/****************************************************************************
* arch/arm/src/lpc17xx/lpc17_clockconfig.c
* arch/arm/src/chip/lpc17_clockconfig.c
*
* Copyright (C) 2010, 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <debug.h>
#include <nuttx/arch.h>
#include <arch/board/board.h>
#include "up_arch.h"
#include "up_internal.h"
#include "lpc17_clockconfig.h"
#include "chip/lpc17_syscon.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef LPC176x
# error "The logic in this file applies only to the LPC176x family"
#endif
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/************************************************************************************
* Name: lpc17_clockconfig
*
* Description:
* Called to initialize the LPC176x. This does whatever setup is needed to put the
* SoC in a usable state. This includes the initialization of clocking using the
* settings in board.h.
*
* The LPC176x and LPC178x system control block is *nearly* identical but we have
* found that the LPC178x is more sensitive to the ordering of certain operations.
* So, although the hardware seems very similar, the safer thing to do is to
* separate the LPC176x and LPC178x into separate files.
*
************************************************************************************/
void lpc17_clockconfig(void)
{
/* Enable the main oscillator (or not) and the frequency range of the main oscillator */
putreg32(BOARD_SCS_VALUE, LPC17_SYSCON_SCS);
/* Wait for the main oscillator to be ready. */
#ifdef CONFIG_LPC17_MAINOSC
while ((getreg32(LPC17_SYSCON_SCS) & SYSCON_SCS_OSCSTAT) == 0);
#endif
/* Setup up the divider value for the CPU clock. The output of the divider is CCLK.
* The input to the divider (PLLCLK) is equal to SYSCLK unless PLL0 is enabled. CCLK
* will be further divided to produce peripheral clocks, but that peripheral clock
* setup is performed in the peripheral device drivers. Here only CCLK is
* configured.
*/
putreg32(BOARD_CCLKCFG_VALUE, LPC17_SYSCON_CCLKCFG);
/* PLL0 is used to generate the CPU clock divider input (PLLCLK). */
#ifdef CONFIG_LPC17_PLL0
/* Select the PLL0 source clock, multiplier, and pre-divider values. NOTE that
* a special "feed" sequence must be written to the PLL0FEED register in order
* for changes to the PLL0CFG register to take effect.
*/
putreg32(BOARD_CLKSRCSEL_VALUE, LPC17_SYSCON_CLKSRCSEL);
putreg32(BOARD_PLL0CFG_VALUE, LPC17_SYSCON_PLL0CFG);
putreg32(0xaa, LPC17_SYSCON_PLL0FEED);
putreg32(0x55, LPC17_SYSCON_PLL0FEED);
/* Enable the PLL. NOTE that a special "feed" sequence must be written to the
* PLL0FEED register in order for changes to the PLL0CON register to take effect.
*/
putreg32(SYSCON_PLLCON_PLLE, LPC17_SYSCON_PLL0CON);
putreg32(0xaa, LPC17_SYSCON_PLL0FEED);
putreg32(0x55, LPC17_SYSCON_PLL0FEED);
/* Wait for PLL0 to lock */
while ((getreg32(LPC17_SYSCON_PLL0STAT) & SYSCON_PLL0STAT_PLOCK) == 0);
/* Enable and connect PLL0 */
putreg32(SYSCON_PLLCON_PLLE|SYSCON_PLLCON_PLLC, LPC17_SYSCON_PLL0CON);
putreg32(0xaa, LPC17_SYSCON_PLL0FEED);
putreg32(0x55, LPC17_SYSCON_PLL0FEED);
/* Wait for PLL to report that it is connected and enabled */
while ((getreg32(LPC17_SYSCON_PLL0STAT) & (SYSCON_PLL0STAT_PLLE|SYSCON_PLL0STAT_PLLC))
!= (SYSCON_PLL0STAT_PLLE|SYSCON_PLL0STAT_PLLC));
#endif /* CONFIG_LPC17_PLL0 */
/* PLL1 receives its clock input from the main oscillator only and can be used to
* provide a fixed 48 MHz clock only to the USB subsystem (if that clock cannot be
* obtained from PLL0).
*/
#ifdef CONFIG_LPC17_PLL1
/* Select the PLL1 multiplier, and pre-divider values. NOTE that a special "feed"
* sequence must be written to the PLL1FEED register in order for changes to the
* PLL1CFG register to take effect.
*/
putreg32(BOARD_PLL1CFG_VALUE, LPC17_SYSCON_PLL1CFG);
putreg32(0xaa, LPC17_SYSCON_PLL1FEED);
putreg32(0x55, LPC17_SYSCON_PLL1FEED);
/* Enable the PLL. NOTE that a special "feed" sequence must be written to the
* PLL1FEED register in order for changes to the PLL1CON register to take effect.
*/
putreg32(SYSCON_PLLCON_PLLE, LPC17_SYSCON_PLL1CON);
putreg32(0xaa, LPC17_SYSCON_PLL1FEED);
putreg32(0x55, LPC17_SYSCON_PLL1FEED);
/* Wait for PLL1 to lock */
while ((getreg32(LPC17_SYSCON_PLL1STAT) & SYSCON_PLL1STAT_PLOCK) == 0);
/* Enable and connect PLL1 */
putreg32(SYSCON_PLLCON_PLLE|SYSCON_PLLCON_PLLC, LPC17_SYSCON_PLL1CON);
putreg32(0xaa, LPC17_SYSCON_PLL1FEED);
putreg32(0x55, LPC17_SYSCON_PLL1FEED);
/* Wait for PLL to report that it is connected and enabled */
while ((getreg32(LPC17_SYSCON_PLL1STAT) & (SYSCON_PLL1STAT_PLLE|SYSCON_PLL1STAT_PLLC))
!= (SYSCON_PLL1STAT_PLLE|SYSCON_PLL1STAT_PLLC));
#else /* CONFIG_LPC17_PLL1 */
/* Otherwise, setup up the USB clock divider to generate the USB clock from PLL0 */
putreg32(BOARD_USBCLKCFG_VALUE, LPC17_SYSCON_USBCLKCFG);
#endif /* CONFIG_LPC17_PLL1 */
/* Disable all peripheral clocks. They must be configured by each device driver
* when the device driver is initialized.
*/
putreg32(0, LPC17_SYSCON_PCLKSEL0);
putreg32(0, LPC17_SYSCON_PCLKSEL1);
/* Disable power to all peripherals (execpt GPIO). Peripherals must be re-powered
* one at a time by each device driver when the driver is initialized.
*/
putreg32(SYSCON_PCONP_PCGPIO, LPC17_SYSCON_PCONP);
/* Disable CLKOUT */
putreg32(0, LPC17_SYSCON_CLKOUTCFG);
/* Configure FLASH */
#ifdef CONFIG_LPC17_FLASH
putreg32(BOARD_FLASHCFG_VALUE, LPC17_SYSCON_FLASHCFG);
#endif
}
