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(v4l2_dev: cxsc->v4l2_dev)->alsa = NULL;
61
62 /* FIXME - take any other stopping actions needed */
63
64 kfree(objp: 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(cxsc: 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(size: 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(v4l2_dev: 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(buf: sc->shortname, size: sizeof(sc->shortname), fmt: "CX18-%d",
103 cx->instance);
104
105 /* sc->longname is read from /proc/asound/cards */
106 snprintf(buf: sc->longname, size: sizeof(sc->longname),
107 fmt: "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(parent: &cx->pci_dev->dev,
127 SNDRV_DEFAULT_IDX1, /* use first available id */
128 SNDRV_DEFAULT_STR1, /* xid from end of shortname*/
129 THIS_MODULE, extra_size: 0, card_ret: &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: &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(card: 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(card: sc);
174 kfree(objp: 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(v4l2_dev: cxsc->v4l2_dev);
229
230 /* FIXME - pointer checks & shutdown cxsc */
231
232 snd_card_free(card: 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(name: "cx18", bus: &pci_bus_type);
266 ret = driver_for_each_device(drv, NULL, NULL, fn: 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);
275

source code of linux/drivers/media/pci/cx18/cx18-alsa-main.c