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
 25static 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
 35static 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
 44static 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
 61static 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
 82int 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
135err_exit_free:
136	if (sc != NULL)
137		snd_card_free(sc);
138	kfree(cobsc);
139err_exit:
140	return ret;
141}
142
143void 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}