1 /*
2 * drivers/mtd/maps/ixp4xx.c
3 *
4 * MTD Map file for IXP4XX based systems. Please do not make per-board
5 * changes in here. If your board needs special setup, do it in your
6 * platform level code in arch/arm/mach-ixp4xx/board-setup.c
7 *
8 * Original Author: Intel Corporation
9 * Maintainer: Deepak Saxena <dsaxena@mvista.com>
10 *
11 * Copyright (C) 2002 Intel Corporation
12 * Copyright (C) 2003-2004 MontaVista Software, Inc.
13 *
14 */
15
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/slab.h>
22 #include <linux/ioport.h>
23 #include <linux/device.h>
24 #include <linux/platform_device.h>
25
26 #include <linux/mtd/mtd.h>
27 #include <linux/mtd/map.h>
28 #include <linux/mtd/partitions.h>
29
30 #include <asm/io.h>
31 #include <asm/mach/flash.h>
32
33 #include <linux/reboot.h>
34
35 /*
36 * Read/write a 16 bit word from flash address 'addr'.
37 *
38 * When the cpu is in little-endian mode it swizzles the address lines
39 * ('address coherency') so we need to undo the swizzling to ensure commands
40 * and the like end up on the correct flash address.
41 *
42 * To further complicate matters, due to the way the expansion bus controller
43 * handles 32 bit reads, the byte stream ABCD is stored on the flash as:
44 * D15 D0
45 * +---+---+
46 * | A | B | 0
47 * +---+---+
48 * | C | D | 2
49 * +---+---+
50 * This means that on LE systems each 16 bit word must be swapped. Note that
51 * this requires CONFIG_MTD_CFI_BE_BYTE_SWAP to be enabled to 'unswap' the CFI
52 * data and other flash commands which are always in D7-D0.
53 */
54 #ifndef __ARMEB__
55 #ifndef CONFIG_MTD_CFI_BE_BYTE_SWAP
56 # error CONFIG_MTD_CFI_BE_BYTE_SWAP required
57 #endif
58
flash_read16(void __iomem * addr)59 static inline u16 flash_read16(void __iomem *addr)
60 {
61 return be16_to_cpu(__raw_readw((void __iomem *)((unsigned long)addr ^ 0x2)));
62 }
63
flash_write16(u16 d,void __iomem * addr)64 static inline void flash_write16(u16 d, void __iomem *addr)
65 {
66 __raw_writew(cpu_to_be16(d), (void __iomem *)((unsigned long)addr ^ 0x2));
67 }
68
69 #define BYTE0(h) ((h) & 0xFF)
70 #define BYTE1(h) (((h) >> 8) & 0xFF)
71
72 #else
73
flash_read16(const void __iomem * addr)74 static inline u16 flash_read16(const void __iomem *addr)
75 {
76 return __raw_readw(addr);
77 }
78
flash_write16(u16 d,void __iomem * addr)79 static inline void flash_write16(u16 d, void __iomem *addr)
80 {
81 __raw_writew(d, addr);
82 }
83
84 #define BYTE0(h) (((h) >> 8) & 0xFF)
85 #define BYTE1(h) ((h) & 0xFF)
86 #endif
87
ixp4xx_read16(struct map_info * map,unsigned long ofs)88 static map_word ixp4xx_read16(struct map_info *map, unsigned long ofs)
89 {
90 map_word val;
91 val.x[0] = flash_read16(map->virt + ofs);
92 return val;
93 }
94
95 /*
96 * The IXP4xx expansion bus only allows 16-bit wide acceses
97 * when attached to a 16-bit wide device (such as the 28F128J3A),
98 * so we can't just memcpy_fromio().
99 */
ixp4xx_copy_from(struct map_info * map,void * to,unsigned long from,ssize_t len)100 static void ixp4xx_copy_from(struct map_info *map, void *to,
101 unsigned long from, ssize_t len)
102 {
103 u8 *dest = (u8 *) to;
104 void __iomem *src = map->virt + from;
105
106 if (len <= 0)
107 return;
108
109 if (from & 1) {
110 *dest++ = BYTE1(flash_read16(src));
111 src++;
112 --len;
113 }
114
115 while (len >= 2) {
116 u16 data = flash_read16(src);
117 *dest++ = BYTE0(data);
118 *dest++ = BYTE1(data);
119 src += 2;
120 len -= 2;
121 }
122
123 if (len > 0)
124 *dest++ = BYTE0(flash_read16(src));
125 }
126
127 /*
128 * Unaligned writes are ignored, causing the 8-bit
129 * probe to fail and proceed to the 16-bit probe (which succeeds).
130 */
ixp4xx_probe_write16(struct map_info * map,map_word d,unsigned long adr)131 static void ixp4xx_probe_write16(struct map_info *map, map_word d, unsigned long adr)
132 {
133 if (!(adr & 1))
134 flash_write16(d.x[0], map->virt + adr);
135 }
136
137 /*
138 * Fast write16 function without the probing check above
139 */
ixp4xx_write16(struct map_info * map,map_word d,unsigned long adr)140 static void ixp4xx_write16(struct map_info *map, map_word d, unsigned long adr)
141 {
142 flash_write16(d.x[0], map->virt + adr);
143 }
144
145 struct ixp4xx_flash_info {
146 struct mtd_info *mtd;
147 struct map_info map;
148 struct mtd_partition *partitions;
149 struct resource *res;
150 };
151
152 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
153
ixp4xx_flash_remove(struct platform_device * dev)154 static int ixp4xx_flash_remove(struct platform_device *dev)
155 {
156 struct flash_platform_data *plat = dev->dev.platform_data;
157 struct ixp4xx_flash_info *info = platform_get_drvdata(dev);
158
159 platform_set_drvdata(dev, NULL);
160
161 if(!info)
162 return 0;
163
164 if (info->mtd) {
165 del_mtd_partitions(info->mtd);
166 map_destroy(info->mtd);
167 }
168 if (info->map.virt)
169 iounmap(info->map.virt);
170
171 kfree(info->partitions);
172
173 if (info->res) {
174 release_resource(info->res);
175 kfree(info->res);
176 }
177
178 if (plat->exit)
179 plat->exit();
180
181 return 0;
182 }
183
ixp4xx_flash_probe(struct platform_device * dev)184 static int ixp4xx_flash_probe(struct platform_device *dev)
185 {
186 struct flash_platform_data *plat = dev->dev.platform_data;
187 struct ixp4xx_flash_info *info;
188 int err = -1;
189
190 if (!plat)
191 return -ENODEV;
192
193 if (plat->init) {
194 err = plat->init();
195 if (err)
196 return err;
197 }
198
199 info = kmalloc(sizeof(struct ixp4xx_flash_info), GFP_KERNEL);
200 if(!info) {
201 err = -ENOMEM;
202 goto Error;
203 }
204 memset(info, 0, sizeof(struct ixp4xx_flash_info));
205
206 platform_set_drvdata(dev, info);
207
208 /*
209 * Tell the MTD layer we're not 1:1 mapped so that it does
210 * not attempt to do a direct access on us.
211 */
212 info->map.phys = NO_XIP;
213 info->map.size = dev->resource->end - dev->resource->start + 1;
214
215 /*
216 * We only support 16-bit accesses for now. If and when
217 * any board use 8-bit access, we'll fixup the driver to
218 * handle that.
219 */
220 info->map.bankwidth = 2;
221 info->map.name = dev_name(&dev->dev);
222 info->map.read = ixp4xx_read16,
223 info->map.write = ixp4xx_probe_write16,
224 info->map.copy_from = ixp4xx_copy_from,
225
226 info->res = request_mem_region(dev->resource->start,
227 dev->resource->end - dev->resource->start + 1,
228 "IXP4XXFlash");
229 if (!info->res) {
230 printk(KERN_ERR "IXP4XXFlash: Could not reserve memory region\n");
231 err = -ENOMEM;
232 goto Error;
233 }
234
235 info->map.virt = ioremap(dev->resource->start,
236 dev->resource->end - dev->resource->start + 1);
237 if (!info->map.virt) {
238 printk(KERN_ERR "IXP4XXFlash: Failed to ioremap region\n");
239 err = -EIO;
240 goto Error;
241 }
242
243 info->mtd = do_map_probe(plat->map_name, &info->map);
244 if (!info->mtd) {
245 printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
246 err = -ENXIO;
247 goto Error;
248 }
249 info->mtd->owner = THIS_MODULE;
250
251 /* Use the fast version */
252 info->map.write = ixp4xx_write16,
253
254 err = parse_mtd_partitions(info->mtd, probes, &info->partitions, dev->resource->start);
255 if (err > 0) {
256 err = add_mtd_partitions(info->mtd, info->partitions, err);
257 if(err)
258 printk(KERN_ERR "Could not parse partitions\n");
259 }
260
261 if (err)
262 goto Error;
263
264 return 0;
265
266 Error:
267 ixp4xx_flash_remove(dev);
268 return err;
269 }
270
271 static struct platform_driver ixp4xx_flash_driver = {
272 .probe = ixp4xx_flash_probe,
273 .remove = ixp4xx_flash_remove,
274 .driver = {
275 .name = "IXP4XX-Flash",
276 .owner = THIS_MODULE,
277 },
278 };
279
ixp4xx_flash_init(void)280 static int __init ixp4xx_flash_init(void)
281 {
282 return platform_driver_register(&ixp4xx_flash_driver);
283 }
284
ixp4xx_flash_exit(void)285 static void __exit ixp4xx_flash_exit(void)
286 {
287 platform_driver_unregister(&ixp4xx_flash_driver);
288 }
289
290
291 module_init(ixp4xx_flash_init);
292 module_exit(ixp4xx_flash_exit);
293
294 MODULE_LICENSE("GPL");
295 MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems");
296 MODULE_AUTHOR("Deepak Saxena");
297 MODULE_ALIAS("platform:IXP4XX-Flash");
298