Re: [alsa-devel] [PATCH 2/3 v4] ALSA: usb-audio: Add mixer control for Digidesign mbox 1 clock source

At Mon, 10 Nov 2014 20:40:36 +1100, Damien Zammit wrote:

This patch provides the infrastructure for the Digidesign Mbox 1 to have a mixer control for selecting the clock source. Valid options are Internal and S/PDIF external sync. A non-documented command is sent to the device to enable this feature found by reverse engineering and bus snooping.

Signed-off-by: Damien Zammit damien@zamaudio.com

Clemens suggested that you forgot to unlock chip->shutdown_rwsem in some error paths. It's not about register_mutex.

Takashi

---

sound/usb/mixer_maps.c | 9 +++ sound/usb/mixer_quirks.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 153 insertions(+)

diff --git a/sound/usb/mixer_maps.c b/sound/usb/mixer_maps.c index d1d72ff..1994d41 100644 --- a/sound/usb/mixer_maps.c +++ b/sound/usb/mixer_maps.c @@ -179,6 +179,11 @@ static struct usbmix_name_map audigy2nx_map[] = { { 0 } /* terminator */ };

+static struct usbmix_name_map mbox1_map[] = {

• { 1, "Clock" },
• { 0 } /* terminator */

+};

static struct usbmix_selector_map c400_selectors[] = { { .id = 0x80, @@ -416,6 +421,10 @@ static struct usbmix_ctl_map usbmix_ctl_maps[] = { .map = aureon_51_2_map, }, {

• .id = USB_ID(0x0dba, 0x1000),
  

• .map = mbox1_map,
  

• },
• { .id = USB_ID(0x13e5, 0x0001), .map = scratch_live_map, .ignore_ctl_error = 1,

diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index 3980bf5..448ac42 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -28,6 +28,7 @@ */

#include <linux/init.h> +#include <linux/mutex.h> #include <linux/slab.h> #include <linux/usb.h> #include <linux/usb/audio.h> @@ -565,6 +566,145 @@ static int snd_xonar_u1_controls_create(struct usb_mixer_interface *mixer) return 0; }

+/* Digidesign Mbox 1 clock source switch (internal/spdif) */

+static int snd_mbox1_switch_get(struct snd_kcontrol *kctl,

• 		struct snd_ctl_elem_value *ucontrol)
  

+{

• if (kctl->private_value) {

• ucontrol->value.enumerated.item[0] = true;
  

• return 0;
  

• }
• ucontrol->value.enumerated.item[0] = false;
• return 0;

+}

+static int snd_mbox1_switch_put(struct snd_kcontrol *kctl,

• 		struct snd_ctl_elem_value *ucontrol)
  

+{

• struct snd_usb_audio *chip;
• struct usb_mixer_interface *mixer;
• int err;
• bool changed, cur_val, new_val;
• bool value;
• unsigned char buff[3];
• changed = false;
• value = false;
• cur_val = kctl->private_value;
• new_val = ucontrol->value.enumerated.item[0];
• mixer = snd_kcontrol_chip(kctl);
• if (snd_BUG_ON(!mixer))

• return -EINVAL;
  

• chip = mixer->chip;
• if (snd_BUG_ON(!chip))

• return -EINVAL;
  

• /* update value if needed */
• if (cur_val != new_val) {

• value = new_val;
  

• down_read(&chip->shutdown_rwsem);
  

• if (chip->shutdown) {
  

• 	err = -ENODEV;
  

• } else {
  

• 	/* Prepare for magic command to toggle clock source */
  

• 	mutex_unlock(&register_mutex);
  

• 	err = snd_usb_ctl_msg(chip->dev,
  

• 		usb_rcvctrlpipe(chip->dev, 0), 0x81,
  

• 		USB_DIR_IN |
  

• 		USB_TYPE_CLASS |
  

• 		USB_RECIP_INTERFACE, 0x00, 0x500, buff, 1);
  

• 	if (err < 0)
  

• 		goto err;
  

• 	err = snd_usb_ctl_msg(chip->dev,
  

• 		usb_rcvctrlpipe(chip->dev, 0), 0x81,
  

• 		USB_DIR_IN |
  

• 		USB_TYPE_CLASS |
  

• 		USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
  

• 	if (err < 0)
  

• 		goto err;
  

• 	/* 2 possibilities: Internal    -> send sample rate
  

• 	 * 		    S/PDIF sync -> send zeroes
  

• 	 * NB: Sample rate locked to 48kHz on purpose to
  

• 	 *     prevent user from resetting the sample rate
  

• 	 *     while S/PDIF sync is enabled and confusing
  

• 	 *     this configuration.
  

• 	 */
  

• 	if (new_val == 0) {
  

• 		buff[0] = 0x80;
  

• 		buff[1] = 0xbb;
  

• 		buff[2] = 0x00;
  

• 	} else {
  

• 		buff[0] = buff[1] = buff[2] = 0x00;
  

• 	}
  

• 	/* Send the magic command to toggle the clock source */
  

• 	err = snd_usb_ctl_msg(chip->dev,
  

• 		usb_sndctrlpipe(chip->dev, 0), 0x1,
  

• 		USB_TYPE_CLASS |
  

• 		USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
  

• 	if (err < 0)
  

• 		goto err;
  

• 	err = snd_usb_ctl_msg(chip->dev,
  

• 		usb_rcvctrlpipe(chip->dev, 0), 0x81,
  

• 		USB_DIR_IN |
  

• 		USB_TYPE_CLASS |
  

• 		USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
  

• 	if (err < 0)
  

• 		goto err;
  

• 	err = snd_usb_ctl_msg(chip->dev,
  

• 		usb_rcvctrlpipe(chip->dev, 0), 0x81,
  

• 		USB_DIR_IN |
  

• 		USB_TYPE_CLASS |
  

• 		USB_RECIP_ENDPOINT, 0x100, 0x2, buff, 3);
  

• 	if (err < 0)
  

• 		goto err;
  

• }
  

• up_read(&chip->shutdown_rwsem);
  

• if (err < 0)
  

• 	goto err;
  

• mutex_lock(&register_mutex);
  

• kctl->private_value = new_val;
  

• changed = true;
  

• }
• return changed;

+err:

• mutex_lock(&register_mutex);
• return err;

+}

+static int snd_mbox1_switch_info(struct snd_kcontrol *kcontrol,

• 		 struct snd_ctl_elem_info *uinfo)
  

+{

• static const char *const texts[2] = {

• "Internal",
  

• "S/PDIF"
  

• };
• return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);

+}

+static struct snd_kcontrol_new snd_mbox1_switch = {

• .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
• .name = "Clock Source",
• .index = 0,
• .access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
• .info = snd_mbox1_switch_info,
• .get = snd_mbox1_switch_get,
• .put = snd_mbox1_switch_put,
• .private_value = 0

+};

+static int snd_mbox1_create_sync_switch(struct usb_mixer_interface *mixer) +{

• return snd_ctl_add(mixer->chip->card,

• 	snd_ctl_new1(&snd_mbox1_switch, mixer));
  

+}

/* Native Instruments device quirks */

#define _MAKE_NI_CONTROL(bRequest,wIndex) ((bRequest) << 16 | (wIndex)) @@ -1632,6 +1772,10 @@ int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer) err = snd_microii_controls_create(mixer); break;

• case USB_ID(0x0dba, 0x1000): /* Digidesign Mbox 1 */

• err = snd_mbox1_create_sync_switch(mixer);
  

• break;
  

• case USB_ID(0x17cc, 0x1011): /* Traktor Audio 6 */ err = snd_nativeinstruments_create_mixer(mixer, snd_nativeinstruments_ta6_mixers,

-- 1.9.1