drivers/media/video/cx18/cx18-alsa-main.c

   1 /*
   2  *  ALSA interface to cx18 PCM capture streams
   3  *
   4  *  Copyright (C) 2009  Andy Walls <awalls@md.metrocast.net>
   5  *  Copyright (C) 2009  Devin Heitmueller <dheitmueller@kernellabs.com>
   6  *
   7  *  Portions of this work were sponsored by ONELAN Limited.
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  22  *  02111-1307  USA
  23  */
  24
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/module.h>
  28 #include <linux/kernel.h>
  29 #include <linux/device.h>
  30 #include <linux/spinlock.h>
  31
  32 #include <media/v4l2-device.h>
  33
  34 #include <sound/core.h>
  35 #include <sound/initval.h>
  36
  37 #include "cx18-driver.h"
  38 #include "cx18-version.h"
  39 #include "cx18-alsa.h"
  40 #include "cx18-alsa-mixer.h"
  41 #include "cx18-alsa-pcm.h"
  42
  43 int cx18_alsa_debug;
  44
  45 #define CX18_DEBUG_ALSA_INFO(fmt, arg...) \
  46         do { \
  47                 if (cx18_alsa_debug & 2) \
  48                         printk(KERN_INFO "%s: " fmt, "cx18-alsa", ## arg); \
  49         } while (0);
  50
  51 module_param_named(debug, cx18_alsa_debug, int, 0644);
  52 MODULE_PARM_DESC(debug,
  53                  "Debug level (bitmask). Default: 0\n"
  54                  "\t\t\t  1/0x0001: warning\n"
  55                  "\t\t\t  2/0x0002: info\n");
  56
  57 MODULE_AUTHOR("Andy Walls");
  58 MODULE_DESCRIPTION("CX23418 ALSA Interface");
  59 MODULE_SUPPORTED_DEVICE("CX23418 MPEG2 encoder");
  60 MODULE_LICENSE("GPL");
  61
  62 MODULE_VERSION(CX18_VERSION);
  63
  64 static inline
  65 struct snd_cx18_card *to_snd_cx18_card(struct v4l2_device *v4l2_dev)
  66 {
  67         return to_cx18(v4l2_dev)->alsa;
  68 }
  69
  70 static inline
  71 struct snd_cx18_card *p_to_snd_cx18_card(struct v4l2_device **v4l2_dev)
  72 {
  73         return container_of(v4l2_dev, struct snd_cx18_card, v4l2_dev);
  74 }
  75
  76 static void snd_cx18_card_free(struct snd_cx18_card *cxsc)
  77 {
  78         if (cxsc == NULL)
  79                 return;
  80
  81         if (cxsc->v4l2_dev != NULL)
  82                 to_cx18(cxsc->v4l2_dev)->alsa = NULL;
  83
  84         /* FIXME - take any other stopping actions needed */
  85
  86         kfree(cxsc);
  87 }
  88
  89 static void snd_cx18_card_private_free(struct snd_card *sc)
  90 {
  91         if (sc == NULL)
  92                 return;
  93         snd_cx18_card_free(sc->private_data);
  94         sc->private_data = NULL;
  95         sc->private_free = NULL;
  96 }
  97
  98 static int snd_cx18_card_create(struct v4l2_device *v4l2_dev,
  99                                        struct snd_card *sc,
 100                                        struct snd_cx18_card **cxsc)
 101 {
 102         *cxsc = kzalloc(sizeof(struct snd_cx18_card), GFP_KERNEL);
 103         if (*cxsc == NULL)
 104                 return -ENOMEM;
 105
 106         (*cxsc)->v4l2_dev = v4l2_dev;
 107         (*cxsc)->sc = sc;
 108
 109         sc->private_data = *cxsc;
 110         sc->private_free = snd_cx18_card_private_free;
 111
 112         return 0;
 113 }
 114
 115 static int snd_cx18_card_set_names(struct snd_cx18_card *cxsc)
 116 {
 117         struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
 118         struct snd_card *sc = cxsc->sc;
 119
 120         /* sc->driver is used by alsa-lib's configurator: simple, unique */
 121         strlcpy(sc->driver, "CX23418", sizeof(sc->driver));
 122
 123         /* sc->shortname is a symlink in /proc/asound: CX18-M -> cardN */
 124         snprintf(sc->shortname,  sizeof(sc->shortname), "CX18-%d",
 125                  cx->instance);
 126
 127         /* sc->longname is read from /proc/asound/cards */
 128         snprintf(sc->longname, sizeof(sc->longname),
 129                  "CX23418 #%d %s TV/FM Radio/Line-In Capture",
 130                  cx->instance, cx->card_name);
 131
 132         return 0;
 133 }
 134
 135 static int snd_cx18_init(struct v4l2_device *v4l2_dev)
 136 {
 137         struct cx18 *cx = to_cx18(v4l2_dev);
 138         struct snd_card *sc = NULL;
 139         struct snd_cx18_card *cxsc;
 140         int ret;
 141
 142         /* Numbrs steps from "Writing an ALSA Driver" by Takashi Iwai */
 143
 144         /* (1) Check and increment the device index */
 145         /* This is a no-op for us.  We'll use the cx->instance */
 146
 147         /* (2) Create a card instance */
 148         ret = snd_card_create(SNDRV_DEFAULT_IDX1, /* use first available id */
 149                               SNDRV_DEFAULT_STR1, /* xid from end of shortname*/
 150                               THIS_MODULE, 0, &sc);
 151         if (ret) {
 152                 CX18_ALSA_ERR("%s: snd_card_create() failed with err %d\n",
 153                               __func__, ret);
 154                 goto err_exit;
 155         }
 156
 157         /* (3) Create a main component */
 158         ret = snd_cx18_card_create(v4l2_dev, sc, &cxsc);
 159         if (ret) {
 160                 CX18_ALSA_ERR("%s: snd_cx18_card_create() failed with err %d\n",
 161                               __func__, ret);
 162                 goto err_exit_free;
 163         }
 164
 165         /* (4) Set the driver ID and name strings */
 166         snd_cx18_card_set_names(cxsc);
 167
 168
 169         ret = snd_cx18_pcm_create(cxsc);
 170         if (ret) {
 171                 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
 172                               __func__, ret);
 173                 goto err_exit_free;
 174         }
 175         /* FIXME - proc files */
 176
 177         /* (7) Set the driver data and return 0 */
 178         /* We do this out of normal order for PCI drivers to avoid races */
 179         cx->alsa = cxsc;
 180
 181         /* (6) Register the card instance */
 182         ret = snd_card_register(sc);
 183         if (ret) {
 184                 cx->alsa = NULL;
 185                 CX18_ALSA_ERR("%s: snd_card_register() failed with err %d\n",
 186                               __func__, ret);
 187                 goto err_exit_free;
 188         }
 189
 190         return 0;
 191
 192 err_exit_free:
 193         if (sc != NULL)
 194                 snd_card_free(sc);
 195         kfree(cxsc);
 196 err_exit:
 197         return ret;
 198 }
 199
 200 int cx18_alsa_load(struct cx18 *cx)
 201 {
 202         struct v4l2_device *v4l2_dev = &cx->v4l2_dev;
 203         struct cx18_stream *s;
 204
 205         if (v4l2_dev == NULL) {
 206                 printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
 207                        __func__);
 208                 return 0;
 209         }
 210
 211         cx = to_cx18(v4l2_dev);
 212         if (cx == NULL) {
 213                 printk(KERN_ERR "cx18-alsa cx is NULL\n");
 214                 return 0;
 215         }
 216
 217         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 218         if (s->video_dev == NULL) {
 219                 CX18_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - "
 220                                      "skipping\n", __func__);
 221                 return 0;
 222         }
 223
 224         if (cx->alsa != NULL) {
 225                 CX18_ALSA_ERR("%s: struct snd_cx18_card * already exists\n",
 226                               __func__);
 227                 return 0;
 228         }
 229
 230         if (snd_cx18_init(v4l2_dev)) {
 231                 CX18_ALSA_ERR("%s: failed to create struct snd_cx18_card\n",
 232                               __func__);
 233         } else {
 234                 CX18_DEBUG_ALSA_INFO("%s: created cx18 ALSA interface instance "
 235                                      "\n", __func__);
 236         }
 237         return 0;
 238 }
 239
 240 static int __init cx18_alsa_init(void)
 241 {
 242         printk(KERN_INFO "cx18-alsa: module loading...\n");
 243         cx18_ext_init = &cx18_alsa_load;
 244         return 0;
 245 }
 246
 247 static void __exit snd_cx18_exit(struct snd_cx18_card *cxsc)
 248 {
 249         struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
 250
 251         /* FIXME - pointer checks & shutdown cxsc */
 252
 253         snd_card_free(cxsc->sc);
 254         cx->alsa = NULL;
 255 }
 256
 257 static int __exit cx18_alsa_exit_callback(struct device *dev, void *data)
 258 {
 259         struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 260         struct snd_cx18_card *cxsc;
 261
 262         if (v4l2_dev == NULL) {
 263                 printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
 264                        __func__);
 265                 return 0;
 266         }
 267
 268         cxsc = to_snd_cx18_card(v4l2_dev);
 269         if (cxsc == NULL) {
 270                 CX18_ALSA_WARN("%s: struct snd_cx18_card * is NULL\n",
 271                                __func__);
 272                 return 0;
 273         }
 274
 275         snd_cx18_exit(cxsc);
 276         return 0;
 277 }
 278
 279 static void __exit cx18_alsa_exit(void)
 280 {
 281         struct device_driver *drv;
 282         int ret;
 283
 284         printk(KERN_INFO "cx18-alsa: module unloading...\n");
 285
 286         drv = driver_find("cx18", &pci_bus_type);
 287         ret = driver_for_each_device(drv, NULL, NULL, cx18_alsa_exit_callback);
 288         (void)ret;      /* suppress compiler warning */
 289
 290         cx18_ext_init = NULL;
 291         printk(KERN_INFO "cx18-alsa: module unload complete\n");
 292 }
 293
 294 module_init(cx18_alsa_init);
 295 module_exit(cx18_alsa_exit);