sii9022.c (4831B)
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 = (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 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 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 } 114 115 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 } 150 151 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 } 161 162 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 } 169 170 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 dc->reset = 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 }; 189 190 static void sii9022_register_types(void) 191 { 192 type_register_static(&sii9022_info); 193 } 194 195 type_init(sii9022_register_types)