Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20211016' into staging
[qemu.git] / include / hw / i2c / smbus_slave.h
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