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@radix.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/module.h>
  27 #include <linux/kernel.h>
  28 #include <linux/device.h>
  29 #include <linux/spinlock.h>
  30
  31 #include <media/v4l2-device.h>
  32
  33 #include <sound/core.h>
  34 #include <sound/initval.h>
  35
  36 #include "cx18-driver.h"
  37 #include "cx18-version.h"
  38 #include "cx18-alsa.h"
  39 #include "cx18-alsa-mixer.h"
  40 #include "cx18-alsa-pcm.h"
  41
  42 int cx18_alsa_debug;
  43
  44 #define CX18_DEBUG_ALSA_INFO(fmt, arg...) \
  45         do { \
  46                 if (cx18_alsa_debug & 2) \
  47                         printk(KERN_INFO "%s: " fmt, "cx18-alsa", ## arg); \
  48         } while (0);
  49
  50 module_param_named(debug, cx18_alsa_debug, int, 0644);
  51 MODULE_PARM_DESC(debug,
  52                  "Debug level (bitmask). Default: 0\n"
  53                  "\t\t\t  1/0x0001: warning\n"
  54                  "\t\t\t  2/0x0002: info\n");
  55
  56 MODULE_AUTHOR("Andy Walls");
  57 MODULE_DESCRIPTION("CX23418 ALSA Interface");
  58 MODULE_SUPPORTED_DEVICE("CX23418 MPEG2 encoder");
  59 MODULE_LICENSE("GPL");
  60
  61 MODULE_VERSION(CX18_VERSION);
  62
  63 static inline
  64 struct snd_cx18_card *to_snd_cx18_card(struct v4l2_device *v4l2_dev)
  65 {
  66         return to_cx18(v4l2_dev)->alsa;
  67 }
  68
  69 static inline
  70 struct snd_cx18_card *p_to_snd_cx18_card(struct v4l2_device **v4l2_dev)
  71 {
  72         return container_of(v4l2_dev, struct snd_cx18_card, v4l2_dev);
  73 }
  74
  75 static void snd_cx18_card_free(struct snd_cx18_card *cxsc)
  76 {
  77         if (cxsc == NULL)
  78                 return;
  79
  80         if (cxsc->v4l2_dev != NULL)
  81                 to_cx18(cxsc->v4l2_dev)->alsa = NULL;
  82
  83         /* FIXME - take any other stopping actions needed */
  84
  85         kfree(cxsc);
  86 }
  87
  88 static void snd_cx18_card_private_free(struct snd_card *sc)
  89 {
  90         if (sc == NULL)
  91                 return;
  92         snd_cx18_card_free(sc->private_data);
  93         sc->private_data = NULL;
  94         sc->private_free = NULL;
  95 }
  96
  97 static int snd_cx18_card_create(struct v4l2_device *v4l2_dev,
  98                                        struct snd_card *sc,
  99                                        struct snd_cx18_card **cxsc)
 100 {
 101         *cxsc = kzalloc(sizeof(struct snd_cx18_card), GFP_KERNEL);
 102         if (*cxsc == NULL)
 103                 return -ENOMEM;
 104
 105         (*cxsc)->v4l2_dev = v4l2_dev;
 106         (*cxsc)->sc = sc;
 107
 108         sc->private_data = *cxsc;
 109         sc->private_free = snd_cx18_card_private_free;
 110
 111         return 0;
 112 }
 113
 114 static int snd_cx18_card_set_names(struct snd_cx18_card *cxsc)
 115 {
 116         struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
 117         struct snd_card *sc = cxsc->sc;
 118
 119         /* sc->driver is used by alsa-lib's configurator: simple, unique */
 120         strlcpy(sc->driver, "CX23418", sizeof(sc->driver));
 121
 122         /* sc->shortname is a symlink in /proc/asound: CX18-M -> cardN */
 123         snprintf(sc->shortname,  sizeof(sc->shortname), "CX18-%d",
 124                  cx->instance);
 125
 126         /* sc->longname is read from /proc/asound/cards */
 127         snprintf(sc->longname, sizeof(sc->longname),
 128                  "CX23418 #%d %s TV/FM Radio/Line-In Capture",
 129                  cx->instance, cx->card_name);
 130
 131         return 0;
 132 }
 133
 134 static int snd_cx18_init(struct v4l2_device *v4l2_dev)
 135 {
 136         struct cx18 *cx = to_cx18(v4l2_dev);
 137         struct snd_card *sc = NULL;
 138         struct snd_cx18_card *cxsc;
 139         int ret;
 140
 141         /* Numbrs steps from "Writing an ALSA Driver" by Takashi Iwai */
 142
 143         /* (1) Check and increment the device index */
 144         /* This is a no-op for us.  We'll use the cx->instance */
 145
 146         /* (2) Create a card instance */
 147         ret = snd_card_create(SNDRV_DEFAULT_IDX1, /* use first available id */
 148                               SNDRV_DEFAULT_STR1, /* xid from end of shortname*/
 149                               THIS_MODULE, 0, &sc);
 150         if (ret) {
 151                 CX18_ALSA_ERR("%s: snd_card_create() failed with err %d\n",
 152                               __func__, ret);
 153                 goto err_exit;
 154         }
 155
 156         /* (3) Create a main component */
 157         ret = snd_cx18_card_create(v4l2_dev, sc, &cxsc);
 158         if (ret) {
 159                 CX18_ALSA_ERR("%s: snd_cx18_card_create() failed with err %d\n",
 160                               __func__, ret);
 161                 goto err_exit_free;
 162         }
 163
 164         /* (4) Set the driver ID and name strings */
 165         snd_cx18_card_set_names(cxsc);
 166
 167
 168         ret = snd_cx18_pcm_create(cxsc);
 169         if (ret) {
 170                 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
 171                               __func__, ret);
 172                 goto err_exit_free;
 173         }
 174         /* FIXME - proc files */
 175
 176         /* (7) Set the driver data and return 0 */
 177         /* We do this out of normal order for PCI drivers to avoid races */
 178         cx->alsa = cxsc;
 179
 180         /* (6) Register the card instance */
 181         ret = snd_card_register(sc);
 182         if (ret) {
 183                 cx->alsa = NULL;
 184                 CX18_ALSA_ERR("%s: snd_card_register() failed with err %d\n",
 185                               __func__, ret);
 186                 goto err_exit_free;
 187         }
 188
 189         return 0;
 190
 191 err_exit_free:
 192         if (sc != NULL)
 193                 snd_card_free(sc);
 194 err_exit:
 195         return ret;
 196 }
 197
 198 int cx18_alsa_load(struct cx18 *cx)
 199 {
 200         struct v4l2_device *v4l2_dev = &cx->v4l2_dev;
 201         struct cx18_stream *s;
 202
 203         if (v4l2_dev == NULL) {
 204                 printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
 205                        __func__);
 206                 return 0;
 207         }
 208
 209         cx = to_cx18(v4l2_dev);
 210         if (cx == NULL) {
 211                 printk(KERN_ERR "cx18-alsa cx is NULL\n");
 212                 return 0;
 213         }
 214
 215         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 216         if (s->video_dev == NULL) {
 217                 CX18_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - "
 218                                      "skipping\n", __func__);
 219                 return 0;
 220         }
 221
 222         if (cx->alsa != NULL) {
 223                 CX18_ALSA_ERR("%s: struct snd_cx18_card * already exists\n",
 224                               __func__);
 225                 return 0;
 226         }
 227
 228         if (snd_cx18_init(v4l2_dev)) {
 229                 CX18_ALSA_ERR("%s: failed to create struct snd_cx18_card\n",
 230                               __func__);
 231         } else {
 232                 CX18_DEBUG_ALSA_INFO("%s: created cx18 ALSA interface instance "
 233                                      "\n", __func__);
 234         }
 235         return 0;
 236 }
 237
 238 static int __init cx18_alsa_init(void)
 239 {
 240         printk(KERN_INFO "cx18-alsa: module loading...\n");
 241         cx18_ext_init = &cx18_alsa_load;
 242         return 0;
 243 }
 244
 245 static void __exit snd_cx18_exit(struct snd_cx18_card *cxsc)
 246 {
 247         struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
 248
 249         /* FIXME - pointer checks & shutdown cxsc */
 250
 251         snd_card_free(cxsc->sc);
 252         cx->alsa = NULL;
 253 }
 254
 255 static int __exit cx18_alsa_exit_callback(struct device *dev, void *data)
 256 {
 257         struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 258         struct snd_cx18_card *cxsc;
 259
 260         if (v4l2_dev == NULL) {
 261                 printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
 262                        __func__);
 263                 return 0;
 264         }
 265
 266         cxsc = to_snd_cx18_card(v4l2_dev);
 267         if (cxsc == NULL) {
 268                 CX18_ALSA_WARN("%s: struct snd_cx18_card * is NULL\n",
 269                                __func__);
 270                 return 0;
 271         }
 272
 273         snd_cx18_exit(cxsc);
 274         return 0;
 275 }
 276
 277 static void __exit cx18_alsa_exit(void)
 278 {
 279         struct device_driver *drv;
 280         int ret;
 281
 282         printk(KERN_INFO "cx18-alsa: module unloading...\n");
 283
 284         drv = driver_find("cx18", &pci_bus_type);
 285         ret = driver_for_each_device(drv, NULL, NULL, cx18_alsa_exit_callback);
 286         put_driver(drv);
 287
 288         cx18_ext_init = NULL;
 289         printk(KERN_INFO "cx18-alsa: module unload complete\n");
 290 }
 291
 292 module_init(cx18_alsa_init);
 293 module_exit(cx18_alsa_exit);