/*
 *  hdac-ext-stream.c - HD-audio extended stream operations.
 *
 *  Copyright (C) 2015 Intel Corp
 *  Author: Jeeja KP <jeeja.kp@intel.com>
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/delay.h>
#include <linux/slab.h>
#include <sound/pcm.h>
#include <sound/hda_register.h>
#include <sound/hdaudio_ext.h>

/**
 * snd_hdac_ext_stream_init - initialize each stream (aka device)
 * @ebus: HD-audio ext core bus
 * @stream: HD-audio ext core stream object to initialize
 * @idx: stream index number
 * @direction: stream direction (SNDRV_PCM_STREAM_PLAYBACK or SNDRV_PCM_STREAM_CAPTURE)
 * @tag: the tag id to assign
 *
 * initialize the stream, if ppcap is enabled then init those and then
 * invoke hdac stream initialization routine
 */
void snd_hdac_ext_stream_init(struct hdac_ext_bus *ebus,
				struct hdac_ext_stream *stream,
				int idx, int direction, int tag)
{
	struct hdac_bus *bus = &ebus->bus;

	if (ebus->ppcap) {
		stream->pphc_addr = ebus->ppcap + AZX_PPHC_BASE +
				AZX_PPHC_INTERVAL * idx;

		stream->pplc_addr = ebus->ppcap + AZX_PPLC_BASE +
				AZX_PPLC_MULTI * ebus->num_streams +
				AZX_PPLC_INTERVAL * idx;
	}

	stream->decoupled = false;
	snd_hdac_stream_init(bus, &stream->hstream, idx, direction, tag);
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_init);

/**
 * snd_hdac_ext_stream_init_all - create and initialize the stream objects
 *   for an extended hda bus
 * @ebus: HD-audio ext core bus
 * @start_idx: start index for streams
 * @num_stream: number of streams to initialize
 * @dir: direction of streams
 */
int snd_hdac_ext_stream_init_all(struct hdac_ext_bus *ebus, int start_idx,
		int num_stream, int dir)
{
	int stream_tag = 0;
	int i, tag, idx = start_idx;

	for (i = 0; i < num_stream; i++) {
		struct hdac_ext_stream *stream =
				kzalloc(sizeof(*stream), GFP_KERNEL);
		if (!stream)
			return -ENOMEM;
		tag = ++stream_tag;
		snd_hdac_ext_stream_init(ebus, stream, idx, dir, tag);
		idx++;
	}

	return 0;

}
EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_init_all);

/**
 * snd_hdac_stream_free_all - free hdac extended stream objects
 *
 * @ebus: HD-audio ext core bus
 */
void snd_hdac_stream_free_all(struct hdac_ext_bus *ebus)
{
	struct hdac_stream *s;
	struct hdac_ext_stream *stream;
	struct hdac_bus *bus = ebus_to_hbus(ebus);

	while (!list_empty(&bus->stream_list)) {
		s = list_first_entry(&bus->stream_list, struct hdac_stream, list);
		stream = stream_to_hdac_ext_stream(s);
		list_del(&s->list);
		kfree(stream);
	}
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_free_all);

/**
 * snd_hdac_ext_stream_decouple - decouple the hdac stream
 * @ebus: HD-audio ext core bus
 * @stream: HD-audio ext core stream object to initialize
 * @decouple: flag to decouple
 */
void snd_hdac_ext_stream_decouple(struct hdac_ext_bus *ebus,
				struct hdac_ext_stream *stream, bool decouple)
{
	struct hdac_stream *hstream = &stream->hstream;
	struct hdac_bus *bus = &ebus->bus;

	spin_lock_irq(&bus->reg_lock);
	if (decouple)
		snd_hdac_updatel(ebus->ppcap, AZX_REG_PP_PPCTL, 0,
				AZX_PPCTL_PROCEN(hstream->index));
	else
		snd_hdac_updatel(ebus->ppcap, AZX_REG_PP_PPCTL,
					AZX_PPCTL_PROCEN(hstream->index), 0);
	stream->decoupled = decouple;
	spin_unlock_irq(&bus->reg_lock);
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_decouple);

/**
 * snd_hdac_ext_linkstream_start - start a stream
 * @stream: HD-audio ext core stream to start
 */
void snd_hdac_ext_link_stream_start(struct hdac_ext_stream *stream)
{
	snd_hdac_updatel(stream->pplc_addr, AZX_REG_PPLCCTL, 0, AZX_PPLCCTL_RUN);
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_link_stream_start);

/**
 * snd_hdac_ext_link_stream_clear - stop a stream DMA
 * @stream: HD-audio ext core stream to stop
 */
void snd_hdac_ext_link_stream_clear(struct hdac_ext_stream *stream)
{
	snd_hdac_updatel(stream->pplc_addr, AZX_REG_PPLCCTL, AZX_PPLCCTL_RUN, 0);
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_link_stream_clear);

/**
 * snd_hdac_ext_link_stream_reset - reset a stream
 * @stream: HD-audio ext core stream to reset
 */
void snd_hdac_ext_link_stream_reset(struct hdac_ext_stream *stream)
{
	unsigned char val;
	int timeout;

	snd_hdac_ext_link_stream_clear(stream);

	snd_hdac_updatel(stream->pplc_addr, AZX_REG_PPLCCTL, 0, AZX_PPLCCTL_STRST);
	udelay(3);
	timeout = 50;
	do {
		val = readl(stream->pplc_addr + AZX_REG_PPLCCTL) &
				AZX_PPLCCTL_STRST;
		if (val)
			break;
		udelay(3);
	} while (--timeout);
	val &= ~AZX_PPLCCTL_STRST;
	writel(val, stream->pplc_addr + AZX_REG_PPLCCTL);
	udelay(3);

	timeout = 50;
	/* waiting for hardware to report that the stream is out of reset */
	do {
		val = readl(stream->pplc_addr + AZX_REG_PPLCCTL) & AZX_PPLCCTL_STRST;
		if (!val)
			break;
		udelay(3);
	} while (--timeout);

}
EXPORT_SYMBOL_GPL(snd_hdac_ext_link_stream_reset);

/**
 * snd_hdac_ext_link_stream_setup -  set up the SD for streaming
 * @stream: HD-audio ext core stream to set up
 * @fmt: stream format
 */
int snd_hdac_ext_link_stream_setup(struct hdac_ext_stream *stream, int fmt)
{
	struct hdac_stream *hstream = &stream->hstream;
	unsigned int val;

	/* make sure the run bit is zero for SD */
	snd_hdac_ext_link_stream_clear(stream);
	/* program the stream_tag */
	val = readl(stream->pplc_addr + AZX_REG_PPLCCTL);
	val = (val & ~AZX_PPLCCTL_STRM_MASK) |
		(hstream->stream_tag << AZX_PPLCCTL_STRM_SHIFT);
	writel(val, stream->pplc_addr + AZX_REG_PPLCCTL);

	/* program the stream format */
	writew(fmt, stream->pplc_addr + AZX_REG_PPLCFMT);

	return 0;
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_link_stream_setup);

/**
 * snd_hdac_ext_link_set_stream_id - maps stream id to link output
 * @link: HD-audio ext link to set up
 * @stream: stream id
 */
void snd_hdac_ext_link_set_stream_id(struct hdac_ext_link *link,
				 int stream)
{
	snd_hdac_updatew(link->ml_addr, AZX_REG_ML_LOSIDV, (1 << stream), 0);
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_link_set_stream_id);

/**
 * snd_hdac_ext_link_clear_stream_id - maps stream id to link output
 * @link: HD-audio ext link to set up
 * @stream: stream id
 */
void snd_hdac_ext_link_clear_stream_id(struct hdac_ext_link *link,
				 int stream)
{
	snd_hdac_updatew(link->ml_addr, AZX_REG_ML_LOSIDV, 0, (1 << stream));
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_link_clear_stream_id);

static struct hdac_ext_stream *
hdac_ext_link_stream_assign(struct hdac_ext_bus *ebus,
				struct snd_pcm_substream *substream)
{
	struct hdac_ext_stream *res = NULL;
	struct hdac_stream *stream = NULL;
	struct hdac_bus *hbus = &ebus->bus;

	if (!ebus->ppcap) {
		dev_err(hbus->dev, "stream type not supported\n");
		return NULL;
	}

	list_for_each_entry(stream, &hbus->stream_list, list) {
		struct hdac_ext_stream *hstream = container_of(stream,
						struct hdac_ext_stream,
						hstream);
		if (stream->direction != substream->stream)
			continue;

		/* check if decoupled stream and not in use is available */
		if (hstream->decoupled && !hstream->link_locked) {
			res = hstream;
			break;
		}

		if (!hstream->link_locked) {
			snd_hdac_ext_stream_decouple(ebus, hstream, true);
			res = hstream;
			break;
		}
	}
	if (res) {
		spin_lock_irq(&hbus->reg_lock);
		res->link_locked = 1;
		res->link_substream = substream;
		spin_unlock_irq(&hbus->reg_lock);
	}
	return res;
}

static struct hdac_ext_stream *
hdac_ext_host_stream_assign(struct hdac_ext_bus *ebus,
				struct snd_pcm_substream *substream)
{
	struct hdac_ext_stream *res = NULL;
	struct hdac_stream *stream = NULL;
	struct hdac_bus *hbus = &ebus->bus;
	int key;

	if (!ebus->ppcap) {
		dev_err(hbus->dev, "stream type not supported\n");
		return NULL;
	}

	/* make a non-zero unique key for the substream */
	key = (substream->pcm->device << 16) | (substream->number << 2) |
			(substream->stream + 1);

	list_for_each_entry(stream, &hbus->stream_list, list) {
		struct hdac_ext_stream *hstream = container_of(stream,
						struct hdac_ext_stream,
						hstream);
		if (stream->direction != substream->stream)
			continue;

		if (!stream->opened) {
			if (!hstream->decoupled)
				snd_hdac_ext_stream_decouple(ebus, hstream, true);
			res = hstream;
			break;
		}
	}
	if (res) {
		spin_lock_irq(&hbus->reg_lock);
		res->hstream.opened = 1;
		res->hstream.running = 0;
		res->hstream.assigned_key = key;
		res->hstream.substream = substream;
		spin_unlock_irq(&hbus->reg_lock);
	}

	return res;
}

/**
 * snd_hdac_ext_stream_assign - assign a stream for the PCM
 * @ebus: HD-audio ext core bus
 * @substream: PCM substream to assign
 * @type: type of stream (coupled, host or link stream)
 *
 * This assigns the stream based on the type (coupled/host/link), for the
 * given PCM substream, assigns it and returns the stream object
 *
 * coupled: Looks for an unused stream
 * host: Looks for an unused decoupled host stream
 * link: Looks for an unused decoupled link stream
 *
 * If no stream is free, returns NULL. The function tries to keep using
 * the same stream object when it's used beforehand.  when a stream is
 * decoupled, it becomes a host stream and link stream.
 */
struct hdac_ext_stream *snd_hdac_ext_stream_assign(struct hdac_ext_bus *ebus,
					   struct snd_pcm_substream *substream,
					   int type)
{
	struct hdac_ext_stream *hstream = NULL;
	struct hdac_stream *stream = NULL;
	struct hdac_bus *hbus = &ebus->bus;

	switch (type) {
	case HDAC_EXT_STREAM_TYPE_COUPLED:
		stream = snd_hdac_stream_assign(hbus, substream);
		if (stream)
			hstream = container_of(stream,
					struct hdac_ext_stream, hstream);
		return hstream;

	case HDAC_EXT_STREAM_TYPE_HOST:
		return hdac_ext_host_stream_assign(ebus, substream);

	case HDAC_EXT_STREAM_TYPE_LINK:
		return hdac_ext_link_stream_assign(ebus, substream);

	default:
		return NULL;
	}
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_assign);

/**
 * snd_hdac_ext_stream_release - release the assigned stream
 * @stream: HD-audio ext core stream to release
 * @type: type of stream (coupled, host or link stream)
 *
 * Release the stream that has been assigned by snd_hdac_ext_stream_assign().
 */
void snd_hdac_ext_stream_release(struct hdac_ext_stream *stream, int type)
{
	struct hdac_bus *bus = stream->hstream.bus;
	struct hdac_ext_bus *ebus = hbus_to_ebus(bus);

	switch (type) {
	case HDAC_EXT_STREAM_TYPE_COUPLED:
		snd_hdac_stream_release(&stream->hstream);
		break;

	case HDAC_EXT_STREAM_TYPE_HOST:
		if (stream->decoupled) {
			snd_hdac_ext_stream_decouple(ebus, stream, false);
			snd_hdac_stream_release(&stream->hstream);
		}
		break;

	case HDAC_EXT_STREAM_TYPE_LINK:
		if (stream->decoupled)
			snd_hdac_ext_stream_decouple(ebus, stream, false);
		spin_lock_irq(&bus->reg_lock);
		stream->link_locked = 0;
		stream->link_substream = NULL;
		spin_unlock_irq(&bus->reg_lock);
		break;

	default:
		dev_dbg(bus->dev, "Invalid type %d\n", type);
	}

}
EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_release);

/**
 * snd_hdac_ext_stream_spbcap_enable - enable SPIB for a stream
 * @ebus: HD-audio ext core bus
 * @enable: flag to enable/disable SPIB
 * @index: stream index for which SPIB need to be enabled
 */
void snd_hdac_ext_stream_spbcap_enable(struct hdac_ext_bus *ebus,
				 bool enable, int index)
{
	u32 mask = 0;
	u32 register_mask = 0;
	struct hdac_bus *bus = &ebus->bus;

	if (!ebus->spbcap) {
		dev_err(bus->dev, "Address of SPB capability is NULL");
		return;
	}

	mask |= (1 << index);

	register_mask = snd_hdac_chip_readl(bus, SPB_SPBFCCTL);

	mask |= register_mask;

	if (enable)
		snd_hdac_updatel(ebus->spbcap, AZX_REG_SPB_SPBFCCTL, 0, mask);
	else
		snd_hdac_updatel(ebus->spbcap, AZX_REG_SPB_SPBFCCTL, mask, 0);
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_stream_spbcap_enable);

/**
 * snd_hdac_ext_stop_streams - stop all stream if running
 * @ebus: HD-audio ext core bus
 */
void snd_hdac_ext_stop_streams(struct hdac_ext_bus *ebus)
{
	struct hdac_bus *bus = ebus_to_hbus(ebus);
	struct hdac_stream *stream;

	if (bus->chip_init) {
		list_for_each_entry(stream, &bus->stream_list, list)
			snd_hdac_stream_stop(stream);
		snd_hdac_bus_stop_chip(bus);
	}
}
EXPORT_SYMBOL_GPL(snd_hdac_ext_stop_streams);