Files
linux/Documentation/devicetree/bindings/firmware/qemu,fw-cfg-mmio.yaml
Rob Herring (Arm) 0b2333183a dt-bindings: Remove extra blank lines
Generally at most 1 blank line is the standard style for DT schema
files. Remove the few cases with more than 1 so that the yamllint check
for this can be enabled.

Acked-by: Lee Jones <lee@kernel.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> # remoteproc
Acked-by: Georgi Djakov <djakov@kernel.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for allwinner,sun4i-a10-pwm.yaml
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> # mtd
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Manivannan Sadhasivam <mani@kernel.org> # For PCI controller bindings
Link: https://patch.msgid.link/20251023143957.2899600-1-robh@kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2025-11-17 11:24:50 -06:00

54 lines
1.4 KiB
YAML

# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/firmware/qemu,fw-cfg-mmio.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: QEMU Firmware Configuration
maintainers:
- Rob Herring <robh@kernel.org>
description: |
Various QEMU emulation / virtualization targets provide the following
Firmware Configuration interface on the "virt" machine type:
- A write-only, 16-bit wide selector (or control) register,
- a read-write, 64-bit wide data register.
QEMU exposes the control and data register to guests as memory mapped
registers; their location is communicated to the guest's UEFI firmware in the
DTB that QEMU places at the bottom of the guest's DRAM.
The authoritative guest-side hardware interface documentation to the fw_cfg
device can be found in "docs/specs/fw_cfg.txt" in the QEMU source tree.
properties:
compatible:
const: qemu,fw-cfg-mmio
reg:
maxItems: 1
description: |
* Bytes 0x0 to 0x7 cover the data register.
* Bytes 0x8 to 0x9 cover the selector register.
* Further registers may be appended to the region in case of future interface
revisions / feature bits.
dma-coherent: true
required:
- compatible
- reg
additionalProperties: false
examples:
- |
fw-cfg@9020000 {
compatible = "qemu,fw-cfg-mmio";
reg = <0x9020000 0xa>;
};
...