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
 28int 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
 36module_param_named(debug, cx18_alsa_debug, int, 0644);
 37MODULE_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
 42MODULE_AUTHOR("Andy Walls");
 43MODULE_DESCRIPTION("CX23418 ALSA Interface");
 44MODULE_LICENSE("GPL");
 45
 46MODULE_VERSION(CX18_VERSION);
 47
 48static inline
 49struct snd_cx18_card *to_snd_cx18_card(struct v4l2_device *v4l2_dev)
 50{
 51	return to_cx18(v4l2_dev)->alsa;
 52}
 53
 54static 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
 67static 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
 76static 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
 93static 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
113static 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
171err_exit_free:
172	if (sc != NULL)
173		snd_card_free(sc);
174	kfree(cxsc);
175err_exit:
176	return ret;
177}
178
179static 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
219static 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
226static 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
236static 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
258static 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
273module_init(cx18_alsa_init);
274module_exit(cx18_alsa_exit);