#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/raspberrypi/vchiq_bus.h>
#include "bcm2835.h"
static bool enable_hdmi;
static bool enable_headphones = true;
static int num_channels = MAX_SUBSTREAMS;
module_param(enable_hdmi, bool, 0444);
MODULE_PARM_DESC(enable_hdmi, "Enables HDMI virtual audio device");
module_param(enable_headphones, bool, 0444);
MODULE_PARM_DESC(enable_headphones, "Enables Headphones virtual audio device");
module_param(num_channels, int, 0644);
MODULE_PARM_DESC(num_channels, "Number of audio channels (default: 8)");
static void bcm2835_devm_free_vchi_ctx(struct device *dev, void *res)
{
struct bcm2835_vchi_ctx *vchi_ctx = res;
bcm2835_free_vchi_ctx(vchi_ctx);
}
static int bcm2835_devm_add_vchi_ctx(struct device *dev)
{
struct bcm2835_vchi_ctx *vchi_ctx;
int ret;
vchi_ctx = devres_alloc(bcm2835_devm_free_vchi_ctx, sizeof(*vchi_ctx),
GFP_KERNEL);
if (!vchi_ctx)
return -ENOMEM;
ret = bcm2835_new_vchi_ctx(dev, vchi_ctx);
if (ret) {
devres_free(vchi_ctx);
return ret;
}
devres_add(dev, vchi_ctx);
return 0;
}
struct bcm2835_audio_driver {
struct device_driver driver;
const char *shortname;
const char *longname;
int minchannels;
int (*newpcm)(struct bcm2835_chip *chip, const char *name,
enum snd_bcm2835_route route, u32 numchannels);
int (*newctl)(struct bcm2835_chip *chip);
enum snd_bcm2835_route route;
};
static int bcm2835_audio_dual_newpcm(struct bcm2835_chip *chip,
const char *name,
enum snd_bcm2835_route route,
u32 numchannels)
{
int err;
err = snd_bcm2835_new_pcm(chip, name, 0, route,
numchannels, false);
if (err)
return err;
err = snd_bcm2835_new_pcm(chip, "IEC958", 1, route, 1, true);
if (err)
return err;
return 0;
}
static int bcm2835_audio_simple_newpcm(struct bcm2835_chip *chip,
const char *name,
enum snd_bcm2835_route route,
u32 numchannels)
{
return snd_bcm2835_new_pcm(chip, name, 0, route, numchannels, false);
}
static struct bcm2835_audio_driver bcm2835_audio_hdmi = {
.driver = {
.name = "bcm2835_hdmi",
.owner = THIS_MODULE,
},
.shortname = "bcm2835 HDMI",
.longname = "bcm2835 HDMI",
.minchannels = 1,
.newpcm = bcm2835_audio_dual_newpcm,
.newctl = snd_bcm2835_new_hdmi_ctl,
.route = AUDIO_DEST_HDMI
};
static struct bcm2835_audio_driver bcm2835_audio_headphones = {
.driver = {
.name = "bcm2835_headphones",
.owner = THIS_MODULE,
},
.shortname = "bcm2835 Headphones",
.longname = "bcm2835 Headphones",
.minchannels = 1,
.newpcm = bcm2835_audio_simple_newpcm,
.newctl = snd_bcm2835_new_headphones_ctl,
.route = AUDIO_DEST_HEADPHONES
};
struct bcm2835_audio_drivers {
struct bcm2835_audio_driver *audio_driver;
const bool *is_enabled;
};
static struct bcm2835_audio_drivers children_devices[] = {
{
.audio_driver = &bcm2835_audio_hdmi,
.is_enabled = &enable_hdmi,
},
{
.audio_driver = &bcm2835_audio_headphones,
.is_enabled = &enable_headphones,
},
};
static void bcm2835_card_free(void *data)
{
snd_card_free(data);
}
static int snd_add_child_device(struct device *dev,
struct bcm2835_audio_driver *audio_driver,
u32 numchans)
{
struct bcm2835_chip *chip;
struct snd_card *card;
int err;
err = snd_card_new(dev, -1, NULL, THIS_MODULE, sizeof(*chip), &card);
if (err < 0) {
dev_err(dev, "Failed to create card");
return err;
}
chip = card->private_data;
chip->card = card;
chip->dev = dev;
mutex_init(&chip->audio_mutex);
chip->vchi_ctx = devres_find(dev,
bcm2835_devm_free_vchi_ctx, NULL, NULL);
if (!chip->vchi_ctx) {
err = -ENODEV;
goto error;
}
strscpy(card->driver, audio_driver->driver.name, sizeof(card->driver));
strscpy(card->shortname, audio_driver->shortname, sizeof(card->shortname));
strscpy(card->longname, audio_driver->longname, sizeof(card->longname));
err = audio_driver->newpcm(chip, audio_driver->shortname,
audio_driver->route,
numchans);
if (err) {
dev_err(dev, "Failed to create pcm, error %d\n", err);
goto error;
}
err = audio_driver->newctl(chip);
if (err) {
dev_err(dev, "Failed to create controls, error %d\n", err);
goto error;
}
err = snd_card_register(card);
if (err) {
dev_err(dev, "Failed to register card, error %d\n", err);
goto error;
}
dev_set_drvdata(dev, chip);
err = devm_add_action(dev, bcm2835_card_free, card);
if (err < 0) {
dev_err(dev, "Failed to add devm action, err %d\n", err);
goto error;
}
dev_info(dev, "card created with %d channels\n", numchans);
return 0;
error:
snd_card_free(card);
return err;
}
static int snd_add_child_devices(struct device *device, u32 numchans)
{
int extrachannels_per_driver = 0;
int extrachannels_remainder = 0;
int count_devices = 0;
int extrachannels = 0;
int minchannels = 0;
int i;
for (i = 0; i < ARRAY_SIZE(children_devices); i++)
if (*children_devices[i].is_enabled)
count_devices++;
if (!count_devices)
return 0;
for (i = 0; i < ARRAY_SIZE(children_devices); i++)
if (*children_devices[i].is_enabled)
minchannels +=
children_devices[i].audio_driver->minchannels;
if (minchannels < numchans) {
extrachannels = numchans - minchannels;
extrachannels_per_driver = extrachannels / count_devices;
extrachannels_remainder = extrachannels % count_devices;
}
dev_dbg(device, "minchannels %d\n", minchannels);
dev_dbg(device, "extrachannels %d\n", extrachannels);
dev_dbg(device, "extrachannels_per_driver %d\n",
extrachannels_per_driver);
dev_dbg(device, "extrachannels_remainder %d\n",
extrachannels_remainder);
for (i = 0; i < ARRAY_SIZE(children_devices); i++) {
struct bcm2835_audio_driver *audio_driver;
int numchannels_this_device;
int err;
if (!*children_devices[i].is_enabled)
continue;
audio_driver = children_devices[i].audio_driver;
if (audio_driver->minchannels > numchans) {
dev_err(device,
"Out of channels, needed %d but only %d left\n",
audio_driver->minchannels,
numchans);
continue;
}
numchannels_this_device =
audio_driver->minchannels + extrachannels_per_driver +
extrachannels_remainder;
extrachannels_remainder = 0;
numchans -= numchannels_this_device;
err = snd_add_child_device(device, audio_driver,
numchannels_this_device);
if (err)
return err;
}
return 0;
}
static int snd_bcm2835_alsa_probe(struct vchiq_device *device)
{
struct device *dev = &device->dev;
int err;
err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
if (err) {
dev_err(dev, "dma_set_mask_and_coherent failed: %d\n", err);
return err;
}
if (num_channels <= 0 || num_channels > MAX_SUBSTREAMS) {
num_channels = MAX_SUBSTREAMS;
dev_warn(dev, "Illegal num_channels value, will use %u\n",
num_channels);
}
err = bcm2835_devm_add_vchi_ctx(dev);
if (err)
return err;
err = snd_add_child_devices(dev, num_channels);
if (err)
return err;
return 0;
}
#ifdef CONFIG_PM
static int snd_bcm2835_alsa_suspend(struct vchiq_device *device,
pm_message_t state)
{
return 0;
}
static int snd_bcm2835_alsa_resume(struct vchiq_device *device)
{
return 0;
}
#endif
static struct vchiq_device_id device_id_table[] = {
{ .name = "bcm2835-audio" },
{}
};
MODULE_DEVICE_TABLE(vchiq, device_id_table);
static struct vchiq_driver bcm2835_alsa_driver = {
.probe = snd_bcm2835_alsa_probe,
#ifdef CONFIG_PM
.suspend = snd_bcm2835_alsa_suspend,
.resume = snd_bcm2835_alsa_resume,
#endif
.id_table = device_id_table,
.driver = {
.name = "bcm2835-audio",
},
};
module_vchiq_driver(bcm2835_alsa_driver);
MODULE_AUTHOR("Dom Cobley");
MODULE_DESCRIPTION("Alsa driver for BCM2835 chip");
MODULE_LICENSE("GPL");
