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 "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
 126static inline bool aspeed_i2c_bus_is_master(AspeedI2CBus *bus)
 127{
 128    return bus->ctrl & I2CD_MASTER_EN;
 129}
 130
 131static inline bool aspeed_i2c_bus_is_enabled(AspeedI2CBus *bus)
 132{
 133    return bus->ctrl & (I2CD_MASTER_EN | I2CD_SLAVE_EN);
 134}
 135
 136static 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
 145static 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
 172static void aspeed_i2c_bus_handle_cmd(AspeedI2CBus *bus, uint64_t value)
 173{
 174    bus->cmd |= value & 0xFFFF;
 175    bus->intr_status = 0;
 176
 177    if (bus->cmd & I2CD_M_START_CMD) {
 178        if (i2c_start_transfer(bus->bus, extract32(bus->buf, 1, 7),
 179                               extract32(bus->buf, 0, 1))) {
 180            bus->intr_status |= I2CD_INTR_TX_NAK;
 181        } else {
 182            bus->intr_status |= I2CD_INTR_TX_ACK;
 183        }
 184
 185    } else if (bus->cmd & I2CD_M_TX_CMD) {
 186        if (i2c_send(bus->bus, bus->buf)) {
 187            bus->intr_status |= (I2CD_INTR_TX_NAK | I2CD_INTR_ABNORMAL);
 188            i2c_end_transfer(bus->bus);
 189        } else {
 190            bus->intr_status |= I2CD_INTR_TX_ACK;
 191        }
 192
 193    } else if (bus->cmd & I2CD_M_RX_CMD) {
 194        int ret = i2c_recv(bus->bus);
 195        if (ret < 0) {
 196            qemu_log_mask(LOG_GUEST_ERROR, "%s: read failed\n", __func__);
 197            ret = 0xff;
 198        } else {
 199            bus->intr_status |= I2CD_INTR_RX_DONE;
 200        }
 201        bus->buf = (ret & I2CD_BYTE_BUF_RX_MASK) << I2CD_BYTE_BUF_RX_SHIFT;
 202    }
 203
 204    if (bus->cmd & (I2CD_M_STOP_CMD | I2CD_M_S_RX_CMD_LAST)) {
 205        if (!i2c_bus_busy(bus->bus)) {
 206            bus->intr_status |= I2CD_INTR_ABNORMAL;
 207        } else {
 208            i2c_end_transfer(bus->bus);
 209            bus->intr_status |= I2CD_INTR_NORMAL_STOP;
 210        }
 211    }
 212
 213    /* command is handled, reset it and check for interrupts  */
 214    bus->cmd &= ~0xFFFF;
 215    aspeed_i2c_bus_raise_interrupt(bus);
 216}
 217
 218static void aspeed_i2c_bus_write(void *opaque, hwaddr offset,
 219                                 uint64_t value, unsigned size)
 220{
 221    AspeedI2CBus *bus = opaque;
 222
 223    switch (offset) {
 224    case I2CD_FUN_CTRL_REG:
 225        if (value & I2CD_SLAVE_EN) {
 226            qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 227                          __func__);
 228            break;
 229        }
 230        bus->ctrl = value & 0x0071C3FF;
 231        break;
 232    case I2CD_AC_TIMING_REG1:
 233        bus->timing[0] = value & 0xFFFFF0F;
 234        break;
 235    case I2CD_AC_TIMING_REG2:
 236        bus->timing[1] = value & 0x7;
 237        break;
 238    case I2CD_INTR_CTRL_REG:
 239        bus->intr_ctrl = value & 0x7FFF;
 240        break;
 241    case I2CD_INTR_STS_REG:
 242        bus->intr_status &= ~(value & 0x7FFF);
 243        bus->controller->intr_status &= ~(1 << bus->id);
 244        qemu_irq_lower(bus->controller->irq);
 245        break;
 246    case I2CD_DEV_ADDR_REG:
 247        qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 248                      __func__);
 249        break;
 250    case I2CD_BYTE_BUF_REG:
 251        bus->buf = (value & I2CD_BYTE_BUF_TX_MASK) << I2CD_BYTE_BUF_TX_SHIFT;
 252        break;
 253    case I2CD_CMD_REG:
 254        if (!aspeed_i2c_bus_is_enabled(bus)) {
 255            break;
 256        }
 257
 258        if (!aspeed_i2c_bus_is_master(bus)) {
 259            qemu_log_mask(LOG_UNIMP, "%s: slave mode not implemented\n",
 260                          __func__);
 261            break;
 262        }
 263
 264        aspeed_i2c_bus_handle_cmd(bus, value);
 265        break;
 266
 267    default:
 268        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 269                      __func__, offset);
 270    }
 271}
 272
 273static uint64_t aspeed_i2c_ctrl_read(void *opaque, hwaddr offset,
 274                                   unsigned size)
 275{
 276    AspeedI2CState *s = opaque;
 277
 278    switch (offset) {
 279    case I2C_CTRL_STATUS:
 280        return s->intr_status;
 281    default:
 282        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 283                      __func__, offset);
 284        break;
 285    }
 286
 287    return -1;
 288}
 289
 290static void aspeed_i2c_ctrl_write(void *opaque, hwaddr offset,
 291                                  uint64_t value, unsigned size)
 292{
 293    switch (offset) {
 294    case I2C_CTRL_STATUS:
 295    default:
 296        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset 0x%" HWADDR_PRIx "\n",
 297                      __func__, offset);
 298        break;
 299    }
 300}
 301
 302static const MemoryRegionOps aspeed_i2c_bus_ops = {
 303    .read = aspeed_i2c_bus_read,
 304    .write = aspeed_i2c_bus_write,
 305    .endianness = DEVICE_LITTLE_ENDIAN,
 306};
 307
 308static const MemoryRegionOps aspeed_i2c_ctrl_ops = {
 309    .read = aspeed_i2c_ctrl_read,
 310    .write = aspeed_i2c_ctrl_write,
 311    .endianness = DEVICE_LITTLE_ENDIAN,
 312};
 313
 314static const VMStateDescription aspeed_i2c_bus_vmstate = {
 315    .name = TYPE_ASPEED_I2C,
 316    .version_id = 1,
 317    .minimum_version_id = 1,
 318    .fields = (VMStateField[]) {
 319        VMSTATE_UINT8(id, AspeedI2CBus),
 320        VMSTATE_UINT32(ctrl, AspeedI2CBus),
 321        VMSTATE_UINT32_ARRAY(timing, AspeedI2CBus, 2),
 322        VMSTATE_UINT32(intr_ctrl, AspeedI2CBus),
 323        VMSTATE_UINT32(intr_status, AspeedI2CBus),
 324        VMSTATE_UINT32(cmd, AspeedI2CBus),
 325        VMSTATE_UINT32(buf, AspeedI2CBus),
 326        VMSTATE_END_OF_LIST()
 327    }
 328};
 329
 330static const VMStateDescription aspeed_i2c_vmstate = {
 331    .name = TYPE_ASPEED_I2C,
 332    .version_id = 1,
 333    .minimum_version_id = 1,
 334    .fields = (VMStateField[]) {
 335        VMSTATE_UINT32(intr_status, AspeedI2CState),
 336        VMSTATE_STRUCT_ARRAY(busses, AspeedI2CState,
 337                             ASPEED_I2C_NR_BUSSES, 1, aspeed_i2c_bus_vmstate,
 338                             AspeedI2CBus),
 339        VMSTATE_END_OF_LIST()
 340    }
 341};
 342
 343static void aspeed_i2c_reset(DeviceState *dev)
 344{
 345    int i;
 346    AspeedI2CState *s = ASPEED_I2C(dev);
 347
 348    s->intr_status = 0;
 349
 350    for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
 351        s->busses[i].intr_ctrl = 0;
 352        s->busses[i].intr_status = 0;
 353        s->busses[i].cmd = 0;
 354        s->busses[i].buf = 0;
 355        i2c_end_transfer(s->busses[i].bus);
 356    }
 357}
 358
 359/*
 360 * Address Definitions
 361 *
 362 *   0x000 ... 0x03F: Global Register
 363 *   0x040 ... 0x07F: Device 1
 364 *   0x080 ... 0x0BF: Device 2
 365 *   0x0C0 ... 0x0FF: Device 3
 366 *   0x100 ... 0x13F: Device 4
 367 *   0x140 ... 0x17F: Device 5
 368 *   0x180 ... 0x1BF: Device 6
 369 *   0x1C0 ... 0x1FF: Device 7
 370 *   0x200 ... 0x2FF: Buffer Pool  (unused in linux driver)
 371 *   0x300 ... 0x33F: Device 8
 372 *   0x340 ... 0x37F: Device 9
 373 *   0x380 ... 0x3BF: Device 10
 374 *   0x3C0 ... 0x3FF: Device 11
 375 *   0x400 ... 0x43F: Device 12
 376 *   0x440 ... 0x47F: Device 13
 377 *   0x480 ... 0x4BF: Device 14
 378 *   0x800 ... 0xFFF: Buffer Pool  (unused in linux driver)
 379 */
 380static void aspeed_i2c_realize(DeviceState *dev, Error **errp)
 381{
 382    int i;
 383    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 384    AspeedI2CState *s = ASPEED_I2C(dev);
 385
 386    sysbus_init_irq(sbd, &s->irq);
 387    memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_i2c_ctrl_ops, s,
 388                          "aspeed.i2c", 0x1000);
 389    sysbus_init_mmio(sbd, &s->iomem);
 390
 391    for (i = 0; i < ASPEED_I2C_NR_BUSSES; i++) {
 392        char name[16];
 393        int offset = i < 7 ? 1 : 5;
 394        snprintf(name, sizeof(name), "aspeed.i2c.%d", i);
 395        s->busses[i].controller = s;
 396        s->busses[i].id = i;
 397        s->busses[i].bus = i2c_init_bus(dev, name);
 398        memory_region_init_io(&s->busses[i].mr, OBJECT(dev),
 399                              &aspeed_i2c_bus_ops, &s->busses[i], name, 0x40);
 400        memory_region_add_subregion(&s->iomem, 0x40 * (i + offset),
 401                                    &s->busses[i].mr);
 402    }
 403}
 404
 405static void aspeed_i2c_class_init(ObjectClass *klass, void *data)
 406{
 407    DeviceClass *dc = DEVICE_CLASS(klass);
 408
 409    dc->vmsd = &aspeed_i2c_vmstate;
 410    dc->reset = aspeed_i2c_reset;
 411    dc->realize = aspeed_i2c_realize;
 412    dc->desc = "Aspeed I2C Controller";
 413}
 414
 415static const TypeInfo aspeed_i2c_info = {
 416    .name          = TYPE_ASPEED_I2C,
 417    .parent        = TYPE_SYS_BUS_DEVICE,
 418    .instance_size = sizeof(AspeedI2CState),
 419    .class_init    = aspeed_i2c_class_init,
 420};
 421
 422static void aspeed_i2c_register_types(void)
 423{
 424    type_register_static(&aspeed_i2c_info);
 425}
 426
 427type_init(aspeed_i2c_register_types)
 428
 429
 430I2CBus *aspeed_i2c_get_bus(DeviceState *dev, int busnr)
 431{
 432    AspeedI2CState *s = ASPEED_I2C(dev);
 433    I2CBus *bus = NULL;
 434
 435    if (busnr >= 0 && busnr < ASPEED_I2C_NR_BUSSES) {
 436        bus = s->busses[busnr].bus;
 437    }
 438
 439    return bus;
 440}
 441