usb_stream: Allow user-set period-size and rate

* usb_stream/pcm_usb_stream.c: Allow user-set period-size and rate.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/usb_stream/pcm_usb_stream.c b/usb_stream/pcm_usb_stream.c
index cd761fb252bcb42d5ad4d6024581a09d49180d34..b1fd68f25701c44a14784b95312074933c1b2310 100644 (file)
--- a/usb_stream/pcm_usb_stream.c
+++ b/usb_stream/pcm_usb_stream.c
@@ -48,6 +48,8 @@
 #define VDBG(f, ...)
 #endif
 
+#define FRAME_SIZE 6
+
 #define LCARD 32
 struct user_usb_stream {
        char                    card[LCARD];
@@ -70,6 +72,8 @@ typedef struct {
        unsigned                periods_done;
 
        unsigned                channels;
+       snd_pcm_uframes_t       period_size;
+       unsigned int            rate;
 } snd_pcm_us_t;
 
 static struct user_usb_stream *uus;
@@ -177,7 +181,7 @@ static int snd_pcm_us_prepare(snd_pcm_ioplug_t *io)
        VDBG("");
 
        us_cfg.version = USB_STREAM_INTERFACE_VERSION;
-       us_cfg.frame_size = 6;
+       us_cfg.frame_size = FRAME_SIZE;
        us_cfg.sample_rate = io->rate;
        us_cfg.period_frames = io->period_size;
 
@@ -373,6 +377,10 @@ static int us_set_hw_constraint(snd_pcm_us_t *us)
        };
 
        int err;
+       unsigned int rate_min = us->rate ? us->rate : 44100,
+               rate_max = us->rate ? us->rate : 96000,
+               period_bytes_min = us->period_size ? FRAME_SIZE * us->period_size : 128,
+               period_bytes_max = us->period_size ? FRAME_SIZE * us->period_size : 64*4096;
 
        if ((err = snd_pcm_ioplug_set_param_list(&us->io, SND_PCM_IOPLUG_HW_ACCESS,
                                                 ARRAY_SIZE(access_list), access_list)) < 0 ||
@@ -381,9 +389,9 @@ static int us_set_hw_constraint(snd_pcm_us_t *us)
            (err = snd_pcm_ioplug_set_param_minmax(&us->io, SND_PCM_IOPLUG_HW_CHANNELS,
                                                   us->channels, us->channels)) < 0 ||
            (err = snd_pcm_ioplug_set_param_minmax(&us->io, SND_PCM_IOPLUG_HW_RATE,
-                                                  44100, 96000)) < 0 ||
+                                                  rate_min, rate_max)) < 0 ||
            (err = snd_pcm_ioplug_set_param_minmax(&us->io, SND_PCM_IOPLUG_HW_PERIOD_BYTES,
-                                                  128, 64*4096)) < 0 ||
+                                                  period_bytes_min, period_bytes_max)) < 0 ||
            (err = snd_pcm_ioplug_set_param_minmax(&us->io, SND_PCM_IOPLUG_HW_PERIODS,
                                                   2, 2)) < 0)
                return err;
@@ -393,7 +401,9 @@ static int us_set_hw_constraint(snd_pcm_us_t *us)
 
 static int snd_pcm_us_open(snd_pcm_t **pcmp, const char *name,
                                   const char *card,
-                                  snd_pcm_stream_t stream, int mode)
+                                  snd_pcm_stream_t stream, int mode,
+                                  snd_pcm_uframes_t period_size,
+                                  unsigned int rate)
 {
        snd_pcm_us_t *us;
        int err;
@@ -424,6 +434,8 @@ static int snd_pcm_us_open(snd_pcm_t **pcmp, const char *name,
        snd_hwdep_poll_descriptors(us->hwdep, &us->pfd, 1);
 
        us->channels = 2;
+       us->period_size = period_size;
+       us->rate = rate;
 
        us->io.version = SND_PCM_IOPLUG_VERSION;
        us->io.name = "ALSA <-> USB_STREAM PCM I/O Plugin";
@@ -458,6 +470,7 @@ SND_PCM_PLUGIN_DEFINE_FUNC(usb_stream)
        snd_config_iterator_t i, next;
        const char *card;
        int err;
+       long period_size = 0, rate = 0;
        
        snd_config_for_each(i, next, conf) {
                snd_config_t *n = snd_config_iterator_entry(i);
@@ -475,11 +488,27 @@ SND_PCM_PLUGIN_DEFINE_FUNC(usb_stream)
                        snd_config_get_string(n, &card);
                        continue;
                }
+               if (strcmp(id, "period_size") == 0) {
+                       if (snd_config_get_type(n) != SND_CONFIG_TYPE_INTEGER) {
+                               SNDERR("Invalid type for %s", id);
+                               return -EINVAL;
+                       }
+                       snd_config_get_integer(n, &period_size);
+                       continue;
+               }
+               if (strcmp(id, "rate") == 0) {
+                       if (snd_config_get_type(n) != SND_CONFIG_TYPE_INTEGER) {
+                               SNDERR("Invalid type for %s", id);
+                               return -EINVAL;
+                       }
+                       snd_config_get_integer(n, &rate);
+                       continue;
+               }
                SNDERR("Unknown field %s", id);
                return -EINVAL;
        }
 
-       err = snd_pcm_us_open(pcmp, name, card, stream, mode);
+       err = snd_pcm_us_open(pcmp, name, card, stream, mode, period_size, rate);
 
        return err;
 }