/*
 * Renesas R-Car SSIU/SSI support
 *
 * Copyright (C) 2013 Renesas Solutions Corp.
 * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
 *
 * Based on fsi.c
 * Kuninori Morimoto <morimoto.kuninori@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 <linux/delay.h>
#include "rsnd.h"
#define RSND_SSI_NAME_SIZE 16

/*
 * SSICR
 */
#define	FORCE		(1 << 31)	/* Fixed */
#define	DMEN		(1 << 28)	/* DMA Enable */
#define	UIEN		(1 << 27)	/* Underflow Interrupt Enable */
#define	OIEN		(1 << 26)	/* Overflow Interrupt Enable */
#define	IIEN		(1 << 25)	/* Idle Mode Interrupt Enable */
#define	DIEN		(1 << 24)	/* Data Interrupt Enable */

#define	DWL_8		(0 << 19)	/* Data Word Length */
#define	DWL_16		(1 << 19)	/* Data Word Length */
#define	DWL_18		(2 << 19)	/* Data Word Length */
#define	DWL_20		(3 << 19)	/* Data Word Length */
#define	DWL_22		(4 << 19)	/* Data Word Length */
#define	DWL_24		(5 << 19)	/* Data Word Length */
#define	DWL_32		(6 << 19)	/* Data Word Length */

#define	SWL_32		(3 << 16)	/* R/W System Word Length */
#define	SCKD		(1 << 15)	/* Serial Bit Clock Direction */
#define	SWSD		(1 << 14)	/* Serial WS Direction */
#define	SCKP		(1 << 13)	/* Serial Bit Clock Polarity */
#define	SWSP		(1 << 12)	/* Serial WS Polarity */
#define	SDTA		(1 << 10)	/* Serial Data Alignment */
#define	DEL		(1 <<  8)	/* Serial Data Delay */
#define	CKDV(v)		(v <<  4)	/* Serial Clock Division Ratio */
#define	TRMD		(1 <<  1)	/* Transmit/Receive Mode Select */
#define	EN		(1 <<  0)	/* SSI Module Enable */

/*
 * SSISR
 */
#define	UIRQ		(1 << 27)	/* Underflow Error Interrupt Status */
#define	OIRQ		(1 << 26)	/* Overflow Error Interrupt Status */
#define	IIRQ		(1 << 25)	/* Idle Mode Interrupt Status */
#define	DIRQ		(1 << 24)	/* Data Interrupt Status Flag */

/*
 * SSIWSR
 */
#define CONT		(1 << 8)	/* WS Continue Function */

struct rsnd_ssi {
	struct clk *clk;
	struct rsnd_ssi_platform_info *info; /* rcar_snd.h */
	struct rsnd_ssi *parent;
	struct rsnd_mod mod;

	struct rsnd_dai *rdai;
	struct rsnd_dai_stream *io;
	u32 cr_own;
	u32 cr_clk;
	u32 cr_etc;
	int err;
	int dma_offset;
	unsigned int usrcnt;
	unsigned int rate;
};

struct rsnd_ssiu {
	u32 ssi_mode0;
	u32 ssi_mode1;

	int ssi_nr;
	struct rsnd_ssi *ssi;
};

#define for_each_rsnd_ssi(pos, priv, i)					\
	for (i = 0;							\
	     (i < rsnd_ssi_nr(priv)) &&					\
		((pos) = ((struct rsnd_ssiu *)((priv)->ssiu))->ssi + i); \
	     i++)

#define rsnd_ssi_nr(priv) (((struct rsnd_ssiu *)((priv)->ssiu))->ssi_nr)
#define rsnd_mod_to_ssi(_mod) container_of((_mod), struct rsnd_ssi, mod)
#define rsnd_dma_to_ssi(dma)  rsnd_mod_to_ssi(rsnd_dma_to_mod(dma))
#define rsnd_ssi_pio_available(ssi) ((ssi)->info->pio_irq > 0)
#define rsnd_ssi_dma_available(ssi) \
	rsnd_dma_available(rsnd_mod_to_dma(&(ssi)->mod))
#define rsnd_ssi_clk_from_parent(ssi) ((ssi)->parent)
#define rsnd_rdai_is_clk_master(rdai) ((rdai)->clk_master)
#define rsnd_ssi_mode_flags(p) ((p)->info->flags)
#define rsnd_ssi_dai_id(ssi) ((ssi)->info->dai_id)
#define rsnd_ssi_to_ssiu(ssi)\
	(((struct rsnd_ssiu *)((ssi) - rsnd_mod_id(&(ssi)->mod))) - 1)

static void rsnd_ssi_mode_init(struct rsnd_priv *priv,
			       struct rsnd_ssiu *ssiu)
{
	struct device *dev = rsnd_priv_to_dev(priv);
	struct rsnd_ssi *ssi;
	u32 flags;
	u32 val;
	int i;

	/*
	 * SSI_MODE0
	 */
	ssiu->ssi_mode0 = 0;
	for_each_rsnd_ssi(ssi, priv, i) {
		flags = rsnd_ssi_mode_flags(ssi);

		/* see also BUSIF_MODE */
		if (!(flags & RSND_SSI_DEPENDENT)) {
			ssiu->ssi_mode0 |= (1 << i);
			dev_dbg(dev, "SSI%d uses INDEPENDENT mode\n", i);
		} else {
			dev_dbg(dev, "SSI%d uses DEPENDENT mode\n", i);
		}
	}

	/*
	 * SSI_MODE1
	 */
#define ssi_parent_set(p, sync, adg, ext)		\
	do {						\
		ssi->parent = ssiu->ssi + p;		\
		if (flags & RSND_SSI_CLK_FROM_ADG)	\
			val = adg;			\
		else					\
			val = ext;			\
		if (flags & RSND_SSI_SYNC)		\
			val |= sync;			\
	} while (0)

	ssiu->ssi_mode1 = 0;
	for_each_rsnd_ssi(ssi, priv, i) {
		flags = rsnd_ssi_mode_flags(ssi);

		if (!(flags & RSND_SSI_CLK_PIN_SHARE))
			continue;

		val = 0;
		switch (i) {
		case 1:
			ssi_parent_set(0, (1 << 4), (0x2 << 0), (0x1 << 0));
			break;
		case 2:
			ssi_parent_set(0, (1 << 4), (0x2 << 2), (0x1 << 2));
			break;
		case 4:
			ssi_parent_set(3, (1 << 20), (0x2 << 16), (0x1 << 16));
			break;
		case 8:
			ssi_parent_set(7, 0, 0, 0);
			break;
		}

		ssiu->ssi_mode1 |= val;
	}
}

static void rsnd_ssi_mode_set(struct rsnd_ssi *ssi)
{
	struct rsnd_ssiu *ssiu = rsnd_ssi_to_ssiu(ssi);

	rsnd_mod_write(&ssi->mod, SSI_MODE0, ssiu->ssi_mode0);
	rsnd_mod_write(&ssi->mod, SSI_MODE1, ssiu->ssi_mode1);
}

static void rsnd_ssi_status_check(struct rsnd_mod *mod,
				  u32 bit)
{
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct device *dev = rsnd_priv_to_dev(priv);
	u32 status;
	int i;

	for (i = 0; i < 1024; i++) {
		status = rsnd_mod_read(mod, SSISR);
		if (status & bit)
			return;

		udelay(50);
	}

	dev_warn(dev, "status check failed\n");
}

static int rsnd_ssi_master_clk_start(struct rsnd_ssi *ssi,
				     unsigned int rate)
{
	struct rsnd_priv *priv = rsnd_mod_to_priv(&ssi->mod);
	struct device *dev = rsnd_priv_to_dev(priv);
	int i, j, ret;
	int adg_clk_div_table[] = {
		1, 6, /* see adg.c */
	};
	int ssi_clk_mul_table[] = {
		1, 2, 4, 8, 16, 6, 12,
	};
	unsigned int main_rate;

	/*
	 * Find best clock, and try to start ADG
	 */
	for (i = 0; i < ARRAY_SIZE(adg_clk_div_table); i++) {
		for (j = 0; j < ARRAY_SIZE(ssi_clk_mul_table); j++) {

			/*
			 * this driver is assuming that
			 * system word is 64fs (= 2 x 32bit)
			 * see rsnd_ssi_start()
			 */
			main_rate = rate / adg_clk_div_table[i]
				* 32 * 2 * ssi_clk_mul_table[j];

			ret = rsnd_adg_ssi_clk_try_start(&ssi->mod, main_rate);
			if (0 == ret) {
				ssi->rate	= rate;
				ssi->cr_clk	= FORCE | SWL_32 |
						  SCKD | SWSD | CKDV(j);

				dev_dbg(dev, "ssi%d outputs %u Hz\n",
					rsnd_mod_id(&ssi->mod), rate);

				return 0;
			}
		}
	}

	dev_err(dev, "unsupported clock rate\n");
	return -EIO;
}

static void rsnd_ssi_master_clk_stop(struct rsnd_ssi *ssi)
{
	ssi->rate = 0;
	ssi->cr_clk = 0;
	rsnd_adg_ssi_clk_stop(&ssi->mod);
}

static void rsnd_ssi_hw_start(struct rsnd_ssi *ssi,
			      struct rsnd_dai *rdai,
			      struct rsnd_dai_stream *io)
{
	struct rsnd_priv *priv = rsnd_mod_to_priv(&ssi->mod);
	struct device *dev = rsnd_priv_to_dev(priv);
	u32 cr;

	if (0 == ssi->usrcnt) {
		clk_enable(ssi->clk);

		if (rsnd_rdai_is_clk_master(rdai)) {
			struct snd_pcm_runtime *runtime;

			runtime = rsnd_io_to_runtime(io);

			if (rsnd_ssi_clk_from_parent(ssi))
				rsnd_ssi_hw_start(ssi->parent, rdai, io);
			else
				rsnd_ssi_master_clk_start(ssi, runtime->rate);
		}
	}

	cr  =	ssi->cr_own	|
		ssi->cr_clk	|
		ssi->cr_etc	|
		EN;

	rsnd_mod_write(&ssi->mod, SSICR, cr);

	ssi->usrcnt++;

	dev_dbg(dev, "ssi%d hw started\n", rsnd_mod_id(&ssi->mod));
}

static void rsnd_ssi_hw_stop(struct rsnd_ssi *ssi,
			     struct rsnd_dai *rdai)
{
	struct rsnd_priv *priv = rsnd_mod_to_priv(&ssi->mod);
	struct device *dev = rsnd_priv_to_dev(priv);
	u32 cr;

	if (0 == ssi->usrcnt) /* stop might be called without start */
		return;

	ssi->usrcnt--;

	if (0 == ssi->usrcnt) {
		/*
		 * disable all IRQ,
		 * and, wait all data was sent
		 */
		cr  =	ssi->cr_own	|
			ssi->cr_clk;

		rsnd_mod_write(&ssi->mod, SSICR, cr | EN);
		rsnd_ssi_status_check(&ssi->mod, DIRQ);

		/*
		 * disable SSI,
		 * and, wait idle state
		 */
		rsnd_mod_write(&ssi->mod, SSICR, cr);	/* disabled all */
		rsnd_ssi_status_check(&ssi->mod, IIRQ);

		if (rsnd_rdai_is_clk_master(rdai)) {
			if (rsnd_ssi_clk_from_parent(ssi))
				rsnd_ssi_hw_stop(ssi->parent, rdai);
			else
				rsnd_ssi_master_clk_stop(ssi);
		}

		clk_disable(ssi->clk);
	}

	dev_dbg(dev, "ssi%d hw stopped\n", rsnd_mod_id(&ssi->mod));
}

/*
 *	SSI mod common functions
 */
static int rsnd_ssi_init(struct rsnd_mod *mod,
			 struct rsnd_dai *rdai,
			 struct rsnd_dai_stream *io)
{
	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct device *dev = rsnd_priv_to_dev(priv);
	struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);
	u32 cr;

	cr = FORCE;

	/*
	 * always use 32bit system word for easy clock calculation.
	 * see also rsnd_ssi_master_clk_enable()
	 */
	cr |= SWL_32;

	/*
	 * init clock settings for SSICR
	 */
	switch (runtime->sample_bits) {
	case 16:
		cr |= DWL_16;
		break;
	case 32:
		cr |= DWL_24;
		break;
	default:
		return -EIO;
	}

	if (rdai->bit_clk_inv)
		cr |= SCKP;
	if (rdai->frm_clk_inv)
		cr |= SWSP;
	if (rdai->data_alignment)
		cr |= SDTA;
	if (rdai->sys_delay)
		cr |= DEL;
	if (rsnd_dai_is_play(rdai, io))
		cr |= TRMD;

	/*
	 * set ssi parameter
	 */
	ssi->rdai	= rdai;
	ssi->io		= io;
	ssi->cr_own	= cr;
	ssi->err	= -1; /* ignore 1st error */

	rsnd_ssi_mode_set(ssi);

	dev_dbg(dev, "%s.%d init\n", rsnd_mod_name(mod), rsnd_mod_id(mod));

	return 0;
}

static int rsnd_ssi_quit(struct rsnd_mod *mod,
			 struct rsnd_dai *rdai,
			 struct rsnd_dai_stream *io)
{
	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct device *dev = rsnd_priv_to_dev(priv);

	dev_dbg(dev, "%s.%d quit\n", rsnd_mod_name(mod), rsnd_mod_id(mod));

	if (ssi->err > 0)
		dev_warn(dev, "ssi under/over flow err = %d\n", ssi->err);

	ssi->rdai	= NULL;
	ssi->io		= NULL;
	ssi->cr_own	= 0;
	ssi->err	= 0;

	return 0;
}

static void rsnd_ssi_record_error(struct rsnd_ssi *ssi, u32 status)
{
	/* under/over flow error */
	if (status & (UIRQ | OIRQ)) {
		ssi->err++;

		/* clear error status */
		rsnd_mod_write(&ssi->mod, SSISR, 0);
	}
}

/*
 *		SSI PIO
 */
static irqreturn_t rsnd_ssi_pio_interrupt(int irq, void *data)
{
	struct rsnd_ssi *ssi = data;
	struct rsnd_dai_stream *io = ssi->io;
	u32 status = rsnd_mod_read(&ssi->mod, SSISR);
	irqreturn_t ret = IRQ_NONE;

	if (io && (status & DIRQ)) {
		struct rsnd_dai *rdai = ssi->rdai;
		struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);
		u32 *buf = (u32 *)(runtime->dma_area +
				   rsnd_dai_pointer_offset(io, 0));

		rsnd_ssi_record_error(ssi, status);

		/*
		 * 8/16/32 data can be assesse to TDR/RDR register
		 * directly as 32bit data
		 * see rsnd_ssi_init()
		 */
		if (rsnd_dai_is_play(rdai, io))
			rsnd_mod_write(&ssi->mod, SSITDR, *buf);
		else
			*buf = rsnd_mod_read(&ssi->mod, SSIRDR);

		rsnd_dai_pointer_update(io, sizeof(*buf));

		ret = IRQ_HANDLED;
	}

	return ret;
}

static int rsnd_ssi_pio_start(struct rsnd_mod *mod,
			      struct rsnd_dai *rdai,
			      struct rsnd_dai_stream *io)
{
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
	struct device *dev = rsnd_priv_to_dev(priv);

	/* enable PIO IRQ */
	ssi->cr_etc = UIEN | OIEN | DIEN;

	rsnd_ssi_hw_start(ssi, rdai, io);

	dev_dbg(dev, "%s.%d start\n", rsnd_mod_name(mod), rsnd_mod_id(mod));

	return 0;
}

static int rsnd_ssi_pio_stop(struct rsnd_mod *mod,
			     struct rsnd_dai *rdai,
			     struct rsnd_dai_stream *io)
{
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct device *dev = rsnd_priv_to_dev(priv);
	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);

	dev_dbg(dev, "%s.%d stop\n", rsnd_mod_name(mod), rsnd_mod_id(mod));

	ssi->cr_etc = 0;

	rsnd_ssi_hw_stop(ssi, rdai);

	return 0;
}

static struct rsnd_mod_ops rsnd_ssi_pio_ops = {
	.name	= "ssi (pio)",
	.init	= rsnd_ssi_init,
	.quit	= rsnd_ssi_quit,
	.start	= rsnd_ssi_pio_start,
	.stop	= rsnd_ssi_pio_stop,
};

static int rsnd_ssi_dma_inquiry(struct rsnd_dma *dma, dma_addr_t *buf, int *len)
{
	struct rsnd_ssi *ssi = rsnd_dma_to_ssi(dma);
	struct rsnd_dai_stream *io = ssi->io;
	struct snd_pcm_runtime *runtime = rsnd_io_to_runtime(io);

	*len = io->byte_per_period;
	*buf = runtime->dma_addr +
		rsnd_dai_pointer_offset(io, ssi->dma_offset + *len);
	ssi->dma_offset = *len; /* it cares A/B plane */

	return 0;
}

static int rsnd_ssi_dma_complete(struct rsnd_dma *dma)
{
	struct rsnd_ssi *ssi = rsnd_dma_to_ssi(dma);
	struct rsnd_dai_stream *io = ssi->io;
	u32 status = rsnd_mod_read(&ssi->mod, SSISR);

	rsnd_ssi_record_error(ssi, status);

	rsnd_dai_pointer_update(ssi->io, io->byte_per_period);

	return 0;
}

static int rsnd_ssi_dma_start(struct rsnd_mod *mod,
			      struct rsnd_dai *rdai,
			      struct rsnd_dai_stream *io)
{
	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
	struct rsnd_dma *dma = rsnd_mod_to_dma(&ssi->mod);

	/* enable DMA transfer */
	ssi->cr_etc = DMEN;
	ssi->dma_offset = 0;

	rsnd_dma_start(dma);

	rsnd_ssi_hw_start(ssi, ssi->rdai, io);

	/* enable WS continue */
	if (rsnd_rdai_is_clk_master(rdai))
		rsnd_mod_write(&ssi->mod, SSIWSR, CONT);

	return 0;
}

static int rsnd_ssi_dma_stop(struct rsnd_mod *mod,
			     struct rsnd_dai *rdai,
			     struct rsnd_dai_stream *io)
{
	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
	struct rsnd_dma *dma = rsnd_mod_to_dma(&ssi->mod);

	ssi->cr_etc = 0;

	rsnd_ssi_hw_stop(ssi, rdai);

	rsnd_dma_stop(dma);

	return 0;
}

static struct rsnd_mod_ops rsnd_ssi_dma_ops = {
	.name	= "ssi (dma)",
	.init	= rsnd_ssi_init,
	.quit	= rsnd_ssi_quit,
	.start	= rsnd_ssi_dma_start,
	.stop	= rsnd_ssi_dma_stop,
};

/*
 *		Non SSI
 */
static int rsnd_ssi_non(struct rsnd_mod *mod,
			struct rsnd_dai *rdai,
			struct rsnd_dai_stream *io)
{
	struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
	struct device *dev = rsnd_priv_to_dev(priv);

	dev_dbg(dev, "%s\n", __func__);

	return 0;
}

static struct rsnd_mod_ops rsnd_ssi_non_ops = {
	.name	= "ssi (non)",
	.init	= rsnd_ssi_non,
	.quit	= rsnd_ssi_non,
	.start	= rsnd_ssi_non,
	.stop	= rsnd_ssi_non,
};

/*
 *		ssi mod function
 */
struct rsnd_mod *rsnd_ssi_mod_get_frm_dai(struct rsnd_priv *priv,
					  int dai_id, int is_play)
{
	struct rsnd_ssi *ssi;
	int i, has_play;

	is_play = !!is_play;

	for_each_rsnd_ssi(ssi, priv, i) {
		if (rsnd_ssi_dai_id(ssi) != dai_id)
			continue;

		has_play = !!(rsnd_ssi_mode_flags(ssi) & RSND_SSI_PLAY);

		if (is_play == has_play)
			return &ssi->mod;
	}

	return NULL;
}

struct rsnd_mod *rsnd_ssi_mod_get(struct rsnd_priv *priv, int id)
{
	BUG_ON(id < 0 || id >= rsnd_ssi_nr(priv));

	return &(((struct rsnd_ssiu *)(priv->ssiu))->ssi + id)->mod;
}

int rsnd_ssi_probe(struct platform_device *pdev,
		   struct rcar_snd_info *info,
		   struct rsnd_priv *priv)
{
	struct rsnd_ssi_platform_info *pinfo;
	struct device *dev = rsnd_priv_to_dev(priv);
	struct rsnd_mod_ops *ops;
	struct clk *clk;
	struct rsnd_ssiu *ssiu;
	struct rsnd_ssi *ssi;
	char name[RSND_SSI_NAME_SIZE];
	int i, nr, ret;

	/*
	 *	init SSI
	 */
	nr	= info->ssi_info_nr;
	ssiu	= devm_kzalloc(dev, sizeof(*ssiu) + (sizeof(*ssi) * nr),
			       GFP_KERNEL);
	if (!ssiu) {
		dev_err(dev, "SSI allocate failed\n");
		return -ENOMEM;
	}

	priv->ssiu	= ssiu;
	ssiu->ssi	= (struct rsnd_ssi *)(ssiu + 1);
	ssiu->ssi_nr	= nr;

	for_each_rsnd_ssi(ssi, priv, i) {
		pinfo = &info->ssi_info[i];

		snprintf(name, RSND_SSI_NAME_SIZE, "ssi.%d", i);

		clk = clk_get(dev, name);
		if (IS_ERR(clk))
			return PTR_ERR(clk);

		ssi->info	= pinfo;
		ssi->clk	= clk;

		ops = &rsnd_ssi_non_ops;

		/*
		 * SSI DMA case
		 */
		if (pinfo->dma_id > 0) {
			ret = rsnd_dma_init(
				priv, rsnd_mod_to_dma(&ssi->mod),
				(rsnd_ssi_mode_flags(ssi) & RSND_SSI_PLAY),
				pinfo->dma_id,
				rsnd_ssi_dma_inquiry,
				rsnd_ssi_dma_complete);
			if (ret < 0)
				dev_info(dev, "SSI DMA failed. try PIO transter\n");
			else
				ops	= &rsnd_ssi_dma_ops;

			dev_dbg(dev, "SSI%d use DMA transfer\n", i);
		}

		/*
		 * SSI PIO case
		 */
		if (!rsnd_ssi_dma_available(ssi) &&
		     rsnd_ssi_pio_available(ssi)) {
			ret = devm_request_irq(dev, pinfo->pio_irq,
					       &rsnd_ssi_pio_interrupt,
					       IRQF_SHARED,
					       dev_name(dev), ssi);
			if (ret) {
				dev_err(dev, "SSI request interrupt failed\n");
				return ret;
			}

			ops	= &rsnd_ssi_pio_ops;

			dev_dbg(dev, "SSI%d use PIO transfer\n", i);
		}

		rsnd_mod_init(priv, &ssi->mod, ops, i);
	}

	rsnd_ssi_mode_init(priv, ssiu);

	dev_dbg(dev, "ssi probed\n");

	return 0;
}

void rsnd_ssi_remove(struct platform_device *pdev,
		   struct rsnd_priv *priv)
{
	struct rsnd_ssi *ssi;
	int i;

	for_each_rsnd_ssi(ssi, priv, i) {
		clk_put(ssi->clk);
		if (rsnd_ssi_dma_available(ssi))
			rsnd_dma_quit(priv, rsnd_mod_to_dma(&ssi->mod));
	}

}