1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2011 Broadcom Corporation. All rights reserved. */
3
4 #include <linux/platform_device.h>
5
6 #include <linux/init.h>
7 #include <linux/slab.h>
8 #include <linux/module.h>
9
10 #include "bcm2835.h"
11
12 static bool enable_hdmi;
13 static bool enable_headphones = true;
14 static int num_channels = MAX_SUBSTREAMS;
15
16 module_param(enable_hdmi, bool, 0444);
17 MODULE_PARM_DESC(enable_hdmi, "Enables HDMI virtual audio device");
18 module_param(enable_headphones, bool, 0444);
19 MODULE_PARM_DESC(enable_headphones, "Enables Headphones virtual audio device");
20 module_param(num_channels, int, 0644);
21 MODULE_PARM_DESC(num_channels, "Number of audio channels (default: 8)");
22
bcm2835_devm_free_vchi_ctx(struct device * dev,void * res)23 static void bcm2835_devm_free_vchi_ctx(struct device *dev, void *res)
24 {
25 struct bcm2835_vchi_ctx *vchi_ctx = res;
26
27 bcm2835_free_vchi_ctx(vchi_ctx);
28 }
29
bcm2835_devm_add_vchi_ctx(struct device * dev)30 static int bcm2835_devm_add_vchi_ctx(struct device *dev)
31 {
32 struct bcm2835_vchi_ctx *vchi_ctx;
33 int ret;
34
35 vchi_ctx = devres_alloc(bcm2835_devm_free_vchi_ctx, sizeof(*vchi_ctx),
36 GFP_KERNEL);
37 if (!vchi_ctx)
38 return -ENOMEM;
39
40 ret = bcm2835_new_vchi_ctx(dev, vchi_ctx);
41 if (ret) {
42 devres_free(vchi_ctx);
43 return ret;
44 }
45
46 devres_add(dev, vchi_ctx);
47
48 return 0;
49 }
50
51 struct bcm2835_audio_driver {
52 struct device_driver driver;
53 const char *shortname;
54 const char *longname;
55 int minchannels;
56 int (*newpcm)(struct bcm2835_chip *chip, const char *name,
57 enum snd_bcm2835_route route, u32 numchannels);
58 int (*newctl)(struct bcm2835_chip *chip);
59 enum snd_bcm2835_route route;
60 };
61
bcm2835_audio_dual_newpcm(struct bcm2835_chip * chip,const char * name,enum snd_bcm2835_route route,u32 numchannels)62 static int bcm2835_audio_dual_newpcm(struct bcm2835_chip *chip,
63 const char *name,
64 enum snd_bcm2835_route route,
65 u32 numchannels)
66 {
67 int err;
68
69 err = snd_bcm2835_new_pcm(chip, name, 0, route,
70 numchannels, false);
71
72 if (err)
73 return err;
74
75 err = snd_bcm2835_new_pcm(chip, "IEC958", 1, route, 1, true);
76 if (err)
77 return err;
78
79 return 0;
80 }
81
bcm2835_audio_simple_newpcm(struct bcm2835_chip * chip,const char * name,enum snd_bcm2835_route route,u32 numchannels)82 static int bcm2835_audio_simple_newpcm(struct bcm2835_chip *chip,
83 const char *name,
84 enum snd_bcm2835_route route,
85 u32 numchannels)
86 {
87 return snd_bcm2835_new_pcm(chip, name, 0, route, numchannels, false);
88 }
89
90 static struct bcm2835_audio_driver bcm2835_audio_hdmi = {
91 .driver = {
92 .name = "bcm2835_hdmi",
93 .owner = THIS_MODULE,
94 },
95 .shortname = "bcm2835 HDMI",
96 .longname = "bcm2835 HDMI",
97 .minchannels = 1,
98 .newpcm = bcm2835_audio_dual_newpcm,
99 .newctl = snd_bcm2835_new_hdmi_ctl,
100 .route = AUDIO_DEST_HDMI
101 };
102
103 static struct bcm2835_audio_driver bcm2835_audio_headphones = {
104 .driver = {
105 .name = "bcm2835_headphones",
106 .owner = THIS_MODULE,
107 },
108 .shortname = "bcm2835 Headphones",
109 .longname = "bcm2835 Headphones",
110 .minchannels = 1,
111 .newpcm = bcm2835_audio_simple_newpcm,
112 .newctl = snd_bcm2835_new_headphones_ctl,
113 .route = AUDIO_DEST_HEADPHONES
114 };
115
116 struct bcm2835_audio_drivers {
117 struct bcm2835_audio_driver *audio_driver;
118 const bool *is_enabled;
119 };
120
121 static struct bcm2835_audio_drivers children_devices[] = {
122 {
123 .audio_driver = &bcm2835_audio_hdmi,
124 .is_enabled = &enable_hdmi,
125 },
126 {
127 .audio_driver = &bcm2835_audio_headphones,
128 .is_enabled = &enable_headphones,
129 },
130 };
131
bcm2835_card_free(void * data)132 static void bcm2835_card_free(void *data)
133 {
134 snd_card_free(data);
135 }
136
snd_add_child_device(struct device * dev,struct bcm2835_audio_driver * audio_driver,u32 numchans)137 static int snd_add_child_device(struct device *dev,
138 struct bcm2835_audio_driver *audio_driver,
139 u32 numchans)
140 {
141 struct bcm2835_chip *chip;
142 struct snd_card *card;
143 int err;
144
145 err = snd_card_new(dev, -1, NULL, THIS_MODULE, sizeof(*chip), &card);
146 if (err < 0) {
147 dev_err(dev, "Failed to create card");
148 return err;
149 }
150
151 chip = card->private_data;
152 chip->card = card;
153 chip->dev = dev;
154 mutex_init(&chip->audio_mutex);
155
156 chip->vchi_ctx = devres_find(dev,
157 bcm2835_devm_free_vchi_ctx, NULL, NULL);
158 if (!chip->vchi_ctx) {
159 err = -ENODEV;
160 goto error;
161 }
162
163 strscpy(card->driver, audio_driver->driver.name, sizeof(card->driver));
164 strscpy(card->shortname, audio_driver->shortname, sizeof(card->shortname));
165 strscpy(card->longname, audio_driver->longname, sizeof(card->longname));
166
167 err = audio_driver->newpcm(chip, audio_driver->shortname,
168 audio_driver->route,
169 numchans);
170 if (err) {
171 dev_err(dev, "Failed to create pcm, error %d\n", err);
172 goto error;
173 }
174
175 err = audio_driver->newctl(chip);
176 if (err) {
177 dev_err(dev, "Failed to create controls, error %d\n", err);
178 goto error;
179 }
180
181 err = snd_card_register(card);
182 if (err) {
183 dev_err(dev, "Failed to register card, error %d\n", err);
184 goto error;
185 }
186
187 dev_set_drvdata(dev, chip);
188
189 err = devm_add_action(dev, bcm2835_card_free, card);
190 if (err < 0) {
191 dev_err(dev, "Failed to add devm action, err %d\n", err);
192 goto error;
193 }
194
195 dev_info(dev, "card created with %d channels\n", numchans);
196 return 0;
197
198 error:
199 snd_card_free(card);
200 return err;
201 }
202
snd_add_child_devices(struct device * device,u32 numchans)203 static int snd_add_child_devices(struct device *device, u32 numchans)
204 {
205 int extrachannels_per_driver = 0;
206 int extrachannels_remainder = 0;
207 int count_devices = 0;
208 int extrachannels = 0;
209 int minchannels = 0;
210 int i;
211
212 for (i = 0; i < ARRAY_SIZE(children_devices); i++)
213 if (*children_devices[i].is_enabled)
214 count_devices++;
215
216 if (!count_devices)
217 return 0;
218
219 for (i = 0; i < ARRAY_SIZE(children_devices); i++)
220 if (*children_devices[i].is_enabled)
221 minchannels +=
222 children_devices[i].audio_driver->minchannels;
223
224 if (minchannels < numchans) {
225 extrachannels = numchans - minchannels;
226 extrachannels_per_driver = extrachannels / count_devices;
227 extrachannels_remainder = extrachannels % count_devices;
228 }
229
230 dev_dbg(device, "minchannels %d\n", minchannels);
231 dev_dbg(device, "extrachannels %d\n", extrachannels);
232 dev_dbg(device, "extrachannels_per_driver %d\n",
233 extrachannels_per_driver);
234 dev_dbg(device, "extrachannels_remainder %d\n",
235 extrachannels_remainder);
236
237 for (i = 0; i < ARRAY_SIZE(children_devices); i++) {
238 struct bcm2835_audio_driver *audio_driver;
239 int numchannels_this_device;
240 int err;
241
242 if (!*children_devices[i].is_enabled)
243 continue;
244
245 audio_driver = children_devices[i].audio_driver;
246
247 if (audio_driver->minchannels > numchans) {
248 dev_err(device,
249 "Out of channels, needed %d but only %d left\n",
250 audio_driver->minchannels,
251 numchans);
252 continue;
253 }
254
255 numchannels_this_device =
256 audio_driver->minchannels + extrachannels_per_driver +
257 extrachannels_remainder;
258 extrachannels_remainder = 0;
259
260 numchans -= numchannels_this_device;
261
262 err = snd_add_child_device(device, audio_driver,
263 numchannels_this_device);
264 if (err)
265 return err;
266 }
267
268 return 0;
269 }
270
snd_bcm2835_alsa_probe(struct platform_device * pdev)271 static int snd_bcm2835_alsa_probe(struct platform_device *pdev)
272 {
273 struct device *dev = &pdev->dev;
274 int err;
275
276 if (num_channels <= 0 || num_channels > MAX_SUBSTREAMS) {
277 num_channels = MAX_SUBSTREAMS;
278 dev_warn(dev, "Illegal num_channels value, will use %u\n",
279 num_channels);
280 }
281
282 err = bcm2835_devm_add_vchi_ctx(dev);
283 if (err)
284 return err;
285
286 err = snd_add_child_devices(dev, num_channels);
287 if (err)
288 return err;
289
290 return 0;
291 }
292
293 #ifdef CONFIG_PM
294
snd_bcm2835_alsa_suspend(struct platform_device * pdev,pm_message_t state)295 static int snd_bcm2835_alsa_suspend(struct platform_device *pdev,
296 pm_message_t state)
297 {
298 return 0;
299 }
300
snd_bcm2835_alsa_resume(struct platform_device * pdev)301 static int snd_bcm2835_alsa_resume(struct platform_device *pdev)
302 {
303 return 0;
304 }
305
306 #endif
307
308 static struct platform_driver bcm2835_alsa_driver = {
309 .probe = snd_bcm2835_alsa_probe,
310 #ifdef CONFIG_PM
311 .suspend = snd_bcm2835_alsa_suspend,
312 .resume = snd_bcm2835_alsa_resume,
313 #endif
314 .driver = {
315 .name = "bcm2835_audio",
316 },
317 };
318 module_platform_driver(bcm2835_alsa_driver);
319
320 MODULE_AUTHOR("Dom Cobley");
321 MODULE_DESCRIPTION("Alsa driver for BCM2835 chip");
322 MODULE_LICENSE("GPL");
323 MODULE_ALIAS("platform:bcm2835_audio");
324