drivers/staging/vc04_services/bcm2835-audio/bcm2835.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /* Copyright 2011 Broadcom Corporation.  All rights reserved. */

 #include <linux/platform_device.h>

 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/module.h>

 #include "bcm2835.h"

 static bool enable_hdmi;
 static bool enable_headphones;
 static bool enable_compat_alsa = 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(enable_compat_alsa, bool, 0444);
 MODULE_PARM_DESC(enable_compat_alsa,
 		 "Enables ALSA compatibility 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;
 }

 typedef int (*bcm2835_audio_newpcm_func)(struct bcm2835_chip *chip,
 					 const char *name,
 					 enum snd_bcm2835_route route,
 					 u32 numchannels);

 typedef int (*bcm2835_audio_newctl_func)(struct bcm2835_chip *chip);

 struct bcm2835_audio_driver {
 	struct device_driver driver;
 	const char *shortname;
 	const char *longname;
 	int minchannels;
 	bcm2835_audio_newpcm_func newpcm;
 	bcm2835_audio_newctl_func newctl;
 	enum snd_bcm2835_route route;
 };

 static int bcm2835_audio_alsa_newpcm(struct bcm2835_chip *chip,
 				     const char *name,
 				     enum snd_bcm2835_route route,
 				     u32 numchannels)
 {
 	int err;

 	err = snd_bcm2835_new_pcm(chip, "bcm2835 ALSA", 0, AUDIO_DEST_AUTO,
 				  numchannels - 1, false);
 	if (err)
 		return err;

 	err = snd_bcm2835_new_pcm(chip, "bcm2835 IEC958/HDMI", 1, 0, 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_alsa = {
 	.driver = {
 		.name = "bcm2835_alsa",
 		.owner = THIS_MODULE,
 	},
 	.shortname = "bcm2835 ALSA",
 	.longname  = "bcm2835 ALSA",
 	.minchannels = 2,
 	.newpcm = bcm2835_audio_alsa_newpcm,
 	.newctl = snd_bcm2835_new_ctl,
 };

 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_simple_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_alsa,
 		.is_enabled = &enable_compat_alsa,
 	},
 	{
 		.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;
 	}

 	strcpy(card->driver, audio_driver->driver.name);
 	strcpy(card->shortname, audio_driver->shortname);
 	strcpy(card->longname, audio_driver->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 platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	int 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 platform_device *pdev,
 				    pm_message_t state)
 {
 	return 0;
 }

 static int snd_bcm2835_alsa_resume(struct platform_device *pdev)
 {
 	return 0;
 }

 #endif

 static struct platform_driver bcm2835_alsa_driver = {
 	.probe = snd_bcm2835_alsa_probe,
 #ifdef CONFIG_PM
 	.suspend = snd_bcm2835_alsa_suspend,
 	.resume = snd_bcm2835_alsa_resume,
 #endif
 	.driver = {
 		.name = "bcm2835_audio",
 	},
 };
 module_platform_driver(bcm2835_alsa_driver);

 MODULE_AUTHOR("Dom Cobley");
 MODULE_DESCRIPTION("Alsa driver for BCM2835 chip");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:bcm2835_audio");
	// SPDX-License-Identifier: GPL-2.0
	/* Copyright 2011 Broadcom Corporation. All rights reserved. */

	#include <linux/platform_device.h>

	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/module.h>

	#include "bcm2835.h"

	static bool enable_hdmi;
	static bool enable_headphones;
	static bool enable_compat_alsa = 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(enable_compat_alsa, bool, 0444);
	MODULE_PARM_DESC(enable_compat_alsa,
	"Enables ALSA compatibility 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;
	}

	typedef int (bcm2835_audio_newpcm_func)(struct bcm2835_chip chip,
	const char *name,
	enum snd_bcm2835_route route,
	u32 numchannels);

	typedef int (bcm2835_audio_newctl_func)(struct bcm2835_chip chip);

	struct bcm2835_audio_driver {
	struct device_driver driver;
	const char *shortname;
	const char *longname;
	int minchannels;
	bcm2835_audio_newpcm_func newpcm;
	bcm2835_audio_newctl_func newctl;
	enum snd_bcm2835_route route;
	};

	static int bcm2835_audio_alsa_newpcm(struct bcm2835_chip *chip,
	const char *name,
	enum snd_bcm2835_route route,
	u32 numchannels)
	{
	int err;

	err = snd_bcm2835_new_pcm(chip, "bcm2835 ALSA", 0, AUDIO_DEST_AUTO,
	numchannels - 1, false);
	if (err)
	return err;

	err = snd_bcm2835_new_pcm(chip, "bcm2835 IEC958/HDMI", 1, 0, 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_alsa = {
	.driver = {
	.name = "bcm2835_alsa",
	.owner = THIS_MODULE,
	},
	.shortname = "bcm2835 ALSA",
	.longname = "bcm2835 ALSA",
	.minchannels = 2,
	.newpcm = bcm2835_audio_alsa_newpcm,
	.newctl = snd_bcm2835_new_ctl,
	};

	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_simple_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_alsa,
	.is_enabled = &enable_compat_alsa,
	},
	{
	.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;
	}

	strcpy(card->driver, audio_driver->driver.name);
	strcpy(card->shortname, audio_driver->shortname);
	strcpy(card->longname, audio_driver->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 platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	int 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 platform_device *pdev,
	pm_message_t state)
	{
	return 0;
	}

	static int snd_bcm2835_alsa_resume(struct platform_device *pdev)
	{
	return 0;
	}

	#endif

	static struct platform_driver bcm2835_alsa_driver = {
	.probe = snd_bcm2835_alsa_probe,
	#ifdef CONFIG_PM
	.suspend = snd_bcm2835_alsa_suspend,
	.resume = snd_bcm2835_alsa_resume,
	#endif
	.driver = {
	.name = "bcm2835_audio",
	},
	};
	module_platform_driver(bcm2835_alsa_driver);

	MODULE_AUTHOR("Dom Cobley");
	MODULE_DESCRIPTION("Alsa driver for BCM2835 chip");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:bcm2835_audio");