linux/sound/ac97_bus.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Linux driver model AC97 bus interface
 *
 * Author:	Nicolas Pitre
 * Created:	Jan 14, 2005
 * Copyright:	(C) MontaVista Software Inc.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/string.h>
#include <sound/ac97_codec.h>

/*
 * snd_ac97_check_id() - Reads and checks the vendor ID of the device
 * @ac97: The AC97 device to check
 * @id: The ID to compare to
 * @id_mask: Mask that is applied to the device ID before comparing to @id
 *
 * If @id is 0 this function returns true if the read device vendor ID is
 * a valid ID. If @id is non 0 this functions returns true if @id
 * matches the read vendor ID. Otherwise the function returns false.
 */
static bool snd_ac97_check_id(struct snd_ac97 *ac97, unsigned int id,
	unsigned int id_mask)
{ … }

/**
 * snd_ac97_reset() - Reset AC'97 device
 * @ac97: The AC'97 device to reset
 * @try_warm: Try a warm reset first
 * @id: Expected device vendor ID
 * @id_mask: Mask that is applied to the device ID before comparing to @id
 *
 * This function resets the AC'97 device. If @try_warm is true the function
 * first performs a warm reset. If the warm reset is successful the function
 * returns 1. Otherwise or if @try_warm is false the function issues cold reset
 * followed by a warm reset. If this is successful the function returns 0,
 * otherwise a negative error code. If @id is 0 any valid device ID will be
 * accepted, otherwise only the ID that matches @id and @id_mask is accepted.
 */
int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id,
	unsigned int id_mask)
{ … }
EXPORT_SYMBOL_GPL(…);

const struct bus_type ac97_bus_type = …;

static int __init ac97_bus_init(void)
{ … }

subsys_initcall(ac97_bus_init);

static void __exit ac97_bus_exit(void)
{ … }

module_exit(ac97_bus_exit);

EXPORT_SYMBOL(…);

MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;