LXR linux/sound/pci/cs5535audio/cs5535audio

   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