ASoC: meson: axg-fifo: add NO_PERIOD_WAKEUP support

On the AXG family, the fifo irq is not necessary for the HW to operate.
It is just used to notify that a period has elapsed. If userpace does not
care for these wakeups (such as pipewire), we are just wasting CPU cycles.

Add support for NO_PERIOD_WAKEUP and disable irq when they are no needed.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20210407145914.311479-1-jbrunet@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/meson/axg-fifo.c b/sound/soc/meson/axg-fifo.c
index b2e8671..b9af2d5 100644 (file)
--- a/sound/soc/meson/axg-fifo.c
+++ b/sound/soc/meson/axg-fifo.c
@@ -27,8 +27,8 @@ static struct snd_pcm_hardware axg_fifo_hw = {
                 SNDRV_PCM_INFO_MMAP |
                 SNDRV_PCM_INFO_MMAP_VALID |
                 SNDRV_PCM_INFO_BLOCK_TRANSFER |
-                SNDRV_PCM_INFO_PAUSE),
-
+                SNDRV_PCM_INFO_PAUSE |
+                SNDRV_PCM_INFO_NO_PERIOD_WAKEUP),
        .formats = AXG_FIFO_FORMATS,
        .rate_min = 5512,
        .rate_max = 192000,
@@ -113,7 +113,7 @@ int axg_fifo_pcm_hw_params(struct snd_soc_component *component,
 {
        struct snd_pcm_runtime *runtime = ss->runtime;
        struct axg_fifo *fifo = axg_fifo_data(ss);
-       unsigned int burst_num, period, threshold;
+       unsigned int burst_num, period, threshold, irq_en;
        dma_addr_t end_ptr;
 
        period = params_period_bytes(params);
@@ -142,10 +142,11 @@ int axg_fifo_pcm_hw_params(struct snd_soc_component *component,
        regmap_field_write(fifo->field_threshold,
                           threshold ? threshold - 1 : 0);
 
-       /* Enable block count irq */
+       /* Enable irq if necessary  */
+       irq_en = runtime->no_period_wakeup ? 0 : FIFO_INT_COUNT_REPEAT;
        regmap_update_bits(fifo->map, FIFO_CTRL0,
                           CTRL0_INT_EN(FIFO_INT_COUNT_REPEAT),
-                          CTRL0_INT_EN(FIFO_INT_COUNT_REPEAT));
+                          CTRL0_INT_EN(irq_en));
 
        return 0;
 }