qemu-e2k/hw/display/sii9022.c

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/*
* Silicon Image SiI9022
*
* This is a pretty hollow emulation: all we do is acknowledge that we
* exist (chip ID) and confirm that we get switched over into DDC mode
* so the emulated host can proceed to read out EDID data. All subsequent
* set-up of connectors etc will be acknowledged and ignored.
*
* Copyright (C) 2018 Linus Walleij
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "hw/i2c/i2c.h"
#include "hw/i2c/i2c-ddc.h"
#include "trace.h"
#define SII9022_SYS_CTRL_DATA 0x1a
#define SII9022_SYS_CTRL_PWR_DWN 0x10
#define SII9022_SYS_CTRL_AV_MUTE 0x08
#define SII9022_SYS_CTRL_DDC_BUS_REQ 0x04
#define SII9022_SYS_CTRL_DDC_BUS_GRTD 0x02
#define SII9022_SYS_CTRL_OUTPUT_MODE 0x01
#define SII9022_SYS_CTRL_OUTPUT_HDMI 1
#define SII9022_SYS_CTRL_OUTPUT_DVI 0
#define SII9022_REG_CHIPID 0x1b
#define SII9022_INT_ENABLE 0x3c
#define SII9022_INT_STATUS 0x3d
#define SII9022_INT_STATUS_HOTPLUG 0x01;
#define SII9022_INT_STATUS_PLUGGED 0x04;
#define TYPE_SII9022 "sii9022"
#define SII9022(obj) OBJECT_CHECK(sii9022_state, (obj), TYPE_SII9022)
typedef struct sii9022_state {
I2CSlave parent_obj;
uint8_t ptr;
bool addr_byte;
bool ddc_req;
bool ddc_skip_finish;
bool ddc;
} sii9022_state;
static const VMStateDescription vmstate_sii9022 = {
.name = "sii9022",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_I2C_SLAVE(parent_obj, sii9022_state),
VMSTATE_UINT8(ptr, sii9022_state),
VMSTATE_BOOL(addr_byte, sii9022_state),
VMSTATE_BOOL(ddc_req, sii9022_state),
VMSTATE_BOOL(ddc_skip_finish, sii9022_state),
VMSTATE_BOOL(ddc, sii9022_state),
VMSTATE_END_OF_LIST()
}
};
static int sii9022_event(I2CSlave *i2c, enum i2c_event event)
{
sii9022_state *s = SII9022(i2c);
switch (event) {
case I2C_START_SEND:
s->addr_byte = true;
break;
case I2C_START_RECV:
break;
case I2C_FINISH:
break;
case I2C_NACK:
break;
}
return 0;
}
static int sii9022_rx(I2CSlave *i2c)
{
sii9022_state *s = SII9022(i2c);
uint8_t res = 0x00;
switch (s->ptr) {
case SII9022_SYS_CTRL_DATA:
if (s->ddc_req) {
/* Acknowledge DDC bus request */
res = SII9022_SYS_CTRL_DDC_BUS_GRTD | SII9022_SYS_CTRL_DDC_BUS_REQ;
}
break;
case SII9022_REG_CHIPID:
res = 0xb0;
break;
case SII9022_INT_STATUS:
/* Something is cold-plugged in, no interrupts */
res = SII9022_INT_STATUS_PLUGGED;
break;
default:
break;
}
trace_sii9022_read_reg(s->ptr, res);
s->ptr++;
return res;
}
static int sii9022_tx(I2CSlave *i2c, uint8_t data)
{
sii9022_state *s = SII9022(i2c);
if (s->addr_byte) {
s->ptr = data;
s->addr_byte = false;
return 0;
}
switch (s->ptr) {
case SII9022_SYS_CTRL_DATA:
if (data & SII9022_SYS_CTRL_DDC_BUS_REQ) {
s->ddc_req = true;
if (data & SII9022_SYS_CTRL_DDC_BUS_GRTD) {
s->ddc = true;
/* Skip this finish since we just switched to DDC */
s->ddc_skip_finish = true;
trace_sii9022_switch_mode("DDC");
}
} else {
s->ddc_req = false;
s->ddc = false;
trace_sii9022_switch_mode("normal");
}
break;
default:
break;
}
trace_sii9022_write_reg(s->ptr, data);
s->ptr++;
return 0;
}
static void sii9022_reset(DeviceState *dev)
{
sii9022_state *s = SII9022(dev);
s->ptr = 0;
s->addr_byte = false;
s->ddc_req = false;
s->ddc_skip_finish = false;
s->ddc = false;
}
static void sii9022_realize(DeviceState *dev, Error **errp)
{
I2CBus *bus;
bus = I2C_BUS(qdev_get_parent_bus(dev));
i2c_create_slave(bus, TYPE_I2CDDC, 0x50);
}
static void sii9022_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
k->event = sii9022_event;
k->recv = sii9022_rx;
k->send = sii9022_tx;
dc->reset = sii9022_reset;
dc->realize = sii9022_realize;
dc->vmsd = &vmstate_sii9022;
}
static const TypeInfo sii9022_info = {
.name = TYPE_SII9022,
.parent = TYPE_I2C_SLAVE,
.instance_size = sizeof(sii9022_state),
.class_init = sii9022_class_init,
};
static void sii9022_register_types(void)
{
type_register_static(&sii9022_info);
}
type_init(sii9022_register_types)