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/err.h>
17 #include <linux/module.h>
18 #include <linux/types.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 * const 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_get_platdata(&dev->dev);
156 struct ixp4xx_flash_info *info = platform_get_drvdata(dev);
157
158 if(!info)
159 return 0;
160
161 if (info->mtd) {
162 mtd_device_unregister(info->mtd);
163 map_destroy(info->mtd);
164 }
165
166 if (plat->exit)
167 plat->exit();
168
169 return 0;
170 }
171
ixp4xx_flash_probe(struct platform_device * dev)172 static int ixp4xx_flash_probe(struct platform_device *dev)
173 {
174 struct flash_platform_data *plat = dev_get_platdata(&dev->dev);
175 struct ixp4xx_flash_info *info;
176 struct mtd_part_parser_data ppdata = {
177 .origin = dev->resource->start,
178 };
179 int err = -1;
180
181 if (!plat)
182 return -ENODEV;
183
184 if (plat->init) {
185 err = plat->init();
186 if (err)
187 return err;
188 }
189
190 info = devm_kzalloc(&dev->dev, sizeof(struct ixp4xx_flash_info),
191 GFP_KERNEL);
192 if(!info) {
193 err = -ENOMEM;
194 goto Error;
195 }
196
197 platform_set_drvdata(dev, info);
198
199 /*
200 * Tell the MTD layer we're not 1:1 mapped so that it does
201 * not attempt to do a direct access on us.
202 */
203 info->map.phys = NO_XIP;
204 info->map.size = resource_size(dev->resource);
205
206 /*
207 * We only support 16-bit accesses for now. If and when
208 * any board use 8-bit access, we'll fixup the driver to
209 * handle that.
210 */
211 info->map.bankwidth = 2;
212 info->map.name = dev_name(&dev->dev);
213 info->map.read = ixp4xx_read16;
214 info->map.write = ixp4xx_probe_write16;
215 info->map.copy_from = ixp4xx_copy_from;
216
217 info->map.virt = devm_ioremap_resource(&dev->dev, dev->resource);
218 if (IS_ERR(info->map.virt)) {
219 err = PTR_ERR(info->map.virt);
220 goto Error;
221 }
222
223 info->mtd = do_map_probe(plat->map_name, &info->map);
224 if (!info->mtd) {
225 printk(KERN_ERR "IXP4XXFlash: map_probe failed\n");
226 err = -ENXIO;
227 goto Error;
228 }
229 info->mtd->dev.parent = &dev->dev;
230
231 /* Use the fast version */
232 info->map.write = ixp4xx_write16;
233
234 err = mtd_device_parse_register(info->mtd, probes, &ppdata,
235 plat->parts, plat->nr_parts);
236 if (err) {
237 printk(KERN_ERR "Could not parse partitions\n");
238 goto Error;
239 }
240
241 return 0;
242
243 Error:
244 ixp4xx_flash_remove(dev);
245 return err;
246 }
247
248 static struct platform_driver ixp4xx_flash_driver = {
249 .probe = ixp4xx_flash_probe,
250 .remove = ixp4xx_flash_remove,
251 .driver = {
252 .name = "IXP4XX-Flash",
253 },
254 };
255
256 module_platform_driver(ixp4xx_flash_driver);
257
258 MODULE_LICENSE("GPL");
259 MODULE_DESCRIPTION("MTD map driver for Intel IXP4xx systems");
260 MODULE_AUTHOR("Deepak Saxena");
261 MODULE_ALIAS("platform:IXP4XX-Flash");
262