1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2001 Maciej W. Rozycki
4 */
5
6 #include <linux/init.h>
7 #include <linux/ioport.h>
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/mtd/mtd.h>
11 #include <linux/slab.h>
12 #include <linux/types.h>
13
14 #include <asm/addrspace.h>
15 #include <asm/bootinfo.h>
16 #include <asm/dec/ioasic_addrs.h>
17 #include <asm/dec/kn02.h>
18 #include <asm/dec/kn03.h>
19 #include <asm/io.h>
20 #include <asm/paccess.h>
21
22 #include "ms02-nv.h"
23
24
25 static char version[] __initdata =
26 "ms02-nv.c: v.1.0.0 13 Aug 2001 Maciej W. Rozycki.\n";
27
28 MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
29 MODULE_DESCRIPTION("DEC MS02-NV NVRAM module driver");
30 MODULE_LICENSE("GPL");
31
32
33 /*
34 * Addresses we probe for an MS02-NV at. Modules may be located
35 * at any 8MiB boundary within a 0MiB up to 112MiB range or at any 32MiB
36 * boundary within a 0MiB up to 448MiB range. We don't support a module
37 * at 0MiB, though.
38 */
39 static ulong ms02nv_addrs[] __initdata = {
40 0x07000000, 0x06800000, 0x06000000, 0x05800000, 0x05000000,
41 0x04800000, 0x04000000, 0x03800000, 0x03000000, 0x02800000,
42 0x02000000, 0x01800000, 0x01000000, 0x00800000
43 };
44
45 static const char ms02nv_name[] = "DEC MS02-NV NVRAM";
46 static const char ms02nv_res_diag_ram[] = "Diagnostic RAM";
47 static const char ms02nv_res_user_ram[] = "General-purpose RAM";
48 static const char ms02nv_res_csr[] = "Control and status register";
49
50 static struct mtd_info *root_ms02nv_mtd;
51
52
ms02nv_read(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,u_char * buf)53 static int ms02nv_read(struct mtd_info *mtd, loff_t from,
54 size_t len, size_t *retlen, u_char *buf)
55 {
56 struct ms02nv_private *mp = mtd->priv;
57
58 memcpy(buf, mp->uaddr + from, len);
59 *retlen = len;
60 return 0;
61 }
62
ms02nv_write(struct mtd_info * mtd,loff_t to,size_t len,size_t * retlen,const u_char * buf)63 static int ms02nv_write(struct mtd_info *mtd, loff_t to,
64 size_t len, size_t *retlen, const u_char *buf)
65 {
66 struct ms02nv_private *mp = mtd->priv;
67
68 memcpy(mp->uaddr + to, buf, len);
69 *retlen = len;
70 return 0;
71 }
72
73
ms02nv_probe_one(ulong addr)74 static inline uint ms02nv_probe_one(ulong addr)
75 {
76 ms02nv_uint *ms02nv_diagp;
77 ms02nv_uint *ms02nv_magicp;
78 uint ms02nv_diag;
79 uint ms02nv_magic;
80 size_t size;
81
82 int err;
83
84 /*
85 * The firmware writes MS02NV_ID at MS02NV_MAGIC and also
86 * a diagnostic status at MS02NV_DIAG.
87 */
88 ms02nv_diagp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_DIAG));
89 ms02nv_magicp = (ms02nv_uint *)(CKSEG1ADDR(addr + MS02NV_MAGIC));
90 err = get_dbe(ms02nv_magic, ms02nv_magicp);
91 if (err)
92 return 0;
93 if (ms02nv_magic != MS02NV_ID)
94 return 0;
95
96 ms02nv_diag = *ms02nv_diagp;
97 size = (ms02nv_diag & MS02NV_DIAG_SIZE_MASK) << MS02NV_DIAG_SIZE_SHIFT;
98 if (size > MS02NV_CSR)
99 size = MS02NV_CSR;
100
101 return size;
102 }
103
ms02nv_init_one(ulong addr)104 static int __init ms02nv_init_one(ulong addr)
105 {
106 struct mtd_info *mtd;
107 struct ms02nv_private *mp;
108 struct resource *mod_res;
109 struct resource *diag_res;
110 struct resource *user_res;
111 struct resource *csr_res;
112 ulong fixaddr;
113 size_t size, fixsize;
114
115 static int version_printed;
116
117 int ret = -ENODEV;
118
119 /* The module decodes 8MiB of address space. */
120 mod_res = kzalloc(sizeof(*mod_res), GFP_KERNEL);
121 if (!mod_res)
122 return -ENOMEM;
123
124 mod_res->name = ms02nv_name;
125 mod_res->start = addr;
126 mod_res->end = addr + MS02NV_SLOT_SIZE - 1;
127 mod_res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
128 if (request_resource(&iomem_resource, mod_res) < 0)
129 goto err_out_mod_res;
130
131 size = ms02nv_probe_one(addr);
132 if (!size)
133 goto err_out_mod_res_rel;
134
135 if (!version_printed) {
136 printk(KERN_INFO "%s", version);
137 version_printed = 1;
138 }
139
140 ret = -ENOMEM;
141 mtd = kzalloc(sizeof(*mtd), GFP_KERNEL);
142 if (!mtd)
143 goto err_out_mod_res_rel;
144 mp = kzalloc(sizeof(*mp), GFP_KERNEL);
145 if (!mp)
146 goto err_out_mtd;
147
148 mtd->priv = mp;
149 mp->resource.module = mod_res;
150
151 /* Firmware's diagnostic NVRAM area. */
152 diag_res = kzalloc(sizeof(*diag_res), GFP_KERNEL);
153 if (!diag_res)
154 goto err_out_mp;
155
156 diag_res->name = ms02nv_res_diag_ram;
157 diag_res->start = addr;
158 diag_res->end = addr + MS02NV_RAM - 1;
159 diag_res->flags = IORESOURCE_BUSY;
160 request_resource(mod_res, diag_res);
161
162 mp->resource.diag_ram = diag_res;
163
164 /* User-available general-purpose NVRAM area. */
165 user_res = kzalloc(sizeof(*user_res), GFP_KERNEL);
166 if (!user_res)
167 goto err_out_diag_res;
168
169 user_res->name = ms02nv_res_user_ram;
170 user_res->start = addr + MS02NV_RAM;
171 user_res->end = addr + size - 1;
172 user_res->flags = IORESOURCE_BUSY;
173 request_resource(mod_res, user_res);
174
175 mp->resource.user_ram = user_res;
176
177 /* Control and status register. */
178 csr_res = kzalloc(sizeof(*csr_res), GFP_KERNEL);
179 if (!csr_res)
180 goto err_out_user_res;
181
182 csr_res->name = ms02nv_res_csr;
183 csr_res->start = addr + MS02NV_CSR;
184 csr_res->end = addr + MS02NV_CSR + 3;
185 csr_res->flags = IORESOURCE_BUSY;
186 request_resource(mod_res, csr_res);
187
188 mp->resource.csr = csr_res;
189
190 mp->addr = phys_to_virt(addr);
191 mp->size = size;
192
193 /*
194 * Hide the firmware's diagnostic area. It may get destroyed
195 * upon a reboot. Take paging into account for mapping support.
196 */
197 fixaddr = (addr + MS02NV_RAM + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
198 fixsize = (size - (fixaddr - addr)) & ~(PAGE_SIZE - 1);
199 mp->uaddr = phys_to_virt(fixaddr);
200
201 mtd->type = MTD_RAM;
202 mtd->flags = MTD_CAP_RAM;
203 mtd->size = fixsize;
204 mtd->name = ms02nv_name;
205 mtd->owner = THIS_MODULE;
206 mtd->_read = ms02nv_read;
207 mtd->_write = ms02nv_write;
208 mtd->writesize = 1;
209
210 ret = -EIO;
211 if (mtd_device_register(mtd, NULL, 0)) {
212 printk(KERN_ERR
213 "ms02-nv: Unable to register MTD device, aborting!\n");
214 goto err_out_csr_res;
215 }
216
217 printk(KERN_INFO "mtd%d: %s at 0x%08lx, size %zuMiB.\n",
218 mtd->index, ms02nv_name, addr, size >> 20);
219
220 mp->next = root_ms02nv_mtd;
221 root_ms02nv_mtd = mtd;
222
223 return 0;
224
225
226 err_out_csr_res:
227 release_resource(csr_res);
228 kfree(csr_res);
229 err_out_user_res:
230 release_resource(user_res);
231 kfree(user_res);
232 err_out_diag_res:
233 release_resource(diag_res);
234 kfree(diag_res);
235 err_out_mp:
236 kfree(mp);
237 err_out_mtd:
238 kfree(mtd);
239 err_out_mod_res_rel:
240 release_resource(mod_res);
241 err_out_mod_res:
242 kfree(mod_res);
243 return ret;
244 }
245
ms02nv_remove_one(void)246 static void __exit ms02nv_remove_one(void)
247 {
248 struct mtd_info *mtd = root_ms02nv_mtd;
249 struct ms02nv_private *mp = mtd->priv;
250
251 root_ms02nv_mtd = mp->next;
252
253 mtd_device_unregister(mtd);
254
255 release_resource(mp->resource.csr);
256 kfree(mp->resource.csr);
257 release_resource(mp->resource.user_ram);
258 kfree(mp->resource.user_ram);
259 release_resource(mp->resource.diag_ram);
260 kfree(mp->resource.diag_ram);
261 release_resource(mp->resource.module);
262 kfree(mp->resource.module);
263 kfree(mp);
264 kfree(mtd);
265 }
266
267
ms02nv_init(void)268 static int __init ms02nv_init(void)
269 {
270 volatile u32 *csr;
271 uint stride = 0;
272 int count = 0;
273 int i;
274
275 switch (mips_machtype) {
276 case MACH_DS5000_200:
277 csr = (volatile u32 *)CKSEG1ADDR(KN02_SLOT_BASE + KN02_CSR);
278 if (*csr & KN02_CSR_BNK32M)
279 stride = 2;
280 break;
281 case MACH_DS5000_2X0:
282 case MACH_DS5900:
283 csr = (volatile u32 *)CKSEG1ADDR(KN03_SLOT_BASE + IOASIC_MCR);
284 if (*csr & KN03_MCR_BNK32M)
285 stride = 2;
286 break;
287 default:
288 return -ENODEV;
289 }
290
291 for (i = 0; i < ARRAY_SIZE(ms02nv_addrs); i++)
292 if (!ms02nv_init_one(ms02nv_addrs[i] << stride))
293 count++;
294
295 return (count > 0) ? 0 : -ENODEV;
296 }
297
ms02nv_cleanup(void)298 static void __exit ms02nv_cleanup(void)
299 {
300 while (root_ms02nv_mtd)
301 ms02nv_remove_one();
302 }
303
304
305 module_init(ms02nv_init);
306 module_exit(ms02nv_cleanup);
307