omap-hdmi.c

Go to the documentation of this file.

/*
 * omap-hdmi.c
 *
 * OMAP ALSA SoC DAI driver for HDMI audio on OMAP4 processors.
 * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com/
 * Authors: Jorge Candelaria <[email protected]>
 *          Ricardo Neri <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <sound/asound.h>
#include <sound/asoundef.h>
#include <video/omapdss.h>

#include "omap-pcm.h"
#include "omap-hdmi.h"

#define DRV_NAME "omap-hdmi-audio-dai"

struct hdmi_priv {
    struct omap_pcm_dma_data dma_params;
    struct omap_dss_audio dss_audio;
    struct snd_aes_iec958 iec;
    struct snd_cea_861_aud_if cea;
    struct omap_dss_device *dssdev;
};

static int omap_hdmi_dai_startup(struct snd_pcm_substream *substream,
                  struct snd_soc_dai *dai)
{
    struct hdmi_priv *priv = snd_soc_dai_get_drvdata(dai);
    int err;
    /*
     * Make sure that the period bytes are multiple of the DMA packet size.
     * Largest packet size we use is 32 32-bit words = 128 bytes
     */
    err = snd_pcm_hw_constraint_step(substream->runtime, 0,
                 SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
    if (err < 0) {
        dev_err(dai->dev, "could not apply constraint\n");
        return err;
    }

    if (!priv->dssdev->driver->audio_supported(priv->dssdev)) {
        dev_err(dai->dev, "audio not supported\n");
        return -ENODEV;
    }

    snd_soc_dai_set_dma_data(dai, substream, &priv->dma_params);

    return 0;
}

static int omap_hdmi_dai_prepare(struct snd_pcm_substream *substream,
                struct snd_soc_dai *dai)
{
    struct hdmi_priv *priv = snd_soc_dai_get_drvdata(dai);

    return priv->dssdev->driver->audio_enable(priv->dssdev);
}

static int omap_hdmi_dai_hw_params(struct snd_pcm_substream *substream,
                    struct snd_pcm_hw_params *params,
                    struct snd_soc_dai *dai)
{
    struct hdmi_priv *priv = snd_soc_dai_get_drvdata(dai);
    struct snd_aes_iec958 *iec = &priv->iec;
    struct snd_cea_861_aud_if *cea = &priv->cea;
    struct omap_pcm_dma_data *dma_data;
    int err = 0;

    dma_data = snd_soc_dai_get_dma_data(dai, substream);

    switch (params_format(params)) {
    case SNDRV_PCM_FORMAT_S16_LE:
        dma_data->packet_size = 16;
        break;
    case SNDRV_PCM_FORMAT_S24_LE:
        dma_data->packet_size = 32;
        break;
    default:
        dev_err(dai->dev, "format not supported!\n");
        return -EINVAL;
    }

    dma_data->data_type = 32;

    /*
     * fill the IEC-60958 channel status word
     */

    /* specify IEC-60958-3 (commercial use) */
    iec->status[0] &= ~IEC958_AES0_PROFESSIONAL;

    /* specify that the audio is LPCM*/
    iec->status[0] &= ~IEC958_AES0_NONAUDIO;

    iec->status[0] |= IEC958_AES0_CON_NOT_COPYRIGHT;

    iec->status[0] |= IEC958_AES0_CON_EMPHASIS_NONE;

    iec->status[0] |= IEC958_AES1_PRO_MODE_NOTID;

    iec->status[1] = IEC958_AES1_CON_GENERAL;

    iec->status[2] |= IEC958_AES2_CON_SOURCE_UNSPEC;

    iec->status[2] |= IEC958_AES2_CON_CHANNEL_UNSPEC;

    switch (params_rate(params)) {
    case 32000:
        iec->status[3] |= IEC958_AES3_CON_FS_32000;
        break;
    case 44100:
        iec->status[3] |= IEC958_AES3_CON_FS_44100;
        break;
    case 48000:
        iec->status[3] |= IEC958_AES3_CON_FS_48000;
        break;
    case 88200:
        iec->status[3] |= IEC958_AES3_CON_FS_88200;
        break;
    case 96000:
        iec->status[3] |= IEC958_AES3_CON_FS_96000;
        break;
    case 176400:
        iec->status[3] |= IEC958_AES3_CON_FS_176400;
        break;
    case 192000:
        iec->status[3] |= IEC958_AES3_CON_FS_192000;
        break;
    default:
        dev_err(dai->dev, "rate not supported!\n");
        return -EINVAL;
    }

    /* specify the clock accuracy */
    iec->status[3] |= IEC958_AES3_CON_CLOCK_1000PPM;

    /*
     * specify the word length. The same word length value can mean
     * two different lengths. Hence, we need to specify the maximum
     * word length as well.
     */
    switch (params_format(params)) {
    case SNDRV_PCM_FORMAT_S16_LE:
        iec->status[4] |= IEC958_AES4_CON_WORDLEN_20_16;
        iec->status[4] &= ~IEC958_AES4_CON_MAX_WORDLEN_24;
        break;
    case SNDRV_PCM_FORMAT_S24_LE:
        iec->status[4] |= IEC958_AES4_CON_WORDLEN_24_20;
        iec->status[4] |= IEC958_AES4_CON_MAX_WORDLEN_24;
        break;
    default:
        dev_err(dai->dev, "format not supported!\n");
        return -EINVAL;
    }

    /*
     * Fill the CEA-861 audio infoframe (see spec for details)
     */

    cea->db1_ct_cc = (params_channels(params) - 1)
        & CEA861_AUDIO_INFOFRAME_DB1CC;
    cea->db1_ct_cc |= CEA861_AUDIO_INFOFRAME_DB1CT_FROM_STREAM;

    cea->db2_sf_ss = CEA861_AUDIO_INFOFRAME_DB2SF_FROM_STREAM;
    cea->db2_sf_ss |= CEA861_AUDIO_INFOFRAME_DB2SS_FROM_STREAM;

    cea->db3 = 0; /* not used, all zeros */

    /*
     * The OMAP HDMI IP requires to use the 8-channel channel code when
     * transmitting more than two channels.
     */
    if (params_channels(params) == 2)
        cea->db4_ca = 0x0;
    else
        cea->db4_ca = 0x13;

    cea->db5_dminh_lsv = CEA861_AUDIO_INFOFRAME_DB5_DM_INH_PROHIBITED;
    /* the expression is trivial but makes clear what we are doing */
    cea->db5_dminh_lsv |= (0 & CEA861_AUDIO_INFOFRAME_DB5_LSV);

    priv->dss_audio.iec = iec;
    priv->dss_audio.cea = cea;

    err = priv->dssdev->driver->audio_config(priv->dssdev,
                         &priv->dss_audio);

    return err;
}

static int omap_hdmi_dai_trigger(struct snd_pcm_substream *substream, int cmd,
                struct snd_soc_dai *dai)
{
    struct hdmi_priv *priv = snd_soc_dai_get_drvdata(dai);
    int err = 0;

    switch (cmd) {
    case SNDRV_PCM_TRIGGER_START:
    case SNDRV_PCM_TRIGGER_RESUME:
    case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
        err = priv->dssdev->driver->audio_start(priv->dssdev);
        break;
    case SNDRV_PCM_TRIGGER_STOP:
    case SNDRV_PCM_TRIGGER_SUSPEND:
    case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
        priv->dssdev->driver->audio_stop(priv->dssdev);
        break;
    default:
        err = -EINVAL;
    }
    return err;
}

static void omap_hdmi_dai_shutdown(struct snd_pcm_substream *substream,
                struct snd_soc_dai *dai)
{
    struct hdmi_priv *priv = snd_soc_dai_get_drvdata(dai);

    priv->dssdev->driver->audio_disable(priv->dssdev);
}

static const struct snd_soc_dai_ops omap_hdmi_dai_ops = {
    .startup    = omap_hdmi_dai_startup,
    .hw_params  = omap_hdmi_dai_hw_params,
    .prepare    = omap_hdmi_dai_prepare,
    .trigger    = omap_hdmi_dai_trigger,
    .shutdown   = omap_hdmi_dai_shutdown,
};

static struct snd_soc_dai_driver omap_hdmi_dai = {
    .playback = {
        .channels_min = 2,
        .channels_max = 8,
        .rates = OMAP_HDMI_RATES,
        .formats = OMAP_HDMI_FORMATS,
    },
    .ops = &omap_hdmi_dai_ops,
};

static __devinit int omap_hdmi_probe(struct platform_device *pdev)
{
    int ret;
    struct resource *hdmi_rsrc;
    struct hdmi_priv *hdmi_data;
    bool hdmi_dev_found = false;

    hdmi_data = devm_kzalloc(&pdev->dev, sizeof(*hdmi_data), GFP_KERNEL);
    if (hdmi_data == NULL) {
        dev_err(&pdev->dev, "Cannot allocate memory for HDMI data\n");
        return -ENOMEM;
    }

    hdmi_rsrc = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!hdmi_rsrc) {
        dev_err(&pdev->dev, "Cannot obtain IORESOURCE_MEM HDMI\n");
        return -ENODEV;
    }

    hdmi_data->dma_params.port_addr =  hdmi_rsrc->start
        + OMAP_HDMI_AUDIO_DMA_PORT;

    hdmi_rsrc = platform_get_resource(pdev, IORESOURCE_DMA, 0);
    if (!hdmi_rsrc) {
        dev_err(&pdev->dev, "Cannot obtain IORESOURCE_DMA HDMI\n");
        return -ENODEV;
    }

    hdmi_data->dma_params.dma_req =  hdmi_rsrc->start;
    hdmi_data->dma_params.name = "HDMI playback";

    /*
     * TODO: We assume that there is only one DSS HDMI device. Future
     * OMAP implementations may support more than one HDMI devices and
     * we should provided separate audio support for all of them.
     */
    /* Find an HDMI device. */
    for_each_dss_dev(hdmi_data->dssdev) {
        omap_dss_get_device(hdmi_data->dssdev);

        if (!hdmi_data->dssdev->driver) {
            omap_dss_put_device(hdmi_data->dssdev);
            continue;
        }

        if (hdmi_data->dssdev->type == OMAP_DISPLAY_TYPE_HDMI) {
            hdmi_dev_found = true;
            break;
        }
    }

    if (!hdmi_dev_found) {
        dev_err(&pdev->dev, "no driver for HDMI display found\n");
        return -ENODEV;
    }

    dev_set_drvdata(&pdev->dev, hdmi_data);
    ret = snd_soc_register_dai(&pdev->dev, &omap_hdmi_dai);

    return ret;
}

static int __devexit omap_hdmi_remove(struct platform_device *pdev)
{
    struct hdmi_priv *hdmi_data = dev_get_drvdata(&pdev->dev);

    snd_soc_unregister_dai(&pdev->dev);

    if (hdmi_data == NULL) {
        dev_err(&pdev->dev, "cannot obtain HDMi data\n");
        return -ENODEV;
    }

    omap_dss_put_device(hdmi_data->dssdev);
    return 0;
}

static struct platform_driver hdmi_dai_driver = {
    .driver = {
        .name = DRV_NAME,
        .owner = THIS_MODULE,
    },
    .probe = omap_hdmi_probe,
    .remove = __devexit_p(omap_hdmi_remove),
};

module_platform_driver(hdmi_dai_driver);

MODULE_AUTHOR("Jorge Candelaria <[email protected]>");
MODULE_AUTHOR("Ricardo Neri <[email protected]>");
MODULE_DESCRIPTION("OMAP HDMI SoC Interface");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);