LXR qemu/include/hw/i2c/smbus

   1/*
   2 * QEMU SMBus device (slave) API
   3 *
   4 * Copyright (c) 2007 Arastra, Inc.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24
  25#ifndef HW_SMBUS_SLAVE_H
  26#define HW_SMBUS_SLAVE_H
  27
  28#include "hw/i2c/i2c.h"
  29#include "qom/object.h"
  30
  31#define TYPE_SMBUS_DEVICE "smbus-device"
  32OBJECT_DECLARE_TYPE(SMBusDevice, SMBusDeviceClass,
  33                    SMBUS_DEVICE)
  34
  35
  36struct SMBusDeviceClass {
  37    I2CSlaveClass parent_class;
  38
  39    /*
  40     * An operation with no data, special in SMBus.
  41     * This may be NULL, quick commands are ignore in that case.
  42     */
  43    void (*quick_cmd)(SMBusDevice *dev, uint8_t read);
  44
  45    /*
  46     * We can't distinguish between a word write and a block write with
  47     * length 1, so pass the whole data block including the length byte
  48     * (if present).  The device is responsible figuring out what type of
  49     * command this is.
  50     * This may be NULL if no data is written to the device.  Writes
  51     * will be ignore in that case.
  52     */
  53    int (*write_data)(SMBusDevice *dev, uint8_t *buf, uint8_t len);
  54
  55    /*
  56     * Likewise we can't distinguish between different reads, or even know
  57     * the length of the read until the read is complete, so read data a
  58     * byte at a time.  The device is responsible for adding the length
  59     * byte on block reads.  This call cannot fail, it should return
  60     * something, preferably 0xff if nothing is available.
  61     * This may be NULL if no data is read from the device.  Reads will
  62     * return 0xff in that case.
  63     */
  64    uint8_t (*receive_byte)(SMBusDevice *dev);
  65};
  66
  67#define SMBUS_DATA_MAX_LEN 34  /* command + len + 32 bytes of data.  */
  68
  69struct SMBusDevice {
  70    /* The SMBus protocol is implemented on top of I2C.  */
  71    I2CSlave i2c;
  72
  73    /* Remaining fields for internal use only.  */
  74    int32_t mode;
  75    int32_t data_len;
  76    uint8_t data_buf[SMBUS_DATA_MAX_LEN];
  77};
  78
  79extern const VMStateDescription vmstate_smbus_device;
  80
  81#define VMSTATE_SMBUS_DEVICE(_field, _state) {                       \
  82    .name       = (stringify(_field)),                               \
  83    .size       = sizeof(SMBusDevice),                               \
  84    .vmsd       = &vmstate_smbus_device,                             \
  85    .flags      = VMS_STRUCT,                                        \
  86    .offset     = vmstate_offset_value(_state, _field, SMBusDevice), \
  87}
  88
  89/*
  90 * Users should call this in their .needed functions to know if the
  91 * SMBus slave data needs to be transferred.
  92 */
  93bool smbus_vmstate_needed(SMBusDevice *dev);
  94
  95#endif
  96