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, 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
258static const char * const part_probes[] = { "cmdlinepart", "RedBoot", NULL };
259
260static 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
288static void 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
296static struct platform_driver sa1100_mtd_driver = {
297	.probe		= sa1100_mtd_probe,
298	.remove_new	= sa1100_mtd_remove,
299	.driver		= {
300		.name	= "sa1100-mtd",
301	},
302};
303
304module_platform_driver(sa1100_mtd_driver);
305
306MODULE_AUTHOR("Nicolas Pitre");
307MODULE_DESCRIPTION("SA1100 CFI map driver");
308MODULE_LICENSE("GPL");
309MODULE_ALIAS("platform:sa1100-mtd");
310