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-1));
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 resource *res;
149 };
150
151 static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
152
ixp4xx_flash_remove(struct platform_device * dev)153 static int ixp4xx_flash_remove(struct platform_device *dev)
154 {
155 struct flash_platform_data *plat = dev->dev.platform_data;
156 struct ixp4xx_flash_info *info = platform_get_drvdata(dev);
157
158 platform_set_drvdata(dev, NULL);
159
160 if(!info)
161 return 0;
162
163 if (info->mtd) {
164 mtd_device_unregister(info->mtd);
165 map_destroy(info->mtd);
166 }
167 if (info->map.virt)
168 iounmap(info->map.virt);
169
170 if (info->res) {
171 release_resource(info->res);
172 kfree(info->res);
173 }
174
175 if (plat->exit)
176 plat->exit();
177
178 return 0;
179 }
180
ixp4xx_flash_probe(struct platform_device * dev)181 static int ixp4xx_flash_probe(struct platform_device *dev)
182 {
183 struct flash_platform_data *plat = dev->dev.platform_data;
184 struct ixp4xx_flash_info *info;
185 int err = -1;
186
187 if (!plat)
188 return -ENODEV;
189
190 if (plat->init) {
191 err = plat->init();
192 if (err)
193 return err;
194 }
195
196 info = kzalloc(sizeof(struct ixp4xx_flash_info), GFP_KERNEL);
197 if(!info) {
198 err = -ENOMEM;
199 goto Error;
200 }
201
202 platform_set_drvdata(dev, info);
203
204 /*
205 * Tell the MTD layer we're not 1:1 mapped so that it does
206 * not attempt to do a direct access on us.
207 */
208 info->map.phys = NO_XIP;
209 info->map.size = resource_size(dev->resource);
210
211 /*
212 * We only support 16-bit accesses for now. If and when
213 * any board use 8-bit access, we'll fixup the driver to
214 * handle that.
215 */
216 info->map.bankwidth = 2;
217 info->map.name = dev_name(&dev->dev);
218 info->map.read = ixp4xx_read16;
219 info->map.write = ixp4xx_probe_write16;
220 info->map.copy_from = ixp4xx_copy_from;
221
222 info->res = request_mem_region(dev->resource->start,
223 resource_size(dev->resource),
224 "IXP4XXFlash");
225 if (!info->res) {
226 printk(KERN_ERR "IXP4XXFlash: Could not reserve memory region\n");
227 err = -ENOMEM;
228 goto Error;
229 }
230
231 info->map.virt = ioremap(dev->resource->start,
232 resource_size(dev->resource));
233 if (!info->map.virt) {
234 printk(KERN_ERR "IXP4XXFlash: Failed to ioremap region\n");
235 err = -EIO;
236 goto Error;
237 }
238
239 info->mtd = do_map_probe(plat->map_name, &info->map);
240 if (!info->mtd) {
241 printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
242 err = -ENXIO;
243 goto Error;
244 }
245 info->mtd->owner = THIS_MODULE;
246
247 /* Use the fast version */
248 info->map.write = ixp4xx_write16;
249
250 err = mtd_device_parse_register(info->mtd, probes, dev->resource->start,
251 plat->parts, plat->nr_parts);
252 if (err) {
253 printk(KERN_ERR "Could not parse partitions\n");
254 goto Error;
255 }
256
257 return 0;
258
259 Error:
260 ixp4xx_flash_remove(dev);
261 return err;
262 }
263
264 static struct platform_driver ixp4xx_flash_driver = {
265 .probe = ixp4xx_flash_probe,
266 .remove = ixp4xx_flash_remove,
267 .driver = {
268 .name = "IXP4XX-Flash",
269 .owner = THIS_MODULE,
270 },
271 };
272
273 module_platform_driver(ixp4xx_flash_driver);
274
275 MODULE_LICENSE("GPL");
276 MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems");
277 MODULE_AUTHOR("Deepak Saxena");
278 MODULE_ALIAS("platform:IXP4XX-Flash");
279