hdmi_panel.c

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/*
 * hdmi_panel.c
 *
 * HDMI library support functions for TI OMAP4 processors.
 *
 * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com/
 * Authors: Mythri P k <[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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <video/omapdss.h>
#include <linux/slab.h>

#include "dss.h"

static struct {
    /* This protects the panel ops, mainly when accessing the HDMI IP. */
    struct mutex lock;
#if defined(CONFIG_OMAP4_DSS_HDMI_AUDIO)
    /* This protects the audio ops, specifically. */
    spinlock_t audio_lock;
#endif
} hdmi;


static int hdmi_panel_probe(struct omap_dss_device *dssdev)
{
    /* Initialize default timings to VGA in DVI mode */
    const struct omap_video_timings default_timings = {
        .x_res      = 640,
        .y_res      = 480,
        .pixel_clock    = 25175,
        .hsw        = 96,
        .hfp        = 16,
        .hbp        = 48,
        .vsw        = 2,
        .vfp        = 11,
        .vbp        = 31,

        .vsync_level    = OMAPDSS_SIG_ACTIVE_LOW,
        .hsync_level    = OMAPDSS_SIG_ACTIVE_LOW,

        .interlace  = false,
    };

    DSSDBG("ENTER hdmi_panel_probe\n");

    dssdev->panel.timings = default_timings;

    DSSDBG("hdmi_panel_probe x_res= %d y_res = %d\n",
        dssdev->panel.timings.x_res,
        dssdev->panel.timings.y_res);

    omapdss_hdmi_display_set_timing(dssdev, &dssdev->panel.timings);

    return 0;
}

static void hdmi_panel_remove(struct omap_dss_device *dssdev)
{

}

#if defined(CONFIG_OMAP4_DSS_HDMI_AUDIO)
static int hdmi_panel_audio_enable(struct omap_dss_device *dssdev)
{
    unsigned long flags;
    int r;

    mutex_lock(&hdmi.lock);
    spin_lock_irqsave(&hdmi.audio_lock, flags);

    /* enable audio only if the display is active and supports audio */
    if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE ||
        !hdmi_mode_has_audio()) {
        DSSERR("audio not supported or display is off\n");
        r = -EPERM;
        goto err;
    }

    r = hdmi_audio_enable();

    if (!r)
        dssdev->audio_state = OMAP_DSS_AUDIO_ENABLED;

err:
    spin_unlock_irqrestore(&hdmi.audio_lock, flags);
    mutex_unlock(&hdmi.lock);
    return r;
}

static void hdmi_panel_audio_disable(struct omap_dss_device *dssdev)
{
    unsigned long flags;

    spin_lock_irqsave(&hdmi.audio_lock, flags);

    hdmi_audio_disable();

    dssdev->audio_state = OMAP_DSS_AUDIO_DISABLED;

    spin_unlock_irqrestore(&hdmi.audio_lock, flags);
}

static int hdmi_panel_audio_start(struct omap_dss_device *dssdev)
{
    unsigned long flags;
    int r;

    spin_lock_irqsave(&hdmi.audio_lock, flags);
    /*
     * No need to check the panel state. It was checked when trasitioning
     * to AUDIO_ENABLED.
     */
    if (dssdev->audio_state != OMAP_DSS_AUDIO_ENABLED) {
        DSSERR("audio start from invalid state\n");
        r = -EPERM;
        goto err;
    }

    r = hdmi_audio_start();

    if (!r)
        dssdev->audio_state = OMAP_DSS_AUDIO_PLAYING;

err:
    spin_unlock_irqrestore(&hdmi.audio_lock, flags);
    return r;
}

static void hdmi_panel_audio_stop(struct omap_dss_device *dssdev)
{
    unsigned long flags;

    spin_lock_irqsave(&hdmi.audio_lock, flags);

    hdmi_audio_stop();
    dssdev->audio_state = OMAP_DSS_AUDIO_ENABLED;

    spin_unlock_irqrestore(&hdmi.audio_lock, flags);
}

static bool hdmi_panel_audio_supported(struct omap_dss_device *dssdev)
{
    bool r = false;

    mutex_lock(&hdmi.lock);

    if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE)
        goto err;

    if (!hdmi_mode_has_audio())
        goto err;

    r = true;
err:
    mutex_unlock(&hdmi.lock);
    return r;
}

static int hdmi_panel_audio_config(struct omap_dss_device *dssdev,
        struct omap_dss_audio *audio)
{
    unsigned long flags;
    int r;

    mutex_lock(&hdmi.lock);
    spin_lock_irqsave(&hdmi.audio_lock, flags);

    /* config audio only if the display is active and supports audio */
    if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE ||
        !hdmi_mode_has_audio()) {
        DSSERR("audio not supported or display is off\n");
        r = -EPERM;
        goto err;
    }

    r = hdmi_audio_config(audio);

    if (!r)
        dssdev->audio_state = OMAP_DSS_AUDIO_CONFIGURED;

err:
    spin_unlock_irqrestore(&hdmi.audio_lock, flags);
    mutex_unlock(&hdmi.lock);
    return r;
}

#else
static int hdmi_panel_audio_enable(struct omap_dss_device *dssdev)
{
    return -EPERM;
}

static void hdmi_panel_audio_disable(struct omap_dss_device *dssdev)
{
}

static int hdmi_panel_audio_start(struct omap_dss_device *dssdev)
{
    return -EPERM;
}

static void hdmi_panel_audio_stop(struct omap_dss_device *dssdev)
{
}

static bool hdmi_panel_audio_supported(struct omap_dss_device *dssdev)
{
    return false;
}

static int hdmi_panel_audio_config(struct omap_dss_device *dssdev,
        struct omap_dss_audio *audio)
{
    return -EPERM;
}
#endif

static int hdmi_panel_enable(struct omap_dss_device *dssdev)
{
    int r = 0;
    DSSDBG("ENTER hdmi_panel_enable\n");

    mutex_lock(&hdmi.lock);

    if (dssdev->state != OMAP_DSS_DISPLAY_DISABLED) {
        r = -EINVAL;
        goto err;
    }

    omapdss_hdmi_display_set_timing(dssdev, &dssdev->panel.timings);

    r = omapdss_hdmi_display_enable(dssdev);
    if (r) {
        DSSERR("failed to power on\n");
        goto err;
    }

    dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;

err:
    mutex_unlock(&hdmi.lock);

    return r;
}

static void hdmi_panel_disable(struct omap_dss_device *dssdev)
{
    mutex_lock(&hdmi.lock);

    if (dssdev->state == OMAP_DSS_DISPLAY_ACTIVE) {
        /*
         * TODO: notify audio users that the display was disabled. For
         * now, disable audio locally to not break our audio state
         * machine.
         */
        hdmi_panel_audio_disable(dssdev);
        omapdss_hdmi_display_disable(dssdev);
    }

    dssdev->state = OMAP_DSS_DISPLAY_DISABLED;

    mutex_unlock(&hdmi.lock);
}

static int hdmi_panel_suspend(struct omap_dss_device *dssdev)
{
    int r = 0;

    mutex_lock(&hdmi.lock);

    if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE) {
        r = -EINVAL;
        goto err;
    }

    /*
     * TODO: notify audio users that the display was suspended. For now,
     * disable audio locally to not break our audio state machine.
     */
    hdmi_panel_audio_disable(dssdev);

    dssdev->state = OMAP_DSS_DISPLAY_SUSPENDED;
    omapdss_hdmi_display_disable(dssdev);

err:
    mutex_unlock(&hdmi.lock);

    return r;
}

static int hdmi_panel_resume(struct omap_dss_device *dssdev)
{
    int r = 0;

    mutex_lock(&hdmi.lock);

    if (dssdev->state != OMAP_DSS_DISPLAY_SUSPENDED) {
        r = -EINVAL;
        goto err;
    }

    r = omapdss_hdmi_display_enable(dssdev);
    if (r) {
        DSSERR("failed to power on\n");
        goto err;
    }
    /* TODO: notify audio users that the panel resumed. */

    dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;

err:
    mutex_unlock(&hdmi.lock);

    return r;
}

static void hdmi_get_timings(struct omap_dss_device *dssdev,
            struct omap_video_timings *timings)
{
    mutex_lock(&hdmi.lock);

    *timings = dssdev->panel.timings;

    mutex_unlock(&hdmi.lock);
}

static void hdmi_set_timings(struct omap_dss_device *dssdev,
            struct omap_video_timings *timings)
{
    DSSDBG("hdmi_set_timings\n");

    mutex_lock(&hdmi.lock);

    /*
     * TODO: notify audio users that there was a timings change. For
     * now, disable audio locally to not break our audio state machine.
     */
    hdmi_panel_audio_disable(dssdev);

    omapdss_hdmi_display_set_timing(dssdev, timings);
    dssdev->panel.timings = *timings;

    mutex_unlock(&hdmi.lock);
}

static int hdmi_check_timings(struct omap_dss_device *dssdev,
            struct omap_video_timings *timings)
{
    int r = 0;

    DSSDBG("hdmi_check_timings\n");

    mutex_lock(&hdmi.lock);

    r = omapdss_hdmi_display_check_timing(dssdev, timings);

    mutex_unlock(&hdmi.lock);
    return r;
}

static int hdmi_read_edid(struct omap_dss_device *dssdev, u8 *buf, int len)
{
    int r;

    mutex_lock(&hdmi.lock);

    if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE) {
        r = omapdss_hdmi_display_enable(dssdev);
        if (r)
            goto err;
    }

    r = omapdss_hdmi_read_edid(buf, len);

    if (dssdev->state == OMAP_DSS_DISPLAY_DISABLED ||
            dssdev->state == OMAP_DSS_DISPLAY_SUSPENDED)
        omapdss_hdmi_display_disable(dssdev);
err:
    mutex_unlock(&hdmi.lock);

    return r;
}

static bool hdmi_detect(struct omap_dss_device *dssdev)
{
    int r;

    mutex_lock(&hdmi.lock);

    if (dssdev->state != OMAP_DSS_DISPLAY_ACTIVE) {
        r = omapdss_hdmi_display_enable(dssdev);
        if (r)
            goto err;
    }

    r = omapdss_hdmi_detect();

    if (dssdev->state == OMAP_DSS_DISPLAY_DISABLED ||
            dssdev->state == OMAP_DSS_DISPLAY_SUSPENDED)
        omapdss_hdmi_display_disable(dssdev);
err:
    mutex_unlock(&hdmi.lock);

    return r;
}

static struct omap_dss_driver hdmi_driver = {
    .probe      = hdmi_panel_probe,
    .remove     = hdmi_panel_remove,
    .enable     = hdmi_panel_enable,
    .disable    = hdmi_panel_disable,
    .suspend    = hdmi_panel_suspend,
    .resume     = hdmi_panel_resume,
    .get_timings    = hdmi_get_timings,
    .set_timings    = hdmi_set_timings,
    .check_timings  = hdmi_check_timings,
    .read_edid  = hdmi_read_edid,
    .detect     = hdmi_detect,
    .audio_enable   = hdmi_panel_audio_enable,
    .audio_disable  = hdmi_panel_audio_disable,
    .audio_start    = hdmi_panel_audio_start,
    .audio_stop = hdmi_panel_audio_stop,
    .audio_supported    = hdmi_panel_audio_supported,
    .audio_config   = hdmi_panel_audio_config,
    .driver         = {
        .name   = "hdmi_panel",
        .owner  = THIS_MODULE,
    },
};

int hdmi_panel_init(void)
{
    mutex_init(&hdmi.lock);

#if defined(CONFIG_OMAP4_DSS_HDMI_AUDIO)
    spin_lock_init(&hdmi.audio_lock);
#endif

    omap_dss_register_driver(&hdmi_driver);

    return 0;
}

void hdmi_panel_exit(void)
{
    omap_dss_unregister_driver(&hdmi_driver);

}