diff options
Diffstat (limited to 'bsps/arm/lpc176x/start/bspstarthooks.c')
| -rw-r--r-- | bsps/arm/lpc176x/start/bspstarthooks.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/bsps/arm/lpc176x/start/bspstarthooks.c b/bsps/arm/lpc176x/start/bspstarthooks.c new file mode 100644 index 0000000000..a60c5bdf89 --- /dev/null +++ b/bsps/arm/lpc176x/start/bspstarthooks.c @@ -0,0 +1,227 @@ +/** + * @file bspstarthooks.c + * + * @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 */ +}
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