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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/mtd/maps/
1/*
2 * Flash memory access on SA11x0 based devices
3 *
4 * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
5 */
6#include <linux/module.h>
7#include <linux/types.h>
8#include <linux/ioport.h>
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/errno.h>
12#include <linux/slab.h>
13#include <linux/platform_device.h>
14#include <linux/err.h>
15#include <linux/io.h>
16
17#include <linux/mtd/mtd.h>
18#include <linux/mtd/map.h>
19#include <linux/mtd/partitions.h>
20#include <linux/mtd/concat.h>
21
22#include <mach/hardware.h>
23#include <asm/sizes.h>
24#include <asm/mach/flash.h>
25
26
27struct sa_subdev_info {
28	char name[16];
29	struct map_info map;
30	struct mtd_info *mtd;
31	struct flash_platform_data *plat;
32};
33
34struct sa_info {
35	struct mtd_partition	*parts;
36	struct mtd_info		*mtd;
37	int			num_subdev;
38	unsigned int		nr_parts;
39	struct sa_subdev_info	subdev[0];
40};
41
42static void sa1100_set_vpp(struct map_info *map, int on)
43{
44	struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map);
45	subdev->plat->set_vpp(on);
46}
47
48static void sa1100_destroy_subdev(struct sa_subdev_info *subdev)
49{
50	if (subdev->mtd)
51		map_destroy(subdev->mtd);
52	if (subdev->map.virt)
53		iounmap(subdev->map.virt);
54	release_mem_region(subdev->map.phys, subdev->map.size);
55}
56
57static int sa1100_probe_subdev(struct sa_subdev_info *subdev, struct resource *res)
58{
59	unsigned long phys;
60	unsigned int size;
61	int ret;
62
63	phys = res->start;
64	size = res->end - phys + 1;
65
66	/*
67	 * Retrieve the bankwidth from the MSC registers.
68	 * We currently only implement CS0 and CS1 here.
69	 */
70	switch (phys) {
71	default:
72		printk(KERN_WARNING "SA1100 flash: unknown base address "
73		       "0x%08lx, assuming CS0\n", phys);
74
75	case SA1100_CS0_PHYS:
76		subdev->map.bankwidth = (MSC0 & MSC_RBW) ? 2 : 4;
77		break;
78
79	case SA1100_CS1_PHYS:
80		subdev->map.bankwidth = ((MSC0 >> 16) & MSC_RBW) ? 2 : 4;
81		break;
82	}
83
84	if (!request_mem_region(phys, size, subdev->name)) {
85		ret = -EBUSY;
86		goto out;
87	}
88
89	if (subdev->plat->set_vpp)
90		subdev->map.set_vpp = sa1100_set_vpp;
91
92	subdev->map.phys = phys;
93	subdev->map.size = size;
94	subdev->map.virt = ioremap(phys, size);
95	if (!subdev->map.virt) {
96		ret = -ENOMEM;
97		goto err;
98	}
99
100	simple_map_init(&subdev->map);
101
102	/*
103	 * Now let's probe for the actual flash.  Do it here since
104	 * specific machine settings might have been set above.
105	 */
106	subdev->mtd = do_map_probe(subdev->plat->map_name, &subdev->map);
107	if (subdev->mtd == NULL) {
108		ret = -ENXIO;
109		goto err;
110	}
111	subdev->mtd->owner = THIS_MODULE;
112
113	printk(KERN_INFO "SA1100 flash: CFI device at 0x%08lx, %uMiB, %d-bit\n",
114		phys, (unsigned)(subdev->mtd->size >> 20),
115		subdev->map.bankwidth * 8);
116
117	return 0;
118
119 err:
120	sa1100_destroy_subdev(subdev);
121 out:
122	return ret;
123}
124
125static void sa1100_destroy(struct sa_info *info, struct flash_platform_data *plat)
126{
127	int i;
128
129	if (info->mtd) {
130		if (info->nr_parts == 0)
131			del_mtd_device(info->mtd);
132#ifdef CONFIG_MTD_PARTITIONS
133		else
134			del_mtd_partitions(info->mtd);
135#endif
136#ifdef CONFIG_MTD_CONCAT
137		if (info->mtd != info->subdev[0].mtd)
138			mtd_concat_destroy(info->mtd);
139#endif
140	}
141
142	kfree(info->parts);
143
144	for (i = info->num_subdev - 1; i >= 0; i--)
145		sa1100_destroy_subdev(&info->subdev[i]);
146	kfree(info);
147
148	if (plat->exit)
149		plat->exit();
150}
151
152static struct sa_info *__devinit
153sa1100_setup_mtd(struct platform_device *pdev, struct flash_platform_data *plat)
154{
155	struct sa_info *info;
156	int nr, size, i, ret = 0;
157
158	/*
159	 * Count number of devices.
160	 */
161	for (nr = 0; ; nr++)
162		if (!platform_get_resource(pdev, IORESOURCE_MEM, nr))
163			break;
164
165	if (nr == 0) {
166		ret = -ENODEV;
167		goto out;
168	}
169
170	size = sizeof(struct sa_info) + sizeof(struct sa_subdev_info) * nr;
171
172	/*
173	 * Allocate the map_info structs in one go.
174	 */
175	info = kzalloc(size, GFP_KERNEL);
176	if (!info) {
177		ret = -ENOMEM;
178		goto out;
179	}
180
181	if (plat->init) {
182		ret = plat->init();
183		if (ret)
184			goto err;
185	}
186
187	/*
188	 * Claim and then map the memory regions.
189	 */
190	for (i = 0; i < nr; i++) {
191		struct sa_subdev_info *subdev = &info->subdev[i];
192		struct resource *res;
193
194		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
195		if (!res)
196			break;
197
198		subdev->map.name = subdev->name;
199		sprintf(subdev->name, "%s-%d", plat->name, i);
200		subdev->plat = plat;
201
202		ret = sa1100_probe_subdev(subdev, res);
203		if (ret)
204			break;
205	}
206
207	info->num_subdev = i;
208
209	/*
210	 * ENXIO is special.  It means we didn't find a chip when we probed.
211	 */
212	if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0))
213		goto err;
214
215	/*
216	 * If we found one device, don't bother with concat support.  If
217	 * we found multiple devices, use concat if we have it available,
218	 * otherwise fail.  Either way, it'll be called "sa1100".
219	 */
220	if (info->num_subdev == 1) {
221		strcpy(info->subdev[0].name, plat->name);
222		info->mtd = info->subdev[0].mtd;
223		ret = 0;
224	} else if (info->num_subdev > 1) {
225#ifdef CONFIG_MTD_CONCAT
226		struct mtd_info *cdev[nr];
227		/*
228		 * We detected multiple devices.  Concatenate them together.
229		 */
230		for (i = 0; i < info->num_subdev; i++)
231			cdev[i] = info->subdev[i].mtd;
232
233		info->mtd = mtd_concat_create(cdev, info->num_subdev,
234					      plat->name);
235		if (info->mtd == NULL)
236			ret = -ENXIO;
237#else
238		printk(KERN_ERR "SA1100 flash: multiple devices "
239		       "found but MTD concat support disabled.\n");
240		ret = -ENXIO;
241#endif
242	}
243
244	if (ret == 0)
245		return info;
246
247 err:
248	sa1100_destroy(info, plat);
249 out:
250	return ERR_PTR(ret);
251}
252
253static const char *part_probes[] = { "cmdlinepart", "RedBoot", NULL };
254
255static int __devinit sa1100_mtd_probe(struct platform_device *pdev)
256{
257	struct flash_platform_data *plat = pdev->dev.platform_data;
258	struct mtd_partition *parts;
259	const char *part_type = NULL;
260	struct sa_info *info;
261	int err, nr_parts = 0;
262
263	if (!plat)
264		return -ENODEV;
265
266	info = sa1100_setup_mtd(pdev, plat);
267	if (IS_ERR(info)) {
268		err = PTR_ERR(info);
269		goto out;
270	}
271
272	/*
273	 * Partition selection stuff.
274	 */
275#ifdef CONFIG_MTD_PARTITIONS
276	nr_parts = parse_mtd_partitions(info->mtd, part_probes, &parts, 0);
277	if (nr_parts > 0) {
278		info->parts = parts;
279		part_type = "dynamic";
280	} else
281#endif
282	{
283		parts = plat->parts;
284		nr_parts = plat->nr_parts;
285		part_type = "static";
286	}
287
288	if (nr_parts == 0) {
289		printk(KERN_NOTICE "SA1100 flash: no partition info "
290			"available, registering whole flash\n");
291		add_mtd_device(info->mtd);
292	} else {
293		printk(KERN_NOTICE "SA1100 flash: using %s partition "
294			"definition\n", part_type);
295		add_mtd_partitions(info->mtd, parts, nr_parts);
296	}
297
298	info->nr_parts = nr_parts;
299
300	platform_set_drvdata(pdev, info);
301	err = 0;
302
303 out:
304	return err;
305}
306
307static int __exit sa1100_mtd_remove(struct platform_device *pdev)
308{
309	struct sa_info *info = platform_get_drvdata(pdev);
310	struct flash_platform_data *plat = pdev->dev.platform_data;
311
312	platform_set_drvdata(pdev, NULL);
313	sa1100_destroy(info, plat);
314
315	return 0;
316}
317
318#ifdef CONFIG_PM
319static void sa1100_mtd_shutdown(struct platform_device *dev)
320{
321	struct sa_info *info = platform_get_drvdata(dev);
322	if (info && info->mtd->suspend(info->mtd) == 0)
323		info->mtd->resume(info->mtd);
324}
325#else
326#define sa1100_mtd_shutdown NULL
327#endif
328
329static struct platform_driver sa1100_mtd_driver = {
330	.probe		= sa1100_mtd_probe,
331	.remove		= __exit_p(sa1100_mtd_remove),
332	.shutdown	= sa1100_mtd_shutdown,
333	.driver		= {
334		.name	= "sa1100-mtd",
335		.owner	= THIS_MODULE,
336	},
337};
338
339static int __init sa1100_mtd_init(void)
340{
341	return platform_driver_register(&sa1100_mtd_driver);
342}
343
344static void __exit sa1100_mtd_exit(void)
345{
346	platform_driver_unregister(&sa1100_mtd_driver);
347}
348
349module_init(sa1100_mtd_init);
350module_exit(sa1100_mtd_exit);
351
352MODULE_AUTHOR("Nicolas Pitre");
353MODULE_DESCRIPTION("SA1100 CFI map driver");
354MODULE_LICENSE("GPL");
355MODULE_ALIAS("platform:sa1100-mtd");
356