1 /*
2 * Silicon Image SiI9022
3 *
4 * This is a pretty hollow emulation: all we do is acknowledge that we
5 * exist (chip ID) and confirm that we get switched over into DDC mode
6 * so the emulated host can proceed to read out EDID data. All subsequent
7 * set-up of connectors etc will be acknowledged and ignored.
8 *
9 * Copyright (C) 2018 Linus Walleij
10 *
11 * This work is licensed under the terms of the GNU GPL, version 2 or later.
12 * See the COPYING file in the top-level directory.
13 * SPDX-License-Identifier: GPL-2.0-or-later
14 */
15
16 #include "qemu/osdep.h"
17 #include "qemu/module.h"
18 #include "hw/i2c/i2c.h"
19 #include "migration/vmstate.h"
20 #include "hw/display/i2c-ddc.h"
21 #include "trace.h"
22 #include "qom/object.h"
23
24 #define SII9022_SYS_CTRL_DATA 0x1a
25 #define SII9022_SYS_CTRL_PWR_DWN 0x10
26 #define SII9022_SYS_CTRL_AV_MUTE 0x08
27 #define SII9022_SYS_CTRL_DDC_BUS_REQ 0x04
28 #define SII9022_SYS_CTRL_DDC_BUS_GRTD 0x02
29 #define SII9022_SYS_CTRL_OUTPUT_MODE 0x01
30 #define SII9022_SYS_CTRL_OUTPUT_HDMI 1
31 #define SII9022_SYS_CTRL_OUTPUT_DVI 0
32 #define SII9022_REG_CHIPID 0x1b
33 #define SII9022_INT_ENABLE 0x3c
34 #define SII9022_INT_STATUS 0x3d
35 #define SII9022_INT_STATUS_HOTPLUG 0x01;
36 #define SII9022_INT_STATUS_PLUGGED 0x04;
37
38 #define TYPE_SII9022 "sii9022"
39 OBJECT_DECLARE_SIMPLE_TYPE(sii9022_state, SII9022)
40
41 struct sii9022_state {
42 I2CSlave parent_obj;
43 uint8_t ptr;
44 bool addr_byte;
45 bool ddc_req;
46 bool ddc_skip_finish;
47 bool ddc;
48 };
49
50 static const VMStateDescription vmstate_sii9022 = {
51 .name = "sii9022",
52 .version_id = 1,
53 .minimum_version_id = 1,
54 .fields = (const VMStateField[]) {
55 VMSTATE_I2C_SLAVE(parent_obj, sii9022_state),
56 VMSTATE_UINT8(ptr, sii9022_state),
57 VMSTATE_BOOL(addr_byte, sii9022_state),
58 VMSTATE_BOOL(ddc_req, sii9022_state),
59 VMSTATE_BOOL(ddc_skip_finish, sii9022_state),
60 VMSTATE_BOOL(ddc, sii9022_state),
61 VMSTATE_END_OF_LIST()
62 }
63 };
64
sii9022_event(I2CSlave * i2c,enum i2c_event event)65 static int sii9022_event(I2CSlave *i2c, enum i2c_event event)
66 {
67 sii9022_state *s = SII9022(i2c);
68
69 switch (event) {
70 case I2C_START_SEND:
71 s->addr_byte = true;
72 break;
73 case I2C_START_RECV:
74 break;
75 case I2C_FINISH:
76 break;
77 case I2C_NACK:
78 break;
79 default:
80 return -1;
81 }
82
83 return 0;
84 }
85
sii9022_rx(I2CSlave * i2c)86 static uint8_t sii9022_rx(I2CSlave *i2c)
87 {
88 sii9022_state *s = SII9022(i2c);
89 uint8_t res = 0x00;
90
91 switch (s->ptr) {
92 case SII9022_SYS_CTRL_DATA:
93 if (s->ddc_req) {
94 /* Acknowledge DDC bus request */
95 res = SII9022_SYS_CTRL_DDC_BUS_GRTD | SII9022_SYS_CTRL_DDC_BUS_REQ;
96 }
97 break;
98 case SII9022_REG_CHIPID:
99 res = 0xb0;
100 break;
101 case SII9022_INT_STATUS:
102 /* Something is cold-plugged in, no interrupts */
103 res = SII9022_INT_STATUS_PLUGGED;
104 break;
105 default:
106 break;
107 }
108
109 trace_sii9022_read_reg(s->ptr, res);
110 s->ptr++;
111
112 return res;
113 }
114
sii9022_tx(I2CSlave * i2c,uint8_t data)115 static int sii9022_tx(I2CSlave *i2c, uint8_t data)
116 {
117 sii9022_state *s = SII9022(i2c);
118
119 if (s->addr_byte) {
120 s->ptr = data;
121 s->addr_byte = false;
122 return 0;
123 }
124
125 switch (s->ptr) {
126 case SII9022_SYS_CTRL_DATA:
127 if (data & SII9022_SYS_CTRL_DDC_BUS_REQ) {
128 s->ddc_req = true;
129 if (data & SII9022_SYS_CTRL_DDC_BUS_GRTD) {
130 s->ddc = true;
131 /* Skip this finish since we just switched to DDC */
132 s->ddc_skip_finish = true;
133 trace_sii9022_switch_mode("DDC");
134 }
135 } else {
136 s->ddc_req = false;
137 s->ddc = false;
138 trace_sii9022_switch_mode("normal");
139 }
140 break;
141 default:
142 break;
143 }
144
145 trace_sii9022_write_reg(s->ptr, data);
146 s->ptr++;
147
148 return 0;
149 }
150
sii9022_reset(DeviceState * dev)151 static void sii9022_reset(DeviceState *dev)
152 {
153 sii9022_state *s = SII9022(dev);
154
155 s->ptr = 0;
156 s->addr_byte = false;
157 s->ddc_req = false;
158 s->ddc_skip_finish = false;
159 s->ddc = false;
160 }
161
sii9022_realize(DeviceState * dev,Error ** errp)162 static void sii9022_realize(DeviceState *dev, Error **errp)
163 {
164 I2CBus *bus;
165
166 bus = I2C_BUS(qdev_get_parent_bus(dev));
167 i2c_slave_create_simple(bus, TYPE_I2CDDC, 0x50);
168 }
169
sii9022_class_init(ObjectClass * klass,void * data)170 static void sii9022_class_init(ObjectClass *klass, void *data)
171 {
172 DeviceClass *dc = DEVICE_CLASS(klass);
173 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
174
175 k->event = sii9022_event;
176 k->recv = sii9022_rx;
177 k->send = sii9022_tx;
178 device_class_set_legacy_reset(dc, sii9022_reset);
179 dc->realize = sii9022_realize;
180 dc->vmsd = &vmstate_sii9022;
181 }
182
183 static const TypeInfo sii9022_info = {
184 .name = TYPE_SII9022,
185 .parent = TYPE_I2C_SLAVE,
186 .instance_size = sizeof(sii9022_state),
187 .class_init = sii9022_class_init,
188 };
189
sii9022_register_types(void)190 static void sii9022_register_types(void)
191 {
192 type_register_static(&sii9022_info);
193 }
194
195 type_init(sii9022_register_types)
196