/*
 * Renesas R-Car Audio DMAC support
 *
 * Copyright (C) 2015 Renesas Electronics Corp.
 * Copyright (c) 2015 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include "rsnd.h"

static void rsnd_dmaen_complete(void *data)
{
	struct rsnd_dma *dma = (struct rsnd_dma *)data;
	struct rsnd_mod *mod = rsnd_dma_to_mod(dma);
	struct rsnd_dai_stream *io = rsnd_mod_to_io(mod);

	/*
	 * Renesas sound Gen1 needs 1 DMAC,
	 * Gen2 needs 2 DMAC.
	 * In Gen2 case, it are Audio-DMAC, and Audio-DMAC-peri-peri.
	 * But, Audio-DMAC-peri-peri doesn't have interrupt,
	 * and this driver is assuming that here.
	 *
	 * If Audio-DMAC-peri-peri has interrpt,
	 * rsnd_dai_pointer_update() will be called twice,
	 * ant it will breaks io->byte_pos
	 */

	rsnd_dai_pointer_update(io, io->byte_per_period);
}

#define DMA_NAME_SIZE 16
static int _rsnd_dmaen_of_name(char *dma_name, struct rsnd_mod *mod)
{
	if (mod)
		return snprintf(dma_name, DMA_NAME_SIZE / 2, "%s%d",
				rsnd_mod_dma_name(mod), rsnd_mod_id(mod));
	else
		return snprintf(dma_name, DMA_NAME_SIZE / 2, "mem");

}

static void rsnd_dmaen_of_name(struct rsnd_mod *mod_from,
			     struct rsnd_mod *mod_to,
			     char *dma_name)
{
	int index = 0;

	index = _rsnd_dmaen_of_name(dma_name + index, mod_from);
	*(dma_name + index++) = '_';
	index = _rsnd_dmaen_of_name(dma_name + index, mod_to);
}

static void rsnd_dmaen_stop(struct rsnd_dma *dma)
{
	dmaengine_terminate_all(dma->chan);
}

static void rsnd_dmaen_start(struct rsnd_dma *dma)
{
	struct rsnd_mod *mod = rsnd_dma_to_mod(dma);
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct rsnd_dai_stream *io = rsnd_mod_to_io(mod);
	struct snd_pcm_substream *substream = io->substream;
	struct device *dev = rsnd_priv_to_dev(priv);
	struct dma_async_tx_descriptor *desc;

	desc = dmaengine_prep_dma_cyclic(dma->chan,
					 (dma->addr) ? dma->addr :
					 substream->runtime->dma_addr,
					 snd_pcm_lib_buffer_bytes(substream),
					 snd_pcm_lib_period_bytes(substream),
					 dma->dir,
					 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

	if (!desc) {
		dev_err(dev, "dmaengine_prep_slave_sg() fail\n");
		return;
	}

	desc->callback		= rsnd_dmaen_complete;
	desc->callback_param	= dma;

	if (dmaengine_submit(desc) < 0) {
		dev_err(dev, "dmaengine_submit() fail\n");
		return;
	}

	dma_async_issue_pending(dma->chan);
}

static int rsnd_dmaen_init(struct rsnd_priv *priv, struct rsnd_dma *dma, int id,
			   struct rsnd_mod *mod_from, struct rsnd_mod *mod_to)
{
	struct device *dev = rsnd_priv_to_dev(priv);
	struct dma_slave_config cfg = {};
	struct rsnd_mod *mod = rsnd_dma_to_mod(dma);
	struct rsnd_dai_stream *io = rsnd_mod_to_io(mod);
	int is_play = rsnd_io_is_play(io);
	char dma_name[DMA_NAME_SIZE];
	dma_cap_mask_t mask;
	int ret;

	if (dma->chan) {
		dev_err(dev, "it already has dma channel\n");
		return -EIO;
	}

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);

	rsnd_dmaen_of_name(mod_from, mod_to, dma_name);

	cfg.direction	= is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
	cfg.src_addr	= dma->src_addr;
	cfg.dst_addr	= dma->dst_addr;
	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;

	dev_dbg(dev, "dma : %s %pad -> %pad\n",
		dma_name, &cfg.src_addr, &cfg.dst_addr);

	dma->chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
						     (void *)id, dev,
						     dma_name);
	if (!dma->chan) {
		dev_err(dev, "can't get dma channel\n");
		goto rsnd_dma_channel_err;
	}

	ret = dmaengine_slave_config(dma->chan, &cfg);
	if (ret < 0)
		goto rsnd_dma_init_err;

	dma->addr = is_play ? cfg.src_addr : cfg.dst_addr;
	dma->dir = is_play ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;

	return 0;

rsnd_dma_init_err:
	rsnd_dma_quit(dma);
rsnd_dma_channel_err:

	/*
	 * DMA failed. try to PIO mode
	 * see
	 *	rsnd_ssi_fallback()
	 *	rsnd_rdai_continuance_probe()
	 */
	return -EAGAIN;
}

static void rsnd_dmaen_quit(struct rsnd_dma *dma)
{
	if (dma->chan)
		dma_release_channel(dma->chan);

	dma->chan = NULL;
}

static struct rsnd_dma_ops rsnd_dmaen_ops = {
	.start	= rsnd_dmaen_start,
	.stop	= rsnd_dmaen_stop,
	.init	= rsnd_dmaen_init,
	.quit	= rsnd_dmaen_quit,
};

/*
 *	DMA read/write register offset
 *
 *	RSND_xxx_I_N	for Audio DMAC input
 *	RSND_xxx_O_N	for Audio DMAC output
 *	RSND_xxx_I_P	for Audio DMAC peri peri input
 *	RSND_xxx_O_P	for Audio DMAC peri peri output
 *
 *	ex) R-Car H2 case
 *	      mod        / DMAC in    / DMAC out   / DMAC PP in / DMAC pp out
 *	SSI : 0xec541000 / 0xec241008 / 0xec24100c
 *	SSIU: 0xec541000 / 0xec100000 / 0xec100000 / 0xec400000 / 0xec400000
 *	SCU : 0xec500000 / 0xec000000 / 0xec004000 / 0xec300000 / 0xec304000
 *	CMD : 0xec500000 /            / 0xec008000                0xec308000
 */
#define RDMA_SSI_I_N(addr, i)	(addr ##_reg - 0x00300000 + (0x40 * i) + 0x8)
#define RDMA_SSI_O_N(addr, i)	(addr ##_reg - 0x00300000 + (0x40 * i) + 0xc)

#define RDMA_SSIU_I_N(addr, i)	(addr ##_reg - 0x00441000 + (0x1000 * i))
#define RDMA_SSIU_O_N(addr, i)	(addr ##_reg - 0x00441000 + (0x1000 * i))

#define RDMA_SSIU_I_P(addr, i)	(addr ##_reg - 0x00141000 + (0x1000 * i))
#define RDMA_SSIU_O_P(addr, i)	(addr ##_reg - 0x00141000 + (0x1000 * i))

#define RDMA_SRC_I_N(addr, i)	(addr ##_reg - 0x00500000 + (0x400 * i))
#define RDMA_SRC_O_N(addr, i)	(addr ##_reg - 0x004fc000 + (0x400 * i))

#define RDMA_SRC_I_P(addr, i)	(addr ##_reg - 0x00200000 + (0x400 * i))
#define RDMA_SRC_O_P(addr, i)	(addr ##_reg - 0x001fc000 + (0x400 * i))

#define RDMA_CMD_O_N(addr, i)	(addr ##_reg - 0x004f8000 + (0x400 * i))
#define RDMA_CMD_O_P(addr, i)	(addr ##_reg - 0x001f8000 + (0x400 * i))

static dma_addr_t
rsnd_gen2_dma_addr(struct rsnd_priv *priv,
		   struct rsnd_mod *mod,
		   int is_play, int is_from)
{
	struct device *dev = rsnd_priv_to_dev(priv);
	struct rsnd_dai_stream *io = rsnd_mod_to_io(mod);
	phys_addr_t ssi_reg = rsnd_gen_get_phy_addr(priv, RSND_GEN2_SSI);
	phys_addr_t src_reg = rsnd_gen_get_phy_addr(priv, RSND_GEN2_SCU);
	int is_ssi = !!(rsnd_io_to_mod_ssi(io) == mod);
	int use_src = !!rsnd_io_to_mod_src(io);
	int use_dvc = !!rsnd_io_to_mod_dvc(io);
	int id = rsnd_mod_id(mod);
	struct dma_addr {
		dma_addr_t out_addr;
		dma_addr_t in_addr;
	} dma_addrs[3][2][3] = {
		/* SRC */
		{{{ 0,				0 },
		  /* Capture */
		  { RDMA_SRC_O_N(src, id),	RDMA_SRC_I_P(src, id) },
		  { RDMA_CMD_O_N(src, id),	RDMA_SRC_I_P(src, id) } },
		 /* Playback */
		 {{ 0,				0, },
		  { RDMA_SRC_O_P(src, id),	RDMA_SRC_I_N(src, id) },
		  { RDMA_CMD_O_P(src, id),	RDMA_SRC_I_N(src, id) } }
		},
		/* SSI */
		/* Capture */
		{{{ RDMA_SSI_O_N(ssi, id),	0 },
		  { RDMA_SSIU_O_P(ssi, id),	0 },
		  { RDMA_SSIU_O_P(ssi, id),	0 } },
		 /* Playback */
		 {{ 0,				RDMA_SSI_I_N(ssi, id) },
		  { 0,				RDMA_SSIU_I_P(ssi, id) },
		  { 0,				RDMA_SSIU_I_P(ssi, id) } }
		},
		/* SSIU */
		/* Capture */
		{{{ RDMA_SSIU_O_N(ssi, id),	0 },
		  { RDMA_SSIU_O_P(ssi, id),	0 },
		  { RDMA_SSIU_O_P(ssi, id),	0 } },
		 /* Playback */
		 {{ 0,				RDMA_SSIU_I_N(ssi, id) },
		  { 0,				RDMA_SSIU_I_P(ssi, id) },
		  { 0,				RDMA_SSIU_I_P(ssi, id) } } },
	};

	/* it shouldn't happen */
	if (use_dvc && !use_src)
		dev_err(dev, "DVC is selected without SRC\n");

	/* use SSIU or SSI ? */
	if (is_ssi && (0 == strcmp(rsnd_mod_dma_name(mod), "ssiu")))
		is_ssi++;

	return (is_from) ?
		dma_addrs[is_ssi][is_play][use_src + use_dvc].out_addr :
		dma_addrs[is_ssi][is_play][use_src + use_dvc].in_addr;
}

static dma_addr_t rsnd_dma_addr(struct rsnd_priv *priv,
				struct rsnd_mod *mod,
				int is_play, int is_from)
{
	/*
	 * gen1 uses default DMA addr
	 */
	if (rsnd_is_gen1(priv))
		return 0;

	if (!mod)
		return 0;

	return rsnd_gen2_dma_addr(priv, mod, is_play, is_from);
}

#define MOD_MAX 4 /* MEM/SSI/SRC/DVC */
static void rsnd_dma_of_path(struct rsnd_dma *dma,
			     int is_play,
			     struct rsnd_mod **mod_from,
			     struct rsnd_mod **mod_to)
{
	struct rsnd_mod *this = rsnd_dma_to_mod(dma);
	struct rsnd_dai_stream *io = rsnd_mod_to_io(this);
	struct rsnd_mod *ssi = rsnd_io_to_mod_ssi(io);
	struct rsnd_mod *src = rsnd_io_to_mod_src(io);
	struct rsnd_mod *dvc = rsnd_io_to_mod_dvc(io);
	struct rsnd_mod *mod[MOD_MAX];
	int i, index;


	for (i = 0; i < MOD_MAX; i++)
		mod[i] = NULL;

	/*
	 * in play case...
	 *
	 * src -> dst
	 *
	 * mem -> SSI
	 * mem -> SRC -> SSI
	 * mem -> SRC -> DVC -> SSI
	 */
	mod[0] = NULL; /* for "mem" */
	index = 1;
	for (i = 1; i < MOD_MAX; i++) {
		if (!src) {
			mod[i] = ssi;
		} else if (!dvc) {
			mod[i] = src;
			src = NULL;
		} else {
			if ((!is_play) && (this == src))
				this = dvc;

			mod[i] = (is_play) ? src : dvc;
			i++;
			mod[i] = (is_play) ? dvc : src;
			src = NULL;
			dvc = NULL;
		}

		if (mod[i] == this)
			index = i;

		if (mod[i] == ssi)
			break;
	}

	if (is_play) {
		*mod_from = mod[index - 1];
		*mod_to   = mod[index];
	} else {
		*mod_from = mod[index];
		*mod_to   = mod[index - 1];
	}
}

void rsnd_dma_stop(struct rsnd_dma *dma)
{
	dma->ops->stop(dma);
}

void rsnd_dma_start(struct rsnd_dma *dma)
{
	dma->ops->start(dma);
}

void rsnd_dma_quit(struct rsnd_dma *dma)
{
	dma->ops->quit(dma);
}

int rsnd_dma_init(struct rsnd_priv *priv, struct rsnd_dma *dma, int id)
{
	struct rsnd_mod *mod = rsnd_dma_to_mod(dma);
	struct rsnd_mod *mod_from;
	struct rsnd_mod *mod_to;
	struct rsnd_dai_stream *io = rsnd_mod_to_io(mod);
	int is_play = rsnd_io_is_play(io);

	rsnd_dma_of_path(dma, is_play, &mod_from, &mod_to);

	dma->src_addr = rsnd_dma_addr(priv, mod_from, is_play, 1);
	dma->dst_addr = rsnd_dma_addr(priv, mod_to,   is_play, 0);

	dma->ops = &rsnd_dmaen_ops;

	return dma->ops->init(priv, dma, id, mod_from, mod_to);
}