sound/pci/cs5535audio/cs5535audio_olpc.c

Source file repositories/reference/linux-study-clean/sound/pci/cs5535audio/cs5535audio_olpc.c

File Facts

System
Linux kernel
Corpus path
sound/pci/cs5535audio/cs5535audio_olpc.c
Extension
.c
Size
4598 bytes
Lines
188
Domain
Driver Families
Bucket
sound/pci
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * OLPC XO-1 additional sound features
 *
 * Copyright © 2006  Jaya Kumar <jayakumar.lkml@gmail.com>
 * Copyright © 2007-2008  Andres Salomon <dilinger@debian.org>
 */
#include <sound/core.h>
#include <sound/info.h>
#include <sound/control.h>
#include <sound/ac97_codec.h>
#include <linux/gpio.h>

#include <asm/olpc.h>
#include "cs5535audio.h"

#define DRV_NAME "cs5535audio-olpc"

/*
 * OLPC has an additional feature on top of the regular AD1888 codec features.
 * It has an Analog Input mode that is switched into (after disabling the
 * High Pass Filter) via GPIO.  It is supported on B2 and later models.
 */
void olpc_analog_input(struct snd_ac97 *ac97, int on)
{
	int err;

	if (!machine_is_olpc())
		return;

	/* update the High Pass Filter (via AC97_AD_TEST2) */
	err = snd_ac97_update_bits(ac97, AC97_AD_TEST2,
			1 << AC97_AD_HPFD_SHIFT, on << AC97_AD_HPFD_SHIFT);
	if (err < 0) {
		dev_err(ac97->bus->card->dev,
			"setting High Pass Filter - %d\n", err);
		return;
	}

	/* set Analog Input through GPIO */
	gpio_set_value(OLPC_GPIO_MIC_AC, on);
}

/*
 * OLPC XO-1's V_REFOUT is a mic bias enable.
 */
void olpc_mic_bias(struct snd_ac97 *ac97, int on)
{
	int err;

	if (!machine_is_olpc())
		return;

	on = on ? 0 : 1;
	err = snd_ac97_update_bits(ac97, AC97_AD_MISC,
			1 << AC97_AD_VREFD_SHIFT, on << AC97_AD_VREFD_SHIFT);
	if (err < 0)
		dev_err(ac97->bus->card->dev, "setting MIC Bias - %d\n", err);
}

static int olpc_dc_info(struct snd_kcontrol *kctl,
		struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 1;
	uinfo->value.integer.min = 0;
	uinfo->value.integer.max = 1;
	return 0;
}

static int olpc_dc_get(struct snd_kcontrol *kctl, struct snd_ctl_elem_value *v)
{
	v->value.integer.value[0] = gpio_get_value(OLPC_GPIO_MIC_AC);
	return 0;
}

static int olpc_dc_put(struct snd_kcontrol *kctl, struct snd_ctl_elem_value *v)
{
	struct cs5535audio *cs5535au = snd_kcontrol_chip(kctl);

	olpc_analog_input(cs5535au->ac97, v->value.integer.value[0]);
	return 1;
}

static int olpc_mic_info(struct snd_kcontrol *kctl,
		struct snd_ctl_elem_info *uinfo)
{
	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
	uinfo->count = 1;
	uinfo->value.integer.min = 0;

Annotation

Implementation Notes