cs5535audio_pm.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Power management for audio on multifunction CS5535 companion device
  4 * Copyright (C) Jaya Kumar
  5 */
  6
  7#include <linux/init.h>
  8#include <linux/pci.h>
  9#include <linux/delay.h>
 10#include <sound/core.h>
 11#include <sound/control.h>
 12#include <sound/initval.h>
 13#include <sound/asoundef.h>
 14#include <sound/pcm.h>
 15#include <sound/ac97_codec.h>
 16#include "cs5535audio.h"
 17
 18static void snd_cs5535audio_stop_hardware(struct cs5535audio *cs5535au)
 19{
 20	/* 
 21	we depend on snd_ac97_suspend to tell the
 22	AC97 codec to shutdown. the amd spec suggests
 23	that the LNK_SHUTDOWN be done at the same time
 24	that the codec power-down is issued. instead,
 25	we do it just after rather than at the same 
 26	time. excluding codec specific build_ops->suspend
 27	ac97 powerdown hits:
 28	0x8000 EAPD 
 29	0x4000 Headphone amplifier 
 30	0x0300 ADC & DAC 
 31	0x0400 Analog Mixer powerdown (Vref on) 
 32	I am not sure if this is the best that we can do.
 33	The remainder to be investigated are:
 34	- analog mixer (vref off) 0x0800
 35	- AC-link powerdown 0x1000
 36	- codec internal clock 0x2000
 37	*/
 38
 39	/* set LNK_SHUTDOWN to shutdown AC link */
 40	cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_SHUTDOWN);
 41
 42}
 43
 44static int __maybe_unused snd_cs5535audio_suspend(struct device *dev)
 45{
 46	struct snd_card *card = dev_get_drvdata(dev);
 47	struct cs5535audio *cs5535au = card->private_data;
 48	int i;
 49
 50	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
 51	snd_ac97_suspend(cs5535au->ac97);
 52	for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) {
 53		struct cs5535audio_dma *dma = &cs5535au->dmas[i];
 54		if (dma && dma->substream)
 55			dma->saved_prd = dma->ops->read_prd(cs5535au);
 56	}
 57	/* save important regs, then disable aclink in hw */
 58	snd_cs5535audio_stop_hardware(cs5535au);
 59	return 0;
 60}
 61
 62static int __maybe_unused snd_cs5535audio_resume(struct device *dev)
 63{
 64	struct snd_card *card = dev_get_drvdata(dev);
 65	struct cs5535audio *cs5535au = card->private_data;
 66	u32 tmp;
 67	int timeout;
 68	int i;
 69
 70	/* set LNK_WRM_RST to reset AC link */
 71	cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_WRM_RST);
 72
 73	timeout = 50;
 74	do {
 75		tmp = cs_readl(cs5535au, ACC_CODEC_STATUS);
 76		if (tmp & PRM_RDY_STS)
 77			break;
 78		udelay(1);
 79	} while (--timeout);
 80
 81	if (!timeout)
 82		dev_err(cs5535au->card->dev, "Failure getting AC Link ready\n");
 83
 84	/* set up rate regs, dma. actual initiation is done in trig */
 85	for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) {
 86		struct cs5535audio_dma *dma = &cs5535au->dmas[i];
 87		if (dma && dma->substream) {
 88			dma->substream->ops->prepare(dma->substream);
 89			dma->ops->setup_prd(cs5535au, dma->saved_prd);
 90		}
 91	}
 92
 93	/* we depend on ac97 to perform the codec power up */
 94	snd_ac97_resume(cs5535au->ac97);
 95	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
 96
 97	return 0;
 98}
 99
100SIMPLE_DEV_PM_OPS(snd_cs5535audio_pm, snd_cs5535audio_suspend, snd_cs5535audio_resume);