1 /*
2  * Power management for audio on multifunction CS5535 companion device
3  * Copyright (C) Jaya Kumar
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
18  *
19  */
20 
21 #include <linux/init.h>
22 #include <linux/pci.h>
23 #include <linux/delay.h>
24 #include <sound/core.h>
25 #include <sound/control.h>
26 #include <sound/initval.h>
27 #include <sound/asoundef.h>
28 #include <sound/pcm.h>
29 #include <sound/ac97_codec.h>
30 #include "cs5535audio.h"
31 
32 static void snd_cs5535audio_stop_hardware(struct cs5535audio *cs5535au)
33 {
34 	/*
35 	we depend on snd_ac97_suspend to tell the
36 	AC97 codec to shutdown. the amd spec suggests
37 	that the LNK_SHUTDOWN be done at the same time
38 	that the codec power-down is issued. instead,
39 	we do it just after rather than at the same
40 	time. excluding codec specific build_ops->suspend
41 	ac97 powerdown hits:
42 	0x8000 EAPD
43 	0x4000 Headphone amplifier
44 	0x0300 ADC & DAC
45 	0x0400 Analog Mixer powerdown (Vref on)
46 	I am not sure if this is the best that we can do.
47 	The remainder to be investigated are:
48 	- analog mixer (vref off) 0x0800
49 	- AC-link powerdown 0x1000
50 	- codec internal clock 0x2000
51 	*/
52 
53 	/* set LNK_SHUTDOWN to shutdown AC link */
54 	cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_SHUTDOWN);
55 
56 }
57 
58 static int __maybe_unused snd_cs5535audio_suspend(struct device *dev)
59 {
60 	struct snd_card *card = dev_get_drvdata(dev);
61 	struct cs5535audio *cs5535au = card->private_data;
62 	int i;
63 
64 	snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
65 	snd_pcm_suspend_all(cs5535au->pcm);
66 	snd_ac97_suspend(cs5535au->ac97);
67 	for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) {
68 		struct cs5535audio_dma *dma = &cs5535au->dmas[i];
69 		if (dma && dma->substream)
70 			dma->saved_prd = dma->ops->read_prd(cs5535au);
71 	}
72 	/* save important regs, then disable aclink in hw */
73 	snd_cs5535audio_stop_hardware(cs5535au);
74 	return 0;
75 }
76 
77 static int __maybe_unused snd_cs5535audio_resume(struct device *dev)
78 {
79 	struct snd_card *card = dev_get_drvdata(dev);
80 	struct cs5535audio *cs5535au = card->private_data;
81 	u32 tmp;
82 	int timeout;
83 	int i;
84 
85 	/* set LNK_WRM_RST to reset AC link */
86 	cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_WRM_RST);
87 
88 	timeout = 50;
89 	do {
90 		tmp = cs_readl(cs5535au, ACC_CODEC_STATUS);
91 		if (tmp & PRM_RDY_STS)
92 			break;
93 		udelay(1);
94 	} while (--timeout);
95 
96 	if (!timeout)
97 		dev_err(cs5535au->card->dev, "Failure getting AC Link ready\n");
98 
99 	/* set up rate regs, dma. actual initiation is done in trig */
100 	for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) {
101 		struct cs5535audio_dma *dma = &cs5535au->dmas[i];
102 		if (dma && dma->substream) {
103 			dma->substream->ops->prepare(dma->substream);
104 			dma->ops->setup_prd(cs5535au, dma->saved_prd);
105 		}
106 	}
107 
108 	/* we depend on ac97 to perform the codec power up */
109 	snd_ac97_resume(cs5535au->ac97);
110 	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
111 
112 	return 0;
113 }
114 
115 SIMPLE_DEV_PM_OPS(snd_cs5535audio_pm, snd_cs5535audio_suspend, snd_cs5535audio_resume);
116