| 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 |