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