linux/sound/soc/davinci/davinci-mcasp.c

/*
 * ALSA SoC McASP Audio Layer for TI DAVINCI processor
 *
 * Multi-channel Audio Serial Port Driver
 *
 * Author: Nirmal Pandey <n-pandey@ti.com>,
 *         Suresh Rajashekara <suresh.r@ti.com>
 *         Steve Chen <schen@.mvista.com>
 *
 * Copyright:   (C) 2009 MontaVista Software, Inc., <source@mvista.com>
 * Copyright:   (C) 2009  Texas Instruments, India
 *
 * 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/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_device.h>

#include <sound/asoundef.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/initval.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>
#include <sound/omap-pcm.h>

#include "davinci-pcm.h"
#include "edma-pcm.h"
#include "davinci-mcasp.h"

#define MCASP_MAX_AFIFO_DEPTH	64

static u32 context_regs[] = {
	DAVINCI_MCASP_TXFMCTL_REG,
	DAVINCI_MCASP_RXFMCTL_REG,
	DAVINCI_MCASP_TXFMT_REG,
	DAVINCI_MCASP_RXFMT_REG,
	DAVINCI_MCASP_ACLKXCTL_REG,
	DAVINCI_MCASP_ACLKRCTL_REG,
	DAVINCI_MCASP_AHCLKXCTL_REG,
	DAVINCI_MCASP_AHCLKRCTL_REG,
	DAVINCI_MCASP_PDIR_REG,
	DAVINCI_MCASP_RXMASK_REG,
	DAVINCI_MCASP_TXMASK_REG,
	DAVINCI_MCASP_RXTDM_REG,
	DAVINCI_MCASP_TXTDM_REG,
};

struct davinci_mcasp_context {
	u32	config_regs[ARRAY_SIZE(context_regs)];
	u32	afifo_regs[2]; /* for read/write fifo control registers */
	u32	*xrsr_regs; /* for serializer configuration */
};

struct davinci_mcasp {
	struct davinci_pcm_dma_params dma_params[2];
	struct snd_dmaengine_dai_dma_data dma_data[2];
	void __iomem *base;
	u32 fifo_base;
	struct device *dev;
	struct snd_pcm_substream *substreams[2];

	/* McASP specific data */
	int	tdm_slots;
	u8	op_mode;
	u8	num_serializer;
	u8	*serial_dir;
	u8	version;
	u8	bclk_div;
	u16	bclk_lrclk_ratio;
	int	streams;
	u32	irq_request[2];

	int	sysclk_freq;
	bool	bclk_master;

	/* McASP FIFO related */
	u8	txnumevt;
	u8	rxnumevt;

	bool	dat_port;

	/* Used for comstraint setting on the second stream */
	u32	channels;

#ifdef CONFIG_PM_SLEEP
	struct davinci_mcasp_context context;
#endif
};

static inline void mcasp_set_bits(struct davinci_mcasp *mcasp, u32 offset,
				  u32 val)
{
	void __iomem *reg = mcasp->base + offset;
	__raw_writel(__raw_readl(reg) | val, reg);
}

static inline void mcasp_clr_bits(struct davinci_mcasp *mcasp, u32 offset,
				  u32 val)
{
	void __iomem *reg = mcasp->base + offset;
	__raw_writel((__raw_readl(reg) & ~(val)), reg);
}

static inline void mcasp_mod_bits(struct davinci_mcasp *mcasp, u32 offset,
				  u32 val, u32 mask)
{
	void __iomem *reg = mcasp->base + offset;
	__raw_writel((__raw_readl(reg) & ~mask) | val, reg);
}

static inline void mcasp_set_reg(struct davinci_mcasp *mcasp, u32 offset,
				 u32 val)
{
	__raw_writel(val, mcasp->base + offset);
}

static inline u32 mcasp_get_reg(struct davinci_mcasp *mcasp, u32 offset)
{
	return (u32)__raw_readl(mcasp->base + offset);
}

static void mcasp_set_ctl_reg(struct davinci_mcasp *mcasp, u32 ctl_reg, u32 val)
{
	int i = 0;

	mcasp_set_bits(mcasp, ctl_reg, val);

	/* programming GBLCTL needs to read back from GBLCTL and verfiy */
	/* loop count is to avoid the lock-up */
	for (i = 0; i < 1000; i++) {
		if ((mcasp_get_reg(mcasp, ctl_reg) & val) == val)
			break;
	}

	if (i == 1000 && ((mcasp_get_reg(mcasp, ctl_reg) & val) != val))
		printk(KERN_ERR "GBLCTL write error\n");
}

static bool mcasp_is_synchronous(struct davinci_mcasp *mcasp)
{
	u32 rxfmctl = mcasp_get_reg(mcasp, DAVINCI_MCASP_RXFMCTL_REG);
	u32 aclkxctl = mcasp_get_reg(mcasp, DAVINCI_MCASP_ACLKXCTL_REG);

	return !(aclkxctl & TX_ASYNC) && rxfmctl & AFSRE;
}

static void mcasp_start_rx(struct davinci_mcasp *mcasp)
{
	if (mcasp->rxnumevt) {	/* enable FIFO */
		u32 reg = mcasp->fifo_base + MCASP_RFIFOCTL_OFFSET;

		mcasp_clr_bits(mcasp, reg, FIFO_ENABLE);
		mcasp_set_bits(mcasp, reg, FIFO_ENABLE);
	}

	/* Start clocks */
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLR_REG, RXHCLKRST);
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLR_REG, RXCLKRST);
	/*
	 * When ASYNC == 0 the transmit and receive sections operate
	 * synchronously from the transmit clock and frame sync. We need to make
	 * sure that the TX signlas are enabled when starting reception.
	 */
	if (mcasp_is_synchronous(mcasp)) {
		mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXHCLKRST);
		mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXCLKRST);
	}

	/* Activate serializer(s) */
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLR_REG, RXSERCLR);
	/* Release RX state machine */
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLR_REG, RXSMRST);
	/* Release Frame Sync generator */
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLR_REG, RXFSRST);
	if (mcasp_is_synchronous(mcasp))
		mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXFSRST);

	/* enable receive IRQs */
	mcasp_set_bits(mcasp, DAVINCI_MCASP_EVTCTLR_REG,
		       mcasp->irq_request[SNDRV_PCM_STREAM_CAPTURE]);
}

static void mcasp_start_tx(struct davinci_mcasp *mcasp)
{
	u32 cnt;

	if (mcasp->txnumevt) {	/* enable FIFO */
		u32 reg = mcasp->fifo_base + MCASP_WFIFOCTL_OFFSET;

		mcasp_clr_bits(mcasp, reg, FIFO_ENABLE);
		mcasp_set_bits(mcasp, reg, FIFO_ENABLE);
	}

	/* Start clocks */
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXHCLKRST);
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXCLKRST);
	/* Activate serializer(s) */
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXSERCLR);

	/* wait for XDATA to be cleared */
	cnt = 0;
	while (!(mcasp_get_reg(mcasp, DAVINCI_MCASP_TXSTAT_REG) &
		 ~XRDATA) && (cnt < 100000))
		cnt++;

	/* Release TX state machine */
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXSMRST);
	/* Release Frame Sync generator */
	mcasp_set_ctl_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, TXFSRST);

	/* enable transmit IRQs */
	mcasp_set_bits(mcasp, DAVINCI_MCASP_EVTCTLX_REG,
		       mcasp->irq_request[SNDRV_PCM_STREAM_PLAYBACK]);
}

static void davinci_mcasp_start(struct davinci_mcasp *mcasp, int stream)
{
	mcasp->streams++;

	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
		mcasp_start_tx(mcasp);
	else
		mcasp_start_rx(mcasp);
}

static void mcasp_stop_rx(struct davinci_mcasp *mcasp)
{
	/* disable IRQ sources */
	mcasp_clr_bits(mcasp, DAVINCI_MCASP_EVTCTLR_REG,
		       mcasp->irq_request[SNDRV_PCM_STREAM_CAPTURE]);

	/*
	 * In synchronous mode stop the TX clocks if no other stream is
	 * running
	 */
	if (mcasp_is_synchronous(mcasp) && !mcasp->streams)
		mcasp_set_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, 0);

	mcasp_set_reg(mcasp, DAVINCI_MCASP_GBLCTLR_REG, 0);
	mcasp_set_reg(mcasp, DAVINCI_MCASP_RXSTAT_REG, 0xFFFFFFFF);

	if (mcasp->rxnumevt) {	/* disable FIFO */
		u32 reg = mcasp->fifo_base + MCASP_RFIFOCTL_OFFSET;

		mcasp_clr_bits(mcasp, reg, FIFO_ENABLE);
	}
}

static void mcasp_stop_tx(struct davinci_mcasp *mcasp)
{
	u32 val = 0;

	/* disable IRQ sources */
	mcasp_clr_bits(mcasp, DAVINCI_MCASP_EVTCTLX_REG,
		       mcasp->irq_request[SNDRV_PCM_STREAM_PLAYBACK]);

	/*
	 * In synchronous mode keep TX clocks running if the capture stream is
	 * still running.
	 */
	if (mcasp_is_synchronous(mcasp) && mcasp->streams)
		val =  TXHCLKRST | TXCLKRST | TXFSRST;

	mcasp_set_reg(mcasp, DAVINCI_MCASP_GBLCTLX_REG, val);
	mcasp_set_reg(mcasp, DAVINCI_MCASP_TXSTAT_REG, 0xFFFFFFFF);

	if (mcasp->txnumevt) {	/* disable FIFO */
		u32 reg = mcasp->fifo_base + MCASP_WFIFOCTL_OFFSET;

		mcasp_clr_bits(mcasp, reg, FIFO_ENABLE);
	}
}

static void davinci_mcasp_stop(struct davinci_mcasp *mcasp, int stream)
{
	mcasp->streams--;

	if (stream == SNDRV_PCM_STREAM_PLAYBACK)
		mcasp_stop_tx(mcasp);
	else
		mcasp_stop_rx(mcasp);
}

static irqreturn_t davinci_mcasp_tx_irq_handler(int irq, void *data)
{
	struct davinci_mcasp *mcasp = (struct davinci_mcasp *)data;
	struct snd_pcm_substream *substream;
	u32 irq_mask = mcasp->irq_request[SNDRV_PCM_STREAM_PLAYBACK];
	u32 handled_mask = 0;
	u32 stat;

	stat = mcasp_get_reg(mcasp, DAVINCI_MCASP_TXSTAT_REG);
	if (stat & XUNDRN & irq_mask) {
		dev_warn(mcasp->dev, "Transmit buffer underflow\n");
		handled_mask |= XUNDRN;

		substream = mcasp->substreams[SNDRV_PCM_STREAM_PLAYBACK];
		if (substream) {
			snd_pcm_stream_lock_irq(substream);
			if (snd_pcm_running(substream))
				snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
			snd_pcm_stream_unlock_irq(substream);
		}
	}

	if (!handled_mask)
		dev_warn(mcasp->dev, "unhandled tx event. txstat: 0x%08x\n",
			 stat);

	if (stat & XRERR)
		handled_mask |= XRERR;

	/* Ack the handled event only */
	mcasp_set_reg(mcasp, DAVINCI_MCASP_TXSTAT_REG, handled_mask);

	return IRQ_RETVAL(handled_mask);
}

static irqreturn_t davinci_mcasp_rx_irq_handler(int irq, void *data)
{
	struct davinci_mcasp *mcasp = (struct davinci_mcasp *)data;
	struct snd_pcm_substream *substream;
	u32 irq_mask = mcasp->irq_request[SNDRV_PCM_STREAM_CAPTURE];
	u32 handled_mask = 0;
	u32 stat;

	stat = mcasp_get_reg(mcasp, DAVINCI_MCASP_RXSTAT_REG);
	if (stat & ROVRN & irq_mask) {
		dev_warn(mcasp->dev, "Receive buffer overflow\n");
		handled_mask |= ROVRN;

		substream = mcasp->substreams[SNDRV_PCM_STREAM_CAPTURE];
		if (substream) {
			snd_pcm_stream_lock_irq(substream);
			if (snd_pcm_running(substream))
				snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
			snd_pcm_stream_unlock_irq(substream);
		}
	}

	if (!handled_mask)
		dev_warn(mcasp->dev, "unhandled rx event. rxstat: 0x%08x\n",
			 stat);

	if (stat & XRERR)
		handled_mask |= XRERR;

	/* Ack the handled event only */
	mcasp_set_reg(mcasp, DAVINCI_MCASP_RXSTAT_REG, handled_mask);

	return IRQ_RETVAL(handled_mask);
}

static int davinci_mcasp_set_dai_fmt(struct snd_soc_dai *cpu_dai,
					 unsigned int fmt)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);
	int ret = 0;
	u32 data_delay;
	bool fs_pol_rising;
	bool inv_fs = false;

	pm_runtime_get_sync(mcasp->dev);
	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
	case SND_SOC_DAIFMT_DSP_A:
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXDUR);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRDUR);
		/* 1st data bit occur one ACLK cycle after the frame sync */
		data_delay = 1;
		break;
	case SND_SOC_DAIFMT_DSP_B:
	case SND_SOC_DAIFMT_AC97:
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXDUR);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRDUR);
		/* No delay after FS */
		data_delay = 0;
		break;
	case SND_SOC_DAIFMT_I2S:
		/* configure a full-word SYNC pulse (LRCLK) */
		mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXDUR);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRDUR);
		/* 1st data bit occur one ACLK cycle after the frame sync */
		data_delay = 1;
		/* FS need to be inverted */
		inv_fs = true;
		break;
	case SND_SOC_DAIFMT_LEFT_J:
		/* configure a full-word SYNC pulse (LRCLK) */
		mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXDUR);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRDUR);
		/* No delay after FS */
		data_delay = 0;
		break;
	default:
		ret = -EINVAL;
		goto out;
	}

	mcasp_mod_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, FSXDLY(data_delay),
		       FSXDLY(3));
	mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, FSRDLY(data_delay),
		       FSRDLY(3));

	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
	case SND_SOC_DAIFMT_CBS_CFS:
		/* codec is clock and frame slave */
		mcasp_set_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, ACLKXE);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, AFSXE);

		mcasp_set_bits(mcasp, DAVINCI_MCASP_ACLKRCTL_REG, ACLKRE);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, AFSRE);

		mcasp_set_bits(mcasp, DAVINCI_MCASP_PDIR_REG, ACLKX | ACLKR);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AFSX | AFSR);
		mcasp->bclk_master = 1;
		break;
	case SND_SOC_DAIFMT_CBM_CFS:
		/* codec is clock master and frame slave */
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, ACLKXE);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, AFSXE);

		mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKRCTL_REG, ACLKRE);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, AFSRE);

		mcasp_clr_bits(mcasp, DAVINCI_MCASP_PDIR_REG, ACLKX | ACLKR);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AFSX | AFSR);
		mcasp->bclk_master = 0;
		break;
	case SND_SOC_DAIFMT_CBM_CFM:
		/* codec is clock and frame master */
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, ACLKXE);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, AFSXE);

		mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKRCTL_REG, ACLKRE);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, AFSRE);

		mcasp_clr_bits(mcasp, DAVINCI_MCASP_PDIR_REG,
			       ACLKX | AHCLKX | AFSX | ACLKR | AHCLKR | AFSR);
		mcasp->bclk_master = 0;
		break;
	default:
		ret = -EINVAL;
		goto out;
	}

	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
	case SND_SOC_DAIFMT_IB_NF:
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, ACLKXPOL);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKRCTL_REG, ACLKRPOL);
		fs_pol_rising = true;
		break;
	case SND_SOC_DAIFMT_NB_IF:
		mcasp_set_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, ACLKXPOL);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_ACLKRCTL_REG, ACLKRPOL);
		fs_pol_rising = false;
		break;
	case SND_SOC_DAIFMT_IB_IF:
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, ACLKXPOL);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKRCTL_REG, ACLKRPOL);
		fs_pol_rising = false;
		break;
	case SND_SOC_DAIFMT_NB_NF:
		mcasp_set_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, ACLKXPOL);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_ACLKRCTL_REG, ACLKRPOL);
		fs_pol_rising = true;
		break;
	default:
		ret = -EINVAL;
		goto out;
	}

	if (inv_fs)
		fs_pol_rising = !fs_pol_rising;

	if (fs_pol_rising) {
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXPOL);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRPOL);
	} else {
		mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG, FSXPOL);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG, FSRPOL);
	}
out:
	pm_runtime_put_sync(mcasp->dev);
	return ret;
}

static int __davinci_mcasp_set_clkdiv(struct snd_soc_dai *dai, int div_id,
				      int div, bool explicit)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(dai);

	switch (div_id) {
	case 0:		/* MCLK divider */
		mcasp_mod_bits(mcasp, DAVINCI_MCASP_AHCLKXCTL_REG,
			       AHCLKXDIV(div - 1), AHCLKXDIV_MASK);
		mcasp_mod_bits(mcasp, DAVINCI_MCASP_AHCLKRCTL_REG,
			       AHCLKRDIV(div - 1), AHCLKRDIV_MASK);
		break;

	case 1:		/* BCLK divider */
		mcasp_mod_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG,
			       ACLKXDIV(div - 1), ACLKXDIV_MASK);
		mcasp_mod_bits(mcasp, DAVINCI_MCASP_ACLKRCTL_REG,
			       ACLKRDIV(div - 1), ACLKRDIV_MASK);
		if (explicit)
			mcasp->bclk_div = div;
		break;

	case 2:		/* BCLK/LRCLK ratio */
		mcasp->bclk_lrclk_ratio = div;
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static int davinci_mcasp_set_clkdiv(struct snd_soc_dai *dai, int div_id,
				    int div)
{
	return __davinci_mcasp_set_clkdiv(dai, div_id, div, 1);
}

static int davinci_mcasp_set_sysclk(struct snd_soc_dai *dai, int clk_id,
				    unsigned int freq, int dir)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(dai);

	if (dir == SND_SOC_CLOCK_OUT) {
		mcasp_set_bits(mcasp, DAVINCI_MCASP_AHCLKXCTL_REG, AHCLKXE);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_AHCLKRCTL_REG, AHCLKRE);
		mcasp_set_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AHCLKX);
	} else {
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_AHCLKXCTL_REG, AHCLKXE);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_AHCLKRCTL_REG, AHCLKRE);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AHCLKX);
	}

	mcasp->sysclk_freq = freq;

	return 0;
}

static int davinci_config_channel_size(struct davinci_mcasp *mcasp,
				       int word_length)
{
	u32 fmt;
	u32 tx_rotate = (word_length / 4) & 0x7;
	u32 mask = (1ULL << word_length) - 1;
	/*
	 * For captured data we should not rotate, inversion and masking is
	 * enoguh to get the data to the right position:
	 * Format	  data from bus		after reverse (XRBUF)
	 * S16_LE:	|LSB|MSB|xxx|xxx|	|xxx|xxx|MSB|LSB|
	 * S24_3LE:	|LSB|DAT|MSB|xxx|	|xxx|MSB|DAT|LSB|
	 * S24_LE:	|LSB|DAT|MSB|xxx|	|xxx|MSB|DAT|LSB|
	 * S32_LE:	|LSB|DAT|DAT|MSB|	|MSB|DAT|DAT|LSB|
	 */
	u32 rx_rotate = 0;

	/*
	 * if s BCLK-to-LRCLK ratio has been configured via the set_clkdiv()
	 * callback, take it into account here. That allows us to for example
	 * send 32 bits per channel to the codec, while only 16 of them carry
	 * audio payload.
	 * The clock ratio is given for a full period of data (for I2S format
	 * both left and right channels), so it has to be divided by number of
	 * tdm-slots (for I2S - divided by 2).
	 */
	if (mcasp->bclk_lrclk_ratio) {
		u32 slot_length = mcasp->bclk_lrclk_ratio / mcasp->tdm_slots;

		/*
		 * When we have more bclk then it is needed for the data, we
		 * need to use the rotation to move the received samples to have
		 * correct alignment.
		 */
		rx_rotate = (slot_length - word_length) / 4;
		word_length = slot_length;
	}

	/* mapping of the XSSZ bit-field as described in the datasheet */
	fmt = (word_length >> 1) - 1;

	if (mcasp->op_mode != DAVINCI_MCASP_DIT_MODE) {
		mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, RXSSZ(fmt),
			       RXSSZ(0x0F));
		mcasp_mod_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, TXSSZ(fmt),
			       TXSSZ(0x0F));
		mcasp_mod_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, TXROT(tx_rotate),
			       TXROT(7));
		mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, RXROT(rx_rotate),
			       RXROT(7));
		mcasp_set_reg(mcasp, DAVINCI_MCASP_RXMASK_REG, mask);
	}

	mcasp_set_reg(mcasp, DAVINCI_MCASP_TXMASK_REG, mask);

	return 0;
}

static int mcasp_common_hw_param(struct davinci_mcasp *mcasp, int stream,
				 int period_words, int channels)
{
	struct davinci_pcm_dma_params *dma_params = &mcasp->dma_params[stream];
	struct snd_dmaengine_dai_dma_data *dma_data = &mcasp->dma_data[stream];
	int i;
	u8 tx_ser = 0;
	u8 rx_ser = 0;
	u8 slots = mcasp->tdm_slots;
	u8 max_active_serializers = (channels + slots - 1) / slots;
	int active_serializers, numevt, n;
	u32 reg;
	/* Default configuration */
	if (mcasp->version < MCASP_VERSION_3)
		mcasp_set_bits(mcasp, DAVINCI_MCASP_PWREMUMGT_REG, MCASP_SOFT);

	/* All PINS as McASP */
	mcasp_set_reg(mcasp, DAVINCI_MCASP_PFUNC_REG, 0x00000000);

	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
		mcasp_set_reg(mcasp, DAVINCI_MCASP_TXSTAT_REG, 0xFFFFFFFF);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_XEVTCTL_REG, TXDATADMADIS);
	} else {
		mcasp_set_reg(mcasp, DAVINCI_MCASP_RXSTAT_REG, 0xFFFFFFFF);
		mcasp_clr_bits(mcasp, DAVINCI_MCASP_REVTCTL_REG, RXDATADMADIS);
	}

	for (i = 0; i < mcasp->num_serializer; i++) {
		mcasp_set_bits(mcasp, DAVINCI_MCASP_XRSRCTL_REG(i),
			       mcasp->serial_dir[i]);
		if (mcasp->serial_dir[i] == TX_MODE &&
					tx_ser < max_active_serializers) {
			mcasp_set_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AXR(i));
			tx_ser++;
		} else if (mcasp->serial_dir[i] == RX_MODE &&
					rx_ser < max_active_serializers) {
			mcasp_clr_bits(mcasp, DAVINCI_MCASP_PDIR_REG, AXR(i));
			rx_ser++;
		} else {
			mcasp_mod_bits(mcasp, DAVINCI_MCASP_XRSRCTL_REG(i),
				       SRMOD_INACTIVE, SRMOD_MASK);
		}
	}

	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
		active_serializers = tx_ser;
		numevt = mcasp->txnumevt;
		reg = mcasp->fifo_base + MCASP_WFIFOCTL_OFFSET;
	} else {
		active_serializers = rx_ser;
		numevt = mcasp->rxnumevt;
		reg = mcasp->fifo_base + MCASP_RFIFOCTL_OFFSET;
	}

	if (active_serializers < max_active_serializers) {
		dev_warn(mcasp->dev, "stream has more channels (%d) than are "
			 "enabled in mcasp (%d)\n", channels,
			 active_serializers * slots);
		return -EINVAL;
	}

	/* AFIFO is not in use */
	if (!numevt) {
		/* Configure the burst size for platform drivers */
		if (active_serializers > 1) {
			/*
			 * If more than one serializers are in use we have one
			 * DMA request to provide data for all serializers.
			 * For example if three serializers are enabled the DMA
			 * need to transfer three words per DMA request.
			 */
			dma_params->fifo_level = active_serializers;
			dma_data->maxburst = active_serializers;
		} else {
			dma_params->fifo_level = 0;
			dma_data->maxburst = 0;
		}
		return 0;
	}

	if (period_words % active_serializers) {
		dev_err(mcasp->dev, "Invalid combination of period words and "
			"active serializers: %d, %d\n", period_words,
			active_serializers);
		return -EINVAL;
	}

	/*
	 * Calculate the optimal AFIFO depth for platform side:
	 * The number of words for numevt need to be in steps of active
	 * serializers.
	 */
	n = numevt % active_serializers;
	if (n)
		numevt += (active_serializers - n);
	while (period_words % numevt && numevt > 0)
		numevt -= active_serializers;
	if (numevt <= 0)
		numevt = active_serializers;

	mcasp_mod_bits(mcasp, reg, active_serializers, NUMDMA_MASK);
	mcasp_mod_bits(mcasp, reg, NUMEVT(numevt), NUMEVT_MASK);

	/* Configure the burst size for platform drivers */
	if (numevt == 1)
		numevt = 0;
	dma_params->fifo_level = numevt;
	dma_data->maxburst = numevt;

	return 0;
}

static int mcasp_i2s_hw_param(struct davinci_mcasp *mcasp, int stream,
			      int channels)
{
	int i, active_slots;
	int total_slots;
	int active_serializers;
	u32 mask = 0;
	u32 busel = 0;

	total_slots = mcasp->tdm_slots;

	/*
	 * If more than one serializer is needed, then use them with
	 * their specified tdm_slots count. Otherwise, one serializer
	 * can cope with the transaction using as many slots as channels
	 * in the stream, requires channels symmetry
	 */
	active_serializers = (channels + total_slots - 1) / total_slots;
	if (active_serializers == 1)
		active_slots = channels;
	else
		active_slots = total_slots;

	for (i = 0; i < active_slots; i++)
		mask |= (1 << i);

	mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, TX_ASYNC);

	if (!mcasp->dat_port)
		busel = TXSEL;

	mcasp_set_reg(mcasp, DAVINCI_MCASP_TXTDM_REG, mask);
	mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, busel | TXORD);
	mcasp_mod_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG,
		       FSXMOD(total_slots), FSXMOD(0x1FF));

	mcasp_set_reg(mcasp, DAVINCI_MCASP_RXTDM_REG, mask);
	mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, busel | RXORD);
	mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG,
		       FSRMOD(total_slots), FSRMOD(0x1FF));

	return 0;
}

/* S/PDIF */
static int mcasp_dit_hw_param(struct davinci_mcasp *mcasp,
			      unsigned int rate)
{
	u32 cs_value = 0;
	u8 *cs_bytes = (u8*) &cs_value;

	/* Set the TX format : 24 bit right rotation, 32 bit slot, Pad 0
	   and LSB first */
	mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, TXROT(6) | TXSSZ(15));

	/* Set TX frame synch : DIT Mode, 1 bit width, internal, rising edge */
	mcasp_set_reg(mcasp, DAVINCI_MCASP_TXFMCTL_REG, AFSXE | FSXMOD(0x180));

	/* Set the TX tdm : for all the slots */
	mcasp_set_reg(mcasp, DAVINCI_MCASP_TXTDM_REG, 0xFFFFFFFF);

	/* Set the TX clock controls : div = 1 and internal */
	mcasp_set_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, ACLKXE | TX_ASYNC);

	mcasp_clr_bits(mcasp, DAVINCI_MCASP_XEVTCTL_REG, TXDATADMADIS);

	/* Only 44100 and 48000 are valid, both have the same setting */
	mcasp_set_bits(mcasp, DAVINCI_MCASP_AHCLKXCTL_REG, AHCLKXDIV(3));

	/* Enable the DIT */
	mcasp_set_bits(mcasp, DAVINCI_MCASP_TXDITCTL_REG, DITEN);

	/* Set S/PDIF channel status bits */
	cs_bytes[0] = IEC958_AES0_CON_NOT_COPYRIGHT;
	cs_bytes[1] = IEC958_AES1_CON_PCM_CODER;

	switch (rate) {
	case 22050:
		cs_bytes[3] |= IEC958_AES3_CON_FS_22050;
		break;
	case 24000:
		cs_bytes[3] |= IEC958_AES3_CON_FS_24000;
		break;
	case 32000:
		cs_bytes[3] |= IEC958_AES3_CON_FS_32000;
		break;
	case 44100:
		cs_bytes[3] |= IEC958_AES3_CON_FS_44100;
		break;
	case 48000:
		cs_bytes[3] |= IEC958_AES3_CON_FS_48000;
		break;
	case 88200:
		cs_bytes[3] |= IEC958_AES3_CON_FS_88200;
		break;
	case 96000:
		cs_bytes[3] |= IEC958_AES3_CON_FS_96000;
		break;
	case 176400:
		cs_bytes[3] |= IEC958_AES3_CON_FS_176400;
		break;
	case 192000:
		cs_bytes[3] |= IEC958_AES3_CON_FS_192000;
		break;
	default:
		printk(KERN_WARNING "unsupported sampling rate: %d\n", rate);
		return -EINVAL;
	}

	mcasp_set_reg(mcasp, DAVINCI_MCASP_DITCSRA_REG, cs_value);
	mcasp_set_reg(mcasp, DAVINCI_MCASP_DITCSRB_REG, cs_value);

	return 0;
}

static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
					struct snd_pcm_hw_params *params,
					struct snd_soc_dai *cpu_dai)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);
	struct davinci_pcm_dma_params *dma_params =
					&mcasp->dma_params[substream->stream];
	int word_length;
	int channels = params_channels(params);
	int period_size = params_period_size(params);
	int ret;

	/*
	 * If mcasp is BCLK master, and a BCLK divider was not provided by
	 * the machine driver, we need to calculate the ratio.
	 */
	if (mcasp->bclk_master && mcasp->bclk_div == 0 && mcasp->sysclk_freq) {
		unsigned int bclk_freq = snd_soc_params_to_bclk(params);
		unsigned int div = mcasp->sysclk_freq / bclk_freq;
		if (mcasp->sysclk_freq % bclk_freq != 0) {
			if (((mcasp->sysclk_freq / div) - bclk_freq) >
			    (bclk_freq - (mcasp->sysclk_freq / (div+1))))
				div++;
			dev_warn(mcasp->dev,
				 "Inaccurate BCLK: %u Hz / %u != %u Hz\n",
				 mcasp->sysclk_freq, div, bclk_freq);
		}
		__davinci_mcasp_set_clkdiv(cpu_dai, 1, div, 0);
	}

	ret = mcasp_common_hw_param(mcasp, substream->stream,
				    period_size * channels, channels);
	if (ret)
		return ret;

	if (mcasp->op_mode == DAVINCI_MCASP_DIT_MODE)
		ret = mcasp_dit_hw_param(mcasp, params_rate(params));
	else
		ret = mcasp_i2s_hw_param(mcasp, substream->stream,
					 channels);

	if (ret)
		return ret;

	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_U8:
	case SNDRV_PCM_FORMAT_S8:
		dma_params->data_type = 1;
		word_length = 8;
		break;

	case SNDRV_PCM_FORMAT_U16_LE:
	case SNDRV_PCM_FORMAT_S16_LE:
		dma_params->data_type = 2;
		word_length = 16;
		break;

	case SNDRV_PCM_FORMAT_U24_3LE:
	case SNDRV_PCM_FORMAT_S24_3LE:
		dma_params->data_type = 3;
		word_length = 24;
		break;

	case SNDRV_PCM_FORMAT_U24_LE:
	case SNDRV_PCM_FORMAT_S24_LE:
		dma_params->data_type = 4;
		word_length = 24;
		break;

	case SNDRV_PCM_FORMAT_U32_LE:
	case SNDRV_PCM_FORMAT_S32_LE:
		dma_params->data_type = 4;
		word_length = 32;
		break;

	default:
		printk(KERN_WARNING "davinci-mcasp: unsupported PCM format");
		return -EINVAL;
	}

	if (mcasp->version == MCASP_VERSION_2 && !dma_params->fifo_level)
		dma_params->acnt = 4;
	else
		dma_params->acnt = dma_params->data_type;

	davinci_config_channel_size(mcasp, word_length);

	if (mcasp->op_mode == DAVINCI_MCASP_IIS_MODE)
		mcasp->channels = channels;

	return 0;
}

static int davinci_mcasp_trigger(struct snd_pcm_substream *substream,
				     int cmd, struct snd_soc_dai *cpu_dai)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);
	int ret = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		davinci_mcasp_start(mcasp, substream->stream);
		break;
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		davinci_mcasp_stop(mcasp, substream->stream);
		break;

	default:
		ret = -EINVAL;
	}

	return ret;
}

static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
				 struct snd_soc_dai *cpu_dai)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);
	u32 max_channels = 0;
	int i, dir;

	mcasp->substreams[substream->stream] = substream;

	if (mcasp->op_mode == DAVINCI_MCASP_DIT_MODE)
		return 0;

	/*
	 * Limit the maximum allowed channels for the first stream:
	 * number of serializers for the direction * tdm slots per serializer
	 */
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		dir = TX_MODE;
	else
		dir = RX_MODE;

	for (i = 0; i < mcasp->num_serializer; i++) {
		if (mcasp->serial_dir[i] == dir)
			max_channels++;
	}
	max_channels *= mcasp->tdm_slots;
	/*
	 * If the already active stream has less channels than the calculated
	 * limnit based on the seirializers * tdm_slots, we need to use that as
	 * a constraint for the second stream.
	 * Otherwise (first stream or less allowed channels) we use the
	 * calculated constraint.
	 */
	if (mcasp->channels && mcasp->channels < max_channels)
		max_channels = mcasp->channels;

	snd_pcm_hw_constraint_minmax(substream->runtime,
				     SNDRV_PCM_HW_PARAM_CHANNELS,
				     2, max_channels);
	return 0;
}

static void davinci_mcasp_shutdown(struct snd_pcm_substream *substream,
				   struct snd_soc_dai *cpu_dai)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(cpu_dai);

	mcasp->substreams[substream->stream] = NULL;

	if (mcasp->op_mode == DAVINCI_MCASP_DIT_MODE)
		return;

	if (!cpu_dai->active)
		mcasp->channels = 0;
}

static const struct snd_soc_dai_ops davinci_mcasp_dai_ops = {
	.startup	= davinci_mcasp_startup,
	.shutdown	= davinci_mcasp_shutdown,
	.trigger	= davinci_mcasp_trigger,
	.hw_params	= davinci_mcasp_hw_params,
	.set_fmt	= davinci_mcasp_set_dai_fmt,
	.set_clkdiv	= davinci_mcasp_set_clkdiv,
	.set_sysclk	= davinci_mcasp_set_sysclk,
};

static int davinci_mcasp_dai_probe(struct snd_soc_dai *dai)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(dai);

	if (mcasp->version >= MCASP_VERSION_3) {
		/* Using dmaengine PCM */
		dai->playback_dma_data =
				&mcasp->dma_data[SNDRV_PCM_STREAM_PLAYBACK];
		dai->capture_dma_data =
				&mcasp->dma_data[SNDRV_PCM_STREAM_CAPTURE];
	} else {
		/* Using davinci-pcm */
		dai->playback_dma_data = mcasp->dma_params;
		dai->capture_dma_data = mcasp->dma_params;
	}

	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int davinci_mcasp_suspend(struct snd_soc_dai *dai)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(dai);
	struct davinci_mcasp_context *context = &mcasp->context;
	u32 reg;
	int i;

	for (i = 0; i < ARRAY_SIZE(context_regs); i++)
		context->config_regs[i] = mcasp_get_reg(mcasp, context_regs[i]);

	if (mcasp->txnumevt) {
		reg = mcasp->fifo_base + MCASP_WFIFOCTL_OFFSET;
		context->afifo_regs[0] = mcasp_get_reg(mcasp, reg);
	}
	if (mcasp->rxnumevt) {
		reg = mcasp->fifo_base + MCASP_RFIFOCTL_OFFSET;
		context->afifo_regs[1] = mcasp_get_reg(mcasp, reg);
	}

	for (i = 0; i < mcasp->num_serializer; i++)
		context->xrsr_regs[i] = mcasp_get_reg(mcasp,
						DAVINCI_MCASP_XRSRCTL_REG(i));

	return 0;
}

static int davinci_mcasp_resume(struct snd_soc_dai *dai)
{
	struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(dai);
	struct davinci_mcasp_context *context = &mcasp->context;
	u32 reg;
	int i;

	for (i = 0; i < ARRAY_SIZE(context_regs); i++)
		mcasp_set_reg(mcasp, context_regs[i], context->config_regs[i]);

	if (mcasp->txnumevt) {
		reg = mcasp->fifo_base + MCASP_WFIFOCTL_OFFSET;
		mcasp_set_reg(mcasp, reg, context->afifo_regs[0]);
	}
	if (mcasp->rxnumevt) {
		reg = mcasp->fifo_base + MCASP_RFIFOCTL_OFFSET;
		mcasp_set_reg(mcasp, reg, context->afifo_regs[1]);
	}

	for (i = 0; i < mcasp->num_serializer; i++)
		mcasp_set_reg(mcasp, DAVINCI_MCASP_XRSRCTL_REG(i),
			      context->xrsr_regs[i]);

	return 0;
}
#else
#define davinci_mcasp_suspend NULL
#define davinci_mcasp_resume NULL
#endif

#define DAVINCI_MCASP_RATES	SNDRV_PCM_RATE_8000_192000

#define DAVINCI_MCASP_PCM_FMTS (SNDRV_PCM_FMTBIT_S8 | \
				SNDRV_PCM_FMTBIT_U8 | \
				SNDRV_PCM_FMTBIT_S16_LE | \
				SNDRV_PCM_FMTBIT_U16_LE | \
				SNDRV_PCM_FMTBIT_S24_LE | \
				SNDRV_PCM_FMTBIT_U24_LE | \
				SNDRV_PCM_FMTBIT_S24_3LE | \
				SNDRV_PCM_FMTBIT_U24_3LE | \
				SNDRV_PCM_FMTBIT_S32_LE | \
				SNDRV_PCM_FMTBIT_U32_LE)

static struct snd_soc_dai_driver davinci_mcasp_dai[] = {
	{
		.name		= "davinci-mcasp.0",
		.probe		= davinci_mcasp_dai_probe,
		.suspend	= davinci_mcasp_suspend,
		.resume		= davinci_mcasp_resume,
		.playback	= {
			.channels_min	= 2,
			.channels_max	= 32 * 16,
			.rates 		= DAVINCI_MCASP_RATES,
			.formats	= DAVINCI_MCASP_PCM_FMTS,
		},
		.capture 	= {
			.channels_min 	= 2,
			.channels_max	= 32 * 16,
			.rates 		= DAVINCI_MCASP_RATES,
			.formats	= DAVINCI_MCASP_PCM_FMTS,
		},
		.ops 		= &davinci_mcasp_dai_ops,

		.symmetric_samplebits	= 1,
	},
	{
		.name		= "davinci-mcasp.1",
		.probe		= davinci_mcasp_dai_probe,
		.playback 	= {
			.channels_min	= 1,
			.channels_max	= 384,
			.rates		= DAVINCI_MCASP_RATES,
			.formats	= DAVINCI_MCASP_PCM_FMTS,
		},
		.ops 		= &davinci_mcasp_dai_ops,
	},

};

static const struct snd_soc_component_driver davinci_mcasp_component = {
	.name		= "davinci-mcasp",
};

/* Some HW specific values and defaults. The rest is filled in from DT. */
static struct davinci_mcasp_pdata dm646x_mcasp_pdata = {
	.tx_dma_offset = 0x400,
	.rx_dma_offset = 0x400,
	.asp_chan_q = EVENTQ_0,
	.version = MCASP_VERSION_1,
};

static struct davinci_mcasp_pdata da830_mcasp_pdata = {
	.tx_dma_offset = 0x2000,
	.rx_dma_offset = 0x2000,
	.asp_chan_q = EVENTQ_0,
	.version = MCASP_VERSION_2,
};

static struct davinci_mcasp_pdata am33xx_mcasp_pdata = {
	.tx_dma_offset = 0,
	.rx_dma_offset = 0,
	.asp_chan_q = EVENTQ_0,
	.version = MCASP_VERSION_3,
};

static struct davinci_mcasp_pdata dra7_mcasp_pdata = {
	.tx_dma_offset = 0x200,
	.rx_dma_offset = 0x284,
	.asp_chan_q = EVENTQ_0,
	.version = MCASP_VERSION_4,
};

static const struct of_device_id mcasp_dt_ids[] = {
	{
		.compatible = "ti,dm646x-mcasp-audio",
		.data = &dm646x_mcasp_pdata,
	},
	{
		.compatible = "ti,da830-mcasp-audio",
		.data = &da830_mcasp_pdata,
	},
	{
		.compatible = "ti,am33xx-mcasp-audio",
		.data = &am33xx_mcasp_pdata,
	},
	{
		.compatible = "ti,dra7-mcasp-audio",
		.data = &dra7_mcasp_pdata,
	},
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mcasp_dt_ids);

static int mcasp_reparent_fck(struct platform_device *pdev)
{
	struct device_node *node = pdev->dev.of_node;
	struct clk *gfclk, *parent_clk;
	const char *parent_name;
	int ret;

	if (!node)
		return 0;

	parent_name = of_get_property(node, "fck_parent", NULL);
	if (!parent_name)
		return 0;

	gfclk = clk_get(&pdev->dev, "fck");
	if (IS_ERR(gfclk)) {
		dev_err(&pdev->dev, "failed to get fck\n");
		return PTR_ERR(gfclk);
	}

	parent_clk = clk_get(NULL, parent_name);
	if (IS_ERR(parent_clk)) {
		dev_err(&pdev->dev, "failed to get parent clock\n");
		ret = PTR_ERR(parent_clk);
		goto err1;
	}

	ret = clk_set_parent(gfclk, parent_clk);
	if (ret) {
		dev_err(&pdev->dev, "failed to reparent fck\n");
		goto err2;
	}

err2:
	clk_put(parent_clk);
err1:
	clk_put(gfclk);
	return ret;
}

static struct davinci_mcasp_pdata *davinci_mcasp_set_pdata_from_of(
						struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct davinci_mcasp_pdata *pdata = NULL;
	const struct of_device_id *match =
			of_match_device(mcasp_dt_ids, &pdev->dev);
	struct of_phandle_args dma_spec;

	const u32 *of_serial_dir32;
	u32 val;
	int i, ret = 0;

	if (pdev->dev.platform_data) {
		pdata = pdev->dev.platform_data;
		return pdata;
	} else if (match) {
		pdata = (struct davinci_mcasp_pdata*) match->data;
	} else {
		/* control shouldn't reach here. something is wrong */
		ret = -EINVAL;
		goto nodata;
	}

	ret = of_property_read_u32(np, "op-mode", &val);
	if (ret >= 0)
		pdata->op_mode = val;

	ret = of_property_read_u32(np, "tdm-slots", &val);
	if (ret >= 0) {
		if (val < 2 || val > 32) {
			dev_err(&pdev->dev,
				"tdm-slots must be in rage [2-32]\n");
			ret = -EINVAL;
			goto nodata;
		}

		pdata->tdm_slots = val;
	}

	of_serial_dir32 = of_get_property(np, "serial-dir", &val);
	val /= sizeof(u32);
	if (of_serial_dir32) {
		u8 *of_serial_dir = devm_kzalloc(&pdev->dev,
						 (sizeof(*of_serial_dir) * val),
						 GFP_KERNEL);
		if (!of_serial_dir) {
			ret = -ENOMEM;
			goto nodata;
		}

		for (i = 0; i < val; i++)
			of_serial_dir[i] = be32_to_cpup(&of_serial_dir32[i]);

		pdata->num_serializer = val;
		pdata->serial_dir = of_serial_dir;
	}

	ret = of_property_match_string(np, "dma-names", "tx");
	if (ret < 0)
		goto nodata;

	ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells", ret,
					 &dma_spec);
	if (ret < 0)
		goto nodata;

	pdata->tx_dma_channel = dma_spec.args[0];

	ret = of_property_match_string(np, "dma-names", "rx");
	if (ret < 0)
		goto nodata;

	ret = of_parse_phandle_with_args(np, "dmas", "#dma-cells", ret,
					 &dma_spec);
	if (ret < 0)
		goto nodata;

	pdata->rx_dma_channel = dma_spec.args[0];

	ret = of_property_read_u32(np, "tx-num-evt", &val);
	if (ret >= 0)
		pdata->txnumevt = val;

	ret = of_property_read_u32(np, "rx-num-evt", &val);
	if (ret >= 0)
		pdata->rxnumevt = val;

	ret = of_property_read_u32(np, "sram-size-playback", &val);
	if (ret >= 0)
		pdata->sram_size_playback = val;

	ret = of_property_read_u32(np, "sram-size-capture", &val);
	if (ret >= 0)
		pdata->sram_size_capture = val;

	return  pdata;

nodata:
	if (ret < 0) {
		dev_err(&pdev->dev, "Error populating platform data, err %d\n",
			ret);
		pdata = NULL;
	}
	return  pdata;
}

static int davinci_mcasp_probe(struct platform_device *pdev)
{
	struct davinci_pcm_dma_params *dma_params;
	struct snd_dmaengine_dai_dma_data *dma_data;
	struct resource *mem, *ioarea, *res, *dat;
	struct davinci_mcasp_pdata *pdata;
	struct davinci_mcasp *mcasp;
	char *irq_name;
	int irq;
	int ret;

	if (!pdev->dev.platform_data && !pdev->dev.of_node) {
		dev_err(&pdev->dev, "No platform data supplied\n");
		return -EINVAL;
	}

	mcasp = devm_kzalloc(&pdev->dev, sizeof(struct davinci_mcasp),
			   GFP_KERNEL);
	if (!mcasp)
		return	-ENOMEM;

	pdata = davinci_mcasp_set_pdata_from_of(pdev);
	if (!pdata) {
		dev_err(&pdev->dev, "no platform data\n");
		return -EINVAL;
	}

	mem = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpu");
	if (!mem) {
		dev_warn(mcasp->dev,
			 "\"mpu\" mem resource not found, using index 0\n");
		mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		if (!mem) {
			dev_err(&pdev->dev, "no mem resource?\n");
			return -ENODEV;
		}
	}

	ioarea = devm_request_mem_region(&pdev->dev, mem->start,
			resource_size(mem), pdev->name);
	if (!ioarea) {
		dev_err(&pdev->dev, "Audio region already claimed\n");
		return -EBUSY;
	}

	pm_runtime_enable(&pdev->dev);

	ret = pm_runtime_get_sync(&pdev->dev);
	if (IS_ERR_VALUE(ret)) {
		dev_err(&pdev->dev, "pm_runtime_get_sync() failed\n");
		pm_runtime_disable(&pdev->dev);
		return ret;
	}

	mcasp->base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
	if (!mcasp->base) {
		dev_err(&pdev->dev, "ioremap failed\n");
		ret = -ENOMEM;
		goto err;
	}

	mcasp->op_mode = pdata->op_mode;
	/* sanity check for tdm slots parameter */
	if (mcasp->op_mode == DAVINCI_MCASP_IIS_MODE) {
		if (pdata->tdm_slots < 2) {
			dev_err(&pdev->dev, "invalid tdm slots: %d\n",
				pdata->tdm_slots);
			mcasp->tdm_slots = 2;
		} else if (pdata->tdm_slots > 32) {
			dev_err(&pdev->dev, "invalid tdm slots: %d\n",
				pdata->tdm_slots);
			mcasp->tdm_slots = 32;
		} else {
			mcasp->tdm_slots = pdata->tdm_slots;
		}
	}

	mcasp->num_serializer = pdata->num_serializer;
#ifdef CONFIG_PM_SLEEP
	mcasp->context.xrsr_regs = devm_kzalloc(&pdev->dev,
					sizeof(u32) * mcasp->num_serializer,
					GFP_KERNEL);
#endif
	mcasp->serial_dir = pdata->serial_dir;
	mcasp->version = pdata->version;
	mcasp->txnumevt = pdata->txnumevt;
	mcasp->rxnumevt = pdata->rxnumevt;

	mcasp->dev = &pdev->dev;

	irq = platform_get_irq_byname(pdev, "rx");
	if (irq >= 0) {
		irq_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s_rx\n",
					  dev_name(&pdev->dev));
		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
						davinci_mcasp_rx_irq_handler,
						IRQF_ONESHOT, irq_name, mcasp);
		if (ret) {
			dev_err(&pdev->dev, "RX IRQ request failed\n");
			goto err;
		}

		mcasp->irq_request[SNDRV_PCM_STREAM_CAPTURE] = ROVRN;
	}

	irq = platform_get_irq_byname(pdev, "tx");
	if (irq >= 0) {
		irq_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s_tx\n",
					  dev_name(&pdev->dev));
		ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
						davinci_mcasp_tx_irq_handler,
						IRQF_ONESHOT, irq_name, mcasp);
		if (ret) {
			dev_err(&pdev->dev, "TX IRQ request failed\n");
			goto err;
		}

		mcasp->irq_request[SNDRV_PCM_STREAM_PLAYBACK] = XUNDRN;
	}

	dat = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
	if (dat)
		mcasp->dat_port = true;

	dma_params = &mcasp->dma_params[SNDRV_PCM_STREAM_PLAYBACK];
	dma_data = &mcasp->dma_data[SNDRV_PCM_STREAM_PLAYBACK];
	dma_params->asp_chan_q = pdata->asp_chan_q;
	dma_params->ram_chan_q = pdata->ram_chan_q;
	dma_params->sram_pool = pdata->sram_pool;
	dma_params->sram_size = pdata->sram_size_playback;
	if (dat)
		dma_params->dma_addr = dat->start;
	else
		dma_params->dma_addr = mem->start + pdata->tx_dma_offset;

	/* Unconditional dmaengine stuff */
	dma_data->addr = dma_params->dma_addr;

	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
	if (res)
		dma_params->channel = res->start;
	else
		dma_params->channel = pdata->tx_dma_channel;

	/* dmaengine filter data for DT and non-DT boot */
	if (pdev->dev.of_node)
		dma_data->filter_data = "tx";
	else
		dma_data->filter_data = &dma_params->channel;

	dma_params = &mcasp->dma_params[SNDRV_PCM_STREAM_CAPTURE];
	dma_data = &mcasp->dma_data[SNDRV_PCM_STREAM_CAPTURE];
	dma_params->asp_chan_q = pdata->asp_chan_q;
	dma_params->ram_chan_q = pdata->ram_chan_q;
	dma_params->sram_pool = pdata->sram_pool;
	dma_params->sram_size = pdata->sram_size_capture;
	if (dat)
		dma_params->dma_addr = dat->start;
	else
		dma_params->dma_addr = mem->start + pdata->rx_dma_offset;

	/* Unconditional dmaengine stuff */
	dma_data->addr = dma_params->dma_addr;

	if (mcasp->version < MCASP_VERSION_3) {
		mcasp->fifo_base = DAVINCI_MCASP_V2_AFIFO_BASE;
		/* dma_params->dma_addr is pointing to the data port address */
		mcasp->dat_port = true;
	} else {
		mcasp->fifo_base = DAVINCI_MCASP_V3_AFIFO_BASE;
	}

	res = platform_get_resource(pdev, IORESOURCE_DMA, 1);
	if (res)
		dma_params->channel = res->start;
	else
		dma_params->channel = pdata->rx_dma_channel;

	/* dmaengine filter data for DT and non-DT boot */
	if (pdev->dev.of_node)
		dma_data->filter_data = "rx";
	else
		dma_data->filter_data = &dma_params->channel;

	dev_set_drvdata(&pdev->dev, mcasp);

	mcasp_reparent_fck(pdev);

	ret = devm_snd_soc_register_component(&pdev->dev,
					&davinci_mcasp_component,
					&davinci_mcasp_dai[pdata->op_mode], 1);

	if (ret != 0)
		goto err;

	switch (mcasp->version) {
#if IS_BUILTIN(CONFIG_SND_DAVINCI_SOC) || \
	(IS_MODULE(CONFIG_SND_DAVINCI_SOC_MCASP) && \
	 IS_MODULE(CONFIG_SND_DAVINCI_SOC))
	case MCASP_VERSION_1:
	case MCASP_VERSION_2:
		ret = davinci_soc_platform_register(&pdev->dev);
		break;
#endif
#if IS_BUILTIN(CONFIG_SND_EDMA_SOC) || \
	(IS_MODULE(CONFIG_SND_DAVINCI_SOC_MCASP) && \
	 IS_MODULE(CONFIG_SND_EDMA_SOC))
	case MCASP_VERSION_3:
		ret = edma_pcm_platform_register(&pdev->dev);
		break;
#endif
#if IS_BUILTIN(CONFIG_SND_OMAP_SOC) || \
	(IS_MODULE(CONFIG_SND_DAVINCI_SOC_MCASP) && \
	 IS_MODULE(CONFIG_SND_OMAP_SOC))
	case MCASP_VERSION_4:
		ret = omap_pcm_platform_register(&pdev->dev);
		break;
#endif
	default:
		dev_err(&pdev->dev, "Invalid McASP version: %d\n",
			mcasp->version);
		ret = -EINVAL;
		break;
	}

	if (ret) {
		dev_err(&pdev->dev, "register PCM failed: %d\n", ret);
		goto err;
	}

	return 0;

err:
	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	return ret;
}

static int davinci_mcasp_remove(struct platform_device *pdev)
{
	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);

	return 0;
}

static struct platform_driver davinci_mcasp_driver = {
	.probe		= davinci_mcasp_probe,
	.remove		= davinci_mcasp_remove,
	.driver		= {
		.name	= "davinci-mcasp",
		.of_match_table = mcasp_dt_ids,
	},
};

module_platform_driver(davinci_mcasp_driver);

MODULE_AUTHOR("Steve Chen");
MODULE_DESCRIPTION("TI DAVINCI McASP SoC Interface");
MODULE_LICENSE("GPL");