tinySA/os/hal/platforms/SPC56x/hal_lld.c

131 lines
5.6 KiB
C

/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file SPC56x/hal_lld.c
* @brief SPC563 HAL subsystem low level driver source.
*
* @addtogroup HAL
* @{
*/
#include "ch.h"
#include "hal.h"
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level HAL driver initialization.
*
* @notapi
*/
void hal_lld_init(void) {
extern void _vectors(void);
uint32_t n;
/* Enables the branch prediction, clears and enables the BTB into the
BUCSR special register (1013).*/
asm volatile ("li %%r3, 0x0201 \t\n"
"mtspr 1013, %%r3": : : "r3");
/* FLASH wait states and prefetching setup.*/
CFLASH0.BIUCR.R = SPC563_FLASH_BIUCR | SPC563_FLASH_WS;
CFLASH0.BIUCR2.R = 0;
CFLASH0.PFCR3.R = 0;
/* Optimal crossbar settings. The DMA priority is placed above the CPU
priority in order to not starve I/O activities while the CPU is
excuting tight loops (FLASH and SRAM slave ports only).
The SRAM is parked on the load/store port, for some unknown reason it
is defaulted on the instructions port and this kills performance.*/
XBAR.SGPCR3.B.PARK = 4; /* RAM slave on load/store port.*/
XBAR.MPR0.R = 0x00030201; /* Flash slave port priorities:
eDMA (1): 0 (highest)
Core Instructions (0): 1
Undocumented (2): 2
Core Data (4): 3 */
XBAR.MPR3.R = 0x00030201; /* SRAM slave port priorities:
eDMA (1): 0 (highest)
Core Instructions (0): 1
Undocumented (2): 2
Core Data (4): 3 */
/* Downcounter timer initialized for system tick use, TB enabled for debug
and measurements.*/
n = SPC563_SYSCLK / CH_FREQUENCY;
asm volatile ("li %%r3, 0 \t\n"
"mtspr 284, %%r3 \t\n" /* Clear TBL register. */
"mtspr 285, %%r3 \t\n" /* Clear TBU register. */
"mtspr 22, %[n] \t\n" /* Init. DEC register. */
"mtspr 54, %[n] \t\n" /* Init. DECAR register.*/
"li %%r3, 0x4000 \t\n" /* TBEN bit. */
"mtspr 1008, %%r3 \t\n" /* HID0 register. */
"lis %%r3, 0x0440 \t\n" /* DIE ARE bits. */
"mtspr 340, %%r3" /* TCR register. */
: : [n] "r" (n) : "r3");
/* INTC initialization, software vector mode, 4 bytes vectors, starting
at priority 0.*/
INTC.MCR.R = 0;
INTC.CPR.R = 0;
INTC.IACKR.R = (uint32_t)_vectors;
}
/**
* @brief SPC563 clocks and PLL initialization.
* @note All the involved constants come from the file @p board.h and
* @p hal_lld.h
* @note This function must be invoked only after the system reset.
*
* @special
*/
void spc563_clock_init(void) {
/* PLL activation.*/
FMPLL.ESYNCR1.B.EMODE = 1;
FMPLL.ESYNCR1.B.CLKCFG &= 1; /* Bypass mode, PLL off.*/
FMPLL.ESYNCR1.B.CLKCFG |= 2; /* PLL on. */
FMPLL.ESYNCR1.B.EPREDIV = SPC563_CLK_PREDIV;
FMPLL.ESYNCR1.B.EMFD = SPC563_CLK_MFD;
FMPLL.ESYNCR2.B.ERFD = SPC563_CLK_RFD;
while (!FMPLL.SYNSR.B.LOCK)
;
FMPLL.ESYNCR1.B.CLKCFG |= 4; /* Clock from the PLL. */
}
/** @} */