summaryrefslogtreecommitdiffstats
path: root/drivers/mtd/maps/plat-ram.c
blob: 4c921dce739664bc8d94f37a58d483b06ef852dc (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
// SPDX-License-Identifier: GPL-2.0-or-later
/* 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 platform device based RAM map
*/

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/platform_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 platdata_mtd_ram	*pdata;
};

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

static inline struct platram_info *to_platram_info(struct platform_device *dev)
{
	return platform_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 platform_device *pdev)
{
	struct platram_info *info = to_platram_info(pdev);

	dev_dbg(&pdev->dev, "removing device\n");

	if (info == NULL)
		return 0;

	if (info->mtd) {
		mtd_device_unregister(info->mtd);
		map_destroy(info->mtd);
	}

	/* ensure ram is left read-only */

	platram_setrw(info, PLATRAM_RO);

	kfree(info);

	return 0;
}

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

static int platram_probe(struct platform_device *pdev)
{
	struct platdata_mtd_ram	*pdata;
	struct platram_info *info;
	struct resource *res;
	int err = 0;

	dev_dbg(&pdev->dev, "probe entered\n");

	if (dev_get_platdata(&pdev->dev) == NULL) {
		dev_err(&pdev->dev, "no platform data supplied\n");
		err = -ENOENT;
		goto exit_error;
	}

	pdata = dev_get_platdata(&pdev->dev);

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (info == NULL) {
		err = -ENOMEM;
		goto exit_error;
	}

	platform_set_drvdata(pdev, info);

	info->dev = &pdev->dev;
	info->pdata = pdata;

	/* get the resource for the memory mapping */
	info->map.virt = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
	if (IS_ERR(info->map.virt)) {
		err = PTR_ERR(info->map.virt);
		goto exit_free;
	}

	dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res,
		(unsigned long long)res->start);

	/* setup map parameters */

	info->map.phys = res->start;
	info->map.size = resource_size(res);
	info->map.name = pdata->mapname != NULL ?
			(char *)pdata->mapname : (char *)pdev->name;
	info->map.bankwidth = pdata->bankwidth;

	dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);

	simple_map_init(&info->map);

	dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");

	/* probe for the right mtd map driver
	 * supplied by the platform_data struct */

	if (pdata->map_probes) {
		const char * const *map_probes = pdata->map_probes;

		for ( ; !info->mtd && *map_probes; map_probes++)
			info->mtd = do_map_probe(*map_probes , &info->map);
	}
	/* fallback to map_ram */
	else
		info->mtd = do_map_probe("map_ram", &info->map);

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

	info->mtd->dev.parent = &pdev->dev;

	platram_setrw(info, PLATRAM_RW);

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

	err = mtd_device_parse_register(info->mtd, pdata->probes, NULL,
					pdata->partitions,
					pdata->nr_partitions);
	if (err) {
		dev_err(&pdev->dev, "failed to register mtd device\n");
		goto exit_free;
	}

	dev_info(&pdev->dev, "registered mtd device\n");

	if (pdata->nr_partitions) {
		/* add the whole device. */
		err = mtd_device_register(info->mtd, NULL, 0);
		if (err) {
			dev_err(&pdev->dev,
				"failed to register the entire device\n");
			goto exit_free;
		}
	}

	return 0;

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

/* device driver info */

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:mtd-ram");

static struct platform_driver platram_driver = {
	.probe		= platram_probe,
	.remove		= platram_remove,
	.driver		= {
		.name	= "mtd-ram",
	},
};

module_platform_driver(platram_driver);

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