cs5535audio_pm.c

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/*
 * Power management for audio on multifunction CS5535 companion device
 * Copyright (C) Jaya Kumar
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/init.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <sound/core.h>
#include <sound/control.h>
#include <sound/initval.h>
#include <sound/asoundef.h>
#include <sound/pcm.h>
#include <sound/ac97_codec.h>
#include "cs5535audio.h"

static void snd_cs5535audio_stop_hardware(struct cs5535audio *cs5535au)
{
    /* 
    we depend on snd_ac97_suspend to tell the
    AC97 codec to shutdown. the amd spec suggests
    that the LNK_SHUTDOWN be done at the same time
    that the codec power-down is issued. instead,
    we do it just after rather than at the same 
    time. excluding codec specific build_ops->suspend
    ac97 powerdown hits:
    0x8000 EAPD 
    0x4000 Headphone amplifier 
    0x0300 ADC & DAC 
    0x0400 Analog Mixer powerdown (Vref on) 
    I am not sure if this is the best that we can do.
    The remainder to be investigated are:
    - analog mixer (vref off) 0x0800
    - AC-link powerdown 0x1000
    - codec internal clock 0x2000
    */

    /* set LNK_SHUTDOWN to shutdown AC link */
    cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_SHUTDOWN);

}

static int snd_cs5535audio_suspend(struct device *dev)
{
    struct pci_dev *pci = to_pci_dev(dev);
    struct snd_card *card = dev_get_drvdata(dev);
    struct cs5535audio *cs5535au = card->private_data;
    int i;

    snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
    snd_pcm_suspend_all(cs5535au->pcm);
    snd_ac97_suspend(cs5535au->ac97);
    for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) {
        struct cs5535audio_dma *dma = &cs5535au->dmas[i];
        if (dma && dma->substream)
            dma->saved_prd = dma->ops->read_prd(cs5535au);
    }
    /* save important regs, then disable aclink in hw */
    snd_cs5535audio_stop_hardware(cs5535au);

    if (pci_save_state(pci)) {
        printk(KERN_ERR "cs5535audio: pci_save_state failed!\n");
        return -EIO;
    }
    pci_disable_device(pci);
    pci_set_power_state(pci, PCI_D3hot);
    return 0;
}

static int snd_cs5535audio_resume(struct device *dev)
{
    struct pci_dev *pci = to_pci_dev(dev);
    struct snd_card *card = dev_get_drvdata(dev);
    struct cs5535audio *cs5535au = card->private_data;
    u32 tmp;
    int timeout;
    int i;

    pci_set_power_state(pci, PCI_D0);
    pci_restore_state(pci);
    if (pci_enable_device(pci) < 0) {
        printk(KERN_ERR "cs5535audio: pci_enable_device failed, "
               "disabling device\n");
        snd_card_disconnect(card);
        return -EIO;
    }
    pci_set_master(pci);

    /* set LNK_WRM_RST to reset AC link */
    cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_WRM_RST);

    timeout = 50;
    do {
        tmp = cs_readl(cs5535au, ACC_CODEC_STATUS);
        if (tmp & PRM_RDY_STS)
            break;
        udelay(1);
    } while (--timeout);

    if (!timeout)
        snd_printk(KERN_ERR "Failure getting AC Link ready\n");

    /* set up rate regs, dma. actual initiation is done in trig */
    for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) {
        struct cs5535audio_dma *dma = &cs5535au->dmas[i];
        if (dma && dma->substream) {
            dma->substream->ops->prepare(dma->substream);
            dma->ops->setup_prd(cs5535au, dma->saved_prd);
        }
    }

    /* we depend on ac97 to perform the codec power up */
    snd_ac97_resume(cs5535au->ac97);
    snd_power_change_state(card, SNDRV_CTL_POWER_D0);

    return 0;
}

SIMPLE_DEV_PM_OPS(snd_cs5535audio_pm, snd_cs5535audio_suspend, snd_cs5535audio_resume);