aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mtd/maps/plat-ram.c
blob: 808f94346add61e5134a1fac88072aa39ca0c315 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
/* drivers/mtd/maps/plat-ram.c
 *
 * (c) 2004-2005 Simtec Electronics
 *	http://www.simtec.co.uk/products/SWLINUX/
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * Generic platfrom device based RAM map
 *
 * $Id: plat-ram.c,v 1.1 2005/01/24 00:37:02 bjd Exp $
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#define DEBUG

#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/device.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/plat-ram.h>

#include <asm/io.h>

/* private structure for each mtd platform ram device created */

struct platram_info {
	struct device		*dev;
	struct mtd_info		*mtd;
	struct map_info		 map;
	struct mtd_partition	*partitions;
	struct resource		*area;
	struct platdata_mtd_ram	*pdata;
};

/* to_platram_info()
 *
 * device private data to struct platram_info conversion
*/

static inline struct platram_info *to_platram_info(struct device *dev)
{
	return (struct platram_info *)dev_get_drvdata(dev);
}

/* platram_setrw
 *
 * call the platform device's set rw/ro control
 *
 * to = 0 => read-only
 *    = 1 => read-write
*/

static inline void platram_setrw(struct platram_info *info, int to)
{
	if (info->pdata == NULL)
		return;

	if (info->pdata->set_rw != NULL)
		(info->pdata->set_rw)(info->dev, to);
}

/* platram_remove
 *
 * called to remove the device from the driver's control
*/

static int platram_remove(struct device *dev)
{
	struct platram_info *info = to_platram_info(dev);

	dev_set_drvdata(dev, NULL);

	dev_dbg(dev, "removing device\n");

	if (info == NULL) 
		return 0;

	if (info->mtd) {
#ifdef CONFIG_MTD_PARTITIONS
		if (info->partitions) {
			del_mtd_partitions(info->mtd);
			kfree(info->partitions);
		}
#endif
		del_mtd_device(info->mtd);
		map_destroy(info->mtd);
	}

	/* ensure ram is left read-only */

	platram_setrw(info, PLATRAM_RO);

	/* release resources */

	if (info->area) {
		release_resource(info->area);
		kfree(info->area);
	}

	if (info->map.virt != NULL)
		iounmap(info->map.virt);
	
	kfree(info);

	return 0;
}

/* platram_probe
 *
 * called from device drive system when a device matching our
 * driver is found.
*/

static int platram_probe(struct device *dev)
{
	struct platform_device *pd = to_platform_device(dev);
	struct platdata_mtd_ram	*pdata;
	struct platram_info *info;
	struct resource *res;
	int err = 0;

	dev_dbg(dev, "probe entered\n");
	
	if (dev->platform_data == NULL) {
		dev_err(dev, "no platform data supplied\n");
		err = -ENOENT;
		goto exit_error;
	}

	pdata = dev->platform_data;

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (info == NULL) {
		dev_err(dev, "no memory for flash info\n");
		err = -ENOMEM;
		goto exit_error;
	}

	memzero(info, sizeof(*info));
	dev_set_drvdata(dev, info);

	info->dev = dev;
	info->pdata = pdata;

	/* get the resource for the memory mapping */

	res = platform_get_resource(pd, IORESOURCE_MEM, 0);

	if (res == NULL) {
		dev_err(dev, "no memory resource specified\n");
		err = -ENOENT;
		goto exit_free;
	}

	dev_dbg(dev, "got platform resource %p (0x%lx)\n", res, res->start);

	/* setup map parameters */

	info->map.phys = res->start;
	info->map.size = (res->end - res->start) + 1;
	info->map.name = pdata->mapname != NULL ? pdata->mapname : pd->name;
	info->map.bankwidth = pdata->bankwidth;

	/* register our usage of the memory area */

	info->area = request_mem_region(res->start, info->map.size, pd->name);
	if (info->area == NULL) {
		dev_err(dev, "failed to request memory region\n");
		err = -EIO;
		goto exit_free;
	}

	/* remap the memory area */

	info->map.virt = ioremap(res->start, info->map.size);
	dev_dbg(dev, "virt %p, %d bytes\n", info->map.virt, info->map.size);

	if (info->map.virt == NULL) {
		dev_err(dev, "failed to ioremap() region\n");
		err = -EIO;
		goto exit_free;
	}

	{
		unsigned int *p = (unsigned int *)info->map.virt;
		printk("%08x %08x %08x %08x\n",
		       readl(p), readl(p+1), readl(p+2), readl(p+3));
	}

	simple_map_init(&info->map);

	dev_dbg(dev, "initialised map, probing for mtd\n");

	/* probe for the right mtd map driver */

	info->mtd = do_map_probe("map_ram" , &info->map);
	if (info->mtd == NULL) {
		dev_err(dev, "failed to probe for map_ram\n");
		err = -ENOMEM;
		goto exit_free;
	}

	info->mtd->owner = THIS_MODULE;

	platram_setrw(info, PLATRAM_RW);

	/* check to see if there are any available partitions, or wether
	 * to add this device whole */

#ifdef CONFIG_MTD_PARTITIONS
	if (pdata->nr_partitions > 0) {
		const char **probes = { NULL };

		if (pdata->probes)
			probes = (const char **)pdata->probes;

		err = parse_mtd_partitions(info->mtd, probes,
					   &info->partitions, 0);
		if (err > 0) {
			err = add_mtd_partitions(info->mtd, info->partitions,
						 err);
		}
	}
#endif /* CONFIG_MTD_PARTITIONS */

	if (add_mtd_device(info->mtd)) {
		dev_err(dev, "add_mtd_device() failed\n");
		err = -ENOMEM;
	}
	
	dev_info(dev, "registered mtd device\n");
	return err;

 exit_free:
	platram_remove(dev);
 exit_error:
	return err;
}

/* device driver info */

static struct device_driver platram_driver = {
	.name		= "mtd-ram",
	.bus		= &platform_bus_type,
	.probe		= platram_probe,
	.remove		= platram_remove,
};

/* module init/exit */

static int __init platram_init(void)
{
	printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
	return driver_register(&platram_driver);
}

static void __exit platram_exit(void)
{
	driver_unregister(&platram_driver);
}

module_init(platram_init);
module_exit(platram_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_DESCRIPTION("MTD platform RAM map driver");