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nuttx/boards/arm/sama5/sama5d3-xplained/src/sam_sdram.c
Fotis Panagiotopoulos 41b4af1ec3 Style fixes.
2022-09-28 09:38:55 +08:00

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/****************************************************************************
* boards/arm/sama5/sama5d3-xplained/src/sam_sdram.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 <debug.h>
#include "arm_internal.h"
#include "sam_periphclks.h"
#include "hardware/sam_memorymap.h"
#include "hardware/sam_pmc.h"
#include "hardware/sam_sfr.h"
#include "hardware/sam_mpddrc.h"
#include "sama5d3-xplained.h"
/* This file requires:
*
* CONFIG_SAMA5_DDRCS -- DRAM support is enabled, and
* !CONFIG_SAMA5_BOOT_SDRAM - We did not boot into SRAM.
*/
#if defined(CONFIG_SAMA5_DDRCS) && !defined(CONFIG_SAMA5_BOOT_SDRAM)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* SDRAM differences */
#if defined(CONFIG_SAMA5D3XPLAINED_MT47H128M16RT)
/* Used for SDRAM command handshaking */
# define DDR2_BA0 (1 << 26)
# define DDR2_BA1 (1 << 27)
#elif defined(CONFIG_SAMA5D3XPLAINED_MT47H64M16HR)
/* Used for SDRAM command handshaking */
# define DDR2_BA0 (1 << 25)
# define DDR2_BA1 (1 << 26)
#else
# error Unknown SDRAM type
#endif
/* The delay loop in sam_sdram_delay requires 6 core cycles per iteration.
*
* At 384MHz:
*
* (6 cycles/iteration) / (0.384 cycles/nanosecond) =
* 15.6250 nanoseconds per iteration
*
* At 396MHz:
*
* (6 cycles/iteration) / (0.396 cycles/nanosecond) =
* 15.1515 nanoseconds per iteration
*
* At 528MHz:
*
* (6 cycles/iteration) / (0.528 cycles/nanosecond) =
* 11.3636 nanoseconds per iteration
*/
#define LOOP_GUARD 100
# define CYCLES_TO_COUNT(cycles) (((cycles) / 6) + LOOP_GUARD)
#if defined(CONFIG_SAMA5D3XPLAINED_384MHZ)
# define NSEC_TO_COUNT(nsec) ((((nsec) * 1000) / 15625) + LOOP_GUARD)
# define USEC_TO_COUNT(usec) ((((usec) * 1000000) / 15625) + LOOP_GUARD)
#elif defined(CONFIG_SAMA5D3XPLAINED_528MHZ)
# define NSEC_TO_COUNT(nsec) ((((nsec) * 1000) / 11364) + LOOP_GUARD)
# define USEC_TO_COUNT(usec) ((((usec) * 1000000) / 11364) + LOOP_GUARD)
#else /* #elif defined(CONFIG_SAMA5D3XPLAINED_396MHZ) */
# define NSEC_TO_COUNT(nsec) ((((nsec) * 1000) / 15152) + LOOP_GUARD)
# define USEC_TO_COUNT(usec) ((((usec) * 1000000) / 15152) + LOOP_GUARD)
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: sam_sdram_delay
*
* Description:
* Precision delay function for SDRAM configuration.
*
* This delay loop requires 6 core cycles per iteration. The actual
* amount of time delayed will then vary with PCK.
*
****************************************************************************/
static inline void sam_sdram_delay(unsigned int loops)
{
volatile unsigned int i;
for (i = 0; i < loops; i++)
{
asm("nop");
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: sam_sdram_config
*
* Description:
* Configures DDR2 (MT47H128M16RT 128MB or, optionally, MT47H64M16HR)
*
* Per the SAMA5D3-Xplained User guide:
* "Two DDR2/SDRAM (MT47H64M16HR) used as main system memory (256 MByte).
* The board includes 2 Gbits of on-board soldered DDR2 (double data rate)
* SDRAM. The footprints can also host two DDR2(MT47H128M16RT) from
* Micron® for a total of 512 MBytes of DDR2 memory.
* The memory bus is 32 bits wide and operates with a frequency of up
* to 166 MHz."
*
* From the Atmel Code Example:
* MT47H64M16HR : 8 Meg x 16 x 8 banks
* Refresh count: 8K
* Row address: A[12:0] (8K)
* Column address A[9:0] (1K)
* Bank address BA[2:0] a(24,25) (8)
*
* This logic was taken from Atmel sample code for the SAMA5D3x-EK.
*
* Input Parameters:
* devtype - Either DDRAM_MT47H128M16RT or DDRAM_MT47H64M16HR
*
* Assumptions:
* The DDR memory regions is configured as strongly ordered memory. When
* we complete initialization of SDRAM and it is ready for use, we will
* make DRAM into normal memory.
*
****************************************************************************/
void sam_sdram_config(void)
{
volatile uint8_t *ddr = (uint8_t *)SAM_DDRCS_VSECTION;
uint32_t regval;
/* Enable x2 clocking to the MPDDRC */
sam_mpddrc_enableclk();
/* Enable DDR clocking */
regval = getreg32(SAM_PMC_SCER);
regval |= PMC_DDRCK;
putreg32(regval, SAM_PMC_SCER);
/* Clear the low power register */
putreg32(0, SAM_MPDDRC_LPR);
/* Enable autofresh during calibration (undocumented) */
regval = getreg32(SAM_MPDDRC_HS);
regval |= MPDDRC_HS_AUTOREFRESH_CAL;
putreg32(regval, SAM_MPDDRC_HS);
/* Force DDR_DQ and DDR_DQS input buffer always on */
regval = getreg32(SAM_SFR_DDRCFG);
regval |= SFR_FDQIEN | SFR_FDQSIEN;
putreg32(regval, SAM_SFR_DDRCFG);
/* Configure the slave offset register */
regval = MPDDRC_DLL_SOR_S0OFF(1) | /* DLL Slave 0 Delay Line Offset */
MPDDRC_DLL_SOR_S1OFF(0) | /* DLL Slave 1 Delay Line Offset */
MPDDRC_DLL_SOR_S2OFF(1) | /* DLL Slave 2 Delay Line Offset */
MPDDRC_DLL_SOR_S3OFF(1); /* DLL Slave 3 Delay Line Offset */
putreg32(regval, SAM_MPDDRC_DLL_SOR);
/* Configure the master offset register (including upper mystery bits) */
regval = MPDDRC_DLL_MOR_MOFF(7) | /* DLL Master Delay Line Offset */
MPDDRC_DLL_MOR_CLK90OFF(31) | /* DLL CLK90 Delay Line Offset */
MPDDRC_DLL_MOR_SELOFF | /* DLL Offset Selection */
MPDDRC_DLL_MOR_KEY; /* Undocumented key */
putreg32(regval, SAM_MPDDRC_DLL_MOR);
/* Configure the I/O calibration register */
regval = getreg32(SAM_MPDDRC_IO_CALIBR);
regval &= ~(MPDDRC_IO_CALIBR_RDIV_MASK | MPDDRC_IO_CALIBR_TZQIO_MASK);
regval |= (MPDDRC_IO_CALIBR_RZQ48_40 | MPDDRC_IO_CALIBR_TZQIO(3));
putreg32(regval, SAM_MPDDRC_IO_CALIBR);
/* Force DDR_DQ and DDR_DQS input buffer always on */
putreg32(SFR_FDQIEN | SFR_FDQSIEN, SAM_SFR_DDRCFG);
/* Step 1: Program the memory device type
*
* DBW = 0 (32-bit bus wide)
* Memory Device = DDR2-SDRAM
*/
putreg32(MPDDRC_MD_DDR2_SDRAM, SAM_MPDDRC_MD);
/* Step 2: Program the features of DDR2-SDRAM device into the Timing
* Register
*/
#if defined(CONFIG_SAMA5D3XPLAINED_MT47H128M16RT)
/* For MT47H128M16RT
*
* NC = 10 DDR column bits
* NR = 14 DDR row bits
* CAS = DDR2/LPDDR2 CAS Latency 4
* DLL = Disable reset (0)
* DIC_DS = 0
* DIS_DLL = Enable PLL (0)
* ZQ = Calibration command after initialization (0)
* OCD = OCD calibration mode exit, maintain setting (0)
* DQMS = Not shared (0)
* ENDRM = Disable read measure (0)
* NB = 8 banks
* NDQS = Not DQS disabled
* DECODE = Sequential decoding (0)
* UNAL = Unaliged access supported
*/
regval = MPDDRC_CR_NC_10 | /* Number of Column Bits */
MPDDRC_CR_NR_14 | /* Number of Row Bits */
MPDDRC_CR_CAS_4 | /* CAS Latency */
MPDDRC_CR_OCD_EXIT | /* Off-chip Driver */
MPDDRC_CR_8BANKS | /* Number of Banks */
MPDDRC_CR_NDQS | /* Not DQS */
MPDDRC_CR_UNAL; /* upport Unaligned Access */
#elif defined(CONFIG_SAMA5D3XPLAINED_MT47H64M16HR)
/* For MT47H64M16HR
*
* NC = 10 DDR column bits
* NR = 13 DDR row bits
* CAS = DDR2/LPDDR2 CAS Latency 3
* DLL = Disable reset (0)
* DIC_DS = 0
* DIS_DLL = Enable PLL (0)
* ZQ = Calibration command after initialization (0)
* OCD = OCD calibration mode exit, maintain setting (0)
* DQMS = Not shared (0)
* ENDRM = Disable read measure (0)
* NB = 8 banks
* NDQS = Not DQS disabled
* DECODE = Sequential decoding (0)
* UNAL = Unaliged access supported
*/
regval = MPDDRC_CR_NC_10 | /* Number of Column Bits */
MPDDRC_CR_NR_13 | /* Number of Row Bits */
MPDDRC_CR_CAS_3 | /* CAS Latency */
MPDDRC_CR_OCD_EXIT | /* Off-chip Driver */
MPDDRC_CR_8BANKS | /* Number of Banks */
MPDDRC_CR_NDQS | /* Not DQS */
MPDDRC_CR_UNAL; /* upport Unaligned Access */
#else
# error Unknown SDRAM type
#endif
putreg32(regval, SAM_MPDDRC_CR);
/* Configure the Timing Parameter 0 Register */
regval = MPDDRC_TPR0_TRAS(6) | /* Active to Precharge Delay: 6 * 7.5 = 45 ns */
MPDDRC_TPR0_TRCD(2) | /* Row to Column Delay: 2 * 7.5 = 15 ns */
MPDDRC_TPR0_TWR(2) | /* Write Recovery Delay: 3 * 7.5 = 22.5 ns */
MPDDRC_TPR0_TRC(8) | /* Row Cycle Delay: 8 * 7.5 = 60 ns */
MPDDRC_TPR0_TRP(2) | /* Row Precharge Delay: 2 * 7.5 = 15 ns */
MPDDRC_TPR0_TRRD(1) | /* Active BankA to Active BankB: 2 * 7.5 = 15 ns */
MPDDRC_TPR0_TWTR(2) | /* Internal Write to Read Delay: 2 clock cycle */
MPDDRC_TPR0_TMRD(2); /* Load Mode Register Command to
* Activate or Refresh Command: 2 clock
* cycles
*/
putreg32(regval, SAM_MPDDRC_TPR0);
/* Configure the Timing Parameter 1 Register */
regval = MPDDRC_TPR1_TRFC(14) | /* Row Cycle Delay:
* 18 * 7.5 = 135 ns
* (min 127.5 ns for 1Gb DDR)
*/
MPDDRC_TPR1_TXSNR(16) | /* Exit Self Refresh Delay to Non Read Command:
* 20 * 7.5 > 142.5ns TXSNR: Exit self refresh
* delay to non read command
*/
MPDDRC_TPR1_TXSRD(208) | /* Exit Self Refresh Delay to Read Command:
* min 200 clock cycles, TXSRD: Exit self refresh
* delay to Read command
*/
MPDDRC_TPR1_TXP(2); /* Exit Power-down Delay to First Command:
* 2 * 7.5 = 15 ns
*/
putreg32(regval, SAM_MPDDRC_TPR1);
/* Configure the Timing Parameter 2 Register */
regval = MPDDRC_TPR2_TXARD(7) | /* Exit Active Power Down Delay to
* Read Command in Mode 'Fast Exit':
* min 2 clock cycles
*/
MPDDRC_TPR2_TXARDS(7) | /* Exit Active Power Down Delay to
* Read Command in Mode 'Slow Exit':
* min 7 clock cycles
*/
MPDDRC_TPR2_TRPA(2) | /* Row Precharge All Delay:
* min 18ns
*/
MPDDRC_TPR2_TRTP(2) | /* Four Active Windows:
* 2 * 7.5 = 15 ns
* (min 7.5ns)
*/
MPDDRC_TPR2_TFAW(10);
putreg32(regval, SAM_MPDDRC_TPR2);
/* DDRSDRC Low-power Register */
sam_sdram_delay(USEC_TO_COUNT(200));
regval = MPDDRC_LPR_LPCB_DISABLED | /* Low-power Feature is inhibited */
MPDDRC_LPR_TIMEOUT_0CLKS | /* Activates low-power mode after the end of transfer */
MPDDRC_LPR_APDE_FAST; /* Active Power Down Exit Time */
putreg32(regval, SAM_MPDDRC_LPR);
/* Step 3: An NOP command is issued to the DDR2-SDRAM. Program the NOP
* command into the Mode Register, the application must set MODE to 1 in
* the Mode Register.
*/
putreg32(MPDDRC_MR_MODE_NOP, SAM_MPDDRC_MR);
/* Perform a write access to any DDR2-SDRAM address to acknowledge this
* command.
*/
*ddr = 0;
/* Now clocks which drive DDR2-SDRAM device are enabled.
*
* A minimum pause of 200 usec is provided to precede any signal toggle.
* (6 core cycles per iteration, core is at 396MHz: min 13200 loops)
*/
sam_sdram_delay(USEC_TO_COUNT(200));
/* Step 4: An NOP command is issued to the DDR2-SDRAM */
putreg32(MPDDRC_MR_MODE_NOP, SAM_MPDDRC_MR);
/* Perform a write access to any DDR2-SDRAM address to
* acknowledge this command.
*/
*ddr = 0;
/* Now CKE is driven high. */
/* Wait 400 ns min */
sam_sdram_delay(NSEC_TO_COUNT(400));
/* Step 5: An all banks precharge command is issued to the DDR2-SDRAM. */
putreg32(MPDDRC_MR_MODE_PRCGALL, SAM_MPDDRC_MR);
/* Perform a write access to any DDR2-SDRAM address to
* acknowledge this command.
*/
*ddr = 0;
/* Wait 400 ns min */
sam_sdram_delay(NSEC_TO_COUNT(400));
/* Step 6: An Extended Mode Register set (EMRS2) cycle is issued to chose
* between commercialor high temperature operations.
*
* The write address must be chosen so that BA[1] is set to 1 and BA[0] is
* set to 0.
*/
putreg32(MPDDRC_MR_MODE_EXTLMR, SAM_MPDDRC_MR);
*((volatile uint8_t *)(ddr + DDR2_BA1)) = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Step 7: An Extended Mode Register set (EMRS3) cycle is issued to set
* all registers to 0.
*
* The write address must be chosen so that BA[1] is set to 1 and BA[0] is
* set to 1.
*/
putreg32(MPDDRC_MR_MODE_LMR, SAM_MPDDRC_MR);
*((volatile uint8_t *)(ddr + DDR2_BA1 + DDR2_BA0)) = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Step 8: An Extended Mode Register set (EMRS1) cycle
* is issued to enable DLL.
*
* The write address must be chosen so that BA[1] is set to
* 0 and BA[0] is set to 1.
*/
putreg32(MPDDRC_MR_MODE_EXTLMR, SAM_MPDDRC_MR);
*((volatile uint8_t *)(ddr + DDR2_BA0)) = 0;
/* An additional 200 cycles of clock are required for locking DLL */
sam_sdram_delay(10000 /* CYCLES_TO_COUNT(200) */);
/* Step 9: Program DLL field into the Configuration Register. */
regval = getreg32(SAM_MPDDRC_CR);
regval |= MPDDRC_CR_DLL;
putreg32(regval, SAM_MPDDRC_CR);
/* Step 10: A Mode Register set (MRS) cycle is issued to reset DLL.
*
* The write address must be chosen so that BA[1:0] bits are set to 0.
*/
putreg32(MPDDRC_MR_MODE_LMR, SAM_MPDDRC_MR);
*ddr = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Step 11: An all banks precharge command is issued to the DDR2-SDRAM.
*
* Perform a write access to any DDR2-SDRAM address to acknowledge this
* command
*/
putreg32(MPDDRC_MR_MODE_PRCGALL, SAM_MPDDRC_MR);
*ddr = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Step 12: Two auto-refresh (CBR) cycles are provided. Program the auto
* refresh command (CBR) into the Mode Register.
*
* Perform a write access to any DDR2-SDRAM address to acknowledge this
* command.
*/
putreg32(MPDDRC_MR_MODE_RFSH, SAM_MPDDRC_MR);
*ddr = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Configure 2nd CBR.
*
* Perform a write access to any DDR2-SDRAM address to
* acknowledge this command.
*/
putreg32(MPDDRC_MR_MODE_RFSH, SAM_MPDDRC_MR);
*ddr = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Step 13: Program DLL field into the Configuration Register to low
* (Disable DLL reset).
*/
regval = getreg32(SAM_MPDDRC_CR);
regval &= ~MPDDRC_CR_DLL;
putreg32(regval, SAM_MPDDRC_CR);
/* Step 14: A Mode Register set (MRS) cycle is issued to program the
* parameters of the DDR2-SDRAM devices.
*
* The write address must be chosen so that BA[1:0] are set to 0.
*/
putreg32(MPDDRC_MR_MODE_LMR, SAM_MPDDRC_MR);
*ddr = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Step 15: Program OCD field into the Configuration Register to high (OCD
* calibration default).
*/
regval = getreg32(SAM_MPDDRC_CR);
regval |= MPDDRC_CR_OCD_DEFAULT;
putreg32(regval, SAM_MPDDRC_CR);
/* Step 16: An Extended Mode Register set (EMRS1) cycle is issued to OCD
* default value.
*
* The write address must be chosen so that BA[1] is set to 0 and BA[0] is
* set to 1.
*/
putreg32(MPDDRC_MR_MODE_EXTLMR, SAM_MPDDRC_MR);
*((volatile uint8_t *)(ddr + DDR2_BA0)) = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Step 17: Program OCD field into the Configuration Register to low (OCD
* calibration mode exit).
*/
#if 0
regval = getreg32(SAM_MPDDRC_CR);
regval &= ~MPDDRC_CR_OCD_MASK;
putreg32(regval, SAM_MPDDRC_CR);
#endif
/* Step 18: An Extended Mode Register set (EMRS1) cycle is issued to
* enable OCD exit.
*
* The write address must be chosen so that BA[1] is set to 0 and BA[0] is
* set to 1.
*/
putreg32(MPDDRC_MR_MODE_EXTLMR, SAM_MPDDRC_MR);
*((volatile uint8_t *)(ddr + DDR2_BA0)) = 0;
/* Wait 2 cycles min */
sam_sdram_delay(100 /* CYCLES_TO_COUNT(2) */);
/* Step 19,20: A mode Normal command is provided. Program the Normal mode
* into Mode Register.
*/
putreg32(MPDDRC_MR_MODE_NORMAL, SAM_MPDDRC_MR);
*ddr = 0;
/* Step 21: Write the refresh rate into the count field in the Refresh
* Timer register. The DDR2-SDRAM device requires a refresh every 15.625
* usec or 7.81 usec.
*
* With a 100MHz frequency, the refresh timer count register must to be
* set with (15.625 /100 MHz) = 1562 i.e. 0x061A or (7.81 /100MHz) = 781
* i.e. 0x030d.
*/
/* For MT47H64M16HR, The refresh period is 64ms (commercial), This equates
* to an average refresh rate of 7.8125usec (commercial), To ensure all
* rows of all banks are properly refreshed, 8192 REFRESH commands must be
* issued every 64ms (commercial)
*/
/* ((64 x 10(^-3))/8192) x133 x (10^6) */
/* Set Refresh timer 7.8125 us */
putreg32(MPDDRC_RTR_COUNT(300), SAM_MPDDRC_RTR);
/* OK now we are ready to work on the DDRSDR */
/* Wait for end of calibration */
sam_sdram_delay(500);
}
#endif /* CONFIG_SAMA5_DDRCS && !CONFIG_SAMA5_BOOT_SDRAM */
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