qemu/hw/i2c/aspeed_i2c.c
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   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 "qemu/module.h"
  25#include "hw/i2c/aspeed_i2c.h"
  26
  27/* I2C Global Register */
  28
  29#define I2C_CTRL_STATUS         0x00        /* Device Interrupt Status */
  30#define I2C_CTRL_ASSIGN         0x08        /* Device Interrupt Target
  31                                               Assignment */
  32
  33/* I2C Device (Bus) Register */
  34
  35#define I2CD_FUN_CTRL_REG       0x00       /* I2CD Function Control  */
  36#define   I2CD_BUFF_SEL_MASK               (0x7 << 20)
  37#define   I2CD_BUFF_SEL(x)                 (x << 20)
  38#define   I2CD_M_SDA_LOCK_EN               (0x1 << 16)
  39#define   I2CD_MULTI_MASTER_DIS            (0x1 << 15)
  40#define   I2CD_M_SCL_DRIVE_EN              (0x1 << 14)
  41#define   I2CD_MSB_STS                     (0x1 << 9)
  42#define   I2CD_SDA_DRIVE_1T_EN             (0x1 << 8)
  43#define   I2CD_M_SDA_DRIVE_1T_EN           (0x1 << 7)
  44#define   I2CD_M_HIGH_SPEED_EN             (0x1 << 6)
  45#define   I2CD_DEF_ADDR_EN                 (0x1 << 5)
  46#define   I2CD_DEF_ALERT_EN                (0x1 << 4)
  47#define   I2CD_DEF_ARP_EN                  (0x1 << 3)
  48#define   I2CD_DEF_GCALL_EN                (0x1 << 2)
  49#define   I2CD_SLAVE_EN                    (0x1 << 1)
  50#define   I2CD_MASTER_EN                   (0x1)
  51
  52#define I2CD_AC_TIMING_REG1     0x04       /* Clock and AC Timing Control #1 */
  53#define I2CD_AC_TIMING_REG2     0x08       /* Clock and AC Timing Control #1 */
  54#define I2CD_INTR_CTRL_REG      0x0c       /* I2CD Interrupt Control */
  55#define I2CD_INTR_STS_REG       0x10       /* I2CD Interrupt Status */
  56
  57#define   I2CD_INTR_SLAVE_ADDR_MATCH       (0x1 << 31) /* 0: addr1 1: addr2 */
  58#define   I2CD_INTR_SLAVE_ADDR_RX_PENDING  (0x1 << 30)
  59/* bits[19-16] Reserved */
  60
  61/* All bits below are cleared by writing 1 */
  62#define   I2CD_INTR_SLAVE_INACTIVE_TIMEOUT (0x1 << 15)
  63#define   I2CD_INTR_SDA_DL_TIMEOUT         (0x1 << 14)
  64#define   I2CD_INTR_BUS_RECOVER_DONE       (0x1 << 13)
  65#define   I2CD_INTR_SMBUS_ALERT            (0x1 << 12) /* Bus [0-3] only */
  66#define   I2CD_INTR_SMBUS_ARP_ADDR         (0x1 << 11) /* Removed */
  67#define   I2CD_INTR_SMBUS_DEV_ALERT_ADDR   (0x1 << 10) /* Removed */
  68#define   I2CD_INTR_SMBUS_DEF_ADDR         (0x1 << 9)  /* Removed */
  69#define   I2CD_INTR_GCALL_ADDR             (0x1 << 8)  /* Removed */
  70#define   I2CD_INTR_SLAVE_ADDR_RX_MATCH    (0x1 << 7)  /* use RX_DONE */
  71#define   I2CD_INTR_SCL_TIMEOUT            (0x1 << 6)
  72#define   I2CD_INTR_ABNORMAL               (0x1 << 5)
  73#define   I2CD_INTR_NORMAL_STOP            (0x1 << 4)
  74#define   I2CD_INTR_ARBIT_LOSS             (0x1 << 3)
  75#define   I2CD_INTR_RX_DONE                (0x1 << 2)
  76#define   I2CD_INTR_TX_NAK                 (0x1 << 1)
  77#define   I2CD_INTR_TX_ACK                 (0x1 << 0)
  78
  79#define I2CD_CMD_REG            0x14       /* I2CD Command/Status */
  80#define   I2CD_SDA_OE                      (0x1 << 28)
  81#define   I2CD_SDA_O                       (0x1 << 27)
  82#define   I2CD_SCL_OE                      (0x1 << 26)
  83#define   I2CD_SCL_O                       (0x1 << 25)
  84#define   I2CD_TX_TIMING                   (0x1 << 24)
  85#define   I2CD_TX_STATUS                   (0x1 << 23)
  86
  87#define   I2CD_TX_STATE_SHIFT              19 /* Tx State Machine */
  88#define   I2CD_TX_STATE_MASK                  0xf
  89#define     I2CD_IDLE                         0x0
  90#define     I2CD_MACTIVE                      0x8
  91#define     I2CD_MSTART                       0x9
  92#define     I2CD_MSTARTR                      0xa
  93#define     I2CD_MSTOP                        0xb
  94#define     I2CD_MTXD                         0xc
  95#define     I2CD_MRXACK                       0xd
  96#define     I2CD_MRXD                         0xe
  97#define     I2CD_MTXACK                       0xf
  98#define     I2CD_SWAIT                        0x1
  99#define     I2CD_SRXD                         0x4
 100#define     I2CD_STXACK                       0x5
 101#define     I2CD_STXD                         0x6
 102#define     I2CD_SRXACK                       0x7
 103#define     I2CD_RECOVER                      0x3
 104
 105#define   I2CD_SCL_LINE_STS                (0x1 << 18)
 106#define   I2CD_SDA_LINE_STS                (0x1 << 17)
 107#define   I2CD_BUS_BUSY_STS                (0x1 << 16)
 108#define   I2CD_SDA_OE_OUT_DIR              (0x1 << 15)
 109#define   I2CD_SDA_O_OUT_DIR               (0x1 << 14)
 110#define   I2CD_SCL_OE_OUT_DIR              (0x1 << 13)
 111#define   I2CD_SCL_O_OUT_DIR               (0x1 << 12)
 112#define   I2CD_BUS_RECOVER_CMD_EN          (0x1 << 11)
 113#define   I2CD_S_ALT_EN                    (0x1 << 10)
 114#define   I2CD_RX_DMA_ENABLE               (0x1 << 9)
 115#define   I2CD_TX_DMA_ENABLE               (0x1 << 8)
 116
 117/* Command Bit */
 118#define   I2CD_M_STOP_CMD                  (0x1 << 5)
 119#define   I2CD_M_S_RX_CMD_LAST             (0x1 << 4)
 120#define   I2CD_M_RX_CMD                    (0x1 << 3)
 121#define   I2CD_S_TX_CMD                    (0x1 << 2)
 122#define   I2CD_M_TX_CMD                    (0x1 << 1)
 123#define   I2CD_M_START_CMD                 (0x1)
 124
 125#define I2CD_DEV_ADDR_REG       0x18       /* Slave Device Address */
 126#define I2CD_BUF_CTRL_REG       0x1c       /* Pool Buffer Control */
 127#define I2CD_BYTE_BUF_REG       0x20       /* Transmit/Receive Byte Buffer */
 128#define   I2CD_BYTE_BUF_TX_SHIFT           0
 129#define   I2CD_BYTE_BUF_TX_MASK            0xff
 130#define   I2CD_BYTE_BUF_RX_SHIFT           8
 131#define   I2CD_BYTE_BUF_RX_MASK            0xff
 132
 133
 134static inline bool aspeed_i2c_bus_is_master(AspeedI2CBus *bus)
 135{
 136    return bus->ctrl & I2CD_MASTER_EN;
 137}
 138
 139static inline bool aspeed_i2c_bus_is_enabled(AspeedI2CBus *bus)
 140{
 141    return bus->ctrl & (I2CD_MASTER_EN | I2CD_SLAVE_EN);
 142}
 143
 144static inline void aspeed_i2c_bus_raise_interrupt(AspeedI2CBus *bus)
 145{
 146    bus->intr_status &= bus->intr_ctrl;
 147    if (bus->intr_status) {
 148        bus->controller->intr_status |= 1 << bus->id;
 149        qemu_irq_raise(bus->controller->irq);
 150    }
 151}
 152
 153static uint64_t aspeed_i2c_bus_read(void *opaque, hwaddr offset,
 154                                    unsigned size)
 155{
 156    AspeedI2CBus *bus = opaque;
 157
 158    switch (offset) {
 159    case I2CD_FUN_CTRL_REG:
 160        return bus->ctrl;
 161    case I2CD_AC_TIMING_REG1:
 162        return bus->timing[0];
 163    case I2CD_AC_TIMING_REG2:
 164        return bus->timing[1];
 165    case I2CD_INTR_CTRL_REG:
 166        return bus->intr_ctrl;
 167    case I2CD_INTR_STS_REG:
 168        return bus->intr_status;
 169    case I2CD_BYTE_BUF_REG:
 170        return bus->buf;
 171    case I2CD_CMD_REG:
 172        return bus->cmd | (i2c_bus_busy(bus->bus) << 16);
 173    default:
 174        qemu_log_mask(LOG_GUEST_ERROR,
 175                      "%s: Bad offset 0x%" HWADDR_PRIx "\n", __func__, offset);
 176        return -1;
 177    }
 178}
 179
 180static void aspeed_i2c_set_state(AspeedI2CBus *bus, uint8_t state)
 181{
 182    bus->cmd &= ~(I2CD_TX_STATE_MASK << I2CD_TX_STATE_SHIFT);
 183    bus->cmd |= (state & I2CD_TX_STATE_MASK) << I2CD_TX_STATE_SHIFT;
 184}
 185
 186static uint8_t aspeed_i2c_get_state(AspeedI2CBus *bus)
 187{
 188    return (bus->cmd >> I2CD_TX_STATE_SHIFT) & I2CD_TX_STATE_MASK;
 189}
 190
 191static void aspeed_i2c_handle_rx_cmd(AspeedI2CBus *bus)
 192{
 193    uint8_t ret;
 194
 195    aspeed_i2c_set_state(bus, I2CD_MRXD);
 196    ret = i2c_recv(bus->bus);
 197    bus->intr_status |= I2CD_INTR_RX_DONE;
 198    bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT;
 199    if (bus->cmd & I2CD_M_S_RX_CMD_LAST) {
 200        i2c_nack(bus->bus);
 201    }
 202    bus->cmd &= ~(I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST);
 203    aspeed_i2c_set_state(bus, I2CD_MACTIVE);
 204}
 205
 206/*
 207 * The state machine needs some refinement. It is only used to track
 208 * invalid STOP commands for the moment.
 209 */
 210static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value)
 211{
 212    bus->cmd &= ~0xFFFF;
 213    bus->cmd |= value & 0xFFFF;
 214
 215    if (bus->cmd & I2CD_M_START_CMD) {
 216        uint8_t state = aspeed_i2c_get_state(bus) & I2CD_MACTIVE ?
 217            I2CD_MSTARTR : I2CD_MSTART;
 218
 219        aspeed_i2c_set_state(bus, state);
 220
 221        if (i2c_start_transfer(bus->bus, extract32(bus->buf, 1, 7),
 222                               extract32(bus->buf, 0, 1))) {
 223            bus->intr_status |= I2CD_INTR_TX_NAK;
 224        } else {
 225            bus->intr_status |= I2CD_INTR_TX_ACK;
 226        }
 227
 228        /* START command is also a TX command, as the slave address is
 229         * sent on the bus */
 230        bus->cmd &= ~(I2CD_M_START_CMD | I2CD_M_TX_CMD);
 231
 232        /* No slave found */
 233        if (!i2c_bus_busy(bus->bus)) {
 234            return;
 235        }
 236        aspeed_i2c_set_state(bus, I2CD_MACTIVE);
 237    }
 238
 239    if (bus->cmd & I2CD_M_TX_CMD) {
 240        aspeed_i2c_set_state(bus, I2CD_MTXD);
 241        if (i2c_send(bus->bus, bus->buf)) {
 242            bus->intr_status |= (I2CD_INTR_TX_NAK);
 243            i2c_end_transfer(bus->bus);
 244        } else {
 245            bus->intr_status |= I2CD_INTR_TX_ACK;
 246        }
 247        bus->cmd &= ~I2CD_M_TX_CMD;
 248        aspeed_i2c_set_state(bus, I2CD_MACTIVE);
 249    }
 250
 251    if ((bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST)) &&
 252        !(bus->intr_status & I2CD_INTR_RX_DONE)) {
 253        aspeed_i2c_handle_rx_cmd(bus);
 254    }
 255
 256    if (bus->cmd & I2CD_M_STOP_CMD) {
 257        if (!(aspeed_i2c_get_state(bus) & I2CD_MACTIVE)) {
 258            qemu_log_mask(LOG_GUEST_ERROR, "%s: abnormal stop\n", __func__);
 259            bus->intr_status |= I2CD_INTR_ABNORMAL;
 260        } else {
 261            aspeed_i2c_set_state(bus, I2CD_MSTOP);
 262            i2c_end_transfer(bus->bus);
 263            bus->intr_status |= I2CD_INTR_NORMAL_STOP;
 264        }
 265        bus->cmd &= ~I2CD_M_STOP_CMD;
 266        aspeed_i2c_set_state(bus, I2CD_IDLE);
 267    }
 268}
 269
 270static void aspeed_i2c_bus_write(void *opaque, hwaddr offset,
 271                                 uint64_t value, unsigned size)
 272{
 273    AspeedI2CBus *bus = opaque;
 274    bool handle_rx;
 275
 276    switch (offset) {
 277    case I2CD_FUN_CTRL_REG:
 278        if (value & I2CD_SLAVE_EN) {
 279            qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 280                          __func__);
 281            break;
 282        }
 283        bus->ctrl = value & 0x0071C3FF;
 284        break;
 285    case I2CD_AC_TIMING_REG1:
 286        bus->timing[0] = value & 0xFFFFF0F;
 287        break;
 288    case I2CD_AC_TIMING_REG2:
 289        bus->timing[1] = value & 0x7;
 290        break;
 291    case I2CD_INTR_CTRL_REG:
 292        bus->intr_ctrl = value & 0x7FFF;
 293        break;
 294    case I2CD_INTR_STS_REG:
 295        handle_rx = (bus->intr_status & I2CD_INTR_RX_DONE) &&
 296                (value & I2CD_INTR_RX_DONE);
 297        bus->intr_status &= ~(value & 0x7FFF);
 298        if (!bus->intr_status) {
 299            bus->controller->intr_status &= ~(1 << bus->id);
 300            qemu_irq_lower(bus->controller->irq);
 301        }
 302        if (handle_rx && (bus->cmd & (I2CD_M_RX_CMD | I2CD_M_S_RX_CMD_LAST))) {
 303            aspeed_i2c_handle_rx_cmd(bus);
 304            aspeed_i2c_bus_raise_interrupt(bus);
 305        }
 306        break;
 307    case I2CD_DEV_ADDR_REG:
 308        qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 309                      __func__);
 310        break;
 311    case I2CD_BYTE_BUF_REG:
 312        bus->buf = (value & I2CD_BYTE_BUF_TX_MASK) << I2CD_BYTE_BUF_TX_SHIFT;
 313        break;
 314    case I2CD_CMD_REG:
 315        if (!aspeed_i2c_bus_is_enabled(bus)) {
 316            break;
 317        }
 318
 319        if (!aspeed_i2c_bus_is_master(bus)) {
 320            qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 321                          __func__);
 322            break;
 323        }
 324
 325        aspeed_i2c_bus_handle_cmd(bus, value);
 326        aspeed_i2c_bus_raise_interrupt(bus);
 327        break;
 328
 329    default:
 330        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 331                      __func__, offset);
 332    }
 333}
 334
 335static uint64_t aspeed_i2c_ctrl_read(void *opaque, hwaddr offset,
 336                                   unsigned size)
 337{
 338    AspeedI2CState *s = opaque;
 339
 340    switch (offset) {
 341    case I2C_CTRL_STATUS:
 342        return s->intr_status;
 343    default:
 344        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 345                      __func__, offset);
 346        break;
 347    }
 348
 349    return -1;
 350}
 351
 352static void aspeed_i2c_ctrl_write(void *opaque, hwaddr offset,
 353                                  uint64_t value, unsigned size)
 354{
 355    switch (offset) {
 356    case I2C_CTRL_STATUS:
 357    default:
 358        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 359                      __func__, offset);
 360        break;
 361    }
 362}
 363
 364static const MemoryRegionOps aspeed_i2c_bus_ops = {
 365    .read = aspeed_i2c_bus_read,
 366    .write = aspeed_i2c_bus_write,
 367    .endianness = DEVICE_LITTLE_ENDIAN,
 368};
 369
 370static const MemoryRegionOps aspeed_i2c_ctrl_ops = {
 371    .read = aspeed_i2c_ctrl_read,
 372    .write = aspeed_i2c_ctrl_write,
 373    .endianness = DEVICE_LITTLE_ENDIAN,
 374};
 375
 376static const VMStateDescription aspeed_i2c_bus_vmstate = {
 377    .name = TYPE_ASPEED_I2C,
 378    .version_id = 1,
 379    .minimum_version_id = 1,
 380    .fields = (VMStateField[]) {
 381        VMSTATE_UINT8(id, AspeedI2CBus),
 382        VMSTATE_UINT32(ctrl, AspeedI2CBus),
 383        VMSTATE_UINT32_ARRAY(timing, AspeedI2CBus, 2),
 384        VMSTATE_UINT32(intr_ctrl, AspeedI2CBus),
 385        VMSTATE_UINT32(intr_status, AspeedI2CBus),
 386        VMSTATE_UINT32(cmd, AspeedI2CBus),
 387        VMSTATE_UINT32(buf, AspeedI2CBus),
 388        VMSTATE_END_OF_LIST()
 389    }
 390};
 391
 392static const VMStateDescription aspeed_i2c_vmstate = {
 393    .name = TYPE_ASPEED_I2C,
 394    .version_id = 1,
 395    .minimum_version_id = 1,
 396    .fields = (VMStateField[]) {
 397        VMSTATE_UINT32(intr_status, AspeedI2CState),
 398        VMSTATE_STRUCT_ARRAY(busses, AspeedI2CState,
 399                             ASPEED_I2C_NR_BUSSES, 1, aspeed_i2c_bus_vmstate,
 400                             AspeedI2CBus),
 401        VMSTATE_END_OF_LIST()
 402    }
 403};
 404
 405static void aspeed_i2c_reset(DeviceState *dev)
 406{
 407    int i;
 408    AspeedI2CState *s = ASPEED_I2C(dev);
 409
 410    s->intr_status = 0;
 411
 412    for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
 413        s->busses[i].intr_ctrl = 0;
 414        s->busses[i].intr_status = 0;
 415        s->busses[i].cmd = 0;
 416        s->busses[i].buf = 0;
 417        i2c_end_transfer(s->busses[i].bus);
 418    }
 419}
 420
 421/*
 422 * Address Definitions
 423 *
 424 *   0x000 ... 0x03F: Global Register
 425 *   0x040 ... 0x07F: Device 1
 426 *   0x080 ... 0x0BF: Device 2
 427 *   0x0C0 ... 0x0FF: Device 3
 428 *   0x100 ... 0x13F: Device 4
 429 *   0x140 ... 0x17F: Device 5
 430 *   0x180 ... 0x1BF: Device 6
 431 *   0x1C0 ... 0x1FF: Device 7
 432 *   0x200 ... 0x2FF: Buffer Pool  (unused in linux driver)
 433 *   0x300 ... 0x33F: Device 8
 434 *   0x340 ... 0x37F: Device 9
 435 *   0x380 ... 0x3BF: Device 10
 436 *   0x3C0 ... 0x3FF: Device 11
 437 *   0x400 ... 0x43F: Device 12
 438 *   0x440 ... 0x47F: Device 13
 439 *   0x480 ... 0x4BF: Device 14
 440 *   0x800 ... 0xFFF: Buffer Pool  (unused in linux driver)
 441 */
 442static void aspeed_i2c_realize(DeviceState *dev, Error **errp)
 443{
 444    int i;
 445    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 446    AspeedI2CState *s = ASPEED_I2C(dev);
 447
 448    sysbus_init_irq(sbd, &s->irq);
 449    memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_i2c_ctrl_ops, s,
 450                          "aspeed.i2c", 0x1000);
 451    sysbus_init_mmio(sbd, &s->iomem);
 452
 453    for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
 454        char name[16];
 455        int offset = i < 7 ? 1 : 5;
 456        snprintf(name, sizeof(name), "aspeed.i2c.%d", i);
 457        s->busses[i].controller = s;
 458        s->busses[i].id = i;
 459        s->busses[i].bus = i2c_init_bus(dev, name);
 460        memory_region_init_io(&s->busses[i].mr, OBJECT(dev),
 461                              &aspeed_i2c_bus_ops, &s->busses[i], name, 0x40);
 462        memory_region_add_subregion(&s->iomem, 0x40 * (i + offset),
 463                                    &s->busses[i].mr);
 464    }
 465}
 466
 467static void aspeed_i2c_class_init(ObjectClass *klass, void *data)
 468{
 469    DeviceClass *dc = DEVICE_CLASS(klass);
 470
 471    dc->vmsd = &aspeed_i2c_vmstate;
 472    dc->reset = aspeed_i2c_reset;
 473    dc->realize = aspeed_i2c_realize;
 474    dc->desc = "Aspeed I2C Controller";
 475}
 476
 477static const TypeInfo aspeed_i2c_info = {
 478    .name          = TYPE_ASPEED_I2C,
 479    .parent        = TYPE_SYS_BUS_DEVICE,
 480    .instance_size = sizeof(AspeedI2CState),
 481    .class_init    = aspeed_i2c_class_init,
 482};
 483
 484static void aspeed_i2c_register_types(void)
 485{
 486    type_register_static(&aspeed_i2c_info);
 487}
 488
 489type_init(aspeed_i2c_register_types)
 490
 491
 492I2CBus *aspeed_i2c_get_bus(DeviceState *dev, int busnr)
 493{
 494    AspeedI2CState *s = ASPEED_I2C(dev);
 495    I2CBus *bus = NULL;
 496
 497    if (busnr >= 0 && busnr < ASPEED_I2C_NR_BUSSES) {
 498        bus = s->busses[busnr].bus;
 499    }
 500
 501    return bus;
 502}
 503