hw/i2c/aspeed_i2c.c

   1 /*
   2  * ARM Aspeed I2C controller
   3  *
   4  * Copyright (C) 2016 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "hw/sysbus.h"
  23 #include "qemu/log.h"
  24 #include "hw/i2c/aspeed_i2c.h"
  25
  26 /* I2C Global Register */
  27
  28 #define I2C_CTRL_STATUS         0x00        /* Device Interrupt Status */
  29 #define I2C_CTRL_ASSIGN         0x08        /* Device Interrupt Target
  30                                                Assignment */
  31
  32 /* I2C Device (Bus) Register */
  33
  34 #define I2CD_FUN_CTRL_REG       0x00       /* I2CD Function Control  */
  35 #define   I2CD_BUFF_SEL_MASK               (0x7 << 20)
  36 #define   I2CD_BUFF_SEL(x)                 (x << 20)
  37 #define   I2CD_M_SDA_LOCK_EN               (0x1 << 16)
  38 #define   I2CD_MULTI_MASTER_DIS            (0x1 << 15)
  39 #define   I2CD_M_SCL_DRIVE_EN              (0x1 << 14)
  40 #define   I2CD_MSB_STS                     (0x1 << 9)
  41 #define   I2CD_SDA_DRIVE_1T_EN             (0x1 << 8)
  42 #define   I2CD_M_SDA_DRIVE_1T_EN           (0x1 << 7)
  43 #define   I2CD_M_HIGH_SPEED_EN             (0x1 << 6)
  44 #define   I2CD_DEF_ADDR_EN                 (0x1 << 5)
  45 #define   I2CD_DEF_ALERT_EN                (0x1 << 4)
  46 #define   I2CD_DEF_ARP_EN                  (0x1 << 3)
  47 #define   I2CD_DEF_GCALL_EN                (0x1 << 2)
  48 #define   I2CD_SLAVE_EN                    (0x1 << 1)
  49 #define   I2CD_MASTER_EN                   (0x1)
  50
  51 #define I2CD_AC_TIMING_REG1     0x04       /* Clock and AC Timing Control #1 */
  52 #define I2CD_AC_TIMING_REG2     0x08       /* Clock and AC Timing Control #1 */
  53 #define I2CD_INTR_CTRL_REG      0x0c       /* I2CD Interrupt Control */
  54 #define I2CD_INTR_STS_REG       0x10       /* I2CD Interrupt Status */
  55 #define   I2CD_INTR_SDA_DL_TIMEOUT         (0x1 << 14)
  56 #define   I2CD_INTR_BUS_RECOVER_DONE       (0x1 << 13)
  57 #define   I2CD_INTR_SMBUS_ALERT            (0x1 << 12) /* Bus [0-3] only */
  58 #define   I2CD_INTR_SMBUS_ARP_ADDR         (0x1 << 11) /* Removed */
  59 #define   I2CD_INTR_SMBUS_DEV_ALERT_ADDR   (0x1 << 10) /* Removed */
  60 #define   I2CD_INTR_SMBUS_DEF_ADDR         (0x1 << 9)  /* Removed */
  61 #define   I2CD_INTR_GCALL_ADDR             (0x1 << 8)  /* Removed */
  62 #define   I2CD_INTR_SLAVE_MATCH            (0x1 << 7)  /* use RX_DONE */
  63 #define   I2CD_INTR_SCL_TIMEOUT            (0x1 << 6)
  64 #define   I2CD_INTR_ABNORMAL               (0x1 << 5)
  65 #define   I2CD_INTR_NORMAL_STOP            (0x1 << 4)
  66 #define   I2CD_INTR_ARBIT_LOSS             (0x1 << 3)
  67 #define   I2CD_INTR_RX_DONE                (0x1 << 2)
  68 #define   I2CD_INTR_TX_NAK                 (0x1 << 1)
  69 #define   I2CD_INTR_TX_ACK                 (0x1 << 0)
  70
  71 #define I2CD_CMD_REG            0x14       /* I2CD Command/Status */
  72 #define   I2CD_SDA_OE                      (0x1 << 28)
  73 #define   I2CD_SDA_O                       (0x1 << 27)
  74 #define   I2CD_SCL_OE                      (0x1 << 26)
  75 #define   I2CD_SCL_O                       (0x1 << 25)
  76 #define   I2CD_TX_TIMING                   (0x1 << 24)
  77 #define   I2CD_TX_STATUS                   (0x1 << 23)
  78
  79 #define   I2CD_TX_STATE_SHIFT              19 /* Tx State Machine */
  80 #define   I2CD_TX_STATE_MASK                  0xf
  81 #define     I2CD_IDLE                         0x0
  82 #define     I2CD_MACTIVE                      0x8
  83 #define     I2CD_MSTART                       0x9
  84 #define     I2CD_MSTARTR                      0xa
  85 #define     I2CD_MSTOP                        0xb
  86 #define     I2CD_MTXD                         0xc
  87 #define     I2CD_MRXACK                       0xd
  88 #define     I2CD_MRXD                         0xe
  89 #define     I2CD_MTXACK                       0xf
  90 #define     I2CD_SWAIT                        0x1
  91 #define     I2CD_SRXD                         0x4
  92 #define     I2CD_STXACK                       0x5
  93 #define     I2CD_STXD                         0x6
  94 #define     I2CD_SRXACK                       0x7
  95 #define     I2CD_RECOVER                      0x3
  96
  97 #define   I2CD_SCL_LINE_STS                (0x1 << 18)
  98 #define   I2CD_SDA_LINE_STS                (0x1 << 17)
  99 #define   I2CD_BUS_BUSY_STS                (0x1 << 16)
 100 #define   I2CD_SDA_OE_OUT_DIR              (0x1 << 15)
 101 #define   I2CD_SDA_O_OUT_DIR               (0x1 << 14)
 102 #define   I2CD_SCL_OE_OUT_DIR              (0x1 << 13)
 103 #define   I2CD_SCL_O_OUT_DIR               (0x1 << 12)
 104 #define   I2CD_BUS_RECOVER_CMD_EN          (0x1 << 11)
 105 #define   I2CD_S_ALT_EN                    (0x1 << 10)
 106 #define   I2CD_RX_DMA_ENABLE               (0x1 << 9)
 107 #define   I2CD_TX_DMA_ENABLE               (0x1 << 8)
 108
 109 /* Command Bit */
 110 #define   I2CD_M_STOP_CMD                  (0x1 << 5)
 111 #define   I2CD_M_S_RX_CMD_LAST             (0x1 << 4)
 112 #define   I2CD_M_RX_CMD                    (0x1 << 3)
 113 #define   I2CD_S_TX_CMD                    (0x1 << 2)
 114 #define   I2CD_M_TX_CMD                    (0x1 << 1)
 115 #define   I2CD_M_START_CMD                 (0x1)
 116
 117 #define I2CD_DEV_ADDR_REG       0x18       /* Slave Device Address */
 118 #define I2CD_BUF_CTRL_REG       0x1c       /* Pool Buffer Control */
 119 #define I2CD_BYTE_BUF_REG       0x20       /* Transmit/Receive Byte Buffer */
 120 #define   I2CD_BYTE_BUF_TX_SHIFT           0
 121 #define   I2CD_BYTE_BUF_TX_MASK            0xff
 122 #define   I2CD_BYTE_BUF_RX_SHIFT           8
 123 #define   I2CD_BYTE_BUF_RX_MASK            0xff
 124
 125
 126 static inline bool aspeed_i2c_bus_is_master(AspeedI2CBus *bus)
 127 {
 128     return bus->ctrl & I2CD_MASTER_EN;
 129 }
 130
 131 static inline bool aspeed_i2c_bus_is_enabled(AspeedI2CBus *bus)
 132 {
 133     return bus->ctrl & (I2CD_MASTER_EN | I2CD_SLAVE_EN);
 134 }
 135
 136 static inline void aspeed_i2c_bus_raise_interrupt(AspeedI2CBus *bus)
 137 {
 138     bus->intr_status &= bus->intr_ctrl;
 139     if (bus->intr_status) {
 140         bus->controller->intr_status |= 1 << bus->id;
 141         qemu_irq_raise(bus->controller->irq);
 142     }
 143 }
 144
 145 static uint64_t aspeed_i2c_bus_read(void *opaque, hwaddr offset,
 146                                     unsigned size)
 147 {
 148     AspeedI2CBus *bus = opaque;
 149
 150     switch (offset) {
 151     case I2CD_FUN_CTRL_REG:
 152         return bus->ctrl;
 153     case I2CD_AC_TIMING_REG1:
 154         return bus->timing[0];
 155     case I2CD_AC_TIMING_REG2:
 156         return bus->timing[1];
 157     case I2CD_INTR_CTRL_REG:
 158         return bus->intr_ctrl;
 159     case I2CD_INTR_STS_REG:
 160         return bus->intr_status;
 161     case I2CD_BYTE_BUF_REG:
 162         return bus->buf;
 163     case I2CD_CMD_REG:
 164         return bus->cmd | (i2c_bus_busy(bus->bus) << 16);
 165     default:
 166         qemu_log_mask(LOG_GUEST_ERROR,
 167                       "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset);
 168         return -1;
 169     }
 170 }
 171
 172 static void aspeed_i2c_set_state(AspeedI2CBus *bus, uint8_t state)
 173 {
 174     bus->cmd &= ~(I2CD_TX_STATE_MASK << I2CD_TX_STATE_SHIFT);
 175     bus->cmd |= (state & I2CD_TX_STATE_MASK) << I2CD_TX_STATE_SHIFT;
 176 }
 177
 178 static uint8_t aspeed_i2c_get_state(AspeedI2CBus *bus)
 179 {
 180     return (bus->cmd >> I2CD_TX_STATE_SHIFT) & I2CD_TX_STATE_MASK;
 181 }
 182
 183 /*
 184  * The state machine needs some refinement. It is only used to track
 185  * invalid STOP commands for the moment.
 186  */
 187 static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value)
 188 {
 189     bus->cmd &= ~0xFFFF;
 190     bus->cmd |= value & 0xFFFF;
 191     bus->intr_status = 0;
 192
 193     if (bus->cmd & I2CD_M_START_CMD) {
 194         uint8_t state = aspeed_i2c_get_state(bus) & I2CD_MACTIVE ?
 195             I2CD_MSTARTR : I2CD_MSTART;
 196
 197         aspeed_i2c_set_state(bus, state);
 198
 199         if (i2c_start_transfer(bus->bus, extract32(bus->buf, 1, 7),
 200                                extract32(bus->buf, 0, 1))) {
 201             bus->intr_status |= I2CD_INTR_TX_NAK;
 202         } else {
 203             bus->intr_status |= I2CD_INTR_TX_ACK;
 204         }
 205
 206         /* START command is also a TX command, as the slave address is
 207          * sent on the bus */
 208         bus->cmd &= ~(I2CD_M_START_CMD | I2CD_M_TX_CMD);
 209
 210         /* No slave found */
 211         if (!i2c_bus_busy(bus->bus)) {
 212             return;
 213         }
 214         aspeed_i2c_set_state(bus, I2CD_MACTIVE);
 215     }
 216
 217     if (bus->cmd & I2CD_M_TX_CMD) {
 218         aspeed_i2c_set_state(bus, I2CD_MTXD);
 219         if (i2c_send(bus->bus, bus->buf)) {
 220             bus->intr_status |= (I2CD_INTR_TX_NAK);
 221             i2c_end_transfer(bus->bus);
 222         } else {
 223             bus->intr_status |= I2CD_INTR_TX_ACK;
 224         }
 225         bus->cmd &= ~I2CD_M_TX_CMD;
 226         aspeed_i2c_set_state(bus, I2CD_MACTIVE);
 227     }
 228
 229     if (bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST)) {
 230         int ret;
 231
 232         aspeed_i2c_set_state(bus, I2CD_MRXD);
 233         ret = i2c_recv(bus->bus);
 234         if (ret < 0) {
 235             qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__);
 236             ret = 0xff;
 237         } else {
 238             bus->intr_status |= I2CD_INTR_RX_DONE;
 239         }
 240         bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT;
 241         if (bus->cmd & I2CD_M_S_RX_CMD_LAST) {
 242             i2c_nack(bus->bus);
 243         }
 244         bus->cmd &= ~(I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST);
 245         aspeed_i2c_set_state(bus, I2CD_MACTIVE);
 246     }
 247
 248     if (bus->cmd & I2CD_M_STOP_CMD) {
 249         if (!(aspeed_i2c_get_state(bus) & I2CD_MACTIVE)) {
 250             qemu_log_mask(LOG_GUEST_ERROR, "%s: abnormal stop\n", __func__);
 251             bus->intr_status |= I2CD_INTR_ABNORMAL;
 252         } else {
 253             aspeed_i2c_set_state(bus, I2CD_MSTOP);
 254             i2c_end_transfer(bus->bus);
 255             bus->intr_status |= I2CD_INTR_NORMAL_STOP;
 256         }
 257         bus->cmd &= ~I2CD_M_STOP_CMD;
 258         aspeed_i2c_set_state(bus, I2CD_IDLE);
 259     }
 260 }
 261
 262 static void aspeed_i2c_bus_write(void *opaque, hwaddr offset,
 263                                  uint64_t value, unsigned size)
 264 {
 265     AspeedI2CBus *bus = opaque;
 266
 267     switch (offset) {
 268     case I2CD_FUN_CTRL_REG:
 269         if (value & I2CD_SLAVE_EN) {
 270             qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 271                           __func__);
 272             break;
 273         }
 274         bus->ctrl = value & 0x0071C3FF;
 275         break;
 276     case I2CD_AC_TIMING_REG1:
 277         bus->timing[0] = value & 0xFFFFF0F;
 278         break;
 279     case I2CD_AC_TIMING_REG2:
 280         bus->timing[1] = value & 0x7;
 281         break;
 282     case I2CD_INTR_CTRL_REG:
 283         bus->intr_ctrl = value & 0x7FFF;
 284         break;
 285     case I2CD_INTR_STS_REG:
 286         bus->intr_status &= ~(value & 0x7FFF);
 287         bus->controller->intr_status &= ~(1 << bus->id);
 288         qemu_irq_lower(bus->controller->irq);
 289         break;
 290     case I2CD_DEV_ADDR_REG:
 291         qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 292                       __func__);
 293         break;
 294     case I2CD_BYTE_BUF_REG:
 295         bus->buf = (value & I2CD_BYTE_BUF_TX_MASK) << I2CD_BYTE_BUF_TX_SHIFT;
 296         break;
 297     case I2CD_CMD_REG:
 298         if (!aspeed_i2c_bus_is_enabled(bus)) {
 299             break;
 300         }
 301
 302         if (!aspeed_i2c_bus_is_master(bus)) {
 303             qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 304                           __func__);
 305             break;
 306         }
 307
 308         aspeed_i2c_bus_handle_cmd(bus, value);
 309         aspeed_i2c_bus_raise_interrupt(bus);
 310         break;
 311
 312     default:
 313         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 314                       __func__, offset);
 315     }
 316 }
 317
 318 static uint64_t aspeed_i2c_ctrl_read(void *opaque, hwaddr offset,
 319                                    unsigned size)
 320 {
 321     AspeedI2CState *s = opaque;
 322
 323     switch (offset) {
 324     case I2C_CTRL_STATUS:
 325         return s->intr_status;
 326     default:
 327         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 328                       __func__, offset);
 329         break;
 330     }
 331
 332     return -1;
 333 }
 334
 335 static void aspeed_i2c_ctrl_write(void *opaque, hwaddr offset,
 336                                   uint64_t value, unsigned size)
 337 {
 338     switch (offset) {
 339     case I2C_CTRL_STATUS:
 340     default:
 341         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 342                       __func__, offset);
 343         break;
 344     }
 345 }
 346
 347 static const MemoryRegionOps aspeed_i2c_bus_ops = {
 348     .read = aspeed_i2c_bus_read,
 349     .write = aspeed_i2c_bus_write,
 350     .endianness = DEVICE_LITTLE_ENDIAN,
 351 };
 352
 353 static const MemoryRegionOps aspeed_i2c_ctrl_ops = {
 354     .read = aspeed_i2c_ctrl_read,
 355     .write = aspeed_i2c_ctrl_write,
 356     .endianness = DEVICE_LITTLE_ENDIAN,
 357 };
 358
 359 static const VMStateDescription aspeed_i2c_bus_vmstate = {
 360     .name = TYPE_ASPEED_I2C,
 361     .version_id = 1,
 362     .minimum_version_id = 1,
 363     .fields = (VMStateField[]) {
 364         VMSTATE_UINT8(id, AspeedI2CBus),
 365         VMSTATE_UINT32(ctrl, AspeedI2CBus),
 366         VMSTATE_UINT32_ARRAY(timing, AspeedI2CBus, 2),
 367         VMSTATE_UINT32(intr_ctrl, AspeedI2CBus),
 368         VMSTATE_UINT32(intr_status, AspeedI2CBus),
 369         VMSTATE_UINT32(cmd, AspeedI2CBus),
 370         VMSTATE_UINT32(buf, AspeedI2CBus),
 371         VMSTATE_END_OF_LIST()
 372     }
 373 };
 374
 375 static const VMStateDescription aspeed_i2c_vmstate = {
 376     .name = TYPE_ASPEED_I2C,
 377     .version_id = 1,
 378     .minimum_version_id = 1,
 379     .fields = (VMStateField[]) {
 380         VMSTATE_UINT32(intr_status, AspeedI2CState),
 381         VMSTATE_STRUCT_ARRAY(busses, AspeedI2CState,
 382                              ASPEED_I2C_NR_BUSSES, 1, aspeed_i2c_bus_vmstate,
 383                              AspeedI2CBus),
 384         VMSTATE_END_OF_LIST()
 385     }
 386 };
 387
 388 static void aspeed_i2c_reset(DeviceState *dev)
 389 {
 390     int i;
 391     AspeedI2CState *s = ASPEED_I2C(dev);
 392
 393     s->intr_status = 0;
 394
 395     for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
 396         s->busses[i].intr_ctrl = 0;
 397         s->busses[i].intr_status = 0;
 398         s->busses[i].cmd = 0;
 399         s->busses[i].buf = 0;
 400         i2c_end_transfer(s->busses[i].bus);
 401     }
 402 }
 403
 404 /*
 405  * Address Definitions
 406  *
 407  *   0x000 ... 0x03F: Global Register
 408  *   0x040 ... 0x07F: Device 1
 409  *   0x080 ... 0x0BF: Device 2
 410  *   0x0C0 ... 0x0FF: Device 3
 411  *   0x100 ... 0x13F: Device 4
 412  *   0x140 ... 0x17F: Device 5
 413  *   0x180 ... 0x1BF: Device 6
 414  *   0x1C0 ... 0x1FF: Device 7
 415  *   0x200 ... 0x2FF: Buffer Pool  (unused in linux driver)
 416  *   0x300 ... 0x33F: Device 8
 417  *   0x340 ... 0x37F: Device 9
 418  *   0x380 ... 0x3BF: Device 10
 419  *   0x3C0 ... 0x3FF: Device 11
 420  *   0x400 ... 0x43F: Device 12
 421  *   0x440 ... 0x47F: Device 13
 422  *   0x480 ... 0x4BF: Device 14
 423  *   0x800 ... 0xFFF: Buffer Pool  (unused in linux driver)
 424  */
 425 static void aspeed_i2c_realize(DeviceState *dev, Error **errp)
 426 {
 427     int i;
 428     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 429     AspeedI2CState *s = ASPEED_I2C(dev);
 430
 431     sysbus_init_irq(sbd, &s->irq);
 432     memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_i2c_ctrl_ops, s,
 433                           "aspeed.i2c", 0x1000);
 434     sysbus_init_mmio(sbd, &s->iomem);
 435
 436     for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
 437         char name[16];
 438         int offset = i < 7 ? 1 : 5;
 439         snprintf(name, sizeof(name), "aspeed.i2c.%d", i);
 440         s->busses[i].controller = s;
 441         s->busses[i].id = i;
 442         s->busses[i].bus = i2c_init_bus(dev, name);
 443         memory_region_init_io(&s->busses[i].mr, OBJECT(dev),
 444                               &aspeed_i2c_bus_ops, &s->busses[i], name, 0x40);
 445         memory_region_add_subregion(&s->iomem, 0x40 * (i + offset),
 446                                     &s->busses[i].mr);
 447     }
 448 }
 449
 450 static void aspeed_i2c_class_init(ObjectClass *klass, void *data)
 451 {
 452     DeviceClass *dc = DEVICE_CLASS(klass);
 453
 454     dc->vmsd = &aspeed_i2c_vmstate;
 455     dc->reset = aspeed_i2c_reset;
 456     dc->realize = aspeed_i2c_realize;
 457     dc->desc = "Aspeed I2C Controller";
 458 }
 459
 460 static const TypeInfo aspeed_i2c_info = {
 461     .name          = TYPE_ASPEED_I2C,
 462     .parent        = TYPE_SYS_BUS_DEVICE,
 463     .instance_size = sizeof(AspeedI2CState),
 464     .class_init    = aspeed_i2c_class_init,
 465 };
 466
 467 static void aspeed_i2c_register_types(void)
 468 {
 469     type_register_static(&aspeed_i2c_info);
 470 }
 471
 472 type_init(aspeed_i2c_register_types)
 473
 474
 475 I2CBus *aspeed_i2c_get_bus(DeviceState *dev, int busnr)
 476 {
 477     AspeedI2CState *s = ASPEED_I2C(dev);
 478     I2CBus *bus = NULL;
 479
 480     if (busnr >= 0 && busnr < ASPEED_I2C_NR_BUSSES) {
 481         bus = s->busses[busnr].bus;
 482     }
 483
 484     return bus;
 485 }