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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  ALSA interface to cobalt PCM capture streams
   4  *
   5  *  Copyright 2014-2015 Cisco Systems, Inc. and/or its affiliates.
   6  *  All rights reserved.
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/device.h>
  14 #include <linux/spinlock.h>
  15
  16 #include <media/v4l2-device.h>
  17
  18 #include <sound/core.h>
  19 #include <sound/initval.h>
  20
  21 #include "cobalt-driver.h"
  22 #include "cobalt-alsa.h"
  23 #include "cobalt-alsa-pcm.h"
  24
  25 static void snd_cobalt_card_free(struct snd_cobalt_card *cobsc)
  26 {
  27         if (cobsc == NULL)
  28                 return;
  29
  30         cobsc->s->alsa = NULL;
  31
  32         kfree(cobsc);
  33 }
  34
  35 static void snd_cobalt_card_private_free(struct snd_card *sc)
  36 {
  37         if (sc == NULL)
  38                 return;
  39         snd_cobalt_card_free(sc->private_data);
  40         sc->private_data = NULL;
  41         sc->private_free = NULL;
  42 }
  43
  44 static int snd_cobalt_card_create(struct cobalt_stream *s,
  45                                        struct snd_card *sc,
  46                                        struct snd_cobalt_card **cobsc)
  47 {
  48         *cobsc = kzalloc(sizeof(struct snd_cobalt_card), GFP_KERNEL);
  49         if (*cobsc == NULL)
  50                 return -ENOMEM;
  51
  52         (*cobsc)->s = s;
  53         (*cobsc)->sc = sc;
  54
  55         sc->private_data = *cobsc;
  56         sc->private_free = snd_cobalt_card_private_free;
  57
  58         return 0;
  59 }
  60
  61 static int snd_cobalt_card_set_names(struct snd_cobalt_card *cobsc)
  62 {
  63         struct cobalt_stream *s = cobsc->s;
  64         struct cobalt *cobalt = s->cobalt;
  65         struct snd_card *sc = cobsc->sc;
  66
  67         /* sc->driver is used by alsa-lib's configurator: simple, unique */
  68         strscpy(sc->driver, "cobalt", sizeof(sc->driver));
  69
  70         /* sc->shortname is a symlink in /proc/asound: COBALT-M -> cardN */
  71         snprintf(sc->shortname,  sizeof(sc->shortname), "cobalt-%d-%d",
  72                  cobalt->instance, s->video_channel);
  73
  74         /* sc->longname is read from /proc/asound/cards */
  75         snprintf(sc->longname, sizeof(sc->longname),
  76                  "Cobalt %d HDMI %d",
  77                  cobalt->instance, s->video_channel);
  78
  79         return 0;
  80 }
  81
  82 int cobalt_alsa_init(struct cobalt_stream *s)
  83 {
  84         struct cobalt *cobalt = s->cobalt;
  85         struct snd_card *sc = NULL;
  86         struct snd_cobalt_card *cobsc;
  87         int ret;
  88
  89         /* Numbrs steps from "Writing an ALSA Driver" by Takashi Iwai */
  90
  91         /* (1) Check and increment the device index */
  92         /* This is a no-op for us.  We'll use the cobalt->instance */
  93
  94         /* (2) Create a card instance */
  95         ret = snd_card_new(&cobalt->pci_dev->dev, SNDRV_DEFAULT_IDX1,
  96                            SNDRV_DEFAULT_STR1, THIS_MODULE, 0, &sc);
  97         if (ret) {
  98                 cobalt_err("snd_card_new() failed with err %d\n", ret);
  99                 goto err_exit;
 100         }
 101
 102         /* (3) Create a main component */
 103         ret = snd_cobalt_card_create(s, sc, &cobsc);
 104         if (ret) {
 105                 cobalt_err("snd_cobalt_card_create() failed with err %d\n",
 106                            ret);
 107                 goto err_exit_free;
 108         }
 109
 110         /* (4) Set the driver ID and name strings */
 111         snd_cobalt_card_set_names(cobsc);
 112
 113         ret = snd_cobalt_pcm_create(cobsc);
 114         if (ret) {
 115                 cobalt_err("snd_cobalt_pcm_create() failed with err %d\n",
 116                            ret);
 117                 goto err_exit_free;
 118         }
 119         /* FIXME - proc files */
 120
 121         /* (7) Set the driver data and return 0 */
 122         /* We do this out of normal order for PCI drivers to avoid races */
 123         s->alsa = cobsc;
 124
 125         /* (6) Register the card instance */
 126         ret = snd_card_register(sc);
 127         if (ret) {
 128                 s->alsa = NULL;
 129                 cobalt_err("snd_card_register() failed with err %d\n", ret);
 130                 goto err_exit_free;
 131         }
 132
 133         return 0;
 134
 135 err_exit_free:
 136         if (sc != NULL)
 137                 snd_card_free(sc);
 138         kfree(cobsc);
 139 err_exit:
 140         return ret;
 141 }
 142
 143 void cobalt_alsa_exit(struct cobalt_stream *s)
 144 {
 145         struct snd_cobalt_card *cobsc = s->alsa;
 146
 147         if (cobsc)
 148                 snd_card_free(cobsc->sc);
 149         s->alsa = NULL;
 150 }