1 /*
2  *  ALSA interface to ivtv PCM capture streams
3  *
4  *  Copyright (C) 2009,2012  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 for the cx18 driver
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 "ivtv-driver.h"
38 #include "ivtv-version.h"
39 #include "ivtv-alsa.h"
40 #include "ivtv-alsa-mixer.h"
41 #include "ivtv-alsa-pcm.h"
42 
43 int ivtv_alsa_debug;
44 
45 #define IVTV_DEBUG_ALSA_INFO(fmt, arg...) \
46 	do { \
47 		if (ivtv_alsa_debug & 2) \
48 			pr_info("%s: " fmt, "ivtv-alsa", ## arg); \
49 	} while (0)
50 
51 module_param_named(debug, ivtv_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("CX23415/CX23416 ALSA Interface");
59 MODULE_SUPPORTED_DEVICE("CX23415/CX23416 MPEG2 encoder");
60 MODULE_LICENSE("GPL");
61 
62 MODULE_VERSION(IVTV_VERSION);
63 
64 static inline
65 struct snd_ivtv_card *to_snd_ivtv_card(struct v4l2_device *v4l2_dev)
66 {
67 	return to_ivtv(v4l2_dev)->alsa;
68 }
69 
70 static inline
71 struct snd_ivtv_card *p_to_snd_ivtv_card(struct v4l2_device **v4l2_dev)
72 {
73 	return container_of(v4l2_dev, struct snd_ivtv_card, v4l2_dev);
74 }
75 
76 static void snd_ivtv_card_free(struct snd_ivtv_card *itvsc)
77 {
78 	if (itvsc == NULL)
79 		return;
80 
81 	if (itvsc->v4l2_dev != NULL)
82 		to_ivtv(itvsc->v4l2_dev)->alsa = NULL;
83 
84 	/* FIXME - take any other stopping actions needed */
85 
86 	kfree(itvsc);
87 }
88 
89 static void snd_ivtv_card_private_free(struct snd_card *sc)
90 {
91 	if (sc == NULL)
92 		return;
93 	snd_ivtv_card_free(sc->private_data);
94 	sc->private_data = NULL;
95 	sc->private_free = NULL;
96 }
97 
98 static int snd_ivtv_card_create(struct v4l2_device *v4l2_dev,
99 				       struct snd_card *sc,
100 				       struct snd_ivtv_card **itvsc)
101 {
102 	*itvsc = kzalloc(sizeof(struct snd_ivtv_card), GFP_KERNEL);
103 	if (*itvsc == NULL)
104 		return -ENOMEM;
105 
106 	(*itvsc)->v4l2_dev = v4l2_dev;
107 	(*itvsc)->sc = sc;
108 
109 	sc->private_data = *itvsc;
110 	sc->private_free = snd_ivtv_card_private_free;
111 
112 	return 0;
113 }
114 
115 static int snd_ivtv_card_set_names(struct snd_ivtv_card *itvsc)
116 {
117 	struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
118 	struct snd_card *sc = itvsc->sc;
119 
120 	/* sc->driver is used by alsa-lib's configurator: simple, unique */
121 	strlcpy(sc->driver, "CX2341[56]", sizeof(sc->driver));
122 
123 	/* sc->shortname is a symlink in /proc/asound: IVTV-M -> cardN */
124 	snprintf(sc->shortname,  sizeof(sc->shortname), "IVTV-%d",
125 		 itv->instance);
126 
127 	/* sc->longname is read from /proc/asound/cards */
128 	snprintf(sc->longname, sizeof(sc->longname),
129 		 "CX2341[56] #%d %s TV/FM Radio/Line-In Capture",
130 		 itv->instance, itv->card_name);
131 
132 	return 0;
133 }
134 
135 static int snd_ivtv_init(struct v4l2_device *v4l2_dev)
136 {
137 	struct ivtv *itv = to_ivtv(v4l2_dev);
138 	struct snd_card *sc = NULL;
139 	struct snd_ivtv_card *itvsc;
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 itv->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 		IVTV_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_ivtv_card_create(v4l2_dev, sc, &itvsc);
159 	if (ret) {
160 		IVTV_ALSA_ERR("%s: snd_ivtv_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_ivtv_card_set_names(itvsc);
167 
168 	/* (5) Create other components: mixer, PCM, & proc files */
169 #if 0
170 	ret = snd_ivtv_mixer_create(itvsc);
171 	if (ret) {
172 		IVTV_ALSA_WARN("%s: snd_ivtv_mixer_create() failed with err %d:"
173 			       " proceeding anyway\n", __func__, ret);
174 	}
175 #endif
176 
177 	ret = snd_ivtv_pcm_create(itvsc);
178 	if (ret) {
179 		IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
180 			      __func__, ret);
181 		goto err_exit_free;
182 	}
183 	/* FIXME - proc files */
184 
185 	/* (7) Set the driver data and return 0 */
186 	/* We do this out of normal order for PCI drivers to avoid races */
187 	itv->alsa = itvsc;
188 
189 	/* (6) Register the card instance */
190 	ret = snd_card_register(sc);
191 	if (ret) {
192 		itv->alsa = NULL;
193 		IVTV_ALSA_ERR("%s: snd_card_register() failed with err %d\n",
194 			      __func__, ret);
195 		goto err_exit_free;
196 	}
197 
198 	return 0;
199 
200 err_exit_free:
201 	if (sc != NULL)
202 		snd_card_free(sc);
203 	kfree(itvsc);
204 err_exit:
205 	return ret;
206 }
207 
208 static int __init ivtv_alsa_load(struct ivtv *itv)
209 {
210 	struct v4l2_device *v4l2_dev = &itv->v4l2_dev;
211 	struct ivtv_stream *s;
212 
213 	if (v4l2_dev == NULL) {
214 		pr_err("ivtv-alsa: %s: struct v4l2_device * is NULL\n",
215 		       __func__);
216 		return 0;
217 	}
218 
219 	itv = to_ivtv(v4l2_dev);
220 	if (itv == NULL) {
221 		pr_err("ivtv-alsa itv is NULL\n");
222 		return 0;
223 	}
224 
225 	s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
226 	if (s->vdev == NULL) {
227 		IVTV_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - "
228 				     "skipping\n", __func__);
229 		return 0;
230 	}
231 
232 	if (itv->alsa != NULL) {
233 		IVTV_ALSA_ERR("%s: struct snd_ivtv_card * already exists\n",
234 			      __func__);
235 		return 0;
236 	}
237 
238 	if (snd_ivtv_init(v4l2_dev)) {
239 		IVTV_ALSA_ERR("%s: failed to create struct snd_ivtv_card\n",
240 			      __func__);
241 	} else {
242 		IVTV_DEBUG_ALSA_INFO("%s: created ivtv ALSA interface instance "
243 				     "\n", __func__);
244 	}
245 	return 0;
246 }
247 
248 static int __init ivtv_alsa_init(void)
249 {
250 	pr_info("ivtv-alsa: module loading...\n");
251 	ivtv_ext_init = &ivtv_alsa_load;
252 	return 0;
253 }
254 
255 static void __exit snd_ivtv_exit(struct snd_ivtv_card *itvsc)
256 {
257 	struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
258 
259 	/* FIXME - pointer checks & shutdown itvsc */
260 
261 	snd_card_free(itvsc->sc);
262 	itv->alsa = NULL;
263 }
264 
265 static int __exit ivtv_alsa_exit_callback(struct device *dev, void *data)
266 {
267 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
268 	struct snd_ivtv_card *itvsc;
269 
270 	if (v4l2_dev == NULL) {
271 		pr_err("ivtv-alsa: %s: struct v4l2_device * is NULL\n",
272 		       __func__);
273 		return 0;
274 	}
275 
276 	itvsc = to_snd_ivtv_card(v4l2_dev);
277 	if (itvsc == NULL) {
278 		IVTV_ALSA_WARN("%s: struct snd_ivtv_card * is NULL\n",
279 			       __func__);
280 		return 0;
281 	}
282 
283 	snd_ivtv_exit(itvsc);
284 	return 0;
285 }
286 
287 static void __exit ivtv_alsa_exit(void)
288 {
289 	struct device_driver *drv;
290 	int ret;
291 
292 	pr_info("ivtv-alsa: module unloading...\n");
293 
294 	drv = driver_find("ivtv", &pci_bus_type);
295 	ret = driver_for_each_device(drv, NULL, NULL, ivtv_alsa_exit_callback);
296 	(void)ret;	/* suppress compiler warning */
297 
298 	ivtv_ext_init = NULL;
299 	pr_info("ivtv-alsa: module unload complete\n");
300 }
301 
302 module_init(ivtv_alsa_init);
303 module_exit(ivtv_alsa_exit);
304