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
  30#define TYPE_SMBUS_DEVICE "smbus-device"
  31#define SMBUS_DEVICE(obj) \
  32     OBJECT_CHECK(SMBusDevice, (obj), TYPE_SMBUS_DEVICE)
  33#define SMBUS_DEVICE_CLASS(klass) \
  34     OBJECT_CLASS_CHECK(SMBusDeviceClass, (klass), TYPE_SMBUS_DEVICE)
  35#define SMBUS_DEVICE_GET_CLASS(obj) \
  36     OBJECT_GET_CLASS(SMBusDeviceClass, (obj), TYPE_SMBUS_DEVICE)
  37
  38typedef struct SMBusDevice SMBusDevice;
  39
  40typedef struct SMBusDeviceClass
  41{
  42    I2CSlaveClass parent_class;
  43
  44    /*
  45     * An operation with no data, special in SMBus.
  46     * This may be NULL, quick commands are ignore in that case.
  47     */
  48    void (*quick_cmd)(SMBusDevice *dev, uint8_t read);
  49
  50    /*
  51     * We can't distinguish between a word write and a block write with
  52     * length 1, so pass the whole data block including the length byte
  53     * (if present).  The device is responsible figuring out what type of
  54     * command this is.
  55     * This may be NULL if no data is written to the device.  Writes
  56     * will be ignore in that case.
  57     */
  58    int (*write_data)(SMBusDevice *dev, uint8_t *buf, uint8_t len);
  59
  60    /*
  61     * Likewise we can't distinguish between different reads, or even know
  62     * the length of the read until the read is complete, so read data a
  63     * byte at a time.  The device is responsible for adding the length
  64     * byte on block reads.  This call cannot fail, it should return
  65     * something, preferably 0xff if nothing is available.
  66     * This may be NULL if no data is read from the device.  Reads will
  67     * return 0xff in that case.
  68     */
  69    uint8_t (*receive_byte)(SMBusDevice *dev);
  70} SMBusDeviceClass;
  71
  72#define SMBUS_DATA_MAX_LEN 34  /* command + len + 32 bytes of data.  */
  73
  74struct SMBusDevice {
  75    /* The SMBus protocol is implemented on top of I2C.  */
  76    I2CSlave i2c;
  77
  78    /* Remaining fields for internal use only.  */
  79    int32_t mode;
  80    int32_t data_len;
  81    uint8_t data_buf[SMBUS_DATA_MAX_LEN];
  82};
  83
  84extern const VMStateDescription vmstate_smbus_device;
  85
  86#define VMSTATE_SMBUS_DEVICE(_field, _state) {                       \
  87    .name       = (stringify(_field)),                               \
  88    .size       = sizeof(SMBusDevice),                               \
  89    .vmsd       = &vmstate_smbus_device,                             \
  90    .flags      = VMS_STRUCT,                                        \
  91    .offset     = vmstate_offset_value(_state, _field, SMBusDevice), \
  92}
  93
  94/*
  95 * Users should call this in their .needed functions to know if the
  96 * SMBus slave data needs to be transferred.
  97 */
  98bool smbus_vmstate_needed(SMBusDevice *dev);
  99
 100#endif
 101