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>
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/kernel.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>
26 * The NOR flash is connected to the same external bus unit (EBU) as PCI.
27 * To make PCI work we need to enable the endianness swapping for the address
28 * written to the EBU. This endianness swapping works for PCI correctly but
29 * fails for attached NOR devices. To workaround this we need to use a complex
30 * map. The workaround involves swapping all addresses whilst probing the chip.
31 * Once probing is complete we stop swapping the addresses but swizzle the
32 * unlock addresses to ensure that access to the NOR device works correctly.
46 static const char ltq_map_name[] = "ltq_nor";
47 static const char *ltq_probe_types[] __devinitconst = {
48 "cmdlinepart", "ofpart", NULL };
51 ltq_read16(struct map_info *map, unsigned long adr)
56 if (map->map_priv_1 == LTQ_NOR_PROBING)
58 spin_lock_irqsave(&ebu_lock, flags);
59 temp.x[0] = *(u16 *)(map->virt + adr);
60 spin_unlock_irqrestore(&ebu_lock, flags);
65 ltq_write16(struct map_info *map, map_word d, unsigned long adr)
69 if (map->map_priv_1 == LTQ_NOR_PROBING)
71 spin_lock_irqsave(&ebu_lock, flags);
72 *(u16 *)(map->virt + adr) = d.x[0];
73 spin_unlock_irqrestore(&ebu_lock, flags);
77 * The following 2 functions copy data between iomem and a cached memory
78 * section. As memcpy() makes use of pre-fetching we cannot use it here.
79 * The normal alternative of using memcpy_{to,from}io also makes use of
80 * memcpy() on MIPS so it is not applicable either. We are therefore stuck
81 * with having to use our own loop.
84 ltq_copy_from(struct map_info *map, void *to,
85 unsigned long from, ssize_t len)
87 unsigned char *f = (unsigned char *)map->virt + from;
88 unsigned char *t = (unsigned char *)to;
91 spin_lock_irqsave(&ebu_lock, flags);
94 spin_unlock_irqrestore(&ebu_lock, flags);
98 ltq_copy_to(struct map_info *map, unsigned long to,
99 const void *from, ssize_t len)
101 unsigned char *f = (unsigned char *)from;
102 unsigned char *t = (unsigned char *)map->virt + to;
105 spin_lock_irqsave(&ebu_lock, flags);
108 spin_unlock_irqrestore(&ebu_lock, flags);
112 ltq_mtd_probe(struct platform_device *pdev)
114 struct mtd_part_parser_data ppdata;
115 struct ltq_mtd *ltq_mtd;
116 struct cfi_private *cfi;
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);
124 dev_err(&pdev->dev, "failed to get memory resource\n");
129 ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
130 ltq_mtd->map->phys = ltq_mtd->res->start;
131 ltq_mtd->map->size = resource_size(ltq_mtd->res);
132 ltq_mtd->map->virt = devm_request_and_ioremap(&pdev->dev, ltq_mtd->res);
133 if (!ltq_mtd->map->virt) {
134 dev_err(&pdev->dev, "failed to remap mem resource\n");
139 ltq_mtd->map->name = ltq_map_name;
140 ltq_mtd->map->bankwidth = 2;
141 ltq_mtd->map->read = ltq_read16;
142 ltq_mtd->map->write = ltq_write16;
143 ltq_mtd->map->copy_from = ltq_copy_from;
144 ltq_mtd->map->copy_to = ltq_copy_to;
146 ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
147 ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
148 ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
151 dev_err(&pdev->dev, "probing failed\n");
156 ltq_mtd->mtd->owner = THIS_MODULE;
158 cfi = ltq_mtd->map->fldrv_priv;
159 cfi->addr_unlock1 ^= 1;
160 cfi->addr_unlock2 ^= 1;
162 ppdata.of_node = pdev->dev.of_node;
163 err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types,
166 dev_err(&pdev->dev, "failed to add partitions\n");
173 map_destroy(ltq_mtd->mtd);
182 ltq_mtd_remove(struct platform_device *pdev)
184 struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
188 mtd_device_unregister(ltq_mtd->mtd);
189 map_destroy(ltq_mtd->mtd);
197 static const struct of_device_id ltq_mtd_match[] = {
198 { .compatible = "lantiq,nor" },
201 MODULE_DEVICE_TABLE(of, ltq_mtd_match);
203 static struct platform_driver ltq_mtd_driver = {
204 .probe = ltq_mtd_probe,
205 .remove = __devexit_p(ltq_mtd_remove),
208 .owner = THIS_MODULE,
209 .of_match_table = ltq_mtd_match,
213 module_platform_driver(ltq_mtd_driver);
215 MODULE_LICENSE("GPL");
216 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
217 MODULE_DESCRIPTION("Lantiq SoC NOR");