qemu/include/hw/i2c/smbus_slave.h

101 lines
3.7 KiB
C

/*
* QEMU SMBus device (slave) API
*
* Copyright (c) 2007 Arastra, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef HW_SMBUS_SLAVE_H
#define HW_SMBUS_SLAVE_H
#include "hw/i2c/i2c.h"
#define TYPE_SMBUS_DEVICE "smbus-device"
#define SMBUS_DEVICE(obj) \
OBJECT_CHECK(SMBusDevice, (obj), TYPE_SMBUS_DEVICE)
#define SMBUS_DEVICE_CLASS(klass) \
OBJECT_CLASS_CHECK(SMBusDeviceClass, (klass), TYPE_SMBUS_DEVICE)
#define SMBUS_DEVICE_GET_CLASS(obj) \
OBJECT_GET_CLASS(SMBusDeviceClass, (obj), TYPE_SMBUS_DEVICE)
typedef struct SMBusDevice SMBusDevice;
typedef struct SMBusDeviceClass
{
I2CSlaveClass parent_class;
/*
* An operation with no data, special in SMBus.
* This may be NULL, quick commands are ignore in that case.
*/
void (*quick_cmd)(SMBusDevice *dev, uint8_t read);
/*
* We can't distinguish between a word write and a block write with
* length 1, so pass the whole data block including the length byte
* (if present). The device is responsible figuring out what type of
* command this is.
* This may be NULL if no data is written to the device. Writes
* will be ignore in that case.
*/
int (*write_data)(SMBusDevice *dev, uint8_t *buf, uint8_t len);
/*
* Likewise we can't distinguish between different reads, or even know
* the length of the read until the read is complete, so read data a
* byte at a time. The device is responsible for adding the length
* byte on block reads. This call cannot fail, it should return
* something, preferably 0xff if nothing is available.
* This may be NULL if no data is read from the device. Reads will
* return 0xff in that case.
*/
uint8_t (*receive_byte)(SMBusDevice *dev);
} SMBusDeviceClass;
#define SMBUS_DATA_MAX_LEN 34 /* command + len + 32 bytes of data. */
struct SMBusDevice {
/* The SMBus protocol is implemented on top of I2C. */
I2CSlave i2c;
/* Remaining fields for internal use only. */
int32_t mode;
int32_t data_len;
uint8_t data_buf[SMBUS_DATA_MAX_LEN];
};
extern const VMStateDescription vmstate_smbus_device;
#define VMSTATE_SMBUS_DEVICE(_field, _state) { \
.name = (stringify(_field)), \
.size = sizeof(SMBusDevice), \
.vmsd = &vmstate_smbus_device, \
.flags = VMS_STRUCT, \
.offset = vmstate_offset_value(_state, _field, SMBusDevice), \
}
/*
* Users should call this in their .needed functions to know if the
* SMBus slave data needs to be transferred.
*/
bool smbus_vmstate_needed(SMBusDevice *dev);
#endif