ia64/linux-2.6.18-xen.hg

view drivers/mtd/maps/ixp4xx.c @ 0:831230e53067

Import 2.6.18 from kernel.org tarball.
author Ian Campbell <ian.campbell@xensource.com>
date Wed Apr 11 14:15:44 2007 +0100 (2007-04-11)
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1 /*
2 * $Id: ixp4xx.c,v 1.13 2005/11/16 16:23:21 dvrabel Exp $
3 *
4 * drivers/mtd/maps/ixp4xx.c
5 *
6 * MTD Map file for IXP4XX based systems. Please do not make per-board
7 * changes in here. If your board needs special setup, do it in your
8 * platform level code in arch/arm/mach-ixp4xx/board-setup.c
9 *
10 * Original Author: Intel Corporation
11 * Maintainer: Deepak Saxena <dsaxena@mvista.com>
12 *
13 * Copyright (C) 2002 Intel Corporation
14 * Copyright (C) 2003-2004 MontaVista Software, Inc.
15 *
16 */
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>
28 #include <linux/mtd/mtd.h>
29 #include <linux/mtd/map.h>
30 #include <linux/mtd/partitions.h>
32 #include <asm/io.h>
33 #include <asm/mach/flash.h>
35 #include <linux/reboot.h>
37 /*
38 * Read/write a 16 bit word from flash address 'addr'.
39 *
40 * When the cpu is in little-endian mode it swizzles the address lines
41 * ('address coherency') so we need to undo the swizzling to ensure commands
42 * and the like end up on the correct flash address.
43 *
44 * To further complicate matters, due to the way the expansion bus controller
45 * handles 32 bit reads, the byte stream ABCD is stored on the flash as:
46 * D15 D0
47 * +---+---+
48 * | A | B | 0
49 * +---+---+
50 * | C | D | 2
51 * +---+---+
52 * This means that on LE systems each 16 bit word must be swapped. Note that
53 * this requires CONFIG_MTD_CFI_BE_BYTE_SWAP to be enabled to 'unswap' the CFI
54 * data and other flash commands which are always in D7-D0.
55 */
56 #ifndef __ARMEB__
57 #ifndef CONFIG_MTD_CFI_BE_BYTE_SWAP
58 # error CONFIG_MTD_CFI_BE_BYTE_SWAP required
59 #endif
61 static inline u16 flash_read16(void __iomem *addr)
62 {
63 return be16_to_cpu(__raw_readw((void __iomem *)((unsigned long)addr ^ 0x2)));
64 }
66 static inline void flash_write16(u16 d, void __iomem *addr)
67 {
68 __raw_writew(cpu_to_be16(d), (void __iomem *)((unsigned long)addr ^ 0x2));
69 }
71 #define BYTE0(h) ((h) & 0xFF)
72 #define BYTE1(h) (((h) >> 8) & 0xFF)
74 #else
76 static inline u16 flash_read16(const void __iomem *addr)
77 {
78 return __raw_readw(addr);
79 }
81 static inline void flash_write16(u16 d, void __iomem *addr)
82 {
83 __raw_writew(d, addr);
84 }
86 #define BYTE0(h) (((h) >> 8) & 0xFF)
87 #define BYTE1(h) ((h) & 0xFF)
88 #endif
90 static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
91 {
92 map_word val;
93 val.x[0] = flash_read16(map->virt + ofs);
94 return val;
95 }
97 /*
98 * The IXP4xx expansion bus only allows 16-bit wide acceses
99 * when attached to a 16-bit wide device (such as the 28F128J3A),
100 * so we can't just memcpy_fromio().
101 */
102 static void ixp4xx_copy_from(struct map_info *map, void *to,
103 unsigned long from, ssize_t len)
104 {
105 u8 *dest = (u8 *) to;
106 void __iomem *src = map->virt + from;
108 if (len <= 0)
109 return;
111 if (from & 1) {
112 *dest++ = BYTE1(flash_read16(src));
113 src++;
114 --len;
115 }
117 while (len >= 2) {
118 u16 data = flash_read16(src);
119 *dest++ = BYTE0(data);
120 *dest++ = BYTE1(data);
121 src += 2;
122 len -= 2;
123 }
125 if (len > 0)
126 *dest++ = BYTE0(flash_read16(src));
127 }
129 /*
130 * Unaligned writes are ignored, causing the 8-bit
131 * probe to fail and proceed to the 16-bit probe (which succeeds).
132 */
133 static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
134 {
135 if (!(adr & 1))
136 flash_write16(d.x[0], map->virt + adr);
137 }
139 /*
140 * Fast write16 function without the probing check above
141 */
142 static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
143 {
144 flash_write16(d.x[0], map->virt + adr);
145 }
147 struct ixp4xx_flash_info {
148 struct mtd_info *mtd;
149 struct map_info map;
150 struct mtd_partition *partitions;
151 struct resource *res;
152 };
154 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
156 static int ixp4xx_flash_remove(struct platform_device *dev)
157 {
158 struct flash_platform_data *plat = dev->dev.platform_data;
159 struct ixp4xx_flash_info *info = platform_get_drvdata(dev);
161 platform_set_drvdata(dev, NULL);
163 if(!info)
164 return 0;
166 if (info->mtd) {
167 del_mtd_partitions(info->mtd);
168 map_destroy(info->mtd);
169 }
170 if (info->map.virt)
171 iounmap(info->map.virt);
173 kfree(info->partitions);
175 if (info->res) {
176 release_resource(info->res);
177 kfree(info->res);
178 }
180 if (plat->exit)
181 plat->exit();
183 return 0;
184 }
186 static int ixp4xx_flash_probe(struct platform_device *dev)
187 {
188 struct flash_platform_data *plat = dev->dev.platform_data;
189 struct ixp4xx_flash_info *info;
190 int err = -1;
192 if (!plat)
193 return -ENODEV;
195 if (plat->init) {
196 err = plat->init();
197 if (err)
198 return err;
199 }
201 info = kmalloc(sizeof(struct ixp4xx_flash_info), GFP_KERNEL);
202 if(!info) {
203 err = -ENOMEM;
204 goto Error;
205 }
206 memzero(info, sizeof(struct ixp4xx_flash_info));
208 platform_set_drvdata(dev, info);
210 /*
211 * Tell the MTD layer we're not 1:1 mapped so that it does
212 * not attempt to do a direct access on us.
213 */
214 info->map.phys = NO_XIP;
215 info->map.size = dev->resource->end - dev->resource->start + 1;
217 /*
218 * We only support 16-bit accesses for now. If and when
219 * any board use 8-bit access, we'll fixup the driver to
220 * handle that.
221 */
222 info->map.bankwidth = 2;
223 info->map.name = dev->dev.bus_id;
224 info->map.read = ixp4xx_read16,
225 info->map.write = ixp4xx_probe_write16,
226 info->map.copy_from = ixp4xx_copy_from,
228 info->res = request_mem_region(dev->resource->start,
229 dev->resource->end - dev->resource->start + 1,
230 "IXP4XXFlash");
231 if (!info->res) {
232 printk(KERN_ERR "IXP4XXFlash: Could not reserve memory region\n");
233 err = -ENOMEM;
234 goto Error;
235 }
237 info->map.virt = ioremap(dev->resource->start,
238 dev->resource->end - dev->resource->start + 1);
239 if (!info->map.virt) {
240 printk(KERN_ERR "IXP4XXFlash: Failed to ioremap region\n");
241 err = -EIO;
242 goto Error;
243 }
245 info->mtd = do_map_probe(plat->map_name, &info->map);
246 if (!info->mtd) {
247 printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
248 err = -ENXIO;
249 goto Error;
250 }
251 info->mtd->owner = THIS_MODULE;
253 /* Use the fast version */
254 info->map.write = ixp4xx_write16,
256 err = parse_mtd_partitions(info->mtd, probes, &info->partitions, 0);
257 if (err > 0) {
258 err = add_mtd_partitions(info->mtd, info->partitions, err);
259 if(err)
260 printk(KERN_ERR "Could not parse partitions\n");
261 }
263 if (err)
264 goto Error;
266 return 0;
268 Error:
269 ixp4xx_flash_remove(dev);
270 return err;
271 }
273 static struct platform_driver ixp4xx_flash_driver = {
274 .probe = ixp4xx_flash_probe,
275 .remove = ixp4xx_flash_remove,
276 .driver = {
277 .name = "IXP4XX-Flash",
278 },
279 };
281 static int __init ixp4xx_flash_init(void)
282 {
283 return platform_driver_register(&ixp4xx_flash_driver);
284 }
286 static void __exit ixp4xx_flash_exit(void)
287 {
288 platform_driver_unregister(&ixp4xx_flash_driver);
289 }
292 module_init(ixp4xx_flash_init);
293 module_exit(ixp4xx_flash_exit);
295 MODULE_LICENSE("GPL");
296 MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems");
297 MODULE_AUTHOR("Deepak Saxena");