xref: /openbmc/linux/drivers/mtd/maps/sa1100-flash.c (revision ead5d1f4d877e92c051e1a1ade623d0d30e71619)
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