1 files changed, 100 insertions, 0 deletions
diff --git a/sound/pci/cs5535audio/cs5535audio_pm.c b/sound/pci/cs5535audio/cs5535audio_pm.c
new file mode 100644
index 0000000000..90fb73a9d9
--- /dev/null
+++ b/sound/pci/cs5535audio/cs5535audio_pm.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Power management for audio on multifunction CS5535 companion device
+ * Copyright (C) Jaya Kumar
+ */
+
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <sound/core.h>
+#include <sound/control.h>
+#include <sound/initval.h>
+#include <sound/asoundef.h>
+#include <sound/pcm.h>
+#include <sound/ac97_codec.h>
+#include "cs5535audio.h"
+
+static void snd_cs5535audio_stop_hardware(struct cs5535audio *cs5535au)
+{
+	/* 
+	we depend on snd_ac97_suspend to tell the
+	AC97 codec to shutdown. the amd spec suggests
+	that the LNK_SHUTDOWN be done at the same time
+	that the codec power-down is issued. instead,
+	we do it just after rather than at the same 
+	time. excluding codec specific build_ops->suspend
+	ac97 powerdown hits:
+	0x8000 EAPD 
+	0x4000 Headphone amplifier 
+	0x0300 ADC & DAC 
+	0x0400 Analog Mixer powerdown (Vref on) 
+	I am not sure if this is the best that we can do.
+	The remainder to be investigated are:
+	- analog mixer (vref off) 0x0800
+	- AC-link powerdown 0x1000
+	- codec internal clock 0x2000
+	*/
+
+	/* set LNK_SHUTDOWN to shutdown AC link */
+	cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_SHUTDOWN);
+
+}
+
+static int __maybe_unused snd_cs5535audio_suspend(struct device *dev)
+{
+	struct snd_card *card = dev_get_drvdata(dev);
+	struct cs5535audio *cs5535au = card->private_data;
+	int i;
+
+	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
+	snd_ac97_suspend(cs5535au->ac97);
+	for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) {
+		struct cs5535audio_dma *dma = &cs5535au->dmas[i];
+		if (dma && dma->substream)
+			dma->saved_prd = dma->ops->read_prd(cs5535au);
+	}
+	/* save important regs, then disable aclink in hw */
+	snd_cs5535audio_stop_hardware(cs5535au);
+	return 0;
+}
+
+static int __maybe_unused snd_cs5535audio_resume(struct device *dev)
+{
+	struct snd_card *card = dev_get_drvdata(dev);
+	struct cs5535audio *cs5535au = card->private_data;
+	u32 tmp;
+	int timeout;
+	int i;
+
+	/* set LNK_WRM_RST to reset AC link */
+	cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_WRM_RST);
+
+	timeout = 50;
+	do {
+		tmp = cs_readl(cs5535au, ACC_CODEC_STATUS);
+		if (tmp & PRM_RDY_STS)
+			break;
+		udelay(1);
+	} while (--timeout);
+
+	if (!timeout)
+		dev_err(cs5535au->card->dev, "Failure getting AC Link ready\n");
+
+	/* set up rate regs, dma. actual initiation is done in trig */
+	for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) {
+		struct cs5535audio_dma *dma = &cs5535au->dmas[i];
+		if (dma && dma->substream) {
+			dma->substream->ops->prepare(dma->substream);
+			dma->ops->setup_prd(cs5535au, dma->saved_prd);
+		}
+	}
+
+	/* we depend on ac97 to perform the codec power up */
+	snd_ac97_resume(cs5535au->ac97);
+	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
+
+	return 0;
+}
+
+SIMPLE_DEV_PM_OPS(snd_cs5535audio_pm, snd_cs5535audio_suspend, snd_cs5535audio_resume);