linux-imx

/*

 * Driver for AT73C213 16-bit stereo DAC connected to Atmel SSC

 *

 * Copyright (C) 2006-2007 Atmel Norway

 *

 * 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.

 */

​

/*#define DEBUG*/

​

#include <linux/clk.h>

#include <linux/err.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/dma-mapping.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/io.h>

​

#include <sound/initval.h>

#include <sound/control.h>

#include <sound/core.h>

#include <sound/pcm.h>

​

#include <linux/atmel-ssc.h>

​

#include <linux/spi/spi.h>

#include <linux/spi/at73c213.h>

​

#include "at73c213.h"

​

#define BITRATE_MIN  8000 /* Hardware limit? */

#define BITRATE_TARGET  CONFIG_SND_AT73C213_TARGET_BITRATE

#define BITRATE_MAX 50000 /* Hardware limit. */

​

/* Initial (hardware reset) AT73C213 register values. */

static u8 snd_at73c213_original_image[18] =

{

    0x00,   /* 00 - CTRL    */

    0x05,   /* 01 - LLIG    */

    0x05,   /* 02 - RLIG    */

    0x08,   /* 03 - LPMG    */

    0x08,   /* 04 - RPMG    */

    0x00,   /* 05 - LLOG    */

    0x00,   /* 06 - RLOG    */

    0x22,   /* 07 - OLC     */

    0x09,   /* 08 - MC      */

    0x00,   /* 09 - CSFC    */

    0x00,   /* 0A - MISC    */

    0x00,   /* 0B -         */

    0x00,   /* 0C - PRECH   */

    0x05,   /* 0D - AUXG    */

    0x00,   /* 0E -         */

    0x00,   /* 0F -         */

    0x00,   /* 10 - RST     */

    0x00,   /* 11 - PA_CTRL */

};

​

struct snd_at73c213 {

    struct snd_card         *card;

    struct snd_pcm          *pcm;

    struct snd_pcm_substream    *substream;

    struct at73c213_board_info  *board;

    int             irq;

    int             period;

    unsigned long           bitrate;

    struct ssc_device       *ssc;

    struct spi_device       *spi;

    u8              spi_wbuffer[2];

    u8              spi_rbuffer[2];

    /* Image of the SPI registers in AT73C213. */

    u8              reg_image[18];

    /* Protect SSC registers against concurrent access. */

    spinlock_t          lock;

    /* Protect mixer registers against concurrent access. */

    struct mutex            mixer_lock;

};

​

#define get_chip(card) ((struct snd_at73c213 *)card->private_data)

​

static int

snd_at73c213_write_reg(struct snd_at73c213 *chip, u8 reg, u8 val)

{

    struct spi_message msg;

    struct spi_transfer msg_xfer = {

        .len        = 2,

        .cs_change  = 0,