staging: bcm2835-audio: initial staging submission

Initial cleanup of bcm2835-audio driver for the
bcm2535(Raspberry PI)

Driver provides HDMI audio through ALSA and is built
on top of the vc04_services driver.

Original version of the driver is available at:
http://www.github.com/raspberry/linux

Driver compiles without any build errors or warnings.

Tested on a RPI 3 running in ARM64 mode with the
vlc player and alsautils.

Signed-off-by: Michael Zoran <mzoran@crowfest.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Electron752

drivers/staging/Kconfig

@@ -102,4 +102,6 @@ source "drivers/staging/greybus/Kconfig"
 
 source "drivers/staging/vc04_services/Kconfig"
 
+source "drivers/staging/bcm2835-audio/Kconfig"
+
 endif # STAGING

drivers/staging/Makefile

@@ -40,3 +40,5 @@ obj-$(CONFIG_MOST)		+= most/
 obj-$(CONFIG_KS7010)		+= ks7010/
 obj-$(CONFIG_GREYBUS)		+= greybus/
 obj-$(CONFIG_BCM2835_VCHIQ)	+= vc04_services/
+obj-$(CONFIG_SND_BCM2835)	+= bcm2835-audio/
+

drivers/staging/bcm2835-audio/Kconfig

@@ -0,0 +1,7 @@
+config SND_BCM2835
+        tristate "BCM2835 ALSA driver"
+        depends on ARCH_BCM2835 && BCM2835_VCHIQ && SND
+        select SND_PCM
+        help
+          Say Y or M if you want to support BCM2835 Alsa pcm card driver
+

drivers/staging/bcm2835-audio/Makefile

@@ -0,0 +1,5 @@
+obj-$(CONFIG_SND_BCM2835)	+= snd-bcm2835.o
+snd-bcm2835-objs		:= bcm2835.o bcm2835-ctl.o bcm2835-pcm.o bcm2835-vchiq.o
+
+ccflags-y += -Idrivers/staging/vc04_services -Idrivers/staging/vc04_services/interface/vcos/linuxkernel -D__VCCOREVER__=0x04000000
+

drivers/staging/bcm2835-audio/bcm2835-ctl.c

@@ -0,0 +1,346 @@
+/*****************************************************************************
+ * Copyright 2011 Broadcom Corporation.  All rights reserved.
+ *
+ * Unless you and Broadcom execute a separate written software license
+ * agreement governing use of this software, this software is licensed to you
+ * under the terms of the GNU General Public License version 2, available at
+ * http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+ *
+ * Notwithstanding the above, under no circumstances may you combine this
+ * software in any way with any other Broadcom software provided under a
+ * license other than the GPL, without Broadcom's express prior written
+ * consent.
+ *****************************************************************************/
+
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/wait.h>
+#include <linux/delay.h>
+#include <linux/moduleparam.h>
+#include <linux/sched.h>
+
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/rawmidi.h>
+#include <sound/initval.h>
+#include <sound/tlv.h>
+#include <sound/asoundef.h>
+
+#include "bcm2835.h"
+
+/* volume maximum and minimum in terms of 0.01dB */
+#define CTRL_VOL_MAX 400
+#define CTRL_VOL_MIN -10239 /* originally -10240 */
+
+static int snd_bcm2835_ctl_info(struct snd_kcontrol *kcontrol,
+				struct snd_ctl_elem_info *uinfo)
+{
+	audio_info(" ... IN\n");
+	if (kcontrol->private_value == PCM_PLAYBACK_VOLUME) {
+		uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+		uinfo->count = 1;
+		uinfo->value.integer.min = CTRL_VOL_MIN;
+		uinfo->value.integer.max = CTRL_VOL_MAX; /* 2303 */
+	} else if (kcontrol->private_value == PCM_PLAYBACK_MUTE) {
+		uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+		uinfo->count = 1;
+		uinfo->value.integer.min = 0;
+		uinfo->value.integer.max = 1;
+	} else if (kcontrol->private_value == PCM_PLAYBACK_DEVICE) {
+		uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+		uinfo->count = 1;
+		uinfo->value.integer.min = 0;
+		uinfo->value.integer.max = AUDIO_DEST_MAX - 1;
+	}
+	audio_info(" ... OUT\n");
+	return 0;
+}
+
+/* toggles mute on or off depending on the value of nmute, and returns
+ * 1 if the mute value was changed, otherwise 0
+ */
+static int toggle_mute(struct bcm2835_chip *chip, int nmute)
+{
+	/* if settings are ok, just return 0 */
+	if (chip->mute == nmute)
+		return 0;
+
+	/* if the sound is muted then we need to unmute */
+	if (chip->mute == CTRL_VOL_MUTE) {
+		chip->volume = chip->old_volume; /* copy the old volume back */
+		audio_info("Unmuting, old_volume = %d, volume = %d ...\n", chip->old_volume, chip->volume);
+	} else /* otherwise we mute */ {
+		chip->old_volume = chip->volume;
+		chip->volume = 26214; /* set volume to minimum level AKA mute */
+		audio_info("Muting, old_volume = %d, volume = %d ...\n", chip->old_volume, chip->volume);
+	}
+
+	chip->mute = nmute;
+	return 1;
+}
+
+static int snd_bcm2835_ctl_get(struct snd_kcontrol *kcontrol,
+			       struct snd_ctl_elem_value *ucontrol)
+{
+	struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+
+	if (mutex_lock_interruptible(&chip->audio_mutex))
+		return -EINTR;
+
+	BUG_ON(!chip && !(chip->avail_substreams & AVAIL_SUBSTREAMS_MASK));
+
+	if (kcontrol->private_value == PCM_PLAYBACK_VOLUME)
+		ucontrol->value.integer.value[0] = chip2alsa(chip->volume);
+	else if (kcontrol->private_value == PCM_PLAYBACK_MUTE)
+		ucontrol->value.integer.value[0] = chip->mute;
+	else if (kcontrol->private_value == PCM_PLAYBACK_DEVICE)
+		ucontrol->value.integer.value[0] = chip->dest;
+
+	mutex_unlock(&chip->audio_mutex);
+	return 0;
+}
+
+static int snd_bcm2835_ctl_put(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+	int changed = 0;
+
+	if (mutex_lock_interruptible(&chip->audio_mutex))
+		return -EINTR;
+
+	if (kcontrol->private_value == PCM_PLAYBACK_VOLUME) {
+		audio_info("Volume change attempted.. volume = %d new_volume = %d\n", chip->volume, (int) ucontrol->value.integer.value[0]);
+		if (chip->mute == CTRL_VOL_MUTE) {
+			/* changed = toggle_mute(chip, CTRL_VOL_UNMUTE); */
+			changed = 1; /* should return 0 to signify no change but the mixer takes this as the opposite sign (no idea why) */
+			goto unlock;
+		}
+		if (changed
+			|| (ucontrol->value.integer.value[0] != chip2alsa(chip->volume))) {
+
+			chip->volume = alsa2chip(ucontrol->value.integer.value[0]);
+			changed = 1;
+		}
+
+	} else if (kcontrol->private_value == PCM_PLAYBACK_MUTE) {
+		/* Now implemented */
+		audio_info(" Mute attempted\n");
+		changed = toggle_mute(chip, ucontrol->value.integer.value[0]);
+
+	} else if (kcontrol->private_value == PCM_PLAYBACK_DEVICE) {
+		if (ucontrol->value.integer.value[0] != chip->dest) {
+			chip->dest = ucontrol->value.integer.value[0];
+			changed = 1;
+		}
+	}
+
+	if (changed) {
+		if (bcm2835_audio_set_ctls(chip))
+			printk(KERN_ERR "Failed to set ALSA controls..\n");
+	}
+
+unlock:
+	mutex_unlock(&chip->audio_mutex);
+	return changed;
+}
+
+static DECLARE_TLV_DB_SCALE(snd_bcm2835_db_scale, CTRL_VOL_MIN, 1, 1);
+
+static struct snd_kcontrol_new snd_bcm2835_ctl[] = {
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "PCM Playback Volume",
+		.index = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE | SNDRV_CTL_ELEM_ACCESS_TLV_READ,
+		.private_value = PCM_PLAYBACK_VOLUME,
+		.info = snd_bcm2835_ctl_info,
+		.get = snd_bcm2835_ctl_get,
+		.put = snd_bcm2835_ctl_put,
+		.count = 1,
+		.tlv =
+		{.p = snd_bcm2835_db_scale}
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "PCM Playback Switch",
+		.index = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.private_value = PCM_PLAYBACK_MUTE,
+		.info = snd_bcm2835_ctl_info,
+		.get = snd_bcm2835_ctl_get,
+		.put = snd_bcm2835_ctl_put,
+		.count = 1,
+	},
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+		.name = "PCM Playback Route",
+		.index = 0,
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+		.private_value = PCM_PLAYBACK_DEVICE,
+		.info = snd_bcm2835_ctl_info,
+		.get = snd_bcm2835_ctl_get,
+		.put = snd_bcm2835_ctl_put,
+		.count = 1,
+	},
+};
+
+static int snd_bcm2835_spdif_default_info(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_IEC958;
+	uinfo->count = 1;
+	return 0;
+}
+
+static int snd_bcm2835_spdif_default_get(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+	int i;
+
+	if (mutex_lock_interruptible(&chip->audio_mutex))
+		return -EINTR;
+
+	for (i = 0; i < 4; i++)
+		ucontrol->value.iec958.status[i] =
+		(chip->spdif_status >> (i * 8)) && 0xff;
+
+	mutex_unlock(&chip->audio_mutex);
+	return 0;
+}
+
+static int snd_bcm2835_spdif_default_put(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+	unsigned int val = 0;
+	int i, change;
+
+	if (mutex_lock_interruptible(&chip->audio_mutex))
+		return -EINTR;
+
+	for (i = 0; i < 4; i++)
+		val |= (unsigned int) ucontrol->value.iec958.status[i] << (i * 8);
+
+	change = val != chip->spdif_status;
+	chip->spdif_status = val;
+
+	mutex_unlock(&chip->audio_mutex);
+	return change;
+}
+
+static int snd_bcm2835_spdif_mask_info(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_IEC958;
+	uinfo->count = 1;
+	return 0;
+}
+
+static int snd_bcm2835_spdif_mask_get(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	/* bcm2835 supports only consumer mode and sets all other format flags
+	 * automatically. So the only thing left is signalling non-audio
+	 * content */
+	ucontrol->value.iec958.status[0] = IEC958_AES0_NONAUDIO;
+	return 0;
+}
+
+static int snd_bcm2835_spdif_stream_info(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_IEC958;
+	uinfo->count = 1;
+	return 0;
+}
+
+static int snd_bcm2835_spdif_stream_get(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+	int i;
+
+	if (mutex_lock_interruptible(&chip->audio_mutex))
+		return -EINTR;
+
+	for (i = 0; i < 4; i++)
+		ucontrol->value.iec958.status[i] =
+		(chip->spdif_status >> (i * 8)) & 0xff;
+
+	mutex_unlock(&chip->audio_mutex);
+	return 0;
+}
+
+static int snd_bcm2835_spdif_stream_put(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct bcm2835_chip *chip = snd_kcontrol_chip(kcontrol);
+	unsigned int val = 0;
+	int i, change;
+
+	if (mutex_lock_interruptible(&chip->audio_mutex))
+		return -EINTR;
+
+	for (i = 0; i < 4; i++)
+		val |= (unsigned int) ucontrol->value.iec958.status[i] << (i * 8);
+	change = val != chip->spdif_status;
+	chip->spdif_status = val;
+
+	mutex_unlock(&chip->audio_mutex);
+	return change;
+}
+
+static struct snd_kcontrol_new snd_bcm2835_spdif[] = {
+	{
+		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
+		.name = SNDRV_CTL_NAME_IEC958("", PLAYBACK, DEFAULT),
+		.info = snd_bcm2835_spdif_default_info,
+		.get = snd_bcm2835_spdif_default_get,
+		.put = snd_bcm2835_spdif_default_put
+	},
+	{
+		.access = SNDRV_CTL_ELEM_ACCESS_READ,
+		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
+		.name = SNDRV_CTL_NAME_IEC958("", PLAYBACK, CON_MASK),
+		.info = snd_bcm2835_spdif_mask_info,
+		.get = snd_bcm2835_spdif_mask_get,
+	},
+	{
+		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
+		SNDRV_CTL_ELEM_ACCESS_INACTIVE,
+		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
+		.name = SNDRV_CTL_NAME_IEC958("", PLAYBACK, PCM_STREAM),
+		.info = snd_bcm2835_spdif_stream_info,
+		.get = snd_bcm2835_spdif_stream_get,
+		.put = snd_bcm2835_spdif_stream_put,
+	},
+};
+
+int snd_bcm2835_new_ctl(struct bcm2835_chip *chip)
+{
+	int err;
+	unsigned int idx;
+
+	strcpy(chip->card->mixername, "Broadcom Mixer");
+	for (idx = 0; idx < ARRAY_SIZE(snd_bcm2835_ctl); idx++) {
+		err = snd_ctl_add(chip->card,
+				  snd_ctl_new1(&snd_bcm2835_ctl[idx], chip));
+		if (err < 0)
+			return err;
+	}
+	for (idx = 0; idx < ARRAY_SIZE(snd_bcm2835_spdif); idx++) {
+		err = snd_ctl_add(chip->card,
+				  snd_ctl_new1(&snd_bcm2835_spdif[idx], chip));
+		if (err < 0)
+			return err;
+	}
+	return 0;
+}