ALSA: usbmixer - introduce /proc/asound/card#/usbmixer file

The usbmixer proc file contains mapping between ALSA control API and
USB mixer control units. The purpose of this file is for debugging
and a problem diagnostics.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

1 files changed, 61 insertions, 14 deletions

diff --git a/sound/usb/usbmixer.c b/sound/usb/usbmixer.c
index dd0c1d7bf3ed..170bfd4fc9f6 100644
--- a/sound/usb/usbmixer.c
+++ b/sound/usb/usbmixer.c
@@ -69,13 +69,16 @@ static const struct rc_config {
         { USB_ID(0x041e, 0x3048), 2, 2, 6, 6,  2,  0x6e91 }, /* Toshiba SB0500 */
 };
 
+#define MAX_ID_ELEMS    256
+
 struct usb_mixer_interface {
         struct snd_usb_audio *chip;
         unsigned int ctrlif;
         struct list_head list;
         unsigned int ignore_ctl_error;
         struct urb *urb;
-        struct usb_mixer_elem_info **id_elems; /* array[256], indexed by unit id */
+        /* array[MAX_ID_ELEMS], indexed by unit id */
+        struct usb_mixer_elem_info **id_elems;
 
         /* Sound Blaster remote control stuff */
         const struct rc_config *rc_cfg;
@@ -1825,6 +1828,45 @@ static void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer,
                                info->elem_id);
 }
 
+static void snd_usb_mixer_dump_cval(struct snd_info_buffer *buffer,
+                                    int unitid,
+                                    struct usb_mixer_elem_info *cval)
+{
+        static char *val_types[] = {"BOOLEAN", "INV_BOOLEAN",
+                                    "S8", "U8", "S16", "U16"};
+        snd_iprintf(buffer, "  Unit: %i\n", unitid);
+        if (cval->elem_id)
+                snd_iprintf(buffer, "    Control: name=\"%s\", index=%i\n",
+                                cval->elem_id->name, cval->elem_id->index);
+        snd_iprintf(buffer, "    Info: id=%i, control=%i, cmask=0x%x, "
+                            "channels=%i, type=\"%s\"\n", cval->id,
+                            cval->control, cval->cmask, cval->channels,
+                            val_types[cval->val_type]);
+        snd_iprintf(buffer, "    Volume: min=%i, max=%i, dBmin=%i, dBmax=%i\n",
+                            cval->min, cval->max, cval->dBmin, cval->dBmax);
+}
+
+static void snd_usb_mixer_proc_read(struct snd_info_entry *entry,
+                                    struct snd_info_buffer *buffer)
+{
+        struct snd_usb_audio *chip = entry->private_data;
+        struct usb_mixer_interface *mixer;
+        struct usb_mixer_elem_info *cval;
+        int unitid;
+
+        list_for_each_entry(mixer, &chip->mixer_list, list) {
+                snd_iprintf(buffer,
+                        "USB Mixer: ctrlif=%i, ctlerr=%i\n",
+                                mixer->ctrlif, mixer->ignore_ctl_error);
+                snd_iprintf(buffer, "Card: %s\n", chip->card->longname);
+                for (unitid = 0; unitid < MAX_ID_ELEMS; unitid++) {
+                        for (cval = mixer->id_elems[unitid]; cval;
+                                                cval = cval->next_id_elem)
+                                snd_usb_mixer_dump_cval(buffer, unitid, cval);
+                }
+        }
+}
+
 static void snd_usb_mixer_memory_change(struct usb_mixer_interface *mixer,
                                         int unitid)
 {
@@ -2187,20 +2229,21 @@ static int snd_xonar_u1_controls_create(struct usb_mixer_interface *mixer)
 }
 
 void snd_emuusb_set_samplerate(struct snd_usb_audio *chip,
-                unsigned char samplerate_id)
+                               unsigned char samplerate_id)
 {
-         struct usb_mixer_interface *mixer;
-         struct usb_mixer_elem_info *cval;
-         int unitid = 12; /* SamleRate ExtensionUnit ID */
+        struct usb_mixer_interface *mixer;
+        struct usb_mixer_elem_info *cval;
+        int unitid = 12; /* SamleRate ExtensionUnit ID */
 
-         list_for_each_entry(mixer, &chip->mixer_list, list) {
-                 cval = mixer->id_elems[unitid];
-                 if (cval) {
-                        set_cur_ctl_value(cval, cval->control << 8, samplerate_id);
+        list_for_each_entry(mixer, &chip->mixer_list, list) {
+                cval = mixer->id_elems[unitid];
+                if (cval) {
+                        set_cur_ctl_value(cval, cval->control << 8,
+                                          samplerate_id);
                         snd_usb_mixer_notify_id(mixer, unitid);
-                 }
-                 break;
-         }
+                }
+                break;
+        }
 }
 
 int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
@@ -2210,6 +2253,7 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
                 .dev_free = snd_usb_mixer_dev_free
         };
         struct usb_mixer_interface *mixer;
+        struct snd_info_entry *entry;
         int err;
 
         strcpy(chip->card->mixername, "USB Mixer");
@@ -2236,8 +2280,6 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
         if (mixer->chip->usb_id == USB_ID(0x041e, 0x3020) ||
             mixer->chip->usb_id == USB_ID(0x041e, 0x3040) ||
             mixer->chip->usb_id == USB_ID(0x041e, 0x3048)) {
-                struct snd_info_entry *entry;
-
                 if ((err = snd_audigy2nx_controls_create(mixer)) < 0)
                         goto _error;
                 if (!snd_card_proc_new(chip->card, "audigy2nx", &entry))
@@ -2255,6 +2297,11 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
         err = snd_device_new(chip->card, SNDRV_DEV_LOWLEVEL, mixer, &dev_ops);
         if (err < 0)
                 goto _error;
+
+        if (list_empty(&chip->mixer_list) &&
+            !snd_card_proc_new(chip->card, "usbmixer", &entry))
+                snd_info_set_text_ops(entry, chip, snd_usb_mixer_proc_read);
+
         list_add(&mixer->list, &chip->mixer_list);
         return 0;