nuttx/boards/arm/stm32f7/stm32f769i-disco/src/stm32_extmem.c
Gustavo Henrique Nihei 105d561a51 arch/arm/src/stm32f7: Refactor FMC functions for STM32F7
This refactor is based on the FMC architecture of STM32H7, with the
exception of the board specific definitions.
2020-06-24 10:51:02 -03:00

194 lines
6.8 KiB
C

/****************************************************************************
* boards/arm/stm32f7/stm32f769i-disco/src/stm32_extmem.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <assert.h>
#include <debug.h>
#include <arch/board/board.h>
#include "chip.h"
#include "arm_arch.h"
#include "stm32_fmc.h"
#include "stm32_gpio.h"
#include "stm32_rcc.h"
#include "stm32f769i-disco.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifndef CONFIG_STM32F7_FMC
# warning "FMC is not enabled"
#endif
#if STM32F7_NGPIO < 8
# error "Required GPIO ports not enabled"
#endif
#define STM32_FMC_NADDRCONFIGS 25
#define STM32_FMC_NDATACONFIGS 32
#define STM32_SDRAM_CLKEN FMC_SDCMR_CTB1 | FMC_SDCMR_MODE_CLK_ENABLE
#define STM32_SDRAM_PALL FMC_SDCMR_CTB1 | FMC_SDCMR_MODE_PALL
#define STM32_SDRAM_REFRESH FMC_SDCMR_CTB1 | FMC_SDCMR_MODE_AUTO_REFRESH |\
FMC_SDCMR_NRFS(8)
#define STM32_SDRAM_MODEREG FMC_SDCMR_CTB1 | FMC_SDCMR_MODE_LOAD_MODE |\
FMC_SDCMR_MRD_BURST_LENGTH_1 | \
FMC_SDCMR_MRD_BURST_TYPE_SEQUENTIAL |\
FMC_SDCMR_MRD_CAS_LATENCY_3 |\
FMC_SDCMR_MRD_OPERATING_MODE_STANDARD |\
FMC_SDCMR_MRD_WRITEBURST_MODE_SINGLE
/****************************************************************************
* Public Data
****************************************************************************/
/* GPIO configurations common to most external memories */
static const uint32_t g_addressconfig[STM32_FMC_NADDRCONFIGS] =
{
GPIO_FMC_A0, GPIO_FMC_A1, GPIO_FMC_A2, GPIO_FMC_A3, GPIO_FMC_A4,
GPIO_FMC_A5, GPIO_FMC_A6, GPIO_FMC_A7, GPIO_FMC_A8, GPIO_FMC_A9,
GPIO_FMC_A10, GPIO_FMC_A11, GPIO_FMC_A12,
GPIO_FMC_NBL0, GPIO_FMC_NBL1, GPIO_FMC_NBL2, GPIO_FMC_NBL3, GPIO_FMC_BA0,
GPIO_FMC_BA1, GPIO_FMC_SDNWE_3, GPIO_FMC_SDNCAS, GPIO_FMC_SDNRAS,
GPIO_FMC_SDNE0_3, GPIO_FMC_SDCKE0_3, GPIO_FMC_SDCLK
};
static const uint32_t g_dataconfig[STM32_FMC_NDATACONFIGS] =
{
GPIO_FMC_D0, GPIO_FMC_D1, GPIO_FMC_D2, GPIO_FMC_D3, GPIO_FMC_D4,
GPIO_FMC_D5, GPIO_FMC_D6, GPIO_FMC_D7, GPIO_FMC_D8, GPIO_FMC_D9,
GPIO_FMC_D10, GPIO_FMC_D11, GPIO_FMC_D12, GPIO_FMC_D13, GPIO_FMC_D14,
GPIO_FMC_D15, GPIO_FMC_D16, GPIO_FMC_D17, GPIO_FMC_D18, GPIO_FMC_D19,
GPIO_FMC_D20, GPIO_FMC_D21, GPIO_FMC_D22, GPIO_FMC_D23, GPIO_FMC_D24,
GPIO_FMC_D25, GPIO_FMC_D26, GPIO_FMC_D27, GPIO_FMC_D28, GPIO_FMC_D29,
GPIO_FMC_D30, GPIO_FMC_D31
};
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: stm32_extmemgpios
*
* Description:
* Initialize GPIOs for external memory usage.
*
****************************************************************************/
static void stm32_extmemgpios(const uint32_t *gpios, int ngpios)
{
int i;
/* Configure GPIOs */
for (i = 0; i < ngpios; i++)
{
stm32_configgpio(gpios[i]);
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: stm32_sdram_initialize
*
* Description:
* Called from stm32_bringup to initialize external SDRAM access.
*
****************************************************************************/
void stm32_sdram_initialize(void)
{
uint32_t val;
volatile int count;
/* Enable GPIOs as FMC / memory pins */
stm32_extmemgpios(g_addressconfig, STM32_FMC_NADDRCONFIGS);
stm32_extmemgpios(g_dataconfig, STM32_FMC_NDATACONFIGS);
/* Initialize the FMC peripheral */
stm32_fmc_init();
/* Configure and enable the SDRAM bank1
*
* FMC clock = 216MHz/2 = 108MHz
* 108MHz = 9,26 ns
* All timings from the datasheet for Speedgrade -6A (=6ns)
*/
val = FMC_SDCR_RPIPE_0 | /* rpipe = 0 hclk */
FMC_SDCR_BURST_READ | /* enable burst read */
FMC_SDCR_SDCLK_2X | /* sdclk = 2 hclk */
FMC_SDCR_CASLAT_3 | /* cas latency = 3 cycles */
FMC_SDCR_BANKS_4 | /* 4 internal banks */
FMC_SDCR_WIDTH_32 | /* width = 32 bits */
FMC_SDCR_ROWBITS_12 | /* numrows = 12 bits */
FMC_SDCR_COLBITS_8; /* numcols = 8 bits */
stm32_fmc_sdram_set_control(1, val);
val = FMC_SDTR_TRCD(2) | /* tRCD min = 18ns */
FMC_SDTR_TRP(2) | /* tRP min = 18ns */
FMC_SDTR_TWR(3) | /* tWR = 3CLK */
FMC_SDTR_TRC(7) | /* tRC min = 64ns */
FMC_SDTR_TRAS(4) | /* tRAS min = 37ns */
FMC_SDTR_TXSR(7) | /* tXSR min = 64ns */
FMC_SDTR_TMRD(2); /* tMRD = 2CLK */
stm32_fmc_sdram_set_timing(1, val);
/* SDRAM Initialization sequence */
stm32_fmc_sdram_command(STM32_SDRAM_CLKEN); /* Clock enable command */
for (count = 0; count < 10000; count++); /* Delay */
stm32_fmc_sdram_command(STM32_SDRAM_PALL); /* Precharge ALL command */
stm32_fmc_sdram_command(STM32_SDRAM_REFRESH); /* Auto refresh command */
stm32_fmc_sdram_command(STM32_SDRAM_MODEREG); /* Mode Register program */
/* Set refresh count
*
* FMC_CLK = 108MHz
* Refresh_Rate = 64ms / 4096 rows = 15.63us
* Counter = (FMC_CLK * Refresh_Rate) - 20
*/
stm32_fmc_sdram_set_refresh_rate(1668);
}