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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  ALSA interface to cx18 PCM capture streams
   4  *
   5  *  Copyright (C) 2009  Andy Walls <awalls@md.metrocast.net>
   6  *  Copyright (C) 2009  Devin Heitmueller <dheitmueller@kernellabs.com>
   7  *
   8  *  Portions of this work were sponsored by ONELAN Limited.
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/slab.h>
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/device.h>
  16 #include <linux/spinlock.h>
  17
  18 #include <media/v4l2-device.h>
  19
  20 #include <sound/core.h>
  21 #include <sound/initval.h>
  22
  23 #include "cx18-driver.h"
  24 #include "cx18-version.h"
  25 #include "cx18-alsa.h"
  26 #include "cx18-alsa-pcm.h"
  27
  28 int cx18_alsa_debug;
  29
  30 #define CX18_DEBUG_ALSA_INFO(fmt, arg...) \
  31         do { \
  32                 if (cx18_alsa_debug & 2) \
  33                         printk(KERN_INFO "%s: " fmt, "cx18-alsa", ## arg); \
  34         } while (0);
  35
  36 module_param_named(debug, cx18_alsa_debug, int, 0644);
  37 MODULE_PARM_DESC(debug,
  38                  "Debug level (bitmask). Default: 0\n"
  39                  "\t\t\t  1/0x0001: warning\n"
  40                  "\t\t\t  2/0x0002: info\n");
  41
  42 MODULE_AUTHOR("Andy Walls");
  43 MODULE_DESCRIPTION("CX23418 ALSA Interface");
  44 MODULE_LICENSE("GPL");
  45
  46 MODULE_VERSION(CX18_VERSION);
  47
  48 static inline
  49 struct snd_cx18_card *to_snd_cx18_card(struct v4l2_device *v4l2_dev)
  50 {
  51         return to_cx18(v4l2_dev)->alsa;
  52 }
  53
  54 static void snd_cx18_card_free(struct snd_cx18_card *cxsc)
  55 {
  56         if (cxsc == NULL)
  57                 return;
  58
  59         if (cxsc->v4l2_dev != NULL)
  60                 to_cx18(cxsc->v4l2_dev)->alsa = NULL;
  61
  62         /* FIXME - take any other stopping actions needed */
  63
  64         kfree(cxsc);
  65 }
  66
  67 static void snd_cx18_card_private_free(struct snd_card *sc)
  68 {
  69         if (sc == NULL)
  70                 return;
  71         snd_cx18_card_free(sc->private_data);
  72         sc->private_data = NULL;
  73         sc->private_free = NULL;
  74 }
  75
  76 static int snd_cx18_card_create(struct v4l2_device *v4l2_dev,
  77                                        struct snd_card *sc,
  78                                        struct snd_cx18_card **cxsc)
  79 {
  80         *cxsc = kzalloc(sizeof(struct snd_cx18_card), GFP_KERNEL);
  81         if (*cxsc == NULL)
  82                 return -ENOMEM;
  83
  84         (*cxsc)->v4l2_dev = v4l2_dev;
  85         (*cxsc)->sc = sc;
  86
  87         sc->private_data = *cxsc;
  88         sc->private_free = snd_cx18_card_private_free;
  89
  90         return 0;
  91 }
  92
  93 static int snd_cx18_card_set_names(struct snd_cx18_card *cxsc)
  94 {
  95         struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
  96         struct snd_card *sc = cxsc->sc;
  97
  98         /* sc->driver is used by alsa-lib's configurator: simple, unique */
  99         strscpy(sc->driver, "CX23418", sizeof(sc->driver));
 100
 101         /* sc->shortname is a symlink in /proc/asound: CX18-M -> cardN */
 102         snprintf(sc->shortname,  sizeof(sc->shortname), "CX18-%d",
 103                  cx->instance);
 104
 105         /* sc->longname is read from /proc/asound/cards */
 106         snprintf(sc->longname, sizeof(sc->longname),
 107                  "CX23418 #%d %s TV/FM Radio/Line-In Capture",
 108                  cx->instance, cx->card_name);
 109
 110         return 0;
 111 }
 112
 113 static int snd_cx18_init(struct v4l2_device *v4l2_dev)
 114 {
 115         struct cx18 *cx = to_cx18(v4l2_dev);
 116         struct snd_card *sc = NULL;
 117         struct snd_cx18_card *cxsc;
 118         int ret;
 119
 120         /* Numbrs steps from "Writing an ALSA Driver" by Takashi Iwai */
 121
 122         /* (1) Check and increment the device index */
 123         /* This is a no-op for us.  We'll use the cx->instance */
 124
 125         /* (2) Create a card instance */
 126         ret = snd_card_new(&cx->pci_dev->dev,
 127                            SNDRV_DEFAULT_IDX1, /* use first available id */
 128                            SNDRV_DEFAULT_STR1, /* xid from end of shortname*/
 129                            THIS_MODULE, 0, &sc);
 130         if (ret) {
 131                 CX18_ALSA_ERR("%s: snd_card_new() failed with err %d\n",
 132                               __func__, ret);
 133                 goto err_exit;
 134         }
 135
 136         /* (3) Create a main component */
 137         ret = snd_cx18_card_create(v4l2_dev, sc, &cxsc);
 138         if (ret) {
 139                 CX18_ALSA_ERR("%s: snd_cx18_card_create() failed with err %d\n",
 140                               __func__, ret);
 141                 goto err_exit_free;
 142         }
 143
 144         /* (4) Set the driver ID and name strings */
 145         snd_cx18_card_set_names(cxsc);
 146
 147
 148         ret = snd_cx18_pcm_create(cxsc);
 149         if (ret) {
 150                 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
 151                               __func__, ret);
 152                 goto err_exit_free;
 153         }
 154         /* FIXME - proc files */
 155
 156         /* (7) Set the driver data and return 0 */
 157         /* We do this out of normal order for PCI drivers to avoid races */
 158         cx->alsa = cxsc;
 159
 160         /* (6) Register the card instance */
 161         ret = snd_card_register(sc);
 162         if (ret) {
 163                 cx->alsa = NULL;
 164                 CX18_ALSA_ERR("%s: snd_card_register() failed with err %d\n",
 165                               __func__, ret);
 166                 goto err_exit_free;
 167         }
 168
 169         return 0;
 170
 171 err_exit_free:
 172         if (sc != NULL)
 173                 snd_card_free(sc);
 174         kfree(cxsc);
 175 err_exit:
 176         return ret;
 177 }
 178
 179 static int cx18_alsa_load(struct cx18 *cx)
 180 {
 181         struct v4l2_device *v4l2_dev = &cx->v4l2_dev;
 182         struct cx18_stream *s;
 183
 184         if (v4l2_dev == NULL) {
 185                 printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
 186                        __func__);
 187                 return 0;
 188         }
 189
 190         cx = to_cx18(v4l2_dev);
 191         if (cx == NULL) {
 192                 printk(KERN_ERR "cx18-alsa cx is NULL\n");
 193                 return 0;
 194         }
 195
 196         s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
 197         if (s->video_dev.v4l2_dev == NULL) {
 198                 CX18_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - skipping\n",
 199                                      __func__);
 200                 return 0;
 201         }
 202
 203         if (cx->alsa != NULL) {
 204                 CX18_ALSA_ERR("%s: struct snd_cx18_card * already exists\n",
 205                               __func__);
 206                 return 0;
 207         }
 208
 209         if (snd_cx18_init(v4l2_dev)) {
 210                 CX18_ALSA_ERR("%s: failed to create struct snd_cx18_card\n",
 211                               __func__);
 212         } else {
 213                 CX18_DEBUG_ALSA_INFO("%s: created cx18 ALSA interface instance\n",
 214                                      __func__);
 215         }
 216         return 0;
 217 }
 218
 219 static int __init cx18_alsa_init(void)
 220 {
 221         printk(KERN_INFO "cx18-alsa: module loading...\n");
 222         cx18_ext_init = &cx18_alsa_load;
 223         return 0;
 224 }
 225
 226 static void __exit snd_cx18_exit(struct snd_cx18_card *cxsc)
 227 {
 228         struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
 229
 230         /* FIXME - pointer checks & shutdown cxsc */
 231
 232         snd_card_free(cxsc->sc);
 233         cx->alsa = NULL;
 234 }
 235
 236 static int __exit cx18_alsa_exit_callback(struct device *dev, void *data)
 237 {
 238         struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
 239         struct snd_cx18_card *cxsc;
 240
 241         if (v4l2_dev == NULL) {
 242                 printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
 243                        __func__);
 244                 return 0;
 245         }
 246
 247         cxsc = to_snd_cx18_card(v4l2_dev);
 248         if (cxsc == NULL) {
 249                 CX18_ALSA_WARN("%s: struct snd_cx18_card * is NULL\n",
 250                                __func__);
 251                 return 0;
 252         }
 253
 254         snd_cx18_exit(cxsc);
 255         return 0;
 256 }
 257
 258 static void __exit cx18_alsa_exit(void)
 259 {
 260         struct device_driver *drv;
 261         int ret;
 262
 263         printk(KERN_INFO "cx18-alsa: module unloading...\n");
 264
 265         drv = driver_find("cx18", &pci_bus_type);
 266         ret = driver_for_each_device(drv, NULL, NULL, cx18_alsa_exit_callback);
 267         (void)ret;      /* suppress compiler warning */
 268
 269         cx18_ext_init = NULL;
 270         printk(KERN_INFO "cx18-alsa: module unload complete\n");
 271 }
 272
 273 module_init(cx18_alsa_init);
 274 module_exit(cx18_alsa_exit);