hw/misc/sifive_u_otp.c

   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/log.h"
  27 #include "qemu/module.h"
  28 #include "hw/misc/sifive_u_otp.h"
  29 #include "sysemu/blockdev.h"
  30 #include "sysemu/block-backend.h"
  31
  32 #define WRITTEN_BIT_ON 0x1
  33
  34 #define SET_FUSEARRAY_BIT(map, i, off, bit)    \
  35     map[i] = bit ? (map[i] | bit << off) : (map[i] & ~(0x1 << off))
  36
  37 #define GET_FUSEARRAY_BIT(map, i, off)    \
  38     ((map[i] >> off) & 0x1)
  39
  40 static uint64_t sifive_u_otp_read(void *opaque, hwaddr addr, unsigned int size)
  41 {
  42     SiFiveUOTPState *s = opaque;
  43
  44     switch (addr) {
  45     case SIFIVE_U_OTP_PA:
  46         return s->pa;
  47     case SIFIVE_U_OTP_PAIO:
  48         return s->paio;
  49     case SIFIVE_U_OTP_PAS:
  50         return s->pas;
  51     case SIFIVE_U_OTP_PCE:
  52         return s->pce;
  53     case SIFIVE_U_OTP_PCLK:
  54         return s->pclk;
  55     case SIFIVE_U_OTP_PDIN:
  56         return s->pdin;
  57     case SIFIVE_U_OTP_PDOUT:
  58         if ((s->pce & SIFIVE_U_OTP_PCE_EN) &&
  59             (s->pdstb & SIFIVE_U_OTP_PDSTB_EN) &&
  60             (s->ptrim & SIFIVE_U_OTP_PTRIM_EN)) {
  61
  62             /* read from backend */
  63             if (s->blk) {
  64                 int32_t buf;
  65
  66                 if (blk_pread(s->blk, s->pa * SIFIVE_U_OTP_FUSE_WORD, &buf,
  67                               SIFIVE_U_OTP_FUSE_WORD) < 0) {
  68                     qemu_log_mask(LOG_GUEST_ERROR,
  69                                   "read error index<%d>\n", 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                                &s->fuse[s->pa], SIFIVE_U_OTP_FUSE_WORD,
 171                                0) < 0) {
 172                     qemu_log_mask(LOG_GUEST_ERROR,
 173                                   "write error index<%d>\n", s->pa);
 174                 }
 175             }
 176
 177             /* update written bit */
 178             SET_FUSEARRAY_BIT(s->fuse_wo, s->pa, s->paio, WRITTEN_BIT_ON);
 179         }
 180
 181         break;
 182     default:
 183         qemu_log_mask(LOG_GUEST_ERROR, "%s: bad write: addr=0x%" HWADDR_PRIx
 184                       " v=0x%x\n", __func__, addr, val32);
 185     }
 186 }
 187
 188 static const MemoryRegionOps sifive_u_otp_ops = {
 189     .read = sifive_u_otp_read,
 190     .write = sifive_u_otp_write,
 191     .endianness = DEVICE_NATIVE_ENDIAN,
 192     .valid = {
 193         .min_access_size = 4,
 194         .max_access_size = 4
 195     }
 196 };
 197
 198 static Property sifive_u_otp_properties[] = {
 199     DEFINE_PROP_UINT32("serial", SiFiveUOTPState, serial, 0),
 200     DEFINE_PROP_DRIVE("drive", SiFiveUOTPState, blk),
 201     DEFINE_PROP_END_OF_LIST(),
 202 };
 203
 204 static void sifive_u_otp_realize(DeviceState *dev, Error **errp)
 205 {
 206     SiFiveUOTPState *s = SIFIVE_U_OTP(dev);
 207     DriveInfo *dinfo;
 208
 209     memory_region_init_io(&s->mmio, OBJECT(dev), &sifive_u_otp_ops, s,
 210                           TYPE_SIFIVE_U_OTP, SIFIVE_U_OTP_REG_SIZE);
 211     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
 212
 213     dinfo = drive_get_next(IF_NONE);
 214     if (dinfo) {
 215         int ret;
 216         uint64_t perm;
 217         int filesize;
 218         BlockBackend *blk;
 219
 220         blk = blk_by_legacy_dinfo(dinfo);
 221         filesize = SIFIVE_U_OTP_NUM_FUSES * SIFIVE_U_OTP_FUSE_WORD;
 222         if (blk_getlength(blk) < filesize) {
 223             error_setg(errp, "OTP drive size < 16K");
 224             return;
 225         }
 226
 227         qdev_prop_set_drive_err(dev, "drive", blk, errp);
 228
 229         if (s->blk) {
 230             perm = BLK_PERM_CONSISTENT_READ |
 231                    (blk_is_read_only(s->blk) ? 0 : BLK_PERM_WRITE);
 232             ret = blk_set_perm(s->blk, perm, BLK_PERM_ALL, errp);
 233             if (ret < 0) {
 234                 return;
 235             }
 236
 237             if (blk_pread(s->blk, 0, s->fuse, filesize) != filesize) {
 238                 error_setg(errp, "failed to read the initial flash content");
 239             }
 240         }
 241     }
 242 }
 243
 244 static void sifive_u_otp_reset(DeviceState *dev)
 245 {
 246     SiFiveUOTPState *s = SIFIVE_U_OTP(dev);
 247
 248     /* Initialize all fuses' initial value to 0xFFs */
 249     memset(s->fuse, 0xff, sizeof(s->fuse));
 250
 251     /* Make a valid content of serial number */
 252     s->fuse[SIFIVE_U_OTP_SERIAL_ADDR] = s->serial;
 253     s->fuse[SIFIVE_U_OTP_SERIAL_ADDR + 1] = ~(s->serial);
 254
 255     if (s->blk) {
 256         /* Put serial number to backend as well*/
 257         uint32_t serial_data;
 258         int index = SIFIVE_U_OTP_SERIAL_ADDR;
 259
 260         serial_data = s->serial;
 261         if (blk_pwrite(s->blk, index * SIFIVE_U_OTP_FUSE_WORD,
 262                        &serial_data, SIFIVE_U_OTP_FUSE_WORD, 0) < 0) {
 263             qemu_log_mask(LOG_GUEST_ERROR,
 264                           "write error index<%d>\n", index);
 265         }
 266
 267         serial_data = ~(s->serial);
 268         if (blk_pwrite(s->blk, (index + 1) * SIFIVE_U_OTP_FUSE_WORD,
 269                        &serial_data, SIFIVE_U_OTP_FUSE_WORD, 0) < 0) {
 270             qemu_log_mask(LOG_GUEST_ERROR,
 271                           "write error index<%d>\n", index + 1);
 272         }
 273     }
 274
 275     /* Initialize write-once map */
 276     memset(s->fuse_wo, 0x00, sizeof(s->fuse_wo));
 277 }
 278
 279 static void sifive_u_otp_class_init(ObjectClass *klass, void *data)
 280 {
 281     DeviceClass *dc = DEVICE_CLASS(klass);
 282
 283     device_class_set_props(dc, sifive_u_otp_properties);
 284     dc->realize = sifive_u_otp_realize;
 285     dc->reset = sifive_u_otp_reset;
 286 }
 287
 288 static const TypeInfo sifive_u_otp_info = {
 289     .name          = TYPE_SIFIVE_U_OTP,
 290     .parent        = TYPE_SYS_BUS_DEVICE,
 291     .instance_size = sizeof(SiFiveUOTPState),
 292     .class_init    = sifive_u_otp_class_init,
 293 };
 294
 295 static void sifive_u_otp_register_types(void)
 296 {
 297     type_register_static(&sifive_u_otp_info);
 298 }
 299
 300 type_init(sifive_u_otp_register_types)