sa1100-flash.c

  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
 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_info		*mtd;
 36	int			num_subdev;
 37	struct sa_subdev_info	subdev[];
 38};
 39
 40static DEFINE_SPINLOCK(sa1100_vpp_lock);
 41static int sa1100_vpp_refcnt;
 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	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
 58static 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
 67static 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
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 *sa1100_setup_mtd(struct platform_device *pdev,
153					struct flash_platform_data *plat)
154{
155	struct sa_info *info;
156	int nr, 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	/*
171	 * Allocate the map_info structs in one go.
172	 */
173	info = kzalloc(struct_size(info, subdev, nr), GFP_KERNEL);
174	if (!info) {
175		ret = -ENOMEM;
176		goto out;
177	}
178
179	if (plat->init) {
180		ret = plat->init();
181		if (ret)
182			goto err;
183	}
184
185	/*
186	 * Claim and then map the memory regions.
187	 */
188	for (i = 0; i < nr; i++) {
189		struct sa_subdev_info *subdev = &info->subdev[i];
190		struct resource *res;
191
192		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
193		if (!res)
194			break;
195
196		subdev->map.name = subdev->name;
197		sprintf(subdev->name, "%s-%d", plat->name, i);
198		subdev->plat = plat;
199
200		ret = sa1100_probe_subdev(subdev, res);
201		if (ret)
202			break;
203	}
204
205	info->num_subdev = i;
206
207	/*
208	 * ENXIO is special.  It means we didn't find a chip when we probed.
209	 */
210	if (ret != 0 && !(ret == -ENXIO && info->num_subdev > 0))
211		goto err;
212
213	/*
214	 * If we found one device, don't bother with concat support.  If
215	 * we found multiple devices, use concat if we have it available,
216	 * otherwise fail.  Either way, it'll be called "sa1100".
217	 */
218	if (info->num_subdev == 1) {
219		strcpy(info->subdev[0].name, plat->name);
220		info->mtd = info->subdev[0].mtd;
221		ret = 0;
222	} else if (info->num_subdev > 1) {
223		struct mtd_info **cdev;
224
225		cdev = kmalloc_array(nr, sizeof(*cdev), GFP_KERNEL);
226		if (!cdev) {
227			ret = -ENOMEM;
228			goto err;
229		}
230
231		/*
232		 * We detected multiple devices.  Concatenate them together.
233		 */
234		for (i = 0; i < info->num_subdev; i++)
235			cdev[i] = info->subdev[i].mtd;
236
237		info->mtd = mtd_concat_create(cdev, info->num_subdev,
238					      plat->name);
239		kfree(cdev);
240		if (info->mtd == NULL) {
241			ret = -ENXIO;
242			goto err;
243		}
244	}
245	info->mtd->dev.parent = &pdev->dev;
246
247	if (ret == 0)
248		return info;
249
250 err:
251	sa1100_destroy(info, plat);
252 out:
253	return ERR_PTR(ret);
254}
255
256static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL };
257
258static int sa1100_mtd_probe(struct platform_device *pdev)
259{
260	struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
261	struct sa_info *info;
262	int err;
263
264	if (!plat)
265		return -ENODEV;
266
267	info = sa1100_setup_mtd(pdev, plat);
268	if (IS_ERR(info)) {
269		err = PTR_ERR(info);
270		goto out;
271	}
272
273	/*
274	 * Partition selection stuff.
275	 */
276	mtd_device_parse_register(info->mtd, part_probes, NULL, plat->parts,
277				  plat->nr_parts);
278
279	platform_set_drvdata(pdev, info);
280	err = 0;
281
282 out:
283	return err;
284}
285
286static void sa1100_mtd_remove(struct platform_device *pdev)
287{
288	struct sa_info *info = platform_get_drvdata(pdev);
289	struct flash_platform_data *plat = dev_get_platdata(&pdev->dev);
290
291	sa1100_destroy(info, plat);
292}
293
294static struct platform_driver sa1100_mtd_driver = {
295	.probe		= sa1100_mtd_probe,
296	.remove		= sa1100_mtd_remove,
297	.driver		= {
298		.name	= "sa1100-mtd",
299	},
300};
301
302module_platform_driver(sa1100_mtd_driver);
303
304MODULE_AUTHOR("Nicolas Pitre");
305MODULE_DESCRIPTION("SA1100 CFI map driver");
306MODULE_LICENSE("GPL");
307MODULE_ALIAS("platform:sa1100-mtd");