/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
 43int 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
 51module_param_named(debug, cx18_alsa_debug, int, 0644);
 52MODULE_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
 57MODULE_AUTHOR("Andy Walls");
 58MODULE_DESCRIPTION("CX23418 ALSA Interface");
 59MODULE_SUPPORTED_DEVICE("CX23418 MPEG2 encoder");
 60MODULE_LICENSE("GPL");
 61
 62MODULE_VERSION(CX18_VERSION);
 63
 64static inline
 65struct snd_cx18_card *to_snd_cx18_card(struct v4l2_device *v4l2_dev)
 66{
 67	return to_cx18(v4l2_dev)->alsa;
 68}
 69
 70static inline
 71struct 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
 76static 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
 89static 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
 98static 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
115static 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
135static 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
192err_exit_free:
193	if (sc != NULL)
194		snd_card_free(sc);
195err_exit:
196	return ret;
197}
198
199int cx18_alsa_load(struct cx18 *cx)
200{
201	struct v4l2_device *v4l2_dev = &cx->v4l2_dev;
202	struct cx18_stream *s;
203
204	if (v4l2_dev == NULL) {
205		printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
206		       __func__);
207		return 0;
208	}
209
210	cx = to_cx18(v4l2_dev);
211	if (cx == NULL) {
212		printk(KERN_ERR "cx18-alsa cx is NULL\n");
213		return 0;
214	}
215
216	s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
217	if (s->video_dev == NULL) {
218		CX18_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - "
219				     "skipping\n", __func__);
220		return 0;
221	}
222
223	if (cx->alsa != NULL) {
224		CX18_ALSA_ERR("%s: struct snd_cx18_card * already exists\n",
225			      __func__);
226		return 0;
227	}
228
229	if (snd_cx18_init(v4l2_dev)) {
230		CX18_ALSA_ERR("%s: failed to create struct snd_cx18_card\n",
231			      __func__);
232	} else {
233		CX18_DEBUG_ALSA_INFO("%s: created cx18 ALSA interface instance "
234				     "\n", __func__);
235	}
236	return 0;
237}
238
239static int __init cx18_alsa_init(void)
240{
241	printk(KERN_INFO "cx18-alsa: module loading...\n");
242	cx18_ext_init = &cx18_alsa_load;
243	return 0;
244}
245
246static void __exit snd_cx18_exit(struct snd_cx18_card *cxsc)
247{
248	struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
249
250	/* FIXME - pointer checks & shutdown cxsc */
251
252	snd_card_free(cxsc->sc);
253	cx->alsa = NULL;
254}
255
256static int __exit cx18_alsa_exit_callback(struct device *dev, void *data)
257{
258	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
259	struct snd_cx18_card *cxsc;
260
261	if (v4l2_dev == NULL) {
262		printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
263		       __func__);
264		return 0;
265	}
266
267	cxsc = to_snd_cx18_card(v4l2_dev);
268	if (cxsc == NULL) {
269		CX18_ALSA_WARN("%s: struct snd_cx18_card * is NULL\n",
270			       __func__);
271		return 0;
272	}
273
274	snd_cx18_exit(cxsc);
275	return 0;
276}
277
278static void __exit cx18_alsa_exit(void)
279{
280	struct device_driver *drv;
281	int ret;
282
283	printk(KERN_INFO "cx18-alsa: module unloading...\n");
284
285	drv = driver_find("cx18", &pci_bus_type);
286	ret = driver_for_each_device(drv, NULL, NULL, cx18_alsa_exit_callback);
287	put_driver(drv);
288
289	cx18_ext_init = NULL;
290	printk(KERN_INFO "cx18-alsa: module unload complete\n");
291}
292
293module_init(cx18_alsa_init);
294module_exit(cx18_alsa_exit);