Various simple devices (usually GPIO related) don't access the 'system bus': no IRQ lines / memory regions exposed via the SysBus API, no memory region mapped.
To reduce complexity, remove the sysbus onion layer from these devices. Introduce the qdev_create_simple() helper similar to the pattern used for other device creation helpers: $ git grep _create_simple include/ include/hw/i2c/i2c.h:175:I2CSlave *i2c_slave_create_simple(I2CBus *bus, const char *name, uint8_t addr); include/hw/isa/isa.h:86:ISADevice *isa_create_simple(ISABus *bus, const char *name); include/hw/misc/led.h:93:LEDState *led_create_simple(Object *parentobj, include/hw/pci/pci.h:735:PCIDevice *pci_create_simple_multifunction(PCIBus *bus, int devfn, include/hw/pci/pci.h:738:PCIDevice *pci_create_simple(PCIBus *bus, int devfn, const char *name); include/hw/sysbus.h:100:static inline DeviceState *sysbus_create_simple(const char *name, include/hw/usb.h:505:USBDevice *usb_create_simple(USBBus *bus, const char *name); Based-on: <20230109084121.72138-1-phi...@linaro.org> "hw/i2c/bitbang_i2c: Housekeeping" Philippe Mathieu-Daudé (9): hw/arm/musicpal: Remove unused dummy MemoryRegion qdev: Add qdev_create_simple() helper hw/i2c/bitbang_i2c: Convert TYPE_GPIO_I2C from SysBus to QDev hw/arm/tosa: Convert TYPE_TOSA_MISC_GPIO from SysBus to QDev hw/arm/palm: Convert TYPE_PALM_MISC_GPIO from SysBus to QDev hw/arm/musicpal: Convert TYPE_MUSICPAL_KEY from SysBus to QDev hw/arm/spitz: Convert TYPE_SPITZ_KEYBOARD from SysBus to QDev hw/arm/tosa: Convert TYPE_SPITZ_MISC_GPIO from SysBus to QDev hw/i386/kvm: Convert TYPE_KVM_CLOCK from SysBus to QDev hw/arm/musicpal.c | 12 ++++-------- hw/arm/palm.c | 9 ++------- hw/arm/spitz.c | 18 ++++++++++++------ hw/arm/tosa.c | 9 ++------- hw/core/qdev.c | 9 +++++++++ hw/i2c/bitbang_i2c.c | 5 ++--- hw/i386/kvm/clock.c | 6 +++--- include/hw/qdev-core.h | 11 +++++++++++ 8 files changed, 45 insertions(+), 34 deletions(-) -- 2.38.1