Merge tag 'dmaengine-4.10-rc1' of git://git.infradead.org/users/vkoul/slave-dma
[linux-2.6-block.git] / drivers / mtd / maps / lantiq-flash.c
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/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>
22 #include <linux/of.h>
23
24 #include <lantiq_soc.h>
25
26 /*
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.
34  */
35
36 enum {
37         LTQ_NOR_PROBING,
38         LTQ_NOR_NORMAL
39 };
40
41 struct ltq_mtd {
42         struct resource *res;
43         struct mtd_info *mtd;
44         struct map_info *map;
45 };
46
47 static const char ltq_map_name[] = "ltq_nor";
48
49 static map_word
50 ltq_read16(struct map_info *map, unsigned long adr)
51 {
52         unsigned long flags;
53         map_word temp;
54
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;
61 }
62
63 static void
64 ltq_write16(struct map_info *map, map_word d, unsigned long adr)
65 {
66         unsigned long flags;
67
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);
73 }
74
75 /*
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.
81  */
82 static void
83 ltq_copy_from(struct map_info *map, void *to,
84         unsigned long from, ssize_t len)
85 {
86         unsigned char *f = (unsigned char *)map->virt + from;
87         unsigned char *t = (unsigned char *)to;
88         unsigned long flags;
89
90         spin_lock_irqsave(&ebu_lock, flags);
91         while (len--)
92                 *t++ = *f++;
93         spin_unlock_irqrestore(&ebu_lock, flags);
94 }
95
96 static void
97 ltq_copy_to(struct map_info *map, unsigned long to,
98         const void *from, ssize_t len)
99 {
100         unsigned char *f = (unsigned char *)from;
101         unsigned char *t = (unsigned char *)map->virt + to;
102         unsigned long flags;
103
104         spin_lock_irqsave(&ebu_lock, flags);
105         while (len--)
106                 *t++ = *f++;
107         spin_unlock_irqrestore(&ebu_lock, flags);
108 }
109
110 static int
111 ltq_mtd_probe(struct platform_device *pdev)
112 {
113         struct ltq_mtd *ltq_mtd;
114         struct cfi_private *cfi;
115         int err;
116
117         if (of_machine_is_compatible("lantiq,falcon") &&
118                         (ltq_boot_select() != BS_FLASH)) {
119                 dev_err(&pdev->dev, "invalid bootstrap options\n");
120                 return -ENODEV;
121         }
122
123         ltq_mtd = devm_kzalloc(&pdev->dev, sizeof(struct ltq_mtd), GFP_KERNEL);
124         if (!ltq_mtd)
125                 return -ENOMEM;
126
127         platform_set_drvdata(pdev, ltq_mtd);
128
129         ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
130         if (!ltq_mtd->res) {
131                 dev_err(&pdev->dev, "failed to get memory resource\n");
132                 return -ENOENT;
133         }
134
135         ltq_mtd->map = devm_kzalloc(&pdev->dev, sizeof(struct map_info),
136                                     GFP_KERNEL);
137         if (!ltq_mtd->map)
138                 return -ENOMEM;
139
140         ltq_mtd->map->phys = ltq_mtd->res->start;
141         ltq_mtd->map->size = resource_size(ltq_mtd->res);
142         ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res);
143         if (IS_ERR(ltq_mtd->map->virt))
144                 return PTR_ERR(ltq_mtd->map->virt);
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                 return -ENXIO;
160         }
161
162         ltq_mtd->mtd->dev.parent = &pdev->dev;
163         mtd_set_of_node(ltq_mtd->mtd, pdev->dev.of_node);
164
165         cfi = ltq_mtd->map->fldrv_priv;
166         cfi->addr_unlock1 ^= 1;
167         cfi->addr_unlock2 ^= 1;
168
169         err = mtd_device_register(ltq_mtd->mtd, NULL, 0);
170         if (err) {
171                 dev_err(&pdev->dev, "failed to add partitions\n");
172                 goto err_destroy;
173         }
174
175         return 0;
176
177 err_destroy:
178         map_destroy(ltq_mtd->mtd);
179         return err;
180 }
181
182 static int
183 ltq_mtd_remove(struct platform_device *pdev)
184 {
185         struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
186
187         if (ltq_mtd && ltq_mtd->mtd) {
188                 mtd_device_unregister(ltq_mtd->mtd);
189                 map_destroy(ltq_mtd->mtd);
190         }
191         return 0;
192 }
193
194 static const struct of_device_id ltq_mtd_match[] = {
195         { .compatible = "lantiq,nor" },
196         {},
197 };
198 MODULE_DEVICE_TABLE(of, ltq_mtd_match);
199
200 static struct platform_driver ltq_mtd_driver = {
201         .probe = ltq_mtd_probe,
202         .remove = ltq_mtd_remove,
203         .driver = {
204                 .name = "ltq-nor",
205                 .of_match_table = ltq_mtd_match,
206         },
207 };
208
209 module_platform_driver(ltq_mtd_driver);
210
211 MODULE_LICENSE("GPL");
212 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
213 MODULE_DESCRIPTION("Lantiq SoC NOR");