This patch provides the code to calibrate the DDR's DQS to DQ signals (RDLVL).
It is based on: VFxxx Controller Reference Manual, Rev. 0, 10/2016, page 1600 10.1.6.16.4.1 "Software Read Leveling in MC Evaluation Mode"
and NXP's community thread: "Vybrid: About DDR leveling feature on DDRMC." https://community.nxp.com/thread/395323
Signed-off-by: Lukasz Majewski lukma@denx.de
---
Changes in v2: - CR93_SWLVL_EXIT -> CR94_SWLVL_EXIT (EXIT is in CR94) - Update Kconfig information regarding DDRMC_VF610_CALIBRATION - Update ddrmc-vf610-calibration. comment - Update code after extending imx-regs.h
arch/arm/mach-imx/Kconfig | 12 + arch/arm/mach-imx/Makefile | 1 + arch/arm/mach-imx/ddrmc-vf610-calibration.c | 342 ++++++++++++++++++++++++++++ arch/arm/mach-imx/ddrmc-vf610-calibration.h | 45 ++++ 4 files changed, 400 insertions(+) create mode 100644 arch/arm/mach-imx/ddrmc-vf610-calibration.c create mode 100644 arch/arm/mach-imx/ddrmc-vf610-calibration.h
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig index a1566cc2ad..8631fbd481 100644 --- a/arch/arm/mach-imx/Kconfig +++ b/arch/arm/mach-imx/Kconfig @@ -78,3 +78,15 @@ config NXP_BOARD_REVISION NXP boards based on i.MX6/7 contain the board revision information stored in the fuses. Select this option if you want to be able to retrieve the board revision information. + +config DDRMC_VF610_CALIBRATION + bool "Enable DDRMC (DDR3) on-chip calibration" + depends on ARCH_VF610 + help + Vybrid (vf610) SoC provides some on-chip facility to tune the DDR3 + memory parameters. Select this option if you want to calculate them + at boot time. + NOTE: + NXP does NOT recommend to perform this calibration at each boot. One + shall perform it on a new PCB and then use those values to program + the ddrmc_cr_setting on relevant board file. diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile index 53d9e5f42b..4a07b1ea69 100644 --- a/arch/arm/mach-imx/Makefile +++ b/arch/arm/mach-imx/Makefile @@ -51,6 +51,7 @@ obj-$(CONFIG_SECURE_BOOT) += hab.o endif ifeq ($(SOC),$(filter $(SOC),vf610)) obj-y += ddrmc-vf610.o +obj-$(CONFIG_DDRMC_VF610_CALIBRATION) += ddrmc-vf610-calibration.o endif ifneq ($(CONFIG_SPL_BUILD),y) obj-$(CONFIG_CMD_BMODE) += cmd_bmode.o diff --git a/arch/arm/mach-imx/ddrmc-vf610-calibration.c b/arch/arm/mach-imx/ddrmc-vf610-calibration.c new file mode 100644 index 0000000000..f29de74c39 --- /dev/null +++ b/arch/arm/mach-imx/ddrmc-vf610-calibration.c @@ -0,0 +1,342 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * ddrmc DDR3 calibration code for NXP's VF610 + * + * Copyright (C) 2018 DENX Software Engineering + * Lukasz Majewski, DENX Software Engineering, lukma@denx.de + * + */ +/* #define DEBUG */ +#include <common.h> +#include <asm/io.h> +#include <asm/arch/imx-regs.h> +#include <linux/bitmap.h> + +#include "ddrmc-vf610-calibration.h" + +/* + * Documents: + * + * [1] "Vybrid: About DDR leveling feature on DDRMC." + * https://community.nxp.com/thread/395323 + * + * [2] VFxxx Controller Reference Manual, Rev. 0, 10/2016 + * + * + * NOTE + * ==== + * + * NXP recommends setting 'fixed' parameters instead of performing the + * training at each boot. + * + * Use those functions to determine those values on new HW, read the + * calculated value from registers and add them to the board specific + * struct ddrmc_cr_setting. + * + * SW leveling supported operations - CR93[SW_LVL_MODE]: + * + * - 0x0 (b'00) - No leveling + * + * - 0x1 (b'01) - WRLVL_DL_X - It is not recommended to perform this tuning + * on HW designs utilizing non-flyback topology + * (Single DDR3 with x16). + * Instead the WRLVL_DL_0/1 fields shall be set + * based on trace length differences from their + * layout. + * Mismatches up to 25% or tCK (clock period) are + * allowed, so the value in the filed doesn’t have + * to be very accurate. + * + * - 0x2 (b'10) - RDLVL_DL_0/1 - refers to adjusting the DQS strobe in relation + * to the DQ signals so that the strobe edge is + * centered in the window of valid read data. + * + * - 0x3 (b'11) - RDLVL_GTDL_0/1 - refers to the delay the PHY uses to un-gate + * the Read DQS strobe pad from the time that the + * PHY enables the pad to input the strobe signal. + * + */ +static int ddr_cal_get_first_edge_index(unsigned long *bmap, enum edge e, + int samples, int start, int max) +{ + int i, ret = -1; + + /* + * We look only for the first value (and filter out + * some wrong data) + */ + switch (e) { + case RISING_EDGE: + for (i = start; i <= max - samples; i++) { + if (test_bit(i, bmap)) { + if (!test_bit(i - 1, bmap) && + test_bit(i + 1, bmap) && + test_bit(i + 2, bmap) && + test_bit(i + 3, bmap)) { + return i; + } + } + } + break; + case FALLING_EDGE: + for (i = start; i <= max - samples; i++) { + if (!test_bit(i, bmap)) { + if (test_bit(i - 1, bmap) && + test_bit(i - 2, bmap) && + test_bit(i - 3, bmap)) { + return i; + } + } + } + } + + return ret; +} + +static void bitmap_print(unsigned long *bmap, int max) +{ + int i; + + debug("BITMAP [0x%p]:\n", bmap); + for (i = 0; i <= max; i++) { + debug("%d ", test_bit(i, bmap) ? 1 : 0); + if (i && (i % 32) == (32 - 1)) + debug("\n"); + } + debug("\n"); +} + +#define sw_leveling_op_done \ + while (!(readl(&ddrmr->cr[94]) & DDRMC_CR94_SWLVL_OP_DONE)) + +#define sw_leveling_load_value \ + do { clrsetbits_le32(&ddrmr->cr[93], DDRMC_CR93_SWLVL_LOAD, \ + DDRMC_CR93_SWLVL_LOAD); } while (0) + +#define sw_leveling_start \ + do { clrsetbits_le32(&ddrmr->cr[93], DDRMC_CR93_SWLVL_START, \ + DDRMC_CR93_SWLVL_START); } while (0) + +#define sw_leveling_exit \ + do { clrsetbits_le32(&ddrmr->cr[94], DDRMC_CR94_SWLVL_EXIT, \ + DDRMC_CR94_SWLVL_EXIT); } while (0) + +/* + * RDLVL_DL calibration: + * + * NXP is _NOT_ recommending performing the leveling at each + * boot. Instead - one shall run this procedure on new boards + * and then use hardcoded values. + * + */ +static int ddrmc_cal_dqs_to_dq(struct ddrmr_regs *ddrmr) +{ + DECLARE_BITMAP(rdlvl_rsp, DDRMC_DQS_DQ_MAX_DELAY + 1); + int rdlvl_dl_0_min = -1, rdlvl_dl_0_max = -1; + int rdlvl_dl_1_min = -1, rdlvl_dl_1_max = -1; + int rdlvl_dl_0, rdlvl_dl_1; + u8 swlvl_rsp; + u32 tmp; + int i; + + /* Read defaults */ + u16 rdlvl_dl_0_def = + (readl(&ddrmr->cr[105]) >> DDRMC_CR105_RDLVL_DL_0_OFF) & 0xFFFF; + u16 rdlvl_dl_1_def = readl(&ddrmr->cr[110]) & 0xFFFF; + + debug("\nRDLVL: ======================\n"); + debug("RDLVL: DQS to DQ (RDLVL)\n"); + + debug("RDLVL: RDLVL_DL_0_DFL:\t 0x%x\n", rdlvl_dl_0_def); + debug("RDLVL: RDLVL_DL_1_DFL:\t 0x%x\n", rdlvl_dl_1_def); + + /* + * Set/Read setup for calibration + * + * Values necessary for leveling from Vybrid RM [2] - page 1600 + */ + writel(0x40703030, &ddrmr->cr[144]); + writel(0x40, &ddrmr->cr[145]); + writel(0x40, &ddrmr->cr[146]); + + tmp = readl(&ddrmr->cr[144]); + debug("RDLVL: PHY_RDLVL_RES:\t 0x%x\n", (tmp >> 24) & 0xFF);// set 0x40 + debug("RDLVL: PHY_RDLV_LOAD:\t 0x%x\n", (tmp >> 16) & 0xFF);// set 0x70 + debug("RDLVL: PHY_RDLV_DLL:\t 0x%x\n", (tmp >> 8) & 0xFF); // set 0x30 + debug("RDLVL: PHY_RDLV_EN:\t 0x%x\n", tmp & 0xFF); //set 0x30 + + tmp = readl(&ddrmr->cr[145]); + debug("RDLVL: PHY_RDLV_RR:\t 0x%x\n", tmp & 0x3FF); //set 0x40 + + tmp = readl(&ddrmr->cr[146]); + debug("RDLVL: PHY_RDLV_RESP:\t 0x%x\n", tmp); //set 0x40 + + /* + * Program/read the leveling edge RDLVL_EDGE = 0 + * + * 0x00 is the correct output on SWLVL_RSP_X + * If by any chance 1s are visible -> wrong number read + */ + clrbits_le32(&ddrmr->cr[101], DDRMC_CR101_PHY_RDLVL_EDGE); + + tmp = readl(&ddrmr->cr[101]); + debug("RDLVL: PHY_RDLVL_EDGE:\t 0x%x\n", + (tmp >> DDRMC_CR101_PHY_RDLVL_EDGE_OFF) & 0x1); //set 0 + + /* Program Leveling mode - CR93[SW_LVL_MODE] to ’b10 */ + clrsetbits_le32(&ddrmr->cr[93], DDRMC_CR93_SW_LVL_MODE(0x3), + DDRMC_CR93_SW_LVL_MODE(0x2)); + tmp = readl(&ddrmr->cr[93]); + debug("RDLVL: SW_LVL_MODE:\t 0x%x\n", + (tmp >> DDRMC_CR93_SW_LVL_MODE_OFF) & 0x3); + + /* Start procedure - CR93[SWLVL_START] to ’b1 */ + sw_leveling_start; + + /* Poll CR94[SWLVL_OP_DONE] */ + sw_leveling_op_done; + + /* + * Program delays for RDLVL_DL_0 + * + * The procedure is to increase the delay values from 0 to 0xFF + * and read the response from the DDRMC + */ + debug("\nRDLVL: ---> RDLVL_DL_0\n"); + bitmap_zero(rdlvl_rsp, DDRMC_DQS_DQ_MAX_DELAY + 1); + + for (i = 0; i <= DDRMC_DQS_DQ_MAX_DELAY; i++) { + clrsetbits_le32(&ddrmr->cr[105], + 0xFFFF << DDRMC_CR105_RDLVL_DL_0_OFF, + i << DDRMC_CR105_RDLVL_DL_0_OFF); + + /* Load values CR93[SWLVL_LOAD] to ’b1 */ + sw_leveling_load_value; + + /* Poll CR94[SWLVL_OP_DONE] */ + sw_leveling_op_done; + + /* + * Read Responses - SWLVL_RESP_0 + * + * The 0x00 (correct response when PHY_RDLVL_EDGE = 0) + * -> 1 in the bit vector + */ + swlvl_rsp = (readl(&ddrmr->cr[94]) >> + DDRMC_CR94_SWLVL_RESP_0_OFF) & 0xF; + if (swlvl_rsp == 0) + generic_set_bit(i, rdlvl_rsp); + } + + bitmap_print(rdlvl_rsp, DDRMC_DQS_DQ_MAX_DELAY); + + /* + * First test for rising edge 0x0 -> 0x1 in bitmap + */ + rdlvl_dl_0_min = ddr_cal_get_first_edge_index(rdlvl_rsp, RISING_EDGE, + N_SAMPLES, N_SAMPLES, + DDRMC_DQS_DQ_MAX_DELAY); + + /* + * Secondly test for falling edge 0x1 -> 0x0 in bitmap + */ + rdlvl_dl_0_max = ddr_cal_get_first_edge_index(rdlvl_rsp, FALLING_EDGE, + N_SAMPLES, rdlvl_dl_0_min, + DDRMC_DQS_DQ_MAX_DELAY); + + debug("RDLVL: DL_0 min: %d [0x%x] DL_0 max: %d [0x%x]\n", + rdlvl_dl_0_min, rdlvl_dl_0_min, rdlvl_dl_0_max, rdlvl_dl_0_max); + rdlvl_dl_0 = (rdlvl_dl_0_max - rdlvl_dl_0_min) / 2; + + if (rdlvl_dl_0_max == -1 || rdlvl_dl_0_min == -1 || rdlvl_dl_0 <= 0) { + debug("RDLVL: The DQS to DQ delay cannot be found!\n"); + debug("RDLVL: Using default - slice 0: %d!\n", rdlvl_dl_0_def); + rdlvl_dl_0 = rdlvl_dl_0_def; + } + + debug("\nRDLVL: ---> RDLVL_DL_1\n"); + bitmap_zero(rdlvl_rsp, DDRMC_DQS_DQ_MAX_DELAY + 1); + + for (i = 0; i <= DDRMC_DQS_DQ_MAX_DELAY; i++) { + clrsetbits_le32(&ddrmr->cr[110], + 0xFFFF << DDRMC_CR110_RDLVL_DL_1_OFF, + i << DDRMC_CR110_RDLVL_DL_1_OFF); + + /* Load values CR93[SWLVL_LOAD] to ’b1 */ + sw_leveling_load_value; + + /* Poll CR94[SWLVL_OP_DONE] */ + sw_leveling_op_done; + + /* + * Read Responses - SWLVL_RESP_1 + * + * The 0x00 (correct response when PHY_RDLVL_EDGE = 0) + * -> 1 in the bit vector + */ + swlvl_rsp = (readl(&ddrmr->cr[95]) >> + DDRMC_CR95_SWLVL_RESP_1_OFF) & 0xF; + if (swlvl_rsp == 0) + generic_set_bit(i, rdlvl_rsp); + } + + bitmap_print(rdlvl_rsp, DDRMC_DQS_DQ_MAX_DELAY); + + /* + * First test for rising edge 0x0 -> 0x1 in bitmap + */ + rdlvl_dl_1_min = ddr_cal_get_first_edge_index(rdlvl_rsp, RISING_EDGE, + N_SAMPLES, N_SAMPLES, + DDRMC_DQS_DQ_MAX_DELAY); + + /* + * Secondly test for falling edge 0x1 -> 0x0 in bitmap + */ + rdlvl_dl_1_max = ddr_cal_get_first_edge_index(rdlvl_rsp, FALLING_EDGE, + N_SAMPLES, rdlvl_dl_1_min, + DDRMC_DQS_DQ_MAX_DELAY); + + debug("RDLVL: DL_1 min: %d [0x%x] DL_1 max: %d [0x%x]\n", + rdlvl_dl_1_min, rdlvl_dl_1_min, rdlvl_dl_1_max, rdlvl_dl_1_max); + rdlvl_dl_1 = (rdlvl_dl_1_max - rdlvl_dl_1_min) / 2; + + if (rdlvl_dl_1_max == -1 || rdlvl_dl_1_min == -1 || rdlvl_dl_1 <= 0) { + debug("RDLVL: The DQS to DQ delay cannot be found!\n"); + debug("RDLVL: Using default - slice 1: %d!\n", rdlvl_dl_1_def); + rdlvl_dl_1 = rdlvl_dl_1_def; + } + + debug("RDLVL: CALIBRATED: rdlvl_dl_0: 0x%x\t rdlvl_dl_1: 0x%x\n", + rdlvl_dl_0, rdlvl_dl_1); + + /* Write new delay values */ + writel(DDRMC_CR105_RDLVL_DL_0(rdlvl_dl_0), &ddrmr->cr[105]); + writel(DDRMC_CR110_RDLVL_DL_1(rdlvl_dl_1), &ddrmr->cr[110]); + + sw_leveling_load_value; + sw_leveling_op_done; + + /* Exit procedure - CR94[SWLVL_EXIT] to ’b1 */ + sw_leveling_exit; + + /* Poll CR94[SWLVL_OP_DONE] */ + sw_leveling_op_done; + + return 0; +} + +/* + * WRLVL_DL calibration: + * + * For non-flyback memory architecture - where one have a single DDR3 x16 + * memory - it is NOT necessary to perform "Write Leveling" + * [3] 'Vybrid DDR3 write leveling' https://community.nxp.com/thread/429362 + * + */ + +int ddrmc_calibration(struct ddrmr_regs *ddrmr) +{ + ddrmc_cal_dqs_to_dq(ddrmr); + + return 0; +} diff --git a/arch/arm/mach-imx/ddrmc-vf610-calibration.h b/arch/arm/mach-imx/ddrmc-vf610-calibration.h new file mode 100644 index 0000000000..e82e217ab3 --- /dev/null +++ b/arch/arm/mach-imx/ddrmc-vf610-calibration.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * ddrmc DDR3 calibration code for NXP's VF610 + * + * Copyright (C) 2018 DENX Software Engineering + * Lukasz Majewski, DENX Software Engineering, lukma@denx.de + * + */ + +#ifndef __DDRMC_VF610_CALIBRATOIN_H_ +#define __DDRMC_VF610_CALIBRATOIN_H_ + +/* + * Number of "samples" in the calibration bitmap + * to be considered during calibration. + */ +#define N_SAMPLES 3 + +/* + * Constants to indicate if we are looking for a rising or + * falling edge in the calibration bitmap + */ +enum edge { + FALLING_EDGE = 1, + RISING_EDGE +}; + +/* + * The max number of delay elements when DQS to DQ setting + */ +#define DDRMC_DQS_DQ_MAX_DELAY 0xFF + +/** + * ddrmc_calibration - Vybrid's (VF610) DDR3 calibration code + * + * This function is calculating proper memory controller values + * during run time. + * + * @param ddrmr_regs - memory controller registers + * + * @return 0 on success, otherwise error code + */ +int ddrmc_calibration(struct ddrmr_regs *ddrmr); + +#endif /* __DDRMC_VF610_CALIBRATOIN_H_ */