sound/hda/hdac_bus.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * HD-audio core bus driver
  */

 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/export.h>
 #include <sound/hdaudio.h>
 #include "local.h"
 #include "trace.h"

 static void snd_hdac_bus_process_unsol_events(struct work_struct *work);

 static const struct hdac_bus_ops default_ops = {
 	.command = snd_hdac_bus_send_cmd,
 	.get_response = snd_hdac_bus_get_response,
 };

 /**
  * snd_hdac_bus_init - initialize a HD-audio bas bus
  * @bus: the pointer to bus object
  * @dev: device pointer
  * @ops: bus verb operators
  *
  * Returns 0 if successful, or a negative error code.
  */
 int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
 		      const struct hdac_bus_ops *ops)
 {
 	memset(bus, 0, sizeof(*bus));
 	bus->dev = dev;
 	if (ops)
 		bus->ops = ops;
 	else
 		bus->ops = &default_ops;
 	bus->dma_type = SNDRV_DMA_TYPE_DEV;
 	INIT_LIST_HEAD(&bus->stream_list);
 	INIT_LIST_HEAD(&bus->codec_list);
 	INIT_WORK(&bus->unsol_work, snd_hdac_bus_process_unsol_events);
 	spin_lock_init(&bus->reg_lock);
 	mutex_init(&bus->cmd_mutex);
 	mutex_init(&bus->lock);
 	INIT_LIST_HEAD(&bus->hlink_list);
 	init_waitqueue_head(&bus->rirb_wq);
 	bus->irq = -1;

 	/*
 	 * Default value of '8' is as per the HD audio specification (Rev 1.0a).
 	 * Following relation is used to derive STRIPE control value.
 	 *  For sample rate <= 48K:
 	 *   { ((num_channels * bits_per_sample) / number of SDOs) >= 8 }
 	 *  For sample rate > 48K:
 	 *   { ((num_channels * bits_per_sample * rate/48000) /
 	 *	number of SDOs) >= 8 }
 	 */
 	bus->sdo_limit = 8;

 	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_hdac_bus_init);

 /**
  * snd_hdac_bus_exit - clean up a HD-audio bas bus
  * @bus: the pointer to bus object
  */
 void snd_hdac_bus_exit(struct hdac_bus *bus)
 {
 	WARN_ON(!list_empty(&bus->stream_list));
 	WARN_ON(!list_empty(&bus->codec_list));
 	cancel_work_sync(&bus->unsol_work);
 }
 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);

 /**
  * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
  * @bus: bus object
  * @addr: the HDAC device address
  * @cmd: HD-audio encoded verb
  * @res: pointer to store the response, NULL if performing asynchronously
  *
  * Returns 0 if successful, or a negative error code.
  */
 int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
 			   unsigned int cmd, unsigned int *res)
 {
 	int err;

 	mutex_lock(&bus->cmd_mutex);
 	err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
 	mutex_unlock(&bus->cmd_mutex);
 	return err;
 }

 /**
  * snd_hdac_bus_exec_verb_unlocked - unlocked version
  * @bus: bus object
  * @addr: the HDAC device address
  * @cmd: HD-audio encoded verb
  * @res: pointer to store the response, NULL if performing asynchronously
  *
  * Returns 0 if successful, or a negative error code.
  */
 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
 				    unsigned int cmd, unsigned int *res)
 {
 	unsigned int tmp;
 	int err;

 	if (cmd == ~0)
 		return -EINVAL;

 	if (res)
 		*res = -1;
 	else if (bus->sync_write)
 		res = &tmp;
 	for (;;) {
 		trace_hda_send_cmd(bus, cmd);
 		err = bus->ops->command(bus, cmd);
 		if (err != -EAGAIN)
 			break;
 		/* process pending verbs */
 		err = bus->ops->get_response(bus, addr, &tmp);
 		if (err)
 			break;
 	}
 	if (!err && res) {
 		err = bus->ops->get_response(bus, addr, res);
 		trace_hda_get_response(bus, addr, *res);
 	}
 	return err;
 }
 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);

 /**
  * snd_hdac_bus_queue_event - add an unsolicited event to queue
  * @bus: the BUS
  * @res: unsolicited event (lower 32bit of RIRB entry)
  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
  *
  * Adds the given event to the queue.  The events are processed in
  * the workqueue asynchronously.  Call this function in the interrupt
  * hanlder when RIRB receives an unsolicited event.
  */
 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
 {
 	unsigned int wp;

 	if (!bus)
 		return;

 	trace_hda_unsol_event(bus, res, res_ex);
 	wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
 	bus->unsol_wp = wp;

 	wp <<= 1;
 	bus->unsol_queue[wp] = res;
 	bus->unsol_queue[wp + 1] = res_ex;

 	schedule_work(&bus->unsol_work);
 }

 /*
  * process queued unsolicited events
  */
 static void snd_hdac_bus_process_unsol_events(struct work_struct *work)
 {
 	struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
 	struct hdac_device *codec;
 	struct hdac_driver *drv;
 	unsigned int rp, caddr, res;

 	spin_lock_irq(&bus->reg_lock);
 	while (bus->unsol_rp != bus->unsol_wp) {
 		rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
 		bus->unsol_rp = rp;
 		rp <<= 1;
 		res = bus->unsol_queue[rp];
 		caddr = bus->unsol_queue[rp + 1];
 		if (!(caddr & (1 << 4))) /* no unsolicited event? */
 			continue;
 		codec = bus->caddr_tbl[caddr & 0x0f];
 		if (!codec || !codec->dev.driver)
 			continue;
 		spin_unlock_irq(&bus->reg_lock);
 		drv = drv_to_hdac_driver(codec->dev.driver);
 		if (drv->unsol_event)
 			drv->unsol_event(codec, res);
 		spin_lock_irq(&bus->reg_lock);
 	}
 	spin_unlock_irq(&bus->reg_lock);
 }

 /**
  * snd_hdac_bus_add_device - Add a codec to bus
  * @bus: HDA core bus
  * @codec: HDA core device to add
  *
  * Adds the given codec to the list in the bus.  The caddr_tbl array
  * and codec_powered bits are updated, as well.
  * Returns zero if success, or a negative error code.
  */
 int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
 {
 	if (bus->caddr_tbl[codec->addr]) {
 		dev_err(bus->dev, "address 0x%x is already occupied\n",
 			codec->addr);
 		return -EBUSY;
 	}

 	list_add_tail(&codec->list, &bus->codec_list);
 	bus->caddr_tbl[codec->addr] = codec;
 	set_bit(codec->addr, &bus->codec_powered);
 	bus->num_codecs++;
 	return 0;
 }

 /**
  * snd_hdac_bus_remove_device - Remove a codec from bus
  * @bus: HDA core bus
  * @codec: HDA core device to remove
  */
 void snd_hdac_bus_remove_device(struct hdac_bus *bus,
 				struct hdac_device *codec)
 {
 	WARN_ON(bus != codec->bus);
 	if (list_empty(&codec->list))
 		return;
 	list_del_init(&codec->list);
 	bus->caddr_tbl[codec->addr] = NULL;
 	clear_bit(codec->addr, &bus->codec_powered);
 	bus->num_codecs--;
 	flush_work(&bus->unsol_work);
 }

 #ifdef CONFIG_SND_HDA_ALIGNED_MMIO
 /* Helpers for aligned read/write of mmio space, for Tegra */
 unsigned int snd_hdac_aligned_read(void __iomem *addr, unsigned int mask)
 {
 	void __iomem *aligned_addr =
 		(void __iomem *)((unsigned long)(addr) & ~0x3);
 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
 	unsigned int v;

 	v = readl(aligned_addr);
 	return (v >> shift) & mask;
 }
 EXPORT_SYMBOL_GPL(snd_hdac_aligned_read);

 void snd_hdac_aligned_write(unsigned int val, void __iomem *addr,
 			    unsigned int mask)
 {
 	void __iomem *aligned_addr =
 		(void __iomem *)((unsigned long)(addr) & ~0x3);
 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
 	unsigned int v;

 	v = readl(aligned_addr);
 	v &= ~(mask << shift);
 	v |= val << shift;
 	writel(v, aligned_addr);
 }
 EXPORT_SYMBOL_GPL(snd_hdac_aligned_write);
 #endif /* CONFIG_SND_HDA_ALIGNED_MMIO */
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* HD-audio core bus driver
	*/

	#include <linux/init.h>
	#include <linux/io.h>
	#include <linux/device.h>
	#include <linux/module.h>
	#include <linux/export.h>
	#include <sound/hdaudio.h>
	#include "local.h"
	#include "trace.h"

	static void snd_hdac_bus_process_unsol_events(struct work_struct *work);

	static const struct hdac_bus_ops default_ops = {
	.command = snd_hdac_bus_send_cmd,
	.get_response = snd_hdac_bus_get_response,
	};

	/**
	* snd_hdac_bus_init - initialize a HD-audio bas bus
	* @bus: the pointer to bus object
	* @dev: device pointer
	* @ops: bus verb operators
	*
	* Returns 0 if successful, or a negative error code.
	*/
	int snd_hdac_bus_init(struct hdac_bus bus, struct device dev,
	const struct hdac_bus_ops *ops)
	{
	memset(bus, 0, sizeof(*bus));
	bus->dev = dev;
	if (ops)
	bus->ops = ops;
	else
	bus->ops = &default_ops;
	bus->dma_type = SNDRV_DMA_TYPE_DEV;
	INIT_LIST_HEAD(&bus->stream_list);
	INIT_LIST_HEAD(&bus->codec_list);
	INIT_WORK(&bus->unsol_work, snd_hdac_bus_process_unsol_events);
	spin_lock_init(&bus->reg_lock);
	mutex_init(&bus->cmd_mutex);
	mutex_init(&bus->lock);
	INIT_LIST_HEAD(&bus->hlink_list);
	init_waitqueue_head(&bus->rirb_wq);
	bus->irq = -1;

	/*
	* Default value of '8' is as per the HD audio specification (Rev 1.0a).
	* Following relation is used to derive STRIPE control value.
	* For sample rate <= 48K:
	* { ((num_channels * bits_per_sample) / number of SDOs) >= 8 }
	* For sample rate > 48K:
	* { ((num_channels * bits_per_sample * rate/48000) /
	* number of SDOs) >= 8 }
	*/
	bus->sdo_limit = 8;

	return 0;
	}
	EXPORT_SYMBOL_GPL(snd_hdac_bus_init);

	/**
	* snd_hdac_bus_exit - clean up a HD-audio bas bus
	* @bus: the pointer to bus object
	*/
	void snd_hdac_bus_exit(struct hdac_bus *bus)
	{
	WARN_ON(!list_empty(&bus->stream_list));
	WARN_ON(!list_empty(&bus->codec_list));
	cancel_work_sync(&bus->unsol_work);
	}
	EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);

	/**
	* snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
	* @bus: bus object
	* @addr: the HDAC device address
	* @cmd: HD-audio encoded verb
	* @res: pointer to store the response, NULL if performing asynchronously
	*
	* Returns 0 if successful, or a negative error code.
	*/
	int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
	unsigned int cmd, unsigned int *res)
	{
	int err;

	mutex_lock(&bus->cmd_mutex);
	err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
	mutex_unlock(&bus->cmd_mutex);
	return err;
	}

	/**
	* snd_hdac_bus_exec_verb_unlocked - unlocked version
	* @bus: bus object
	* @addr: the HDAC device address
	* @cmd: HD-audio encoded verb
	* @res: pointer to store the response, NULL if performing asynchronously
	*
	* Returns 0 if successful, or a negative error code.
	*/
	int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
	unsigned int cmd, unsigned int *res)
	{
	unsigned int tmp;
	int err;

	if (cmd == ~0)
	return -EINVAL;

	if (res)
	*res = -1;
	else if (bus->sync_write)
	res = &tmp;
	for (;;) {
	trace_hda_send_cmd(bus, cmd);
	err = bus->ops->command(bus, cmd);
	if (err != -EAGAIN)
	break;
	/* process pending verbs */
	err = bus->ops->get_response(bus, addr, &tmp);
	if (err)
	break;
	}
	if (!err && res) {
	err = bus->ops->get_response(bus, addr, res);
	trace_hda_get_response(bus, addr, *res);
	}
	return err;
	}
	EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);

	/**
	* snd_hdac_bus_queue_event - add an unsolicited event to queue
	* @bus: the BUS
	* @res: unsolicited event (lower 32bit of RIRB entry)
	* @res_ex: codec addr and flags (upper 32bit or RIRB entry)
	*
	* Adds the given event to the queue. The events are processed in
	* the workqueue asynchronously. Call this function in the interrupt
	* hanlder when RIRB receives an unsolicited event.
	*/
	void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
	{
	unsigned int wp;

	if (!bus)
	return;

	trace_hda_unsol_event(bus, res, res_ex);
	wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
	bus->unsol_wp = wp;

	wp <<= 1;
	bus->unsol_queue[wp] = res;
	bus->unsol_queue[wp + 1] = res_ex;

	schedule_work(&bus->unsol_work);
	}

	/*
	* process queued unsolicited events
	*/
	static void snd_hdac_bus_process_unsol_events(struct work_struct *work)
	{
	struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
	struct hdac_device *codec;
	struct hdac_driver *drv;
	unsigned int rp, caddr, res;

	spin_lock_irq(&bus->reg_lock);
	while (bus->unsol_rp != bus->unsol_wp) {
	rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
	bus->unsol_rp = rp;
	rp <<= 1;
	res = bus->unsol_queue[rp];
	caddr = bus->unsol_queue[rp + 1];
	if (!(caddr & (1 << 4))) /* no unsolicited event? */
	continue;
	codec = bus->caddr_tbl[caddr & 0x0f];
	if (!codec \|\| !codec->dev.driver)
	continue;
	spin_unlock_irq(&bus->reg_lock);
	drv = drv_to_hdac_driver(codec->dev.driver);
	if (drv->unsol_event)
	drv->unsol_event(codec, res);
	spin_lock_irq(&bus->reg_lock);
	}
	spin_unlock_irq(&bus->reg_lock);
	}

	/**
	* snd_hdac_bus_add_device - Add a codec to bus
	* @bus: HDA core bus
	* @codec: HDA core device to add
	*
	* Adds the given codec to the list in the bus. The caddr_tbl array
	* and codec_powered bits are updated, as well.
	* Returns zero if success, or a negative error code.
	*/
	int snd_hdac_bus_add_device(struct hdac_bus bus, struct hdac_device codec)
	{
	if (bus->caddr_tbl[codec->addr]) {
	dev_err(bus->dev, "address 0x%x is already occupied\n",
	codec->addr);
	return -EBUSY;
	}

	list_add_tail(&codec->list, &bus->codec_list);
	bus->caddr_tbl[codec->addr] = codec;
	set_bit(codec->addr, &bus->codec_powered);
	bus->num_codecs++;
	return 0;
	}

	/**
	* snd_hdac_bus_remove_device - Remove a codec from bus
	* @bus: HDA core bus
	* @codec: HDA core device to remove
	*/
	void snd_hdac_bus_remove_device(struct hdac_bus *bus,
	struct hdac_device *codec)
	{
	WARN_ON(bus != codec->bus);
	if (list_empty(&codec->list))
	return;
	list_del_init(&codec->list);
	bus->caddr_tbl[codec->addr] = NULL;
	clear_bit(codec->addr, &bus->codec_powered);
	bus->num_codecs--;
	flush_work(&bus->unsol_work);
	}

	#ifdef CONFIG_SND_HDA_ALIGNED_MMIO
	/* Helpers for aligned read/write of mmio space, for Tegra */
	unsigned int snd_hdac_aligned_read(void __iomem *addr, unsigned int mask)
	{
	void __iomem *aligned_addr =
	(void __iomem *)((unsigned long)(addr) & ~0x3);
	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
	unsigned int v;

	v = readl(aligned_addr);
	return (v >> shift) & mask;
	}
	EXPORT_SYMBOL_GPL(snd_hdac_aligned_read);

	void snd_hdac_aligned_write(unsigned int val, void __iomem *addr,
	unsigned int mask)
	{
	void __iomem *aligned_addr =
	(void __iomem *)((unsigned long)(addr) & ~0x3);
	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
	unsigned int v;

	v = readl(aligned_addr);
	v &= ~(mask << shift);
	v \|= val << shift;
	writel(v, aligned_addr);
	}
	EXPORT_SYMBOL_GPL(snd_hdac_aligned_write);
	#endif /* CONFIG_SND_HDA_ALIGNED_MMIO */