u-boot/include/misc.h
John Keeping e44d2f5df9 misc: mark write buffer const
The write operation in misc_ops already takes a "const void *" buffer,
but misc_write() takes a mutable "void *".  There's no reason for this,
so make misc_write() consistent with the standard write() prototype.

Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2022-01-24 10:35:10 -05:00

147 lines
4.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw>
*/
#ifndef _MISC_H_
#define _MISC_H_
struct udevice;
/**
* misc_read() - Read the device to buffer, optional.
* @dev: the device
* @offset: offset to read the device
* @buf: pointer to data buffer
* @size: data size in bytes to read the device
*
* Return: number of bytes read if OK (may be 0 if EOF), -ve on error
*/
int misc_read(struct udevice *dev, int offset, void *buf, int size);
/**
* misc_write() - Write buffer to the device, optional.
* @dev: the device
* @offset: offset to write the device
* @buf: pointer to data buffer
* @size: data size in bytes to write the device
*
* Return: number of bytes written if OK (may be < @size), -ve on error
*/
int misc_write(struct udevice *dev, int offset, const void *buf, int size);
/**
* misc_ioctl() - Assert command to the device, optional.
* @dev: the device
* @request: command to be sent to the device
* @buf: pointer to buffer related to the request
*
* Return: 0 if OK, -ve on error
*/
int misc_ioctl(struct udevice *dev, unsigned long request, void *buf);
/**
* misc_call() - Send a message to the device and wait for a response.
* @dev: the device.
* @msgid: the message ID/number to send.
* @tx_msg: the request/transmit message payload.
* @tx_size: the size of the buffer pointed at by tx_msg.
* @rx_msg: the buffer to receive the response message payload. May be NULL if
* the caller only cares about the error code.
* @rx_size: the size of the buffer pointed at by rx_msg.
*
* The caller provides the message type/ID and payload to be sent.
* The callee constructs any message header required, transmits it to the
* target, waits for a response, checks any error code in the response,
* strips any message header from the response, and returns the error code
* (or a parsed version of it) and the response message payload.
*
* Return: the response message size if OK, -ve on error
*/
int misc_call(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
void *rx_msg, int rx_size);
/**
* misc_set_enabled() - Enable or disable a device.
* @dev: the device to enable or disable.
* @val: the flag that tells the driver to either enable or disable the device.
*
* The semantics of "disable" and "enable" should be understood here as
* activating or deactivating the device's primary function, hence a "disabled"
* device should be dormant, but still answer to commands and queries.
*
* A probed device may start in a disabled or enabled state, depending on the
* driver and hardware.
*
* Return: -ve on error, 0 if the previous state was "disabled", 1 if the
* previous state was "enabled"
*/
int misc_set_enabled(struct udevice *dev, bool val);
/*
* struct misc_ops - Driver model Misc operations
*
* The uclass interface is implemented by all miscellaneous devices which
* use driver model.
*/
struct misc_ops {
/**
* Read the device to buffer, optional.
* @dev: the device
* @offset: offset to read the device
* @buf: pointer to data buffer
* @size: data size in bytes to read the device
*
* Return: number of bytes read if OK (may be 0 if EOF), -ve on error
*/
int (*read)(struct udevice *dev, int offset, void *buf, int size);
/**
* Write buffer to the device, optional.
* @dev: the device
* @offset: offset to write the device
* @buf: pointer to data buffer
* @size: data size in bytes to write the device
*
* Return: number of bytes written if OK (may be < @size), -ve on error
*/
int (*write)(struct udevice *dev, int offset, const void *buf,
int size);
/**
* Assert command to the device, optional.
* @dev: the device
* @request: command to be sent to the device
* @buf: pointer to buffer related to the request
*
* Return: 0 if OK, -ve on error
*/
int (*ioctl)(struct udevice *dev, unsigned long request, void *buf);
/**
* Send a message to the device and wait for a response.
* @dev: the device
* @msgid: the message ID/number to send
* @tx_msg: the request/transmit message payload
* @tx_size: the size of the buffer pointed at by tx_msg
* @rx_msg: the buffer to receive the response message payload. May be
* NULL if the caller only cares about the error code.
* @rx_size: the size of the buffer pointed at by rx_msg
*
* Return: the response message size if OK, -ve on error
*/
int (*call)(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
void *rx_msg, int rx_size);
/**
* Enable or disable a device, optional.
* @dev: the device to enable.
* @val: the flag that tells the driver to either enable or disable the
* device.
*
* Return: -ve on error, 0 if the previous state was "disabled", 1 if
* the previous state was "enabled"
*/
int (*set_enabled)(struct udevice *dev, bool val);
};
#endif /* _MISC_H_ */