
194	info->map.copy_to = ixp2000_flash_copy_to;
195
196	info->res = request_mem_region(dev->resource->start,
197			dev->resource->end - dev->resource->start + 1,
198			dev_name(&dev->dev));
199	if (!info->res) {
200		dev_err(&dev->dev, "Could not reserve memory region\n");
201		err = -ENOMEM;
202		goto Error;
203	}
204
205	info->map.map_priv_1 = (unsigned long) ioremap(dev->resource->start,
206			    	dev->resource->end - dev->resource->start + 1);
207	if (!info->map.map_priv_1) {
208		dev_err(&dev->dev, "Failed to ioremap flash region\n");
209		err = -EIO;
210		goto Error;
211	}
212
213#if defined(__ARMEB__)
214
215	erratum44_workaround = ixp2000_has_broken_slowport();
216	dev_info(&dev->dev, "Erratum 44 workaround %s\n",
217	       erratum44_workaround ? "enabled" : "disabled");
218#endif
219
220	info->mtd = do_map_probe(plat->map_name, &info->map);
221	if (!info->mtd) {
222		dev_err(&dev->dev, "map_probe failed\n");
223		err = -ENXIO;
224		goto Error;
225	}
226	info->mtd->owner = THIS_MODULE;
227
228	err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
229	if (err > 0) {
230		err = add_mtd_partitions(info->mtd, info->partitions, err);
231		if(err)
232			dev_err(&dev->dev, "Could not parse partitions\n");
233	}
234
235	if (err)
236		goto Error;
237
238	return 0;
239
240Error:
241	ixp2000_flash_remove(dev);
242	return err;
243}
244
245static struct platform_driver ixp2000_flash_driver = {
246	.probe		= ixp2000_flash_probe,
247	.remove		= ixp2000_flash_remove,
248	.driver		= {
249		.name	= "IXP2000-Flash",
250		.owner	= THIS_MODULE,
251	},
252};
253
254static int __init ixp2000_flash_init(void)
255{
256	return platform_driver_register(&ixp2000_flash_driver);
257}
258
259static void __exit ixp2000_flash_exit(void)
260{
261	platform_driver_unregister(&ixp2000_flash_driver);
262}
263
264module_init(ixp2000_flash_init);
265module_exit(ixp2000_flash_exit);
266MODULE_LICENSE("GPL");
267MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
268MODULE_ALIAS("platform:IXP2000-Flash");
269