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