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
26struct sa_subdev_info {
27	char name[16];
28	struct map_info map;
29	struct mtd_info *mtd;
30	struct flash_platform_data *plat;
31};
32
33struct sa_info {
34	struct mtd_info		*mtd;
35	int			num_subdev;
36	struct sa_subdev_info	subdev[0];
37};
38
39static DEFINE_SPINLOCK(sa1100_vpp_lock);
40static int sa1100_vpp_refcnt;
41static void sa1100_set_vpp(struct map_info *map, int on)
42{
43	struct sa_subdev_info *subdev = container_of(map, struct sa_subdev_info, map);
44	unsigned long flags;
45
46	spin_lock_irqsave(&sa1100_vpp_lock, flags);
47	if (on) {
48		if (++sa1100_vpp_refcnt == 1)   /* first nested 'on' */
49			subdev->plat->set_vpp(1);
50	} else {
51		if (--sa1100_vpp_refcnt == 0)   /* last nested 'off' */
52			subdev->plat->set_vpp(0);
53	}
54	spin_unlock_irqrestore(&sa1100_vpp_lock, flags);
55}
56
57static void sa1100_destroy_subdev(struct sa_subdev_info *subdev)
58{
59	if (subdev->mtd)
60		map_destroy(subdev->mtd);
61	if (subdev->map.virt)
62		iounmap(subdev->map.virt);
63	release_mem_region(subdev->map.phys, subdev->map.size);
64}
65
66static int sa1100_probe_subdev(struct sa_subdev_info *subdev, struct resource *res)
67{
68	unsigned long phys;
69	unsigned int size;
70	int ret;
71
72	phys = res->start;
73	size = res->end - phys + 1;
74
75	/*
76	 * Retrieve the bankwidth from the MSC registers.
77	 * We currently only implement CS0 and CS1 here.
78	 */
79	switch (phys) {
80	default:
81		printk(KERN_WARNING "SA1100 flash: unknown base address "
82		       "0x%08lx, assuming CS0\n", phys);
83
84	case SA1100_CS0_PHYS:
85		subdev->map.bankwidth = (MSC0 & MSC_RBW) ? 2 : 4;
86		break;
87
88	case SA1100_CS1_PHYS:
89		subdev->map.bankwidth = ((MSC0 >> 16) & MSC_RBW) ? 2 : 4;
90		break;
91	}
92
93	if (!request_mem_region(phys, size, subdev->name)) {
94		ret = -EBUSY;
95		goto out;
96	}
97
98	if (subdev->plat->set_vpp)
99		subdev->map.set_vpp = sa1100_set_vpp;
100
101	subdev->map.phys = phys;
102	subdev->map.size = size;
103	subdev->map.virt = ioremap(phys, size);
104	if (!subdev->map.virt) {
105		ret = -ENOMEM;
106		goto err;
107	}
108
109	simple_map_init(&subdev->map);
110
111	/*
112	 * Now let's probe for the actual flash.  Do it here since
113	 * specific machine settings might have been set above.
114	 */
115	subdev->mtd = do_map_probe(subdev->plat->map_name, &subdev->map);
116	if (subdev->mtd == NULL) {
117		ret = -ENXIO;
118		goto err;
119	}
120	subdev->mtd->owner = THIS_MODULE;
121
122	printk(KERN_INFO "SA1100 flash: CFI device at 0x%08lx, %uMiB, %d-bit\n",
123		phys, (unsigned)(subdev->mtd->size >> 20),
124		subdev->map.bankwidth * 8);
125
126	return 0;
127
128 err:
129	sa1100_destroy_subdev(subdev);
130 out:
131	return ret;
132}
133
134static void sa1100_destroy(struct sa_info *info, struct flash_platform_data *plat)
135{
136	int i;
137
138	if (info->mtd) {
139		mtd_device_unregister(info->mtd);
140		if (info->mtd != info->subdev[0].mtd)
141			mtd_concat_destroy(info->mtd);
142	}
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		struct mtd_info *cdev[nr];
226		/*
227		 * We detected multiple devices.  Concatenate them together.
228		 */
229		for (i = 0; i < info->num_subdev; i++)
230			cdev[i] = info->subdev[i].mtd;
231
232		info->mtd = mtd_concat_create(cdev, info->num_subdev,
233					      plat->name);
234		if (info->mtd == NULL)
235			ret = -ENXIO;
236	}
237
238	if (ret == 0)
239		return info;
240
241 err:
242	sa1100_destroy(info, plat);
243 out:
244	return ERR_PTR(ret);
245}
246
247static const char *part_probes[] = { "cmdlinepart", "RedBoot", NULL };
248
249static int __devinit sa1100_mtd_probe(struct platform_device *pdev)
250{
251	struct flash_platform_data *plat = pdev->dev.platform_data;
252	struct sa_info *info;
253	int err;
254
255	if (!plat)
256		return -ENODEV;
257
258	info = sa1100_setup_mtd(pdev, plat);
259	if (IS_ERR(info)) {
260		err = PTR_ERR(info);
261		goto out;
262	}
263
264	/*
265	 * Partition selection stuff.
266	 */
267	mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
268				  plat->nr_parts);
269
270	platform_set_drvdata(pdev, info);
271	err = 0;
272
273 out:
274	return err;
275}
276
277static int __exit sa1100_mtd_remove(struct platform_device *pdev)
278{
279	struct sa_info *info = platform_get_drvdata(pdev);
280	struct flash_platform_data *plat = pdev->dev.platform_data;
281
282	platform_set_drvdata(pdev, NULL);
283	sa1100_destroy(info, plat);
284
285	return 0;
286}
287
288static struct platform_driver sa1100_mtd_driver = {
289	.probe		= sa1100_mtd_probe,
290	.remove		= __exit_p(sa1100_mtd_remove),
291	.driver		= {
292		.name	= "sa1100-mtd",
293		.owner	= THIS_MODULE,
294	},
295};
296
297module_platform_driver(sa1100_mtd_driver);
298
299MODULE_AUTHOR("Nicolas Pitre");
300MODULE_DESCRIPTION("SA1100 CFI map driver");
301MODULE_LICENSE("GPL");
302MODULE_ALIAS("platform:sa1100-mtd");
303