ALSA: virtuoso: Xonar DS: add stereo upmixing to center/LFE channels

Add the possibility to route a mix of the two channels of stereo data to
the center and LFE outputs.  Due to a WM8766 restriction, all surround
and back channels also get the mixed L/R signal in this case.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/oxygen/xonar_wm87x6.c b/sound/pci/oxygen/xonar_wm87x6.c
index cee07fe3aa3640cb093ec1d1c00d3ec38c169bff..aceaaa036da6a07ec30074a7f8a4329f9f6d7b49 100644 (file)
--- a/sound/pci/oxygen/xonar_wm87x6.c
+++ b/sound/pci/oxygen/xonar_wm87x6.c
@@ -377,6 +377,24 @@ static void update_wm87x6_mute(struct oxygen *chip)
                            (chip->dac_mute ? WM8766_DMUTE_MASK : 0));
 }
 
+static void update_wm8766_center_lfe_mix(struct oxygen *chip, bool mixed)
+{
+       struct xonar_wm87x6 *data = chip->model_data;
+       unsigned int reg;
+
+       /*
+        * The WM8766 can mix left and right channels, but this setting
+        * applies to all three stereo pairs.
+        */
+       reg = data->wm8766_regs[WM8766_DAC_CTRL] &
+               ~(WM8766_PL_LEFT_MASK | WM8766_PL_RIGHT_MASK);
+       if (mixed)
+               reg |= WM8766_PL_LEFT_LRMIX | WM8766_PL_RIGHT_LRMIX;
+       else
+               reg |= WM8766_PL_LEFT_LEFT | WM8766_PL_RIGHT_RIGHT;
+       wm8766_write_cached(chip, WM8766_DAC_CTRL, reg);
+}
+
 static void xonar_ds_gpio_changed(struct oxygen *chip)
 {
        xonar_ds_handle_hp_jack(chip);
@@ -1067,6 +1085,7 @@ static const struct oxygen_model model_xonar_ds = {
        .set_adc_params = set_wm8776_adc_params,
        .update_dac_volume = update_wm87x6_volume,
        .update_dac_mute = update_wm87x6_mute,
+       .update_center_lfe_mix = update_wm8766_center_lfe_mix,
        .gpio_changed = xonar_ds_gpio_changed,
        .dac_tlv = wm87x6_dac_db_scale,
        .model_data_size = sizeof(struct xonar_wm87x6),