blob: dc790f3eb0e0bd5df45a9bb1391981759b94e717 (
plain) (
tree)
|
|
/**
* @file
*
* @ingroup lpc176x
*
* @brief First configurations and initializations to the correct
* functionality of the board.
*/
/*
* Copyright (c) 2014 Taller Technologies.
*
* @author Boretto Martin (martin.boretto@tallertechnologies.com)
* @author Diaz Marcos (marcos.diaz@tallertechnologies.com)
* @author Lenarduzzi Federico (federico.lenarduzzi@tallertechnologies.com)
* @author Daniel Chicco (daniel.chicco@tallertechnologies.com)
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#include <bsp.h>
#include <bsp/start.h>
#include <bsp/io.h>
/**
* @brief Initializes the oscillator according to the lpc176x board.
*/
static BSP_START_TEXT_SECTION void lpc176x_init_main_oscillator( void )
{
if ( ( LPC176X_SCB.scs & LPC176X_SCB_SCS_OSC_STATUS ) == 0u ) {
LPC176X_SCB.scs |= LPC176X_SCB_SCS_OSC_ENABLE;
while ( ( LPC176X_SCB.scs & LPC176X_SCB_SCS_OSC_STATUS ) == 0u ) {
/* Wait. */
}
}
/* else implies that the oscillator is initialized. Also,
there is nothing to do. */
}
/**
* @brief Sets the PLL configuration.
*
* @param pll Value to set.
* @param val Set value.
*/
static BSP_START_TEXT_SECTION void lpc176x_pll_config( const uint32_t val )
{
( LPC176X_SCB.pll_0 ).con = val;
/* The two register writes must be in correct sequence. */
( LPC176X_SCB.pll_0 ).feed = LPC176X_PLL0CON;
( LPC176X_SCB.pll_0 ).feed = LPC176X_PLL0CFG;
}
/**
* @brief Sets the PLL.
*
* @param msel Multiplier value.
* @param psel Divider value.
* @param cclkdiv Divisor clock.
*/
static BSP_START_TEXT_SECTION void lpc176x_set_pll(
const unsigned msel,
const unsigned psel,
const unsigned cclkdiv
)
{
const uint32_t pllcfg = LPC176X_PLL_SEL_MSEL( msel ) |
LPC176X_PLL_SEL_PSEL( psel );
const uint32_t pllstat = LPC176X_PLL_STAT_PLLE | LPC176X_PLL_STAT_PLOCK |
pllcfg;
const uint32_t cclksel_cclkdiv = LPC176X_SCB_CCLKSEL_CCLKDIV( cclkdiv );
if ( ( LPC176X_SCB.pll_0 ).stat != pllstat
|| LPC176X_SCB.cclksel != cclksel_cclkdiv
|| LPC176X_SCB.clksrcsel != LPC176X_SCB_CLKSRCSEL_CLKSRC ) {
lpc176x_pll_config( ( LPC176X_SCB.pll_0 ).con & ~LPC176X_PLL_CON_PLLC );
/* Turn off USB. */
LPC176X_SCB.usbclksel = 0u;
/* Disable PLL. */
lpc176x_pll_config( 0u );
/* Use SYSCLK for CCLK. */
LPC176X_SCB.cclksel = LPC176X_SCB_CCLKSEL_CCLKDIV( 0u );
/* Set the CCLK, PCLK and EMCCLK divider. */
LPC176X_SCB.cclksel = cclksel_cclkdiv;
/* Select main oscillator as clock source. */
LPC176X_SCB.clksrcsel = LPC176X_SCB_CLKSRCSEL_CLKSRC;
/* The two register writes must be in correct sequence. */
/* Set PLL configuration. */
( LPC176X_SCB.pll_0 ).cfg = pllcfg;
( LPC176X_SCB.pll_0 ).feed = LPC176X_PLL0CON;
( LPC176X_SCB.pll_0 ).feed = LPC176X_PLL0CFG;
/* Enable PLL. */
lpc176x_pll_config( LPC176X_PLL_CON_PLLE );
/* Wait for lock. */
while ( ( ( LPC176X_SCB.pll_0 ).stat & LPC176X_PLL_STAT_PLOCK ) == 0u ) {
/* Wait */
}
/* Connect PLL. */
lpc176x_pll_config( ( LPC176X_PLL_CON_PLLE | LPC176X_PLL_CON_PLLC ) );
/* Wait for connected and enabled. */
while ( ( ( LPC176X_SCB.pll_0 ).stat & ( LPC176X_PLL_STAT_PLLE |
LPC176X_PLL_STAT_PLLC ) ) ==
0u ) {
/* Wait */
}
}
/* else implies that the pll has a wrong value. Also,
there is nothing to do. */
}
/**
* @brief Pll initialization.
*/
static BSP_START_TEXT_SECTION void lpc176x_init_pll( void )
{
#if ( LPC176X_OSCILLATOR_MAIN == 12000000u )
#if ( LPC176X_CCLK == 96000000U )
lpc176x_set_pll( 11u, 0u, 2u );
#else
#error "unexpected CCLK"
#endif
#else
#error "unexpected main oscillator frequency"
#endif
}
/**
* @brief Memory map initialization.
*/
static BSP_START_TEXT_SECTION void lpc176x_init_memory_map( void )
{
LPC176X_SCB.memmap = LPC176X_SCB_MEMMAP_MAP;
}
/**
* @brief Memory accelerator initialization.
*/
static BSP_START_TEXT_SECTION void lpc176x_init_memory_accelerator( void )
{
#if ( LPC176X_CCLK <= 20000000U )
LPC176X_SCB.flashcfg = LPC176X_SCB_FLASHCFG_FLASHTIM( 0x0U );
#elif ( LPC176X_CCLK <= 40000000U )
LPC176X_SCB.flashcfg = LPC176X_SCB_FLASHCFG_FLASHTIM( 0x1U );
#elif ( LPC176X_CCLK <= 60000000U )
LPC176X_SCB.flashcfg = LPC176X_SCB_FLASHCFG_FLASHTIM( 0x2U );
#elif ( LPC176X_CCLK <= 80000000U )
LPC176X_SCB.flashcfg = LPC176X_SCB_FLASHCFG_FLASHTIM( 0x3U );
#elif ( LPC176X_CCLK <= 100000000U )
LPC176X_SCB.flashcfg = LPC176X_SCB_FLASHCFG_FLASHTIM( 0x4U );
#else
LPC176X_SCB.flashcfg = LPC176X_SCB_FLASHCFG_FLASHTIM( 0x5U );
#endif
}
/**
* @brief Stops the gpdma device.
*/
static BSP_START_TEXT_SECTION void lpc176x_stop_gpdma( void )
{
#ifdef LPC176X_STOP_GPDMA
bool has_power = ( LPC176X_SCB.pconp & LPC176X_SCB_PCONP_GPDMA ) != 0u;
if ( has_power ) {
GPDMA_CONFIG = 0u;
LPC176X_SCB.pconp &= ~LPC176X_SCB_PCONP_GPDMA;
}
/* else implies that the current module (gpdma) is turn off. Also,
there is nothing to do. */
#endif
}
/**
* @brief Stops the usb device.
*/
static BSP_START_TEXT_SECTION void lpc176x_stop_usb( void )
{
#ifdef LPC176X_STOP_USB
bool has_power = ( LPC176X_SCB.pconp & LPC176X_SCB_PCONP_USB ) != 0u;
if ( has_power ) {
OTG_CLK_CTRL = 0u;
LPC176X_SCB.pconp &= ~LPC176X_SCB_PCONP_USB;
LPC176X_SCB.usbclksel = 0u;
}
/* else implies that the current module (usb) is turn off. Also,
there is nothing to do. */
#endif
}
BSP_START_TEXT_SECTION void bsp_start_hook_0( void )
{
lpc176x_init_main_oscillator();
lpc176x_init_pll();
}
BSP_START_TEXT_SECTION void bsp_start_hook_1( void )
{
lpc176x_init_memory_map();
lpc176x_init_memory_accelerator();
lpc176x_stop_gpdma();
lpc176x_stop_usb();
bsp_start_copy_sections();
bsp_start_clear_bss();
/* At this point we can use objects outside the .start section */
}
|