xref: /openbmc/linux/drivers/mtd/maps/sa1100-flash.c (revision 025a06c1)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Flash memory access on SA11x0 based devices
4  *
5  * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
6  */
7 #include <linux/module.h>
8 #include <linux/types.h>
9 #include <linux/ioport.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/slab.h>
14 #include <linux/platform_device.h>
15 #include <linux/err.h>
16 #include <linux/io.h>
17 
18 #include <linux/mtd/mtd.h>
19 #include <linux/mtd/map.h>
20 #include <linux/mtd/partitions.h>
21 #include <linux/mtd/concat.h>
22 
23 #include <mach/hardware.h>
24 #include <linux/sizes.h>
25 #include <asm/mach/flash.h>
26 
27 struct 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 
34 struct sa_info {
35 	struct mtd_info		*mtd;
36 	int			num_subdev;
37 	struct sa_subdev_info	subdev[];
38 };
39 
40 static DEFINE_SPINLOCK(sa1100_vpp_lock);
41 static int sa1100_vpp_refcnt;
sa1100_set_vpp(struct map_info * map,int on)42 static 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 	unsigned long flags;
46 
47 	spin_lock_irqsave(&sa1100_vpp_lock, flags);
48 	if (on) {
49 		if (++sa1100_vpp_refcnt == 1)   /* first nested 'on' */
50 			subdev->plat->set_vpp(1);
51 	} else {
52 		if (--sa1100_vpp_refcnt == 0)   /* last nested 'off' */
53 			subdev->plat->set_vpp(0);
54 	}
55 	spin_unlock_irqrestore(&sa1100_vpp_lock, flags);
56 }
57 
sa1100_destroy_subdev(struct sa_subdev_info * subdev)58 static void sa1100_destroy_subdev(struct sa_subdev_info *subdev)
59 {
60 	if (subdev->mtd)
61 		map_destroy(subdev->mtd);
62 	if (subdev->map.virt)
63 		iounmap(subdev->map.virt);
64 	release_mem_region(subdev->map.phys, subdev->map.size);
65 }
66 
sa1100_probe_subdev(struct sa_subdev_info * subdev,struct resource * res)67 static int sa1100_probe_subdev(struct sa_subdev_info *subdev, struct resource *res)
68 {
69 	unsigned long phys;
70 	unsigned int size;
71 	int ret;
72 
73 	phys = res->start;
74 	size = res->end - phys + 1;
75 
76 	/*
77 	 * Retrieve the bankwidth from the MSC registers.
78 	 * We currently only implement CS0 and CS1 here.
79 	 */
80 	switch (phys) {
81 	default:
82 		printk(KERN_WARNING "SA1100 flash: unknown base address "
83 		       "0x%08lx, assuming CS0\n", phys);
84 		fallthrough;
85 	case SA1100_CS0_PHYS:
86 		subdev->map.bankwidth = (MSC0 & MSC_RBW) ? 2 : 4;
87 		break;
88 
89 	case SA1100_CS1_PHYS:
90 		subdev->map.bankwidth = ((MSC0 >> 16) & MSC_RBW) ? 2 : 4;
91 		break;
92 	}
93 
94 	if (!request_mem_region(phys, size, subdev->name)) {
95 		ret = -EBUSY;
96 		goto out;
97 	}
98 
99 	if (subdev->plat->set_vpp)
100 		subdev->map.set_vpp = sa1100_set_vpp;
101 
102 	subdev->map.phys = phys;
103 	subdev->map.size = size;
104 	subdev->map.virt = ioremap(phys, size);
105 	if (!subdev->map.virt) {
106 		ret = -ENOMEM;
107 		goto err;
108 	}
109 
110 	simple_map_init(&subdev->map);
111 
112 	/*
113 	 * Now let's probe for the actual flash.  Do it here since
114 	 * specific machine settings might have been set above.
115 	 */
116 	subdev->mtd = do_map_probe(subdev->plat->map_name, &subdev->map);
117 	if (subdev->mtd == NULL) {
118 		ret = -ENXIO;
119 		goto err;
120 	}
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 
sa1100_destroy(struct sa_info * info,struct flash_platform_data * plat)134 static 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 
sa1100_setup_mtd(struct platform_device * pdev,struct flash_platform_data * plat)152 static struct sa_info *sa1100_setup_mtd(struct platform_device *pdev,
153 					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;
226 
227 		cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL);
228 		if (!cdev) {
229 			ret = -ENOMEM;
230 			goto err;
231 		}
232 
233 		/*
234 		 * We detected multiple devices.  Concatenate them together.
235 		 */
236 		for (i = 0; i < info->num_subdev; i++)
237 			cdev[i] = info->subdev[i].mtd;
238 
239 		info->mtd = mtd_concat_create(cdev, info->num_subdev,
240 					      plat->name);
241 		kfree(cdev);
242 		if (info->mtd == NULL) {
243 			ret = -ENXIO;
244 			goto err;
245 		}
246 	}
247 	info->mtd->dev.parent = &pdev->dev;
248 
249 	if (ret == 0)
250 		return info;
251 
252  err:
253 	sa1100_destroy(info, plat);
254  out:
255 	return ERR_PTR(ret);
256 }
257 
258 static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL };
259 
sa1100_mtd_probe(struct platform_device * pdev)260 static int sa1100_mtd_probe(struct platform_device *pdev)
261 {
262 	struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
263 	struct sa_info *info;
264 	int err;
265 
266 	if (!plat)
267 		return -ENODEV;
268 
269 	info = sa1100_setup_mtd(pdev, plat);
270 	if (IS_ERR(info)) {
271 		err = PTR_ERR(info);
272 		goto out;
273 	}
274 
275 	/*
276 	 * Partition selection stuff.
277 	 */
278 	mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
279 				  plat->nr_parts);
280 
281 	platform_set_drvdata(pdev, info);
282 	err = 0;
283 
284  out:
285 	return err;
286 }
287 
sa1100_mtd_remove(struct platform_device * pdev)288 static int sa1100_mtd_remove(struct platform_device *pdev)
289 {
290 	struct sa_info *info = platform_get_drvdata(pdev);
291 	struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
292 
293 	sa1100_destroy(info, plat);
294 
295 	return 0;
296 }
297 
298 static struct platform_driver sa1100_mtd_driver = {
299 	.probe		= sa1100_mtd_probe,
300 	.remove		= sa1100_mtd_remove,
301 	.driver		= {
302 		.name	= "sa1100-mtd",
303 	},
304 };
305 
306 module_platform_driver(sa1100_mtd_driver);
307 
308 MODULE_AUTHOR("Nicolas Pitre");
309 MODULE_DESCRIPTION("SA1100 CFI map driver");
310 MODULE_LICENSE("GPL");
311 MODULE_ALIAS("platform:sa1100-mtd");
312