aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mtd/devices/ms02-nv.c
blob: 182849d39c61acb34c40a79ab6bf04e30162da79 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
/*
 *	Copyright (c) 2001 Maciej W. Rozycki
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mtd/mtd.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/dec/ioasic_addrs.h>
#include <asm/dec/kn02.h>
#include <asm/dec/kn03.h>
#include <asm/io.h>
#include <asm/paccess.h>

#include "ms02-nv.h"


static char version[] __initdata =
	"ms02-nv.c: v.1.0.0  13 Aug 2001  Maciej W. Rozycki.\n";

MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
MODULE_DESCRIPTION("DEC MS02-NV NVRAM module driver");
MODULE_LICENSE("GPL");


/*
 * Addresses we probe for an MS02-NV at.  Modules may be located
 * at any 8MiB boundary within a 0MiB up to 112MiB range or at any 32MiB
 * boundary within a 0MiB up to 448MiB range.  We don't support a module
 * at 0MiB, though.
 */
static ulong ms02nv_addrs[] __initdata = {
	0x07000000, 0x06800000, 0x06000000, 0x05800000, 0x05000000,
	0x04800000, 0x04000000, 0x03800000, 0x03000000, 0x02800000,
	0x02000000, 0x01800000, 0x01000000, 0x00800000
};

static const char ms02nv_name[] = "DEC MS02-NV NVRAM";
static const char ms02nv_res_diag_ram[] = "Diagnostic RAM";
static const char ms02nv_res_user_ram[] = "General-purpose RAM";
static const char ms02nv_res_csr[] = "Control and status register";

static struct mtd_info *root_ms02nv_mtd;


static int ms02nv_read(struct mtd_info *mtd, loff_t from,
			size_t len, size_t *retlen, u_char *buf)
{
	struct ms02nv_private *mp = mtd->priv;

	memcpy(buf, mp->uaddr + from, len);
	*retlen = len;
	return 0;
}

static int ms02nv_write(struct mtd_info *mtd, loff_t to,
			size_t len, size_t *retlen, const u_char *buf)
{
	struct ms02nv_private *mp = mtd->priv;

	memcpy(mp->uaddr + to, buf, len);
	*retlen = len;
	return 0;
}


static inline uint ms02nv_probe_one(ulong addr)
{
	ms02nv_uint *ms02nv_diagp;
	ms02nv_uint *ms02nv_magicp;
	uint ms02nv_diag;
	uint ms02nv_magic;
	size_t size;

	int err;

	/*
	 * The firmware writes MS02NV_ID at MS02NV_MAGIC and also
	 * a diagnostic status at MS02NV_DIAG.
	 */
	ms02nv_diagp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_DIAG));
	ms02nv_magicp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_MAGIC));
	err = get_dbe(ms02nv_magic, ms02nv_magicp);
	if (err)
		return 0;
	if (ms02nv_magic != MS02NV_ID)
		return 0;

	ms02nv_diag = *ms02nv_diagp;
	size = (ms02nv_diag & MS02NV_DIAG_SIZE_MASK) << MS02NV_DIAG_SIZE_SHIFT;
	if (size > MS02NV_CSR)
		size = MS02NV_CSR;

	return size;
}

static int __init ms02nv_init_one(ulong addr)
{
	struct mtd_info *mtd;
	struct ms02nv_private *mp;
	struct resource *mod_res;
	struct resource *diag_res;
	struct resource *user_res;
	struct resource *csr_res;
	ulong fixaddr;
	size_t size, fixsize;

	static int version_printed;

	int ret = -ENODEV;

	/* The module decodes 8MiB of address space. */
	mod_res = kzalloc(sizeof(*mod_res), GFP_KERNEL);
	if (!mod_res)
		return -ENOMEM;

	mod_res->name = ms02nv_name;
	mod_res->start = addr;
	mod_res->end = addr + MS02NV_SLOT_SIZE - 1;
	mod_res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
	if (request_resource(&iomem_resource, mod_res) < 0)
		goto err_out_mod_res;

	size = ms02nv_probe_one(addr);
	if (!size)
		goto err_out_mod_res_rel;

	if (!version_printed) {
		printk(KERN_INFO "%s", version);
		version_printed = 1;
	}

	ret = -ENOMEM;
	mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
	if (!mtd)
		goto err_out_mod_res_rel;
	mp = kzalloc(sizeof(*mp), GFP_KERNEL);
	if (!mp)
		goto err_out_mtd;

	mtd->priv = mp;
	mp->resource.module = mod_res;

	/* Firmware's diagnostic NVRAM area. */
	diag_res = kzalloc(sizeof(*diag_res), GFP_KERNEL);
	if (!diag_res)
		goto err_out_mp;

	diag_res->name = ms02nv_res_diag_ram;
	diag_res->start = addr;
	diag_res->end = addr + MS02NV_RAM - 1;
	diag_res->flags = IORESOURCE_BUSY;
	request_resource(mod_res, diag_res);

	mp->resource.diag_ram = diag_res;

	/* User-available general-purpose NVRAM area. */
	user_res = kzalloc(sizeof(*user_res), GFP_KERNEL);
	if (!user_res)
		goto err_out_diag_res;

	user_res->name = ms02nv_res_user_ram;
	user_res->start = addr + MS02NV_RAM;
	user_res->end = addr + size - 1;
	user_res->flags = IORESOURCE_BUSY;
	request_resource(mod_res, user_res);

	mp->resource.user_ram = user_res;

	/* Control and status register. */
	csr_res = kzalloc(sizeof(*csr_res), GFP_KERNEL);
	if (!csr_res)
		goto err_out_user_res;

	csr_res->name = ms02nv_res_csr;
	csr_res->start = addr + MS02NV_CSR;
	csr_res->end = addr + MS02NV_CSR + 3;
	csr_res->flags = IORESOURCE_BUSY;
	request_resource(mod_res, csr_res);

	mp->resource.csr = csr_res;

	mp->addr = phys_to_virt(addr);
	mp->size = size;

	/*
	 * Hide the firmware's diagnostic area.  It may get destroyed
	 * upon a reboot.  Take paging into account for mapping support.
	 */
	fixaddr = (addr + MS02NV_RAM + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
	fixsize = (size - (fixaddr - addr)) & ~(PAGE_SIZE - 1);
	mp->uaddr = phys_to_virt(fixaddr);

	mtd->type = MTD_RAM;
	mtd->flags = MTD_CAP_RAM;
	mtd->size = fixsize;
	mtd->name = (char *)ms02nv_name;
	mtd->owner = THIS_MODULE;
	mtd->_read = ms02nv_read;
	mtd->_write = ms02nv_write;
	mtd->writesize = 1;

	ret = -EIO;
	if (mtd_device_register(mtd, NULL, 0)) {
		printk(KERN_ERR
			"ms02-nv: Unable to register MTD device, aborting!\n");
		goto err_out_csr_res;
	}

	printk(KERN_INFO "mtd%d: %s at 0x%08lx, size %zuMiB.\n",
		mtd->index, ms02nv_name, addr, size >> 20);

	mp->next = root_ms02nv_mtd;
	root_ms02nv_mtd = mtd;

	return 0;


err_out_csr_res:
	release_resource(csr_res);
	kfree(csr_res);
err_out_user_res:
	release_resource(user_res);
	kfree(user_res);
err_out_diag_res:
	release_resource(diag_res);
	kfree(diag_res);
err_out_mp:
	kfree(mp);
err_out_mtd:
	kfree(mtd);
err_out_mod_res_rel:
	release_resource(mod_res);
err_out_mod_res:
	kfree(mod_res);
	return ret;
}

static void __exit ms02nv_remove_one(void)
{
	struct mtd_info *mtd = root_ms02nv_mtd;
	struct ms02nv_private *mp = mtd->priv;

	root_ms02nv_mtd = mp->next;

	mtd_device_unregister(mtd);

	release_resource(mp->resource.csr);
	kfree(mp->resource.csr);
	release_resource(mp->resource.user_ram);
	kfree(mp->resource.user_ram);
	release_resource(mp->resource.diag_ram);
	kfree(mp->resource.diag_ram);
	release_resource(mp->resource.module);
	kfree(mp->resource.module);
	kfree(mp);
	kfree(mtd);
}


static int __init ms02nv_init(void)
{
	volatile u32 *csr;
	uint stride = 0;
	int count = 0;
	int i;

	switch (mips_machtype) {
	case MACH_DS5000_200:
		csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE + KN02_CSR);
		if (*csr & KN02_CSR_BNK32M)
			stride = 2;
		break;
	case MACH_DS5000_2X0:
	case MACH_DS5900:
		csr = (volatile u32 *)CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_MCR);
		if (*csr & KN03_MCR_BNK32M)
			stride = 2;
		break;
	default:
		return -ENODEV;
		break;
	}

	for (i = 0; i < ARRAY_SIZE(ms02nv_addrs); i++)
		if (!ms02nv_init_one(ms02nv_addrs[i] << stride))
			count++;

	return (count > 0) ? 0 : -ENODEV;
}

static void __exit ms02nv_cleanup(void)
{
	while (root_ms02nv_mtd)
		ms02nv_remove_one();
}


module_init(ms02nv_init);
module_exit(ms02nv_cleanup);