Add bridged amplifiers to cs42l43

Merge series from Charles Keepax <[email protected]>:

In some cs42l43 systems a couple of cs35l56 amplifiers are attached
to the cs42l43's SPI and I2S. On Windows the cs42l43 is controlled
by a SDCA class driver and these two amplifiers are controlled by
firmware running on the cs42l43. However, under Linux the decision
was made to interact with the cs42l43 directly, affording the user
greater control over the audio system. However, this has resulted
in an issue where these two bridged cs35l56 amplifiers are not
populated in ACPI and must be added manually. There is at least an
SDCA extension unit DT entry we can key off.

The process of adding this is handled using a software node, firstly the
ability to add native chip selects to software nodes must be added.
Secondly, an additional flag for naming the SPI devices is added this
allows the machine driver to key to the correct amplifier. Then finally,
the cs42l43 SPI driver adds the two amplifiers directly onto its SPI
bus.

An additional series will follow soon to add the audio machine driver
parts (in the sof-sdw driver), however that is fairly orthogonal to
this part of the process, getting the actual amplifiers registered.

1 files changed, 14 insertions, 3 deletions

diff --git a/sound/sh/aica.c b/sound/sh/aica.c
index 320ac792c7fe..3182c634464d 100644
--- a/sound/sh/aica.c
+++ b/sound/sh/aica.c
@@ -278,7 +278,8 @@ static void run_spu_dma(struct work_struct *work)
 		dreamcastcard->clicks++;
 		if (unlikely(dreamcastcard->clicks >= AICA_PERIOD_NUMBER))
 			dreamcastcard->clicks %= AICA_PERIOD_NUMBER;
-		mod_timer(&dreamcastcard->timer, jiffies + 1);
+		if (snd_pcm_running(dreamcastcard->substream))
+			mod_timer(&dreamcastcard->timer, jiffies + 1);
 	}
 }
 
@@ -290,6 +291,8 @@ static void aica_period_elapsed(struct timer_list *t)
 	/*timer function - so cannot sleep */
 	int play_period;
 	struct snd_pcm_runtime *runtime;
+	if (!snd_pcm_running(substream))
+		return;
 	runtime = substream->runtime;
 	dreamcastcard = substream->pcm->private_data;
 	/* Have we played out an additional period? */
@@ -350,12 +353,19 @@ static int snd_aicapcm_pcm_open(struct snd_pcm_substream
 	return 0;
 }
 
+static int snd_aicapcm_pcm_sync_stop(struct snd_pcm_substream *substream)
+{
+	struct snd_card_aica *dreamcastcard = substream->pcm->private_data;
+
+	del_timer_sync(&dreamcastcard->timer);
+	cancel_work_sync(&dreamcastcard->spu_dma_work);
+	return 0;
+}
+
 static int snd_aicapcm_pcm_close(struct snd_pcm_substream
 				 *substream)
 {
 	struct snd_card_aica *dreamcastcard = substream->pcm->private_data;
-	flush_work(&(dreamcastcard->spu_dma_work));
-	del_timer(&dreamcastcard->timer);
 	dreamcastcard->substream = NULL;
 	kfree(dreamcastcard->channel);
 	spu_disable();
@@ -401,6 +411,7 @@ static const struct snd_pcm_ops snd_aicapcm_playback_ops = {
 	.prepare = snd_aicapcm_pcm_prepare,
 	.trigger = snd_aicapcm_pcm_trigger,
 	.pointer = snd_aicapcm_pcm_pointer,
+	.sync_stop = snd_aicapcm_pcm_sync_stop,
 };
 
 /* TO DO: set up to handle more than one pcm instance */