/************************************************************************
* arch/arm/src/lpc313x/lpc313x_fdcndx.c
*
* Copyright (C) 2009-2010 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 "lpc313x_cgudrvr.h"
/************************************************************************
* Pre-processor Definitions
************************************************************************/
/* The select register in the ESR registers vary in width from 1-3 bits.
* Below is a macro to select the widest case (which is OK because the
* undefined bits will be read as zero). Within the field, bits 0-7 to
* indicate the offset from the base FDC index.
*/
#define CGU_ESRSEL(n) (((n)>>1)&7)
/************************************************************************
* Private Data
************************************************************************/
static const uint8_t g_fdcbase[CGU_NDOMAINS] =
{
FRACDIV_BASE0_LOW, /* Domain 0: SYS_BASE */
FRACDIV_BASE1_LOW, /* Domain 1: AHB0APB0_BASE */
FRACDIV_BASE2_LOW, /* Domain 2: AHB0APB1_BASE */
FRACDIV_BASE3_LOW, /* Domain 3: AHB0APB2_BASE */
FRACDIV_BASE4_LOW, /* Domain 4: AHB0APB3_BASE */
FRACDIV_BASE5_LOW, /* Domain 5: PCM_BASE */
FRACDIV_BASE6_LOW, /* Domain 6: UART_BASE */
FRACDIV_BASE7_LOW, /* Domain 7: CLK1024FS_BASE */
0, /* Domain 8: BCK0_BASE (no ESR register) */
0, /* Domain 9: BCK1_BASE (no ESR register) */
FRACDIV_BASE10_LOW, /* Domain 10: SPI_BASE */
0, /* Domain 11: SYSCLKO_BASE (no ESR register) */
};
/************************************************************************
* Private Functions
************************************************************************/
/************************************************************************
* Public Functions
************************************************************************/
/************************************************************************
* Name: lpc313x_fdcndx
*
* Description:
* Given a clock ID and its domain ID, return the index of the
* corresponding fractional divider register (or FDCNDX_INVALID if
* there is no fractional divider associated with this clock).
*
************************************************************************/
int lpc313x_fdcndx(enum lpc313x_clockid_e clkid, enum lpc313x_domainid_e dmnid)
{
int esrndx;
int fdcndx = FDCNDX_INVALID;
/* Check if there is an ESR register associate with this clock ID */
esrndx = lpc313x_esrndx(clkid);
if (esrndx != ESRNDX_INVALID)
{
/* Read the clock's ESR to get the fractional divider */
uint32_t regval = getreg32(LPC313X_CGU_ESR(esrndx));
/* Check if any fractional divider is enabled for this clock. */
if ((regval & CGU_ESR_ESREN) != 0)
{
/* Yes.. The FDC index is an offset from this fractional
* divider base for this domain.
*/
fdcndx = CGU_ESRSEL(regval) + (int)g_fdcbase[dmnid];
}
}
return fdcndx;
}