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/************************************************************************
* arch/arm/src/lpc31xx/lpc31_esrndx.c
*
* Copyright (C) 2009-2010 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* References:
* - UM10314 LPC3130/31 User manual Rev. 1.01 � 9 September 2009
* - lpc313x.cdl.drivers.zip example driver code
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************/
/************************************************************************
* Included Files
************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include "up_arch.h"
#include "lpc31_cgudrvr.h"
/************************************************************************
* Pre-processor Definitions
************************************************************************/
/************************************************************************
* Private Data
************************************************************************/
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Name: lpc31_esrndx
*
* Description:
* Given a clock ID, return the index of the corresponding ESR
* register (or ESRNDX_INVALID if there is no ESR associated with
* this clock ID). Indexing of ESRs differs slightly from the clock
* ID: There are 92 clock IDs but only 89 ESR regisers. There are no
* ESR registers for :
*
*
* CLKID_I2SRXBCK0 Clock ID 87: I2SRX_BCK0
* CLKID_I2SRXBCK1, Clock ID 88: I2SRX_BCK1
*
* and
*
* CLKID_SYSCLKO Clock ID 91: SYSCLK_O
*
************************************************************************/
int lpc31_esrndx(enum lpc31_clockid_e clkid)
{
int esrndx = (int)clkid;
/* There ar 89 Enable Select Registers (ESR). Indexing for these
* registers is identical to indexing to other registers (like PCR),
* except that there are no ESR registers for
*
*
* CLKID_I2SRXBCK0 Clock ID 87: I2SRX_BCK0
* CLKID_I2SRXBCK1, Clock ID 88: I2SRX_BCK1
*
* and
*
* CLKID_SYSCLKO Clock ID 91: SYSCLK_O
*/
switch (clkid)
{
/* There are no ESR registers corresponding to the following
* three clocks:
*/
case CLKID_I2SRXBCK0:
case CLKID_I2SRXBCK1:
case CLKID_SYSCLKO:
esrndx = ESRNDX_INVALID;
break;
/* These clock IDs are a special case and need to be adjusted
* by two:
*
* CLKID_SPICLK Clock ID 89, ESR index 87
* CLKID_SPICLKGATED Clock ID 90, ESR index 88
*/
case CLKID_SPICLK:
case CLKID_SPICLKGATED:
esrndx = esrndx - 2;
break;
/* The rest of the indices match up and we don't have to do anything. */
default:
break;
}
return esrndx;
}
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