tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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.
5 *
6 * Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
7 * Copyright (C) 2010 John Crispin <blogic@openwrt.org>
8 */
9
10#include <linux/err.h>
11#include <linux/module.h>
12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/io.h>
15#include <linux/slab.h>
16#include <linux/init.h>
17#include <linux/mtd/mtd.h>
18#include <linux/mtd/map.h>
19#include <linux/mtd/partitions.h>
20#include <linux/mtd/cfi.h>
21#include <linux/platform_device.h>
22#include <linux/mtd/physmap.h>
23#include <linux/of.h>
24
25#include <lantiq_soc.h>
26
27/*
28 * The NOR flash is connected to the same external bus unit (EBU) as PCI.
29 * To make PCI work we need to enable the endianness swapping for the address
30 * written to the EBU. This endianness swapping works for PCI correctly but
31 * fails for attached NOR devices. To workaround this we need to use a complex
32 * map. The workaround involves swapping all addresses whilst probing the chip.
33 * Once probing is complete we stop swapping the addresses but swizzle the
34 * unlock addresses to ensure that access to the NOR device works correctly.
35 */
36
37enum {
38 LTQ_NOR_PROBING,
39 LTQ_NOR_NORMAL
40};
41
42struct ltq_mtd {
43 struct resource *res;
44 struct mtd_info *mtd;
45 struct map_info *map;
46};
47
48static const char ltq_map_name[] = "ltq_nor";
49static const char *ltq_probe_types[] = {
50 "cmdlinepart", "ofpart", NULL };
51
52static map_word
53ltq_read16(struct map_info *map, unsigned long adr)
54{
55 unsigned long flags;
56 map_word temp;
57
58 if (map->map_priv_1 == LTQ_NOR_PROBING)
59 adr ^= 2;
60 spin_lock_irqsave(&ebu_lock, flags);
61 temp.x[0] = *(u16 *)(map->virt + adr);
62 spin_unlock_irqrestore(&ebu_lock, flags);
63 return temp;
64}
65
66static void
67ltq_write16(struct map_info *map, map_word d, unsigned long adr)
68{
69 unsigned long flags;
70
71 if (map->map_priv_1 == LTQ_NOR_PROBING)
72 adr ^= 2;
73 spin_lock_irqsave(&ebu_lock, flags);
74 *(u16 *)(map->virt + adr) = d.x[0];
75 spin_unlock_irqrestore(&ebu_lock, flags);
76}
77
78/*
79 * The following 2 functions copy data between iomem and a cached memory
80 * section. As memcpy() makes use of pre-fetching we cannot use it here.
81 * The normal alternative of using memcpy_{to,from}io also makes use of
82 * memcpy() on MIPS so it is not applicable either. We are therefore stuck
83 * with having to use our own loop.
84 */
85static void
86ltq_copy_from(struct map_info *map, void *to,
87 unsigned long from, ssize_t len)
88{
89 unsigned char *f = (unsigned char *)map->virt + from;
90 unsigned char *t = (unsigned char *)to;
91 unsigned long flags;
92
93 spin_lock_irqsave(&ebu_lock, flags);
94 while (len--)
95 *t++ = *f++;
96 spin_unlock_irqrestore(&ebu_lock, flags);
97}
98
99static void
100ltq_copy_to(struct map_info *map, unsigned long to,
101 const void *from, ssize_t len)
102{
103 unsigned char *f = (unsigned char *)from;
104 unsigned char *t = (unsigned char *)map->virt + to;
105 unsigned long flags;
106
107 spin_lock_irqsave(&ebu_lock, flags);
108 while (len--)
109 *t++ = *f++;
110 spin_unlock_irqrestore(&ebu_lock, flags);
111}
112
113static int
114ltq_mtd_probe(struct platform_device *pdev)
115{
116 struct mtd_part_parser_data ppdata;
117 struct ltq_mtd *ltq_mtd;
118 struct cfi_private *cfi;
119 int err;
120
121 if (of_machine_is_compatible("lantiq,falcon") &&
122 (ltq_boot_select() != BS_FLASH)) {
123 dev_err(&pdev->dev, "invalid bootstrap options\n");
124 return -ENODEV;
125 }
126
127 ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
128 platform_set_drvdata(pdev, ltq_mtd);
129
130 ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
131 if (!ltq_mtd->res) {
132 dev_err(&pdev->dev, "failed to get memory resource\n");
133 err = -ENOENT;
134 goto err_out;
135 }
136
137 ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
138 ltq_mtd->map->phys = ltq_mtd->res->start;
139 ltq_mtd->map->size = resource_size(ltq_mtd->res);
140 ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res);
141 if (IS_ERR(ltq_mtd->map->virt)) {
142 err = PTR_ERR(ltq_mtd->map->virt);
143 goto err_out;
144 }
145
146 ltq_mtd->map->name = ltq_map_name;
147 ltq_mtd->map->bankwidth = 2;
148 ltq_mtd->map->read = ltq_read16;
149 ltq_mtd->map->write = ltq_write16;
150 ltq_mtd->map->copy_from = ltq_copy_from;
151 ltq_mtd->map->copy_to = ltq_copy_to;
152
153 ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
154 ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
155 ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
156
157 if (!ltq_mtd->mtd) {
158 dev_err(&pdev->dev, "probing failed\n");
159 err = -ENXIO;
160 goto err_free;
161 }
162
163 ltq_mtd->mtd->owner = THIS_MODULE;
164
165 cfi = ltq_mtd->map->fldrv_priv;
166 cfi->addr_unlock1 ^= 1;
167 cfi->addr_unlock2 ^= 1;
168
169 ppdata.of_node = pdev->dev.of_node;
170 err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types,
171 &ppdata, NULL, 0);
172 if (err) {
173 dev_err(&pdev->dev, "failed to add partitions\n");
174 goto err_destroy;
175 }
176
177 return 0;
178
179err_destroy:
180 map_destroy(ltq_mtd->mtd);
181err_free:
182 kfree(ltq_mtd->map);
183err_out:
184 kfree(ltq_mtd);
185 return err;
186}
187
188static int
189ltq_mtd_remove(struct platform_device *pdev)
190{
191 struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
192
193 if (ltq_mtd) {
194 if (ltq_mtd->mtd) {
195 mtd_device_unregister(ltq_mtd->mtd);
196 map_destroy(ltq_mtd->mtd);
197 }
198 kfree(ltq_mtd->map);
199 kfree(ltq_mtd);
200 }
201 return 0;
202}
203
204static const struct of_device_id ltq_mtd_match[] = {
205 { .compatible = "lantiq,nor" },
206 {},
207};
208MODULE_DEVICE_TABLE(of, ltq_mtd_match);
209
210static struct platform_driver ltq_mtd_driver = {
211 .probe = ltq_mtd_probe,
212 .remove = ltq_mtd_remove,
213 .driver = {
214 .name = "ltq-nor",
215 .owner = THIS_MODULE,
216 .of_match_table = ltq_mtd_match,
217 },
218};
219
220module_platform_driver(ltq_mtd_driver);
221
222MODULE_LICENSE("GPL");
223MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
224MODULE_DESCRIPTION("Lantiq SoC NOR");