path: root/sound/soc/fsl/fsl_spdif.c

/*
 * Freescale S/PDIF ALSA SoC Digital Audio Interface (DAI) driver
 *
 * Copyright (C) 2013 Freescale Semiconductor, Inc.
 *
 * Based on stmp3xxx_spdif_dai.c
 * Vladimir Barinov <vbarinov@embeddedalley.com>
 * Copyright 2008 SigmaTel, Inc
 * Copyright 2008 Embedded Alley Solutions, Inc
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2.  This program  is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#include <linux/module.h>
#include <linux/clk.h>
#include <linux/clk-private.h>
#include <linux/bitrev.h>
#include <linux/regmap.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>

#include <sound/asoundef.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>

#include "fsl_spdif.h"
#include "imx-pcm.h"

#define FSL_SPDIF_TXFIFO_WML	0x8
#define FSL_SPDIF_RXFIFO_WML	0x8

#define INTR_FOR_PLAYBACK (INT_TXFIFO_RESYNC)
#define INTR_FOR_CAPTURE (INT_SYM_ERR | INT_BIT_ERR | INT_URX_FUL | INT_URX_OV|\
		INT_QRX_FUL | INT_QRX_OV | INT_UQ_SYNC | INT_UQ_ERR |\
		INT_RXFIFO_RESYNC | INT_LOSS_LOCK | INT_DPLL_LOCKED)

/* Index list for the values that has if (DPLL Locked) condition */
static u8 srpc_dpll_locked[] = { 0x0, 0x1, 0x2, 0x3, 0x4, 0xa, 0xb };
#define SRPC_NODPLL_START1	0x5
#define SRPC_NODPLL_START2	0xc

#define DEFAULT_RXCLK_SRC	1

/*
 * SPDIF control structure
 * Defines channel status, subcode and Q sub
 */
struct spdif_mixer_control {
	/* spinlock to access control data */
	spinlock_t ctl_lock;

	/* IEC958 channel tx status bit */
	unsigned char ch_status[4];

	/* User bits */
	unsigned char subcode[2 * SPDIF_UBITS_SIZE];

	/* Q subcode part of user bits */
	unsigned char qsub[2 * SPDIF_QSUB_SIZE];

	/* Buffer offset for U/Q */
	u32 upos;
	u32 qpos;

	/* Ready buffer index of the two buffers */
	u32 ready_buf;
};

struct fsl_spdif_priv {
	struct spdif_mixer_control fsl_spdif_control;
	struct snd_soc_dai_driver cpu_dai_drv;
	struct platform_device *pdev;
	struct regmap *regmap;
	bool dpll_locked;
	u8 txclk_div[SPDIF_TXRATE_MAX];
	u8 txclk_src[SPDIF_TXRATE_MAX];
	u8 rxclk_src;
	struct clk *txclk[SPDIF_TXRATE_MAX];
	struct clk *rxclk;
	struct snd_dmaengine_dai_dma_data dma_params_tx;
	struct snd_dmaengine_dai_dma_data dma_params_rx;

	/* The name space will be allocated dynamically */
	char name[0];
};


/* DPLL locked and lock loss interrupt handler */
static void spdif_irq_dpll_lock(struct fsl_spdif_priv *spdif_priv)
{
	struct regmap *regmap = spdif_priv->regmap;
	struct platform_device *pdev = spdif_priv->pdev;
	u32 locked;

	regmap_read(regmap, REG_SPDIF_SRPC, &locked);
	locked &= SRPC_DPLL_LOCKED;

	dev_dbg(&pdev->dev, "isr: Rx dpll %s \n",
			locked ? "locked" : "loss lock");

	spdif_priv->dpll_locked = locked ? true : false;
}

/* Receiver found illegal symbol interrupt handler */
static void spdif_irq_sym_error(struct fsl_spdif_priv *spdif_priv)
{
	struct regmap *regmap = spdif_priv->regmap;
	struct platform_device *pdev = spdif_priv->pdev;

	dev_dbg(&pdev->dev, "isr: receiver found illegal symbol\n");

	if (!spdif_priv->dpll_locked) {
		/* DPLL unlocked seems no audio stream */
		regmap_update_bits(regmap, REG_SPDIF_SIE, INT_SYM_ERR, 0);
	}
}

/* U/Q Channel receive register full */
static void spdif_irq_uqrx_full(struct fsl_spdif_priv *spdif_priv, char<