1/* drivers/mtd/maps/plat-ram.c
2 *
3 * (c) 2004-2005 Simtec Electronics
4 *	http://www.simtec.co.uk/products/SWLINUX/
5 *	Ben Dooks <ben@simtec.co.uk>
6 *
7 * Generic platfrom device based RAM map
8 *
9 * $Id: plat-ram.c,v 1.1.1.1 2007/08/03 18:52:44 Exp $
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
24*/
25
26#include <linux/module.h>
27#include <linux/types.h>
28#include <linux/init.h>
29#include <linux/kernel.h>
30#include <linux/string.h>
31#include <linux/ioport.h>
32#include <linux/device.h>
33#include <linux/slab.h>
34#include <linux/platform_device.h>
35
36#include <linux/mtd/mtd.h>
37#include <linux/mtd/map.h>
38#include <linux/mtd/partitions.h>
39#include <linux/mtd/plat-ram.h>
40
41#include <asm/io.h>
42
43/* private structure for each mtd platform ram device created */
44
45struct platram_info {
46	struct device		*dev;
47	struct mtd_info		*mtd;
48	struct map_info		 map;
49	struct mtd_partition	*partitions;
50	struct resource		*area;
51	struct platdata_mtd_ram	*pdata;
52};
53
54/* to_platram_info()
55 *
56 * device private data to struct platram_info conversion
57*/
58
59static inline struct platram_info *to_platram_info(struct platform_device *dev)
60{
61	return (struct platram_info *)platform_get_drvdata(dev);
62}
63
64/* platram_setrw
65 *
66 * call the platform device's set rw/ro control
67 *
68 * to = 0 => read-only
69 *    = 1 => read-write
70*/
71
72static inline void platram_setrw(struct platram_info *info, int to)
73{
74	if (info->pdata == NULL)
75		return;
76
77	if (info->pdata->set_rw != NULL)
78		(info->pdata->set_rw)(info->dev, to);
79}
80
81/* platram_remove
82 *
83 * called to remove the device from the driver's control
84*/
85
86static int platram_remove(struct platform_device *pdev)
87{
88	struct platram_info *info = to_platram_info(pdev);
89
90	platform_set_drvdata(pdev, NULL);
91
92	dev_dbg(&pdev->dev, "removing device\n");
93
94	if (info == NULL)
95		return 0;
96
97	if (info->mtd) {
98#ifdef CONFIG_MTD_PARTITIONS
99		if (info->partitions) {
100			del_mtd_partitions(info->mtd);
101			kfree(info->partitions);
102		}
103#endif
104		del_mtd_device(info->mtd);
105		map_destroy(info->mtd);
106	}
107
108	/* ensure ram is left read-only */
109
110	platram_setrw(info, PLATRAM_RO);
111
112	/* release resources */
113
114	if (info->area) {
115		release_resource(info->area);
116		kfree(info->area);
117	}
118
119	if (info->map.virt != NULL)
120		iounmap(info->map.virt);
121
122	kfree(info);
123
124	return 0;
125}
126
127/* platram_probe
128 *
129 * called from device drive system when a device matching our
130 * driver is found.
131*/
132
133static int platram_probe(struct platform_device *pdev)
134{
135	struct platdata_mtd_ram	*pdata;
136	struct platram_info *info;
137	struct resource *res;
138	int err = 0;
139
140	dev_dbg(&pdev->dev, "probe entered\n");
141
142	if (pdev->dev.platform_data == NULL) {
143		dev_err(&pdev->dev, "no platform data supplied\n");
144		err = -ENOENT;
145		goto exit_error;
146	}
147
148	pdata = pdev->dev.platform_data;
149
150	info = kzalloc(sizeof(*info), GFP_KERNEL);
151	if (info == NULL) {
152		dev_err(&pdev->dev, "no memory for flash info\n");
153		err = -ENOMEM;
154		goto exit_error;
155	}
156
157	platform_set_drvdata(pdev, info);
158
159	info->dev = &pdev->dev;
160	info->pdata = pdata;
161
162	/* get the resource for the memory mapping */
163
164	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
165
166	if (res == NULL) {
167		dev_err(&pdev->dev, "no memory resource specified\n");
168		err = -ENOENT;
169		goto exit_free;
170	}
171
172	dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res,
173		(unsigned long long)res->start);
174
175	/* setup map parameters */
176
177	info->map.phys = res->start;
178	info->map.size = (res->end - res->start) + 1;
179	info->map.name = pdata->mapname != NULL ? pdata->mapname : (char *)pdev->name;
180	info->map.bankwidth = pdata->bankwidth;
181
182	/* register our usage of the memory area */
183
184	info->area = request_mem_region(res->start, info->map.size, pdev->name);
185	if (info->area == NULL) {
186		dev_err(&pdev->dev, "failed to request memory region\n");
187		err = -EIO;
188		goto exit_free;
189	}
190
191	/* remap the memory area */
192
193	info->map.virt = ioremap(res->start, info->map.size);
194	dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
195
196	if (info->map.virt == NULL) {
197		dev_err(&pdev->dev, "failed to ioremap() region\n");
198		err = -EIO;
199		goto exit_free;
200	}
201
202	simple_map_init(&info->map);
203
204	dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");
205
206	/* probe for the right mtd map driver */
207
208	info->mtd = do_map_probe("map_ram" , &info->map);
209	if (info->mtd == NULL) {
210		dev_err(&pdev->dev, "failed to probe for map_ram\n");
211		err = -ENOMEM;
212		goto exit_free;
213	}
214
215	info->mtd->owner = THIS_MODULE;
216
217	platram_setrw(info, PLATRAM_RW);
218
219	/* check to see if there are any available partitions, or wether
220	 * to add this device whole */
221
222#ifdef CONFIG_MTD_PARTITIONS
223	if (pdata->nr_partitions > 0) {
224		const char **probes = { NULL };
225
226		if (pdata->probes)
227			probes = (const char **)pdata->probes;
228
229		err = parse_mtd_partitions(info->mtd, probes,
230					   &info->partitions, 0);
231		if (err > 0) {
232			err = add_mtd_partitions(info->mtd, info->partitions,
233						 err);
234		}
235	}
236#endif /* CONFIG_MTD_PARTITIONS */
237
238	if (add_mtd_device(info->mtd)) {
239		dev_err(&pdev->dev, "add_mtd_device() failed\n");
240		err = -ENOMEM;
241	}
242
243	dev_info(&pdev->dev, "registered mtd device\n");
244	return err;
245
246 exit_free:
247	platram_remove(pdev);
248 exit_error:
249	return err;
250}
251
252/* device driver info */
253
254static struct platform_driver platram_driver = {
255	.probe		= platram_probe,
256	.remove		= platram_remove,
257	.driver		= {
258		.name	= "mtd-ram",
259		.owner	= THIS_MODULE,
260	},
261};
262
263/* module init/exit */
264
265static int __init platram_init(void)
266{
267	printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
268	return platform_driver_register(&platram_driver);
269}
270
271static void __exit platram_exit(void)
272{
273	platform_driver_unregister(&platram_driver);
274}
275
276module_init(platram_init);
277module_exit(platram_exit);
278
279MODULE_LICENSE("GPL");
280MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
281MODULE_DESCRIPTION("MTD platform RAM map driver");
282