QEMU fw_cfg

Interface for the QEMU firmware configuration (fw_cfg) driver. More...

Files
file	qemu_fwcfg.h
	Header for the QEMU firmware configuration (fw_cfg) driver.

Functions
int	qemu_fwcfg_read_item (const struct device *dev, uint16_t key, void *buf, size_t len)
	Read data from an fw_cfg item.
int	qemu_fwcfg_write_item (const struct device *dev, uint16_t key, const void *buf, size_t len)
	Write data to an fw_cfg item.
int	qemu_fwcfg_get_features (const struct device *dev, uint32_t *features)
	Get fw_cfg feature bits reported by the device.
int	qemu_fwcfg_find_file (const struct device *dev, const char *file, uint16_t *select, uint32_t *size)
	Look up a file entry in fw_cfg file directory.
bool	qemu_fwcfg_dma_supported (const struct device *dev)
	Check whether fw_cfg DMA feature is available.

Detailed Description

Interface for the QEMU firmware configuration (fw_cfg) driver.

Since

4.4.0

Version

0.1.0

Function Documentation

qemu_fwcfg_dma_supported()

bool qemu_fwcfg_dma_supported

(

const struct device *

dev

)

#include <zephyr/drivers/firmware/qemu_fwcfg/qemu_fwcfg.h>

Check whether fw_cfg DMA feature is available.

Parameters

dev	fw_cfg device

Return values

true	if DMA feature is available
false	otherwise

qemu_fwcfg_find_file()

int qemu_fwcfg_find_file	(	const struct device *	dev,
		const char *	file,
		uint16_t *	select,
		uint32_t *	size )

#include <zephyr/drivers/firmware/qemu_fwcfg/qemu_fwcfg.h>

Look up a file entry in fw_cfg file directory.

Parameters

dev	fw_cfg device
file	file name to search for
select	pointer to store selector key for the file
size	pointer to store file size in bytes

Return values

0	if successful
-ENOENT	if the file does not exist

qemu_fwcfg_get_features()

int qemu_fwcfg_get_features	(	const struct device *	dev,
		uint32_t *	features )

#include <zephyr/drivers/firmware/qemu_fwcfg/qemu_fwcfg.h>

Get fw_cfg feature bits reported by the device.

Parameters

dev	fw_cfg device
features	pointer to store feature bits

Return values

0	if successful

qemu_fwcfg_read_item()

int qemu_fwcfg_read_item	(	const struct device *	dev,
		uint16_t	key,
		void *	buf,
		size_t	len )

#include <zephyr/drivers/firmware/qemu_fwcfg/qemu_fwcfg.h>

Read data from an fw_cfg item.

Parameters

dev	fw_cfg device
key	selector key for the fw_cfg item
buf	destination buffer
len	number of bytes to read

Return values

0	if successful
-EIO	if the device reports an I/O error
-ETIMEDOUT	if DMA transfer does not complete in time

qemu_fwcfg_write_item()

int qemu_fwcfg_write_item	(	const struct device *	dev,
		uint16_t	key,
		const void *	buf,
		size_t	len )

#include <zephyr/drivers/firmware/qemu_fwcfg/qemu_fwcfg.h>

Write data to an fw_cfg item.

Writes are supported only when the fw_cfg DMA feature is available

Parameters

dev	fw_cfg device
key	selector key for the fw_cfg item
buf	source buffer
len	number of bytes to write

Return values

0	if successful
-ENOTSUP	if DMA write is not supported
-EIO	if the device reports an I/O error
-ETIMEDOUT	if DMA transfer does not complete in time