1 /* A simple I2C slave for returning monitor EDID data via DDC.
3 * Copyright (c) 2011 Linaro Limited
4 * Written by Peter Maydell
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, see <http://www.gnu.org/licenses/>.
19 #include "qemu/osdep.h"
20 #include "qemu-common.h"
22 #include "hw/i2c/i2c.h"
23 #include "hw/i2c/i2c-ddc.h"
26 #define DEBUG_I2CDDC 0
29 #define DPRINTF(fmt, ...) do { \
31 qemu_log("i2c-ddc: " fmt , ## __VA_ARGS__); \
35 static void i2c_ddc_reset(DeviceState
*ds
)
37 I2CDDCState
*s
= I2CDDC(ds
);
43 static int i2c_ddc_event(I2CSlave
*i2c
, enum i2c_event event
)
45 I2CDDCState
*s
= I2CDDC(i2c
);
47 if (event
== I2C_START_SEND
) {
54 static int i2c_ddc_rx(I2CSlave
*i2c
)
56 I2CDDCState
*s
= I2CDDC(i2c
);
59 value
= s
->edid_blob
[s
->reg
];
64 static int i2c_ddc_tx(I2CSlave
*i2c
, uint8_t data
)
66 I2CDDCState
*s
= I2CDDC(i2c
);
70 DPRINTF("[EDID] Written new pointer: %u\n", data
);
74 /* Ignore all writes */
79 static void i2c_ddc_init(Object
*obj
)
81 I2CDDCState
*s
= I2CDDC(obj
);
83 qemu_edid_generate(s
->edid_blob
, sizeof(s
->edid_blob
), &s
->edid_info
);
86 static const VMStateDescription vmstate_i2c_ddc
= {
89 .fields
= (VMStateField
[]) {
90 VMSTATE_BOOL(firstbyte
, I2CDDCState
),
91 VMSTATE_UINT8(reg
, I2CDDCState
),
96 static Property i2c_ddc_properties
[] = {
97 DEFINE_EDID_PROPERTIES(I2CDDCState
, edid_info
),
98 DEFINE_PROP_END_OF_LIST(),
101 static void i2c_ddc_class_init(ObjectClass
*oc
, void *data
)
103 DeviceClass
*dc
= DEVICE_CLASS(oc
);
104 I2CSlaveClass
*isc
= I2C_SLAVE_CLASS(oc
);
106 dc
->reset
= i2c_ddc_reset
;
107 dc
->vmsd
= &vmstate_i2c_ddc
;
108 dc
->props
= i2c_ddc_properties
;
109 isc
->event
= i2c_ddc_event
;
110 isc
->recv
= i2c_ddc_rx
;
111 isc
->send
= i2c_ddc_tx
;
114 static TypeInfo i2c_ddc_info
= {
116 .parent
= TYPE_I2C_SLAVE
,
117 .instance_size
= sizeof(I2CDDCState
),
118 .instance_init
= i2c_ddc_init
,
119 .class_init
= i2c_ddc_class_init
122 static void ddc_register_devices(void)
124 type_register_static(&i2c_ddc_info
);
127 type_init(ddc_register_devices
);