bhnd_nvram_if.m

#-
# Copyright (c) 2016 Landon Fuller <[email protected]>
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#
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#include <sys/types.h>
#include <sys/bus.h>

#include <dev/bhnd/bhnd.h>

INTERFACE bhnd_nvram;

#
# bhnd(4) NVRAM device interface.
#
# Provides a shared interface to HND NVRAM, OTP, and SPROM devices that provide
# access to a common set of hardware/device configuration variables.
#

/**
 * Read an NVRAM variable.
 *
 * @param		dev	The NVRAM device.
 * @param		name	The NVRAM variable name.
 * @param[out]		buf	On success, the requested value will be written
 *				to this buffer. This argment may be NULL if
 *				the value is not desired.
 * @param[in,out]	len	The maximum capacity of @p buf. On success,
 *				will be set to the actual size of the requested
 *				value.
 * @param		type	The data type to be written to @p buf.
 *
 * @retval 0		success
 * @retval ENOENT	The requested variable was not found.
 * @retval ENOMEM	If @p buf is non-NULL and a buffer of @p len is too
 *			small to hold the requested value.
 * @retval ENODEV	If no supported NVRAM hardware is accessible via this
 *			device.
 * @retval EOPNOTSUPP	If any coercion to @p type is unsupported.
 * @retval EFTYPE	If the @p name's data type cannot be coerced to @p type.
 * @retval ERANGE	If value coercion would overflow @p type.
 * @retval non-zero	If reading @p name otherwise fails, a regular unix
 *			error code will be returned.
 */
METHOD int getvar {
	device_t	 dev;
	const char	*name;
	void		*buf;
	size_t		*len;
	bhnd_nvram_type	 type;
};

/**
 * Set an NVRAM variable's value.
 *
 * No changes will be written to non-volatile storage until explicitly
 * committed.
 *
 * @param	dev	The NVRAM device.
 * @param	name	The NVRAM variable name.
 * @param	value	The new value.
 * @param	len	The size of @p value.
 * @param	type	The data type of @p value.
 *
 * @retval 0		success
 * @retval ENOENT	The specified variable name is not recognized.
 * @retval ENODEV	If no supported NVRAM hardware is accessible via this
 *			device.
 * @retval EOPNOTSUPP	If any coercion to @p type is unsupported.
 * @retval EFTYPE	If the @p name's data type cannot be coerced to @p type.
 * @retval ERANGE	If value coercion from  @p type would overflow.
 * @retval non-zero	If reading @p name otherwise fails, a regular unix
 *			error code will be returned.
 */
METHOD int setvar {
	device_t	 dev;
	const char	*name;
	const void	*value;
	size_t		 len;
	bhnd_nvram_type	 type;
};