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 struct 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
33 struct sa_info {
34 struct mtd_info *mtd;
35 int num_subdev;
36 struct sa_subdev_info subdev[0];
37 };
38
39 static DEFINE_SPINLOCK(sa1100_vpp_lock);
40 static int sa1100_vpp_refcnt;
sa1100_set_vpp(struct map_info * map,int on)41 static 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
sa1100_destroy_subdev(struct sa_subdev_info * subdev)57 static 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
sa1100_probe_subdev(struct sa_subdev_info * subdev,struct resource * res)66 static 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
121 printk(KERN_INFO "SA1100 flash: CFI device at 0x%08lx, %uMiB, %d-bit\n",
122 phys, (unsigned)(subdev->mtd->size >> 20),
123 subdev->map.bankwidth * 8);
124
125 return 0;
126
127 err:
128 sa1100_destroy_subdev(subdev);
129 out:
130 return ret;
131 }
132
sa1100_destroy(struct sa_info * info,struct flash_platform_data * plat)133 static void sa1100_destroy(struct sa_info *info, struct flash_platform_data *plat)
134 {
135 int i;
136
137 if (info->mtd) {
138 mtd_device_unregister(info->mtd);
139 if (info->mtd != info->subdev[0].mtd)
140 mtd_concat_destroy(info->mtd);
141 }
142
143 for (i = info->num_subdev - 1; i >= 0; i--)
144 sa1100_destroy_subdev(&info->subdev[i]);
145 kfree(info);
146
147 if (plat->exit)
148 plat->exit();
149 }
150
sa1100_setup_mtd(struct platform_device * pdev,struct flash_platform_data * plat)151 static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev,
152 struct flash_platform_data *plat)
153 {
154 struct sa_info *info;
155 int nr, size, i, ret = 0;
156
157 /*
158 * Count number of devices.
159 */
160 for (nr = 0; ; nr++)
161 if (!platform_get_resource(pdev, IORESOURCE_MEM, nr))
162 break;
163
164 if (nr == 0) {
165 ret = -ENODEV;
166 goto out;
167 }
168
169 size = sizeof(struct sa_info) + sizeof(struct sa_subdev_info) * nr;
170
171 /*
172 * Allocate the map_info structs in one go.
173 */
174 info = kzalloc(size, GFP_KERNEL);
175 if (!info) {
176 ret = -ENOMEM;
177 goto out;
178 }
179
180 if (plat->init) {
181 ret = plat->init();
182 if (ret)
183 goto err;
184 }
185
186 /*
187 * Claim and then map the memory regions.
188 */
189 for (i = 0; i < nr; i++) {
190 struct sa_subdev_info *subdev = &info->subdev[i];
191 struct resource *res;
192
193 res = platform_get_resource(pdev, IORESOURCE_MEM, i);
194 if (!res)
195 break;
196
197 subdev->map.name = subdev->name;
198 sprintf(subdev->name, "%s-%d", plat->name, i);
199 subdev->plat = plat;
200
201 ret = sa1100_probe_subdev(subdev, res);
202 if (ret)
203 break;
204 }
205
206 info->num_subdev = i;
207
208 /*
209 * ENXIO is special. It means we didn't find a chip when we probed.
210 */
211 if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0))
212 goto err;
213
214 /*
215 * If we found one device, don't bother with concat support. If
216 * we found multiple devices, use concat if we have it available,
217 * otherwise fail. Either way, it'll be called "sa1100".
218 */
219 if (info->num_subdev == 1) {
220 strcpy(info->subdev[0].name, plat->name);
221 info->mtd = info->subdev[0].mtd;
222 ret = 0;
223 } else if (info->num_subdev > 1) {
224 struct mtd_info *cdev[nr];
225 /*
226 * We detected multiple devices. Concatenate them together.
227 */
228 for (i = 0; i < info->num_subdev; i++)
229 cdev[i] = info->subdev[i].mtd;
230
231 info->mtd = mtd_concat_create(cdev, info->num_subdev,
232 plat->name);
233 if (info->mtd == NULL) {
234 ret = -ENXIO;
235 goto err;
236 }
237 }
238 info->mtd->dev.parent = &pdev->dev;
239
240 if (ret == 0)
241 return info;
242
243 err:
244 sa1100_destroy(info, plat);
245 out:
246 return ERR_PTR(ret);
247 }
248
249 static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL };
250
sa1100_mtd_probe(struct platform_device * pdev)251 static int sa1100_mtd_probe(struct platform_device *pdev)
252 {
253 struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
254 struct sa_info *info;
255 int err;
256
257 if (!plat)
258 return -ENODEV;
259
260 info = sa1100_setup_mtd(pdev, plat);
261 if (IS_ERR(info)) {
262 err = PTR_ERR(info);
263 goto out;
264 }
265
266 /*
267 * Partition selection stuff.
268 */
269 mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
270 plat->nr_parts);
271
272 platform_set_drvdata(pdev, info);
273 err = 0;
274
275 out:
276 return err;
277 }
278
sa1100_mtd_remove(struct platform_device * pdev)279 static int sa1100_mtd_remove(struct platform_device *pdev)
280 {
281 struct sa_info *info = platform_get_drvdata(pdev);
282 struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
283
284 sa1100_destroy(info, plat);
285
286 return 0;
287 }
288
289 static struct platform_driver sa1100_mtd_driver = {
290 .probe = sa1100_mtd_probe,
291 .remove = sa1100_mtd_remove,
292 .driver = {
293 .name = "sa1100-mtd",
294 },
295 };
296
297 module_platform_driver(sa1100_mtd_driver);
298
299 MODULE_AUTHOR("Nicolas Pitre");
300 MODULE_DESCRIPTION("SA1100 CFI map driver");
301 MODULE_LICENSE("GPL");
302 MODULE_ALIAS("platform:sa1100-mtd");
303