Use dentry_path() to create full path to inode object
[pohmelfs.git] / drivers / mtd / maps / lantiq-flash.c
blob7b889de9477bcf4b0bf6c9936c38e6246e039a3a
1 /*
2 * This program is free software; you can redistribute it and/or modify it
3 * under the terms of the GNU General Public License version 2 as published
4 * by the Free Software Foundation.
6 * Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
7 * Copyright (C) 2010 John Crispin <blogic@openwrt.org>
8 */
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/io.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/mtd/map.h>
18 #include <linux/mtd/partitions.h>
19 #include <linux/mtd/cfi.h>
20 #include <linux/platform_device.h>
21 #include <linux/mtd/physmap.h>
23 #include <lantiq_soc.h>
24 #include <lantiq_platform.h>
27 * The NOR flash is connected to the same external bus unit (EBU) as PCI.
28 * To make PCI work we need to enable the endianness swapping for the address
29 * written to the EBU. This endianness swapping works for PCI correctly but
30 * fails for attached NOR devices. To workaround this we need to use a complex
31 * map. The workaround involves swapping all addresses whilst probing the chip.
32 * Once probing is complete we stop swapping the addresses but swizzle the
33 * unlock addresses to ensure that access to the NOR device works correctly.
36 enum {
37 LTQ_NOR_PROBING,
38 LTQ_NOR_NORMAL
41 struct ltq_mtd {
42 struct resource *res;
43 struct mtd_info *mtd;
44 struct map_info *map;
47 static char ltq_map_name[] = "ltq_nor";
49 static map_word
50 ltq_read16(struct map_info *map, unsigned long adr)
52 unsigned long flags;
53 map_word temp;
55 if (map->map_priv_1 == LTQ_NOR_PROBING)
56 adr ^= 2;
57 spin_lock_irqsave(&ebu_lock, flags);
58 temp.x[0] = *(u16 *)(map->virt + adr);
59 spin_unlock_irqrestore(&ebu_lock, flags);
60 return temp;
63 static void
64 ltq_write16(struct map_info *map, map_word d, unsigned long adr)
66 unsigned long flags;
68 if (map->map_priv_1 == LTQ_NOR_PROBING)
69 adr ^= 2;
70 spin_lock_irqsave(&ebu_lock, flags);
71 *(u16 *)(map->virt + adr) = d.x[0];
72 spin_unlock_irqrestore(&ebu_lock, flags);
76 * The following 2 functions copy data between iomem and a cached memory
77 * section. As memcpy() makes use of pre-fetching we cannot use it here.
78 * The normal alternative of using memcpy_{to,from}io also makes use of
79 * memcpy() on MIPS so it is not applicable either. We are therefore stuck
80 * with having to use our own loop.
82 static void
83 ltq_copy_from(struct map_info *map, void *to,
84 unsigned long from, ssize_t len)
86 unsigned char *f = (unsigned char *)map->virt + from;
87 unsigned char *t = (unsigned char *)to;
88 unsigned long flags;
90 spin_lock_irqsave(&ebu_lock, flags);
91 while (len--)
92 *t++ = *f++;
93 spin_unlock_irqrestore(&ebu_lock, flags);
96 static void
97 ltq_copy_to(struct map_info *map, unsigned long to,
98 const void *from, ssize_t len)
100 unsigned char *f = (unsigned char *)from;
101 unsigned char *t = (unsigned char *)map->virt + to;
102 unsigned long flags;
104 spin_lock_irqsave(&ebu_lock, flags);
105 while (len--)
106 *t++ = *f++;
107 spin_unlock_irqrestore(&ebu_lock, flags);
110 static int __init
111 ltq_mtd_probe(struct platform_device *pdev)
113 struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev);
114 struct ltq_mtd *ltq_mtd;
115 struct resource *res;
116 struct cfi_private *cfi;
117 int err;
119 ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
120 platform_set_drvdata(pdev, ltq_mtd);
122 ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
123 if (!ltq_mtd->res) {
124 dev_err(&pdev->dev, "failed to get memory resource");
125 err = -ENOENT;
126 goto err_out;
129 res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start,
130 resource_size(ltq_mtd->res), dev_name(&pdev->dev));
131 if (!ltq_mtd->res) {
132 dev_err(&pdev->dev, "failed to request mem resource");
133 err = -EBUSY;
134 goto err_out;
137 ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
138 ltq_mtd->map->phys = res->start;
139 ltq_mtd->map->size = resource_size(res);
140 ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev,
141 ltq_mtd->map->phys, ltq_mtd->map->size);
142 if (!ltq_mtd->map->virt) {
143 dev_err(&pdev->dev, "failed to ioremap!\n");
144 err = -ENOMEM;
145 goto err_free;
148 ltq_mtd->map->name = ltq_map_name;
149 ltq_mtd->map->bankwidth = 2;
150 ltq_mtd->map->read = ltq_read16;
151 ltq_mtd->map->write = ltq_write16;
152 ltq_mtd->map->copy_from = ltq_copy_from;
153 ltq_mtd->map->copy_to = ltq_copy_to;
155 ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
156 ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
157 ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
159 if (!ltq_mtd->mtd) {
160 dev_err(&pdev->dev, "probing failed\n");
161 err = -ENXIO;
162 goto err_free;
165 ltq_mtd->mtd->owner = THIS_MODULE;
167 cfi = ltq_mtd->map->fldrv_priv;
168 cfi->addr_unlock1 ^= 1;
169 cfi->addr_unlock2 ^= 1;
171 err = mtd_device_parse_register(ltq_mtd->mtd, NULL, 0,
172 ltq_mtd_data->parts, ltq_mtd_data->nr_parts);
173 if (err) {
174 dev_err(&pdev->dev, "failed to add partitions\n");
175 goto err_destroy;
178 return 0;
180 err_destroy:
181 map_destroy(ltq_mtd->mtd);
182 err_free:
183 kfree(ltq_mtd->map);
184 err_out:
185 kfree(ltq_mtd);
186 return err;
189 static int __devexit
190 ltq_mtd_remove(struct platform_device *pdev)
192 struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
194 if (ltq_mtd) {
195 if (ltq_mtd->mtd) {
196 mtd_device_unregister(ltq_mtd->mtd);
197 map_destroy(ltq_mtd->mtd);
199 kfree(ltq_mtd->map);
200 kfree(ltq_mtd);
202 return 0;
205 static struct platform_driver ltq_mtd_driver = {
206 .remove = __devexit_p(ltq_mtd_remove),
207 .driver = {
208 .name = "ltq_nor",
209 .owner = THIS_MODULE,
213 static int __init
214 init_ltq_mtd(void)
216 int ret = platform_driver_probe(&ltq_mtd_driver, ltq_mtd_probe);
218 if (ret)
219 pr_err("ltq_nor: error registering platform driver");
220 return ret;
223 static void __exit
224 exit_ltq_mtd(void)
226 platform_driver_unregister(&ltq_mtd_driver);
229 module_init(init_ltq_mtd);
230 module_exit(exit_ltq_mtd);
232 MODULE_LICENSE("GPL");
233 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
234 MODULE_DESCRIPTION("Lantiq SoC NOR");