arm/vexpress: Add proper display connector emulation

This adds the SiI9022 (and implicitly EDID I2C) device to the ARM
Versatile Express machine, and selects the two I2C devices necessary
in the arm-softmmu.mak configuration so everything will build
smoothly.

I am implementing proper handling of the graphics in the Linux
kernel and adding proper emulation of SiI9022 and EDID makes the
driver probe as nicely as before, retrieving the resolutions
supported by the "QEMU monitor" and overall just working nice.

Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Message-id: 20180227104903.21353-6-linus.walleij@linaro.org
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

default-configs/arm-softmmu.mak

@@ -21,6 +21,8 @@ CONFIG_STELLARIS_INPUT=y
 CONFIG_STELLARIS_ENET=y
 CONFIG_SSD0303=y
 CONFIG_SSD0323=y
+CONFIG_DDC=y
+CONFIG_SII9022=y
 CONFIG_ADS7846=y
 CONFIG_MAX111X=y
 CONFIG_SSI=y

hw/arm/vexpress.c

@@ -29,6 +29,7 @@
 #include "hw/arm/arm.h"
 #include "hw/arm/primecell.h"
 #include "hw/devices.h"
+#include "hw/i2c/i2c.h"
 #include "net/net.h"
 #include "sysemu/sysemu.h"
 #include "hw/boards.h"
@@ -537,6 +538,7 @@ static void vexpress_common_init(MachineState *machine)
     uint32_t sys_id;
     DriveInfo *dinfo;
     pflash_t *pflash0;
+    I2CBus *i2c;
     ram_addr_t vram_size, sram_size;
     MemoryRegion *sysmem = get_system_memory();
     MemoryRegion *vram = g_new(MemoryRegion, 1);
@@ -628,7 +630,9 @@ static void vexpress_common_init(MachineState *machine)
     sysbus_create_simple("sp804", map[VE_TIMER01], pic[2]);
     sysbus_create_simple("sp804", map[VE_TIMER23], pic[3]);
 
-    /* VE_SERIALDVI: not modelled */
+    dev = sysbus_create_simple("versatile_i2c", map[VE_SERIALDVI], NULL);
+    i2c = (I2CBus *)qdev_get_child_bus(dev, "i2c");
+    i2c_create_slave(i2c, "sii9022", 0x39);
 
     sysbus_create_simple("pl031", map[VE_RTC], pic[4]); /* RTC */