/****************************************************************************
* arch/mips/src/pic32/pic32mz-lowinit.c
*
* Copyright (C) 2015 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 <assert.h>
#include <arch/pic32mz/cp0.h>
#include <arch/board/board.h>
#include "up_internal.h"
#include "up_arch.h"
#include "chip/pic32mz-features.h"
#include "chip/pic32mz-prefetch.h"
#include "chip/pic32mz-osc.h"
#include "pic32mz-config.h"
#include "pic32mz-lowconsole.h"
#include "pic32mz-lowinit.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Maximum Frequencies ******************************************************/
#if CONFIG_PIC32MZ_ECC_OPTION == 3
# define MAX_FLASH_HZ 83000000 /* Maximum FLASH speed (Hz) without ECC */
#else
# define MAX_FLASH_HZ 66000000 /* Maximum FLASH speed (Hz) with ECC */
#endif
#define MAX_PBCLK 100000000 /* Max peripheral bus speed (Hz) */
#define MAX_PBCLK7 200000000 /* Max peripheral bus speed (Hz) for PBCLK7 */
/* Sanity checks ************************************************************/
/* Make sure that the selected clock parameters are sane */
#define CALC_SYSCLOCK (((BOARD_PLL_INPUT / BOARD_PLL_IDIV) * BOARD_PLL_MULT) / BOARD_PLL_ODIV)
#if CALC_SYSCLOCK != BOARD_CPU_CLOCK
# error "Bad BOARD_CPU_CLOCK calculcation in board.h"
#endif
#define CALC_PBCLK1 (CALC_SYSCLOCK / BOARD_PB1DIV)
#if CALC_PBCLK1 != BOARD_PBCLK1
# error "Bad BOARD_PBCLK1 calculcation in board.h"
#endif
#if CALC_PBCLK1 > MAX_PBCLK
# error "PBCLK1 exceeds maximum value"
#endif
#ifdef BOARD_PBCLK2_ENABLE
# define CALC_PBCLK2 (CALC_SYSCLOCK / BOARD_PB2DIV)
# if CALC_PBCLK2 != BOARD_PBCLK2
# error "Bad BOARD_PBCLK2 calculcation in board.h"
# endif
# if CALC_PBCLK2 > MAX_PBCLK
# error "PBCLK2 exceeds maximum value"
# endif
#endif
#ifdef BOARD_PBCLK3_ENABLE
# define CALC_PBCLK3 (CALC_SYSCLOCK / BOARD_PB3DIV)
# if CALC_PBCLK3 != BOARD_PBCLK3
# error "Bad BOARD_PBCLK3 calculcation in board.h"
# endif
# if CALC_PBCLK3 > MAX_PBCLK
# error "PBCLK3 exceeds maximum value"
# endif
#endif
#ifdef BOARD_PBCLK4_ENABLE
# define CALC_PBCLK4 (CALC_SYSCLOCK / BOARD_PB4DIV)
# if CALC_PBCLK4 != BOARD_PBCLK4
# error "Bad BOARD_PBCLK4 calculcation in board.h"
# endif
# if CALC_PBCLK4 > MAX_PBCLK
# error "PBCLK4 exceeds maximum value"
# endif
#endif
#ifdef BOARD_PBCLK5_ENABLE
# define CALC_PBCLK5 (CALC_SYSCLOCK / BOARD_PB5DIV)
# if CALC_PBCLK5 != BOARD_PBCLK5
# error "Bad BOARD_PBCLK5 calculcation in board.h"
# endif
# if CALC_PBCLK5 > MAX_PBCLK
# error "PBCLK5 exceeds maximum value"
# endif
#endif
#ifdef BOARD_PBCLK6_ENABLE
# define CALC_PBCLK6 (CALC_SYSCLOCK / BOARD_PB6DIV)
# if CALC_PBCLK6 != BOARD_PBCLK6
# error "Bad BOARD_PBCLK6 calculcation in board.h"
# endif
# if CALC_PBCLK6 > MAX_PBCLK
# error "PBCLK6 exceeds maximum value"
# endif
#endif
#ifdef BOARD_PBCLK7_ENABLE
# define CALC_PBCLK7 (CALC_SYSCLOCK / BOARD_PB7DIV)
# if CALC_PBCLK7 != BOARD_PBCLK7
# error "Bad BOARD_PBCLK7 calculcation in board.h"
# endif
# if CALC_PBCLK7 > MAX_PBCLK7
# error "PBCLK7 exceeds maximum value"
# endif
#endif
#ifdef BOARD_PBCLK8_ENABLE
# define CALC_PBCLK8 (CALC_SYSCLOCK / BOARD_PB8DIV)
# if CALC_PBCLK8 != BOARD_PBCLK8
# error "Bad BOARD_PBCLK8 calculcation in board.h"
# endif
# if CALC_PBCLK8 > MAX_PBCLK
# error "PBCLK8 exceeds maximum value"
# endif
#endif
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Private Variables
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: pic32mz_prefetch
*
* Description:
* Configure the prefetch module setting:
*
* 1. The optimal number of FLASH wait states.
* 2. Enable prefetch on CPU instructions and data
*
* Assumptions:
* Interrupts are disabled.
*
****************************************************************************/
static inline void pic32mz_prefetch(void)
{
unsigned int nwaits;
unsigned int residual;
uint32_t regval;
/* Configure pre-fetch cache FLASH wait states (assuming ECC is enabled).
* REVISIT: Is this calculation right? It seems like residual should be
*
* residual = BOARD_CPU_CLOCK / nwaits
*
* This logic uses:
*
* BOARD_CPU_CLOCK - nwaits * MAX_FLASH_HZ
*/
residual = BOARD_CPU_CLOCK;
nwaits = 0;
while (residual > MAX_FLASH_HZ)
{
nwaits++;
residual -= MAX_FLASH_HZ;
}
DEBUGASSERT(nwaits < 8);
/* Set the FLASH wait states and enabled prefetch on CPU instructions and
* data.
*/
regval = (PRECON_PREFEN_CPUID | PRECON_PFMWS(nwaits));
putreg32(regval, PIC32MZ_PRECON);
}
/****************************************************************************
* Name: pic32mz_k0cache
*
* Description:
* Enable caching in KSEG0.
*
* Assumptions:
* Interrupts are disabled.
*
****************************************************************************/
static inline void pic32mz_k0cache(void)
{
register uint32_t regval;
/* Enable cache on KSEG 0 in the CP0 CONFIG register*/
asm("\tmfc0 %0,$16,0\n" : "=r"(regval));
regval &= ~CP0_CONFIG_K23_MASK;
regval |= CP0_CONFIG_K23_CACHEABLE;
asm("\tmtc0 %0,$16,0\n" : : "r" (regval));
UNUSED(regval);
}
/****************************************************************************
* Name: pic32mz_pbclk
*
* Description:
* Configure peripheral bus clocking
*
* Assumptions:
* Interrupts are disabled.
*
****************************************************************************/
static inline void pic32mz_pbclk(void)
{
uint32_t regval;
/* Perform the unlock sequence */
putreg32(UNLOCK_SYSKEY_0, PIC32MZ_SYSKEY);
putreg32(UNLOCK_SYSKEY_1, PIC32MZ_SYSKEY);
/* PBCLK1
* Peripherals: OSC2 pin
*
* NOTES:
* - PBCLK1 is used by system modules and cannot be turned off
* - PBCLK1 divided by 2 is available on the OSC2 pin in certain clock
* modes.
*/
regval = (PBDIV_ON | PBDIV(BOARD_PB1DIV));
putreg32(regval, PIC32MZ_PB1DIV);
/* PBCLK2
* Peripherals: PMP, I2C, UART, SPI
*/
#ifdef BOARD_PBCLK2_ENABLE
regval = (PBDIV_ON | PBDIV(BOARD_PB2DIV));
#else
regval = 0;
#endif
putreg32(regval, PIC32MZ_PB2DIV);
/* PBCLK3
* Peripherals: ADC, Comparator, Timers, Output Compare, Input Compare
*
* NOTES:
* - Timer 1 uses SOSC
*/
#ifdef BOARD_PBCLK3_ENABLE
regval = (PBDIV_ON | PBDIV(BOARD_PB3DIV));
#else
regval = 0;
#endif
putreg32(regval, PIC32MZ_PB3DIV);
/* PBCLK4
* Peripherals: Ports
*/
#ifdef BOARD_PBCLK4_ENABLE
regval = (PBDIV_ON | PBDIV(BOARD_PB4DIV));
#else
regval = 0;
#endif
putreg32(regval, PIC32MZ_PB4DIV);
/* PBCLK5
* Peripherals: Flash, Crypto, RND, USB, CAN, Ethernet, SQI
*
* NOTES:
* - PBCLK5 is used to fetch data from/to the Flash Controller, while the
* FRC clock is used for programming
*/
#ifdef BOARD_PBCLK5_ENABLE
regval = (PBDIV_ON | PBDIV(BOARD_PB5DIV));
#else
regval = 0;
#endif
putreg32(regval, PIC32MZ_PB5DIV);
/* PBCLK6
* Peripherals:
*/
#ifdef BOARD_PBCLK6_ENABLE
regval = (PBDIV_ON | PBDIV(BOARD_PB6DIV));
#else
regval = 0;
#endif
putreg32(regval, PIC32MZ_PB6DIV);
/* PBCLK7
* Peripherals: CPU, Deadman timer
*/
#ifdef BOARD_PBCLK7_ENABLE
regval = (PBDIV_ON | PBDIV(BOARD_PB7DIV));
#else
regval = 0;
#endif
putreg32(regval, PIC32MZ_PB7DIV);
/* PBCLK8
* Peripherals: EBI
*/
#ifdef BOARD_PBCLK8_ENABLE
regval = (PBDIV_ON | PBDIV(BOARD_PB8DIV));
#else
regval = 0;
#endif
putreg32(regval, PIC32MZ_PB8DIV);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: pic32mz_lowinit
*
* Description:
* This performs basic low-level initialization of the system.
*
* Assumptions:
* Interrupts have not yet been enabled.
*
****************************************************************************/
void pic32mz_lowinit(void)
{
/* Initialize FLASH wait states */
pic32mz_prefetch();
/* Enable caching in KSEG0 */
pic32mz_k0cache();
/* Configure peripheral clocking */
pic32mz_pbclk();
/* Initialize a console (probably a serial console) */
pic32mz_consoleinit();
/* Perform early serial initialization (so that we will have debug output
* available as soon as possible).
*/
#ifdef USE_EARLYSERIALINIT
up_earlyserialinit();
#endif
/* Perform board-level initialization */
pic32mz_boardinitialize();
}