smbus_slave.h (3547B)
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" 32 OBJECT_DECLARE_TYPE(SMBusDevice, SMBusDeviceClass, 33 SMBUS_DEVICE) 34 35 36 struct 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 69 struct 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 79 extern 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 */ 93 bool smbus_vmstate_needed(SMBusDevice *dev); 94 95 #endif