xref: /openbmc/qemu/hw/misc/sifive_u_otp.c (revision 93e0932b)
1 /*
2  * QEMU SiFive U OTP (One-Time Programmable) Memory interface
3  *
4  * Copyright (c) 2019 Bin Meng <bmeng.cn@gmail.com>
5  *
6  * Simple model of the OTP to emulate register reads made by the SDK BSP
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms and conditions of the GNU General Public License,
10  * version 2 or later, as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along with
18  * this program.  If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "qapi/error.h"
23 #include "hw/qdev-properties.h"
24 #include "hw/qdev-properties-system.h"
25 #include "hw/sysbus.h"
26 #include "qemu/error-report.h"
27 #include "qemu/log.h"
28 #include "qemu/module.h"
29 #include "hw/misc/sifive_u_otp.h"
30 #include "sysemu/blockdev.h"
31 #include "sysemu/block-backend.h"
32 
33 #define WRITTEN_BIT_ON 0x1
34 
35 #define SET_FUSEARRAY_BIT(map, i, off, bit)    \
36     map[i] = bit ? (map[i] | bit << off) : (map[i] & ~(0x1 << off))
37 
38 #define GET_FUSEARRAY_BIT(map, i, off)    \
39     ((map[i] >> off) & 0x1)
40 
41 static uint64_t sifive_u_otp_read(void *opaque, hwaddr addr, unsigned int size)
42 {
43     SiFiveUOTPState *s = opaque;
44 
45     switch (addr) {
46     case SIFIVE_U_OTP_PA:
47         return s->pa;
48     case SIFIVE_U_OTP_PAIO:
49         return s->paio;
50     case SIFIVE_U_OTP_PAS:
51         return s->pas;
52     case SIFIVE_U_OTP_PCE:
53         return s->pce;
54     case SIFIVE_U_OTP_PCLK:
55         return s->pclk;
56     case SIFIVE_U_OTP_PDIN:
57         return s->pdin;
58     case SIFIVE_U_OTP_PDOUT:
59         if ((s->pce & SIFIVE_U_OTP_PCE_EN) &&
60             (s->pdstb & SIFIVE_U_OTP_PDSTB_EN) &&
61             (s->ptrim & SIFIVE_U_OTP_PTRIM_EN)) {
62 
63             /* read from backend */
64             if (s->blk) {
65                 int32_t buf;
66 
67                 if (blk_pread(s->blk, s->pa * SIFIVE_U_OTP_FUSE_WORD,
68                               SIFIVE_U_OTP_FUSE_WORD, &buf, 0) < 0) {
69                     error_report("read error index<%d>", s->pa);
70                     return 0xff;
71                 }
72 
73                 return buf;
74             }
75 
76             return s->fuse[s->pa & SIFIVE_U_OTP_PA_MASK];
77         } else {
78             return 0xff;
79         }
80     case SIFIVE_U_OTP_PDSTB:
81         return s->pdstb;
82     case SIFIVE_U_OTP_PPROG:
83         return s->pprog;
84     case SIFIVE_U_OTP_PTC:
85         return s->ptc;
86     case SIFIVE_U_OTP_PTM:
87         return s->ptm;
88     case SIFIVE_U_OTP_PTM_REP:
89         return s->ptm_rep;
90     case SIFIVE_U_OTP_PTR:
91         return s->ptr;
92     case SIFIVE_U_OTP_PTRIM:
93         return s->ptrim;
94     case SIFIVE_U_OTP_PWE:
95         return s->pwe;
96     }
97 
98     qemu_log_mask(LOG_GUEST_ERROR, "%s: read: addr=0x%" HWADDR_PRIx "\n",
99                   __func__, addr);
100     return 0;
101 }
102 
103 static void sifive_u_otp_write(void *opaque, hwaddr addr,
104                                uint64_t val64, unsigned int size)
105 {
106     SiFiveUOTPState *s = opaque;
107     uint32_t val32 = (uint32_t)val64;
108 
109     switch (addr) {
110     case SIFIVE_U_OTP_PA:
111         s->pa = val32 & SIFIVE_U_OTP_PA_MASK;
112         break;
113     case SIFIVE_U_OTP_PAIO:
114         s->paio = val32;
115         break;
116     case SIFIVE_U_OTP_PAS:
117         s->pas = val32;
118         break;
119     case SIFIVE_U_OTP_PCE:
120         s->pce = val32;
121         break;
122     case SIFIVE_U_OTP_PCLK:
123         s->pclk = val32;
124         break;
125     case SIFIVE_U_OTP_PDIN:
126         s->pdin = val32;
127         break;
128     case SIFIVE_U_OTP_PDOUT:
129         /* read-only */
130         break;
131     case SIFIVE_U_OTP_PDSTB:
132         s->pdstb = val32;
133         break;
134     case SIFIVE_U_OTP_PPROG:
135         s->pprog = val32;
136         break;
137     case SIFIVE_U_OTP_PTC:
138         s->ptc = val32;
139         break;
140     case SIFIVE_U_OTP_PTM:
141         s->ptm = val32;
142         break;
143     case SIFIVE_U_OTP_PTM_REP:
144         s->ptm_rep = val32;
145         break;
146     case SIFIVE_U_OTP_PTR:
147         s->ptr = val32;
148         break;
149     case SIFIVE_U_OTP_PTRIM:
150         s->ptrim = val32;
151         break;
152     case SIFIVE_U_OTP_PWE:
153         s->pwe = val32 & SIFIVE_U_OTP_PWE_EN;
154 
155         /* PWE is enabled. Ignore PAS=1 (no redundancy cell) */
156         if (s->pwe && !s->pas) {
157             if (GET_FUSEARRAY_BIT(s->fuse_wo, s->pa, s->paio)) {
158                 qemu_log_mask(LOG_GUEST_ERROR,
159                               "write once error: idx<%u>, bit<%u>\n",
160                               s->pa, s->paio);
161                 break;
162             }
163 
164             /* write bit data */
165             SET_FUSEARRAY_BIT(s->fuse, s->pa, s->paio, s->pdin);
166 
167             /* write to backend */
168             if (s->blk) {
169                 if (blk_pwrite(s->blk, s->pa * SIFIVE_U_OTP_FUSE_WORD,
170                                SIFIVE_U_OTP_FUSE_WORD, &s->fuse[s->pa], 0)
171                     < 0) {
172                     error_report("write error index<%d>", s->pa);
173                 }
174             }
175 
176             /* update written bit */
177             SET_FUSEARRAY_BIT(s->fuse_wo, s->pa, s->paio, WRITTEN_BIT_ON);
178         }
179 
180         break;
181     default:
182         qemu_log_mask(LOG_GUEST_ERROR, "%s: bad write: addr=0x%" HWADDR_PRIx
183                       " v=0x%x\n", __func__, addr, val32);
184     }
185 }
186 
187 static const MemoryRegionOps sifive_u_otp_ops = {
188     .read = sifive_u_otp_read,
189     .write = sifive_u_otp_write,
190     .endianness = DEVICE_NATIVE_ENDIAN,
191     .valid = {
192         .min_access_size = 4,
193         .max_access_size = 4
194     }
195 };
196 
197 static Property sifive_u_otp_properties[] = {
198     DEFINE_PROP_UINT32("serial", SiFiveUOTPState, serial, 0),
199     DEFINE_PROP_DRIVE("drive", SiFiveUOTPState, blk),
200     DEFINE_PROP_END_OF_LIST(),
201 };
202 
203 static void sifive_u_otp_realize(DeviceState *dev, Error **errp)
204 {
205     SiFiveUOTPState *s = SIFIVE_U_OTP(dev);
206     DriveInfo *dinfo;
207 
208     memory_region_init_io(&s->mmio, OBJECT(dev), &sifive_u_otp_ops, s,
209                           TYPE_SIFIVE_U_OTP, SIFIVE_U_OTP_REG_SIZE);
210     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
211 
212     dinfo = drive_get(IF_PFLASH, 0, 0);
213     if (dinfo) {
214         int ret;
215         uint64_t perm;
216         int filesize;
217         BlockBackend *blk;
218 
219         blk = blk_by_legacy_dinfo(dinfo);
220         filesize = SIFIVE_U_OTP_NUM_FUSES * SIFIVE_U_OTP_FUSE_WORD;
221         if (blk_getlength(blk) < filesize) {
222             error_setg(errp, "OTP drive size < 16K");
223             return;
224         }
225 
226         qdev_prop_set_drive_err(dev, "drive", blk, errp);
227 
228         if (s->blk) {
229             perm = BLK_PERM_CONSISTENT_READ |
230                    (blk_supports_write_perm(s->blk) ? BLK_PERM_WRITE : 0);
231             ret = blk_set_perm(s->blk, perm, BLK_PERM_ALL, errp);
232             if (ret < 0) {
233                 return;
234             }
235 
236             if (blk_pread(s->blk, 0, filesize, s->fuse, 0) < 0) {
237                 error_setg(errp, "failed to read the initial flash content");
238                 return;
239             }
240         }
241     }
242 
243     /* Initialize all fuses' initial value to 0xFFs */
244     memset(s->fuse, 0xff, sizeof(s->fuse));
245 
246     /* Make a valid content of serial number */
247     s->fuse[SIFIVE_U_OTP_SERIAL_ADDR] = s->serial;
248     s->fuse[SIFIVE_U_OTP_SERIAL_ADDR + 1] = ~(s->serial);
249 
250     if (s->blk) {
251         /* Put serial number to backend as well*/
252         uint32_t serial_data;
253         int index = SIFIVE_U_OTP_SERIAL_ADDR;
254 
255         serial_data = s->serial;
256         if (blk_pwrite(s->blk, index * SIFIVE_U_OTP_FUSE_WORD,
257                        SIFIVE_U_OTP_FUSE_WORD, &serial_data, 0) < 0) {
258             error_setg(errp, "failed to write index<%d>", index);
259             return;
260         }
261 
262         serial_data = ~(s->serial);
263         if (blk_pwrite(s->blk, (index + 1) * SIFIVE_U_OTP_FUSE_WORD,
264                        SIFIVE_U_OTP_FUSE_WORD, &serial_data, 0) < 0) {
265             error_setg(errp, "failed to write index<%d>", index + 1);
266             return;
267         }
268     }
269 
270     /* Initialize write-once map */
271     memset(s->fuse_wo, 0x00, sizeof(s->fuse_wo));
272 }
273 
274 static void sifive_u_otp_class_init(ObjectClass *klass, void *data)
275 {
276     DeviceClass *dc = DEVICE_CLASS(klass);
277 
278     device_class_set_props(dc, sifive_u_otp_properties);
279     dc->realize = sifive_u_otp_realize;
280 }
281 
282 static const TypeInfo sifive_u_otp_info = {
283     .name          = TYPE_SIFIVE_U_OTP,
284     .parent        = TYPE_SYS_BUS_DEVICE,
285     .instance_size = sizeof(SiFiveUOTPState),
286     .class_init    = sifive_u_otp_class_init,
287 };
288 
289 static void sifive_u_otp_register_types(void)
290 {
291     type_register_static(&sifive_u_otp_info);
292 }
293 
294 type_init(sifive_u_otp_register_types)
295