rockbox/firmware/target/arm/imx31/gigabeat-s/wmcodec-imx31.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Gigabeat  S specific code for the WM8978 codec
 *
 * Based on code from the ipodlinux project - http://ipodlinux.org/
 * Adapted for Rockbox in December 2005
 *
 * Original file: linux/arch/armnommu/mach-ipod/audio.c
 *
 * Copyright (c) 2003-2005 Bernard Leach (leachbj@bouncycastle.org)
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include "cpu.h"
#include "kernel.h"
#include "sound.h"
#include "i2c-imx31.h"

/* NOTE: Some port-specific bits will have to be moved away (node and GPIO
 * writes) for cleanest implementation. */

static struct i2c_node wm8978_i2c_node =
{
    .num  = I2C1_NUM,
    .ifdr = I2C_IFDR_DIV192, /* 66MHz/.4MHz = 165, closest = 192 = 343750Hz */
                             /* Just hard-code for now - scaling may require 
                              * updating */
    .addr = WM8978_I2C_ADDR,
};

void audiohw_init(void)
{
    i2c_enable_node(&wm8978_i2c_node, true);
    GPIO3_DR |= (1 << 21); /* Turn on analogue LDO */
    sleep(HZ/10);          /* Wait for things to stabilize */
    audiohw_preinit();
}

void wmcodec_write(int reg, int data)
{
    unsigned char d[2];
    /* |aaaaaaad|dddddddd| */
    d[0] = (reg << 1) | ((data & 0x100) >> 8);
    d[1] = data;
    i2c_write(&wm8978_i2c_node, d, 2);
}