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 
18 static 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 
44 static 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 
62 static 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 
100 SIMPLE_DEV_PM_OPS(snd_cs5535audio_pm, snd_cs5535audio_suspend, snd_cs5535audio_resume);
101