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 
28 int 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 
36 module_param_named(debug, cx18_alsa_debug, int, 0644);
37 MODULE_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 
42 MODULE_AUTHOR("Andy Walls");
43 MODULE_DESCRIPTION("CX23418 ALSA Interface");
44 MODULE_SUPPORTED_DEVICE("CX23418 MPEG2 encoder");
45 MODULE_LICENSE("GPL");
46 
47 MODULE_VERSION(CX18_VERSION);
48 
49 static inline
50 struct snd_cx18_card *to_snd_cx18_card(struct v4l2_device *v4l2_dev)
51 {
52 	return to_cx18(v4l2_dev)->alsa;
53 }
54 
55 static inline
56 struct snd_cx18_card *p_to_snd_cx18_card(struct v4l2_device **v4l2_dev)
57 {
58 	return container_of(v4l2_dev, struct snd_cx18_card, v4l2_dev);
59 }
60 
61 static void snd_cx18_card_free(struct snd_cx18_card *cxsc)
62 {
63 	if (cxsc == NULL)
64 		return;
65 
66 	if (cxsc->v4l2_dev != NULL)
67 		to_cx18(cxsc->v4l2_dev)->alsa = NULL;
68 
69 	/* FIXME - take any other stopping actions needed */
70 
71 	kfree(cxsc);
72 }
73 
74 static void snd_cx18_card_private_free(struct snd_card *sc)
75 {
76 	if (sc == NULL)
77 		return;
78 	snd_cx18_card_free(sc->private_data);
79 	sc->private_data = NULL;
80 	sc->private_free = NULL;
81 }
82 
83 static int snd_cx18_card_create(struct v4l2_device *v4l2_dev,
84 				       struct snd_card *sc,
85 				       struct snd_cx18_card **cxsc)
86 {
87 	*cxsc = kzalloc(sizeof(struct snd_cx18_card), GFP_KERNEL);
88 	if (*cxsc == NULL)
89 		return -ENOMEM;
90 
91 	(*cxsc)->v4l2_dev = v4l2_dev;
92 	(*cxsc)->sc = sc;
93 
94 	sc->private_data = *cxsc;
95 	sc->private_free = snd_cx18_card_private_free;
96 
97 	return 0;
98 }
99 
100 static int snd_cx18_card_set_names(struct snd_cx18_card *cxsc)
101 {
102 	struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
103 	struct snd_card *sc = cxsc->sc;
104 
105 	/* sc->driver is used by alsa-lib's configurator: simple, unique */
106 	strscpy(sc->driver, "CX23418", sizeof(sc->driver));
107 
108 	/* sc->shortname is a symlink in /proc/asound: CX18-M -> cardN */
109 	snprintf(sc->shortname,  sizeof(sc->shortname), "CX18-%d",
110 		 cx->instance);
111 
112 	/* sc->longname is read from /proc/asound/cards */
113 	snprintf(sc->longname, sizeof(sc->longname),
114 		 "CX23418 #%d %s TV/FM Radio/Line-In Capture",
115 		 cx->instance, cx->card_name);
116 
117 	return 0;
118 }
119 
120 static int snd_cx18_init(struct v4l2_device *v4l2_dev)
121 {
122 	struct cx18 *cx = to_cx18(v4l2_dev);
123 	struct snd_card *sc = NULL;
124 	struct snd_cx18_card *cxsc;
125 	int ret;
126 
127 	/* Numbrs steps from "Writing an ALSA Driver" by Takashi Iwai */
128 
129 	/* (1) Check and increment the device index */
130 	/* This is a no-op for us.  We'll use the cx->instance */
131 
132 	/* (2) Create a card instance */
133 	ret = snd_card_new(&cx->pci_dev->dev,
134 			   SNDRV_DEFAULT_IDX1, /* use first available id */
135 			   SNDRV_DEFAULT_STR1, /* xid from end of shortname*/
136 			   THIS_MODULE, 0, &sc);
137 	if (ret) {
138 		CX18_ALSA_ERR("%s: snd_card_new() failed with err %d\n",
139 			      __func__, ret);
140 		goto err_exit;
141 	}
142 
143 	/* (3) Create a main component */
144 	ret = snd_cx18_card_create(v4l2_dev, sc, &cxsc);
145 	if (ret) {
146 		CX18_ALSA_ERR("%s: snd_cx18_card_create() failed with err %d\n",
147 			      __func__, ret);
148 		goto err_exit_free;
149 	}
150 
151 	/* (4) Set the driver ID and name strings */
152 	snd_cx18_card_set_names(cxsc);
153 
154 
155 	ret = snd_cx18_pcm_create(cxsc);
156 	if (ret) {
157 		CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
158 			      __func__, ret);
159 		goto err_exit_free;
160 	}
161 	/* FIXME - proc files */
162 
163 	/* (7) Set the driver data and return 0 */
164 	/* We do this out of normal order for PCI drivers to avoid races */
165 	cx->alsa = cxsc;
166 
167 	/* (6) Register the card instance */
168 	ret = snd_card_register(sc);
169 	if (ret) {
170 		cx->alsa = NULL;
171 		CX18_ALSA_ERR("%s: snd_card_register() failed with err %d\n",
172 			      __func__, ret);
173 		goto err_exit_free;
174 	}
175 
176 	return 0;
177 
178 err_exit_free:
179 	if (sc != NULL)
180 		snd_card_free(sc);
181 	kfree(cxsc);
182 err_exit:
183 	return ret;
184 }
185 
186 static int cx18_alsa_load(struct cx18 *cx)
187 {
188 	struct v4l2_device *v4l2_dev = &cx->v4l2_dev;
189 	struct cx18_stream *s;
190 
191 	if (v4l2_dev == NULL) {
192 		printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
193 		       __func__);
194 		return 0;
195 	}
196 
197 	cx = to_cx18(v4l2_dev);
198 	if (cx == NULL) {
199 		printk(KERN_ERR "cx18-alsa cx is NULL\n");
200 		return 0;
201 	}
202 
203 	s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
204 	if (s->video_dev.v4l2_dev == NULL) {
205 		CX18_DEBUG_ALSA_INFO("%s: PCM stream for card is disabled - skipping\n",
206 				     __func__);
207 		return 0;
208 	}
209 
210 	if (cx->alsa != NULL) {
211 		CX18_ALSA_ERR("%s: struct snd_cx18_card * already exists\n",
212 			      __func__);
213 		return 0;
214 	}
215 
216 	if (snd_cx18_init(v4l2_dev)) {
217 		CX18_ALSA_ERR("%s: failed to create struct snd_cx18_card\n",
218 			      __func__);
219 	} else {
220 		CX18_DEBUG_ALSA_INFO("%s: created cx18 ALSA interface instance\n",
221 				     __func__);
222 	}
223 	return 0;
224 }
225 
226 static int __init cx18_alsa_init(void)
227 {
228 	printk(KERN_INFO "cx18-alsa: module loading...\n");
229 	cx18_ext_init = &cx18_alsa_load;
230 	return 0;
231 }
232 
233 static void __exit snd_cx18_exit(struct snd_cx18_card *cxsc)
234 {
235 	struct cx18 *cx = to_cx18(cxsc->v4l2_dev);
236 
237 	/* FIXME - pointer checks & shutdown cxsc */
238 
239 	snd_card_free(cxsc->sc);
240 	cx->alsa = NULL;
241 }
242 
243 static int __exit cx18_alsa_exit_callback(struct device *dev, void *data)
244 {
245 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
246 	struct snd_cx18_card *cxsc;
247 
248 	if (v4l2_dev == NULL) {
249 		printk(KERN_ERR "cx18-alsa: %s: struct v4l2_device * is NULL\n",
250 		       __func__);
251 		return 0;
252 	}
253 
254 	cxsc = to_snd_cx18_card(v4l2_dev);
255 	if (cxsc == NULL) {
256 		CX18_ALSA_WARN("%s: struct snd_cx18_card * is NULL\n",
257 			       __func__);
258 		return 0;
259 	}
260 
261 	snd_cx18_exit(cxsc);
262 	return 0;
263 }
264 
265 static void __exit cx18_alsa_exit(void)
266 {
267 	struct device_driver *drv;
268 	int ret;
269 
270 	printk(KERN_INFO "cx18-alsa: module unloading...\n");
271 
272 	drv = driver_find("cx18", &pci_bus_type);
273 	ret = driver_for_each_device(drv, NULL, NULL, cx18_alsa_exit_callback);
274 	(void)ret;	/* suppress compiler warning */
275 
276 	cx18_ext_init = NULL;
277 	printk(KERN_INFO "cx18-alsa: module unload complete\n");
278 }
279 
280 module_init(cx18_alsa_init);
281 module_exit(cx18_alsa_exit);
282