cx18-alsa-main.c

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/*
 *  ALSA interface to cx18 PCM capture streams
 *
 *  Copyright (C) 2009  Andy Walls <[email protected]>
 *  Copyright (C) 2009  Devin Heitmueller <[email protected]>
 *
 *  Portions of this work were sponsored by ONELAN Limited.
 *
 *  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/slab.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/spinlock.h>

#include <media/v4l2-device.h>

#include <sound/core.h>
#include <sound/initval.h>

#include "cx18-driver.h"
#include "cx18-version.h"
#include "cx18-alsa.h"
#include "cx18-alsa-mixer.h"
#include "cx18-alsa-pcm.h"

int cx18_alsa_debug;

#define CX18_DEBUG_ALSA_INFO(fmt, arg...) \
    do { \
        if (cx18_alsa_debug & 2) \
            printk(KERN_INFO "%s: " fmt, "cx18-alsa", ## arg); \
    } while (0);

module_param_named(debug, cx18_alsa_debug, int, 0644);
MODULE_PARM_DESC(debug,
         "Debug level (bitmask). Default: 0\n"
         "\t\t\t  1/0x0001: warning\n"
         "\t\t\t  2/0x0002: info\n");

MODULE_AUTHOR("Andy Walls");
MODULE_DESCRIPTION("CX23418 ALSA Interface");
MODULE_SUPPORTED_DEVICE("CX23418 MPEG2 encoder");
MODULE_LICENSE("GPL");

MODULE_VERSION(CX18_VERSION);

static inline
struct snd_cx18_card *to_snd_cx18_card(struct v4l2_device *v4l2_dev)
{
    return to_cx18(v4l2_dev)->alsa;
}

static inline
struct snd_cx18_card *p_to_snd_cx18_card(struct v4l2_device **v4l2_dev)
{
    return container_of(v4l2_dev, struct snd_cx18_card, v4l2_dev);
}

static void snd_cx18_card_free(struct snd_cx18_card *cxsc)
{
    if (cxsc == NULL)
        return;

    if (cxsc->v4l2_dev != NULL)
        to_cx18(cxsc->v4l2_dev)->alsa = NULL;

    /* FIXME - take any other stopping actions needed */

    kfree(cxsc);
}

static void snd_cx18_card_private_free(struct snd_card *sc)
{
    if (sc == NULL)
        return;
    snd_cx18_card_free(sc->private_data);
    sc->private_data = NULL;
    sc->private_free = NULL;
}

static int snd_cx18_card_create(struct v4l2_device *v4l2_dev,
                       struct snd_card *sc,
                       struct snd_cx18_card **cxsc)
{
    *cxsc = kzalloc(sizeof(struct snd_cx18_card), GFP_KERNEL);
    if (*cxsc == NULL)
        return -ENOMEM;

    (*cxsc)->v4l2_dev = v4l2_dev;
    (*cxsc)->sc = sc;

    sc->private_data = *cxsc;
    sc->private_free = snd_cx18_card_private_free;

    return 0;
}

static int snd_cx18_card_set_names(struct snd_cx18_card *cxsc)
{
    struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
    struct snd_card *sc = cxsc->sc;

    /* sc->driver is used by alsa-lib's configurator: simple, unique */
    strlcpy(sc->driver, "CX23418", sizeof(sc->driver));

    /* sc->shortname is a symlink in /proc/asound: CX18-M -> cardN */
    snprintf(sc->shortname,  sizeof(sc->shortname), "CX18-%d",
         cx->instance);

    /* sc->longname is read from /proc/asound/cards */
    snprintf(sc->longname, sizeof(sc->longname),
         "CX23418 #%d %s TV/FM Radio/Line-In Capture",
         cx->instance, cx->card_name);

    return 0;
}

static int snd_cx18_init(struct v4l2_device *v4l2_dev)
{
    struct cx18 *cx = to_cx18(v4l2_dev);
    struct snd_card *sc = NULL;
    struct snd_cx18_card *cxsc;
    int ret;

    /* Numbrs steps from "Writing an ALSA Driver" by Takashi Iwai */

    /* (1) Check and increment the device index */
    /* This is a no-op for us.  We'll use the cx->instance */

    /* (2) Create a card instance */
    ret = snd_card_create(SNDRV_DEFAULT_IDX1, /* use first available id */
                  SNDRV_DEFAULT_STR1, /* xid from end of shortname*/
                  THIS_MODULE, 0, &sc);
    if (ret) {
        CX18_ALSA_ERR("%s: snd_card_create() failed with err %d\n",
                  __func__, ret);
        goto err_exit;
    }

    /* (3) Create a main component */
    ret = snd_cx18_card_create(v4l2_dev, sc, &cxsc);
    if (ret) {
        CX18_ALSA_ERR("%s: snd_cx18_card_create() failed with err %d\n",
                  __func__, ret);
        goto err_exit_free;
    }

    /* (4) Set the driver ID and name strings */
    snd_cx18_card_set_names(cxsc);


    ret = snd_cx18_pcm_create(cxsc);
    if (ret) {
        CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
                  __func__, ret);
        goto err_exit_free;
    }
    /* FIXME - proc files */

    /* (7) Set the driver data and return 0 */
    /* We do this out of normal order for PCI drivers to avoid races */
    cx->alsa = cxsc;

    /* (6) Register the card instance */
    ret = snd_card_register(sc);
    if (ret) {
        cx->alsa = NULL;
        CX18_ALSA_ERR("%s: snd_card_register() failed with err %d\n",
                  __func__, ret);
        goto err_exit_free;
    }

    return 0;

err_exit_free:
    if (sc != NULL)
        snd_card_free(sc);
    kfree(cxsc);
err_exit:
    return ret;
}

int cx18_alsa_load(struct cx18 *cx)
{
    struct v4l2_device *v4l2_dev = &cx->v4l2_dev;
    struct cx18_stream *s;

    if (v4l2_dev == NULL) {
        printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
               __func__);
        return 0;
    }

    cx = to_cx18(v4l2_dev);
    if (cx == NULL) {
        printk(KERN_ERR "cx18-alsa cx is NULL\n");
        return 0;
    }

    s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
    if (s->video_dev == NULL) {
        CX18_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - "
                     "skipping\n", __func__);
        return 0;
    }

    if (cx->alsa != NULL) {
        CX18_ALSA_ERR("%s: struct snd_cx18_card * already exists\n",
                  __func__);
        return 0;
    }

    if (snd_cx18_init(v4l2_dev)) {
        CX18_ALSA_ERR("%s: failed to create struct snd_cx18_card\n",
                  __func__);
    } else {
        CX18_DEBUG_ALSA_INFO("%s: created cx18 ALSA interface instance "
                     "\n", __func__);
    }
    return 0;
}

static int __init cx18_alsa_init(void)
{
    printk(KERN_INFO "cx18-alsa: module loading...\n");
    cx18_ext_init = &cx18_alsa_load;
    return 0;
}

static void __exit snd_cx18_exit(struct snd_cx18_card *cxsc)
{
    struct cx18 *cx = to_cx18(cxsc->v4l2_dev);

    /* FIXME - pointer checks & shutdown cxsc */

    snd_card_free(cxsc->sc);
    cx->alsa = NULL;
}

static int __exit cx18_alsa_exit_callback(struct device *dev, void *data)
{
    struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
    struct snd_cx18_card *cxsc;

    if (v4l2_dev == NULL) {
        printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
               __func__);
        return 0;
    }

    cxsc = to_snd_cx18_card(v4l2_dev);
    if (cxsc == NULL) {
        CX18_ALSA_WARN("%s: struct snd_cx18_card * is NULL\n",
                   __func__);
        return 0;
    }

    snd_cx18_exit(cxsc);
    return 0;
}

static void __exit cx18_alsa_exit(void)
{
    struct device_driver *drv;
    int ret;

    printk(KERN_INFO "cx18-alsa: module unloading...\n");

    drv = driver_find("cx18", &pci_bus_type);
    ret = driver_for_each_device(drv, NULL, NULL, cx18_alsa_exit_callback);
    (void)ret;  /* suppress compiler warning */

    cx18_ext_init = NULL;
    printk(KERN_INFO "cx18-alsa: module unload complete\n");
}

module_init(cx18_alsa_init);
module_exit(cx18_alsa_exit);