1 /*
2 * Interface for NOR flash driver whose high address lines are latched
3 *
4 * Copyright © 2000 Nicolas Pitre <nico@cam.org>
5 * Copyright © 2005-2008 Analog Devices Inc.
6 * Copyright © 2008 MontaVista Software, Inc. <source@mvista.com>
7 *
8 * This file is licensed under the terms of the GNU General Public License
9 * version 2. This program is licensed "as is" without any warranty of any
10 * kind, whether express or implied.
11 */
12
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/mtd/map.h>
18 #include <linux/mtd/partitions.h>
19 #include <linux/platform_device.h>
20 #include <linux/mtd/latch-addr-flash.h>
21 #include <linux/slab.h>
22
23 #define DRIVER_NAME "latch-addr-flash"
24
25 struct latch_addr_flash_info {
26 struct mtd_info *mtd;
27 struct map_info map;
28 struct resource *res;
29
30 void (*set_window)(unsigned long offset, void *data);
31 void *data;
32
33 /* cache; could be found out of res */
34 unsigned long win_mask;
35
36 spinlock_t lock;
37 };
38
lf_read(struct map_info * map,unsigned long ofs)39 static map_word lf_read(struct map_info *map, unsigned long ofs)
40 {
41 struct latch_addr_flash_info *info;
42 map_word datum;
43
44 info = (struct latch_addr_flash_info *)map->map_priv_1;
45
46 spin_lock(&info->lock);
47
48 info->set_window(ofs, info->data);
49 datum = inline_map_read(map, info->win_mask & ofs);
50
51 spin_unlock(&info->lock);
52
53 return datum;
54 }
55
lf_write(struct map_info * map,map_word datum,unsigned long ofs)56 static void lf_write(struct map_info *map, map_word datum, unsigned long ofs)
57 {
58 struct latch_addr_flash_info *info;
59
60 info = (struct latch_addr_flash_info *)map->map_priv_1;
61
62 spin_lock(&info->lock);
63
64 info->set_window(ofs, info->data);
65 inline_map_write(map, datum, info->win_mask & ofs);
66
67 spin_unlock(&info->lock);
68 }
69
lf_copy_from(struct map_info * map,void * to,unsigned long from,ssize_t len)70 static void lf_copy_from(struct map_info *map, void *to,
71 unsigned long from, ssize_t len)
72 {
73 struct latch_addr_flash_info *info =
74 (struct latch_addr_flash_info *) map->map_priv_1;
75 unsigned n;
76
77 while (len > 0) {
78 n = info->win_mask + 1 - (from & info->win_mask);
79 if (n > len)
80 n = len;
81
82 spin_lock(&info->lock);
83
84 info->set_window(from, info->data);
85 memcpy_fromio(to, map->virt + (from & info->win_mask), n);
86
87 spin_unlock(&info->lock);
88
89 to += n;
90 from += n;
91 len -= n;
92 }
93 }
94
95 static char *rom_probe_types[] = { "cfi_probe", NULL };
96
latch_addr_flash_remove(struct platform_device * dev)97 static int latch_addr_flash_remove(struct platform_device *dev)
98 {
99 struct latch_addr_flash_info *info;
100 struct latch_addr_flash_data *latch_addr_data;
101
102 info = platform_get_drvdata(dev);
103 if (info == NULL)
104 return 0;
105 platform_set_drvdata(dev, NULL);
106
107 latch_addr_data = dev->dev.platform_data;
108
109 if (info->mtd != NULL) {
110 mtd_device_unregister(info->mtd);
111 map_destroy(info->mtd);
112 }
113
114 if (info->map.virt != NULL)
115 iounmap(info->map.virt);
116
117 if (info->res != NULL)
118 release_mem_region(info->res->start, resource_size(info->res));
119
120 kfree(info);
121
122 if (latch_addr_data->done)
123 latch_addr_data->done(latch_addr_data->data);
124
125 return 0;
126 }
127
latch_addr_flash_probe(struct platform_device * dev)128 static int __devinit latch_addr_flash_probe(struct platform_device *dev)
129 {
130 struct latch_addr_flash_data *latch_addr_data;
131 struct latch_addr_flash_info *info;
132 resource_size_t win_base = dev->resource->start;
133 resource_size_t win_size = resource_size(dev->resource);
134 char **probe_type;
135 int chipsel;
136 int err;
137
138 latch_addr_data = dev->dev.platform_data;
139 if (latch_addr_data == NULL)
140 return -ENODEV;
141
142 pr_notice("latch-addr platform flash device: %#llx byte "
143 "window at %#.8llx\n",
144 (unsigned long long)win_size, (unsigned long long)win_base);
145
146 chipsel = dev->id;
147
148 if (latch_addr_data->init) {
149 err = latch_addr_data->init(latch_addr_data->data, chipsel);
150 if (err != 0)
151 return err;
152 }
153
154 info = kzalloc(sizeof(struct latch_addr_flash_info), GFP_KERNEL);
155 if (info == NULL) {
156 err = -ENOMEM;
157 goto done;
158 }
159
160 platform_set_drvdata(dev, info);
161
162 info->res = request_mem_region(win_base, win_size, DRIVER_NAME);
163 if (info->res == NULL) {
164 dev_err(&dev->dev, "Could not reserve memory region\n");
165 err = -EBUSY;
166 goto free_info;
167 }
168
169 info->map.name = DRIVER_NAME;
170 info->map.size = latch_addr_data->size;
171 info->map.bankwidth = latch_addr_data->width;
172
173 info->map.phys = NO_XIP;
174 info->map.virt = ioremap(win_base, win_size);
175 if (!info->map.virt) {
176 err = -ENOMEM;
177 goto free_res;
178 }
179
180 info->map.map_priv_1 = (unsigned long)info;
181
182 info->map.read = lf_read;
183 info->map.copy_from = lf_copy_from;
184 info->map.write = lf_write;
185 info->set_window = latch_addr_data->set_window;
186 info->data = latch_addr_data->data;
187 info->win_mask = win_size - 1;
188
189 spin_lock_init(&info->lock);
190
191 for (probe_type = rom_probe_types; !info->mtd && *probe_type;
192 probe_type++)
193 info->mtd = do_map_probe(*probe_type, &info->map);
194
195 if (info->mtd == NULL) {
196 dev_err(&dev->dev, "map_probe failed\n");
197 err = -ENODEV;
198 goto iounmap;
199 }
200 info->mtd->owner = THIS_MODULE;
201
202 mtd_device_parse_register(info->mtd, NULL, 0,
203 latch_addr_data->parts, latch_addr_data->nr_parts);
204 return 0;
205
206 iounmap:
207 iounmap(info->map.virt);
208 free_res:
209 release_mem_region(info->res->start, resource_size(info->res));
210 free_info:
211 kfree(info);
212 done:
213 if (latch_addr_data->done)
214 latch_addr_data->done(latch_addr_data->data);
215 return err;
216 }
217
218 static struct platform_driver latch_addr_flash_driver = {
219 .probe = latch_addr_flash_probe,
220 .remove = __devexit_p(latch_addr_flash_remove),
221 .driver = {
222 .name = DRIVER_NAME,
223 },
224 };
225
226 module_platform_driver(latch_addr_flash_driver);
227
228 MODULE_AUTHOR("David Griego <dgriego@mvista.com>");
229 MODULE_DESCRIPTION("MTD map driver for flashes addressed physically with upper "
230 "address lines being set board specifically");
231 MODULE_LICENSE("GPL v2");
232