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);
101