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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 
43 int 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 
51 module_param_named(debug, cx18_alsa_debug, int, 0644);
52 MODULE_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 
57 MODULE_AUTHOR("Andy Walls");
58 MODULE_DESCRIPTION("CX23418 ALSA Interface");
59 MODULE_SUPPORTED_DEVICE("CX23418 MPEG2 encoder");
60 MODULE_LICENSE("GPL");
61 
62 MODULE_VERSION(CX18_VERSION);
63 
64 static inline
to_snd_cx18_card(struct v4l2_device * v4l2_dev)65 struct snd_cx18_card *to_snd_cx18_card(struct v4l2_device *v4l2_dev)
66 {
67 	return to_cx18(v4l2_dev)->alsa;
68 }
69 
70 static inline
p_to_snd_cx18_card(struct v4l2_device ** v4l2_dev)71 struct 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 
snd_cx18_card_free(struct snd_cx18_card * cxsc)76 static 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 
snd_cx18_card_private_free(struct snd_card * sc)89 static 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 
snd_cx18_card_create(struct v4l2_device * v4l2_dev,struct snd_card * sc,struct snd_cx18_card ** cxsc)98 static 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 
snd_cx18_card_set_names(struct snd_cx18_card * cxsc)115 static 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 
snd_cx18_init(struct v4l2_device * v4l2_dev)135 static 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_new(&cx->pci_dev->dev,
149 			   SNDRV_DEFAULT_IDX1, /* use first available id */
150 			   SNDRV_DEFAULT_STR1, /* xid from end of shortname*/
151 			   THIS_MODULE, 0, &sc);
152 	if (ret) {
153 		CX18_ALSA_ERR("%s: snd_card_new() failed with err %d\n",
154 			      __func__, ret);
155 		goto err_exit;
156 	}
157 
158 	/* (3) Create a main component */
159 	ret = snd_cx18_card_create(v4l2_dev, sc, &cxsc);
160 	if (ret) {
161 		CX18_ALSA_ERR("%s: snd_cx18_card_create() failed with err %d\n",
162 			      __func__, ret);
163 		goto err_exit_free;
164 	}
165 
166 	/* (4) Set the driver ID and name strings */
167 	snd_cx18_card_set_names(cxsc);
168 
169 
170 	ret = snd_cx18_pcm_create(cxsc);
171 	if (ret) {
172 		CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
173 			      __func__, ret);
174 		goto err_exit_free;
175 	}
176 	/* FIXME - proc files */
177 
178 	/* (7) Set the driver data and return 0 */
179 	/* We do this out of normal order for PCI drivers to avoid races */
180 	cx->alsa = cxsc;
181 
182 	/* (6) Register the card instance */
183 	ret = snd_card_register(sc);
184 	if (ret) {
185 		cx->alsa = NULL;
186 		CX18_ALSA_ERR("%s: snd_card_register() failed with err %d\n",
187 			      __func__, ret);
188 		goto err_exit_free;
189 	}
190 
191 	return 0;
192 
193 err_exit_free:
194 	if (sc != NULL)
195 		snd_card_free(sc);
196 	kfree(cxsc);
197 err_exit:
198 	return ret;
199 }
200 
cx18_alsa_load(struct cx18 * cx)201 static int cx18_alsa_load(struct cx18 *cx)
202 {
203 	struct v4l2_device *v4l2_dev = &cx->v4l2_dev;
204 	struct cx18_stream *s;
205 
206 	if (v4l2_dev == NULL) {
207 		printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
208 		       __func__);
209 		return 0;
210 	}
211 
212 	cx = to_cx18(v4l2_dev);
213 	if (cx == NULL) {
214 		printk(KERN_ERR "cx18-alsa cx is NULL\n");
215 		return 0;
216 	}
217 
218 	s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
219 	if (s->video_dev.v4l2_dev == NULL) {
220 		CX18_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - "
221 				     "skipping\n", __func__);
222 		return 0;
223 	}
224 
225 	if (cx->alsa != NULL) {
226 		CX18_ALSA_ERR("%s: struct snd_cx18_card * already exists\n",
227 			      __func__);
228 		return 0;
229 	}
230 
231 	if (snd_cx18_init(v4l2_dev)) {
232 		CX18_ALSA_ERR("%s: failed to create struct snd_cx18_card\n",
233 			      __func__);
234 	} else {
235 		CX18_DEBUG_ALSA_INFO("%s: created cx18 ALSA interface instance "
236 				     "\n", __func__);
237 	}
238 	return 0;
239 }
240 
cx18_alsa_init(void)241 static int __init cx18_alsa_init(void)
242 {
243 	printk(KERN_INFO "cx18-alsa: module loading...\n");
244 	cx18_ext_init = &cx18_alsa_load;
245 	return 0;
246 }
247 
snd_cx18_exit(struct snd_cx18_card * cxsc)248 static void __exit snd_cx18_exit(struct snd_cx18_card *cxsc)
249 {
250 	struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
251 
252 	/* FIXME - pointer checks & shutdown cxsc */
253 
254 	snd_card_free(cxsc->sc);
255 	cx->alsa = NULL;
256 }
257 
cx18_alsa_exit_callback(struct device * dev,void * data)258 static int __exit cx18_alsa_exit_callback(struct device *dev, void *data)
259 {
260 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
261 	struct snd_cx18_card *cxsc;
262 
263 	if (v4l2_dev == NULL) {
264 		printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
265 		       __func__);
266 		return 0;
267 	}
268 
269 	cxsc = to_snd_cx18_card(v4l2_dev);
270 	if (cxsc == NULL) {
271 		CX18_ALSA_WARN("%s: struct snd_cx18_card * is NULL\n",
272 			       __func__);
273 		return 0;
274 	}
275 
276 	snd_cx18_exit(cxsc);
277 	return 0;
278 }
279 
cx18_alsa_exit(void)280 static void __exit cx18_alsa_exit(void)
281 {
282 	struct device_driver *drv;
283 	int ret;
284 
285 	printk(KERN_INFO "cx18-alsa: module unloading...\n");
286 
287 	drv = driver_find("cx18", &pci_bus_type);
288 	ret = driver_for_each_device(drv, NULL, NULL, cx18_alsa_exit_callback);
289 	(void)ret;	/* suppress compiler warning */
290 
291 	cx18_ext_init = NULL;
292 	printk(KERN_INFO "cx18-alsa: module unload complete\n");
293 }
294 
295 module_init(cx18_alsa_init);
296 module_exit(cx18_alsa_exit);
297