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ARM: imx6: DHCOM i.MX6 PDK: use Kconfig for inclusion of DDR calibration

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The four x16 DDR3 are wired in T-topology. From NXP AN4467:
'Although not required, T-Topologies may also benefit from performing
Write Leveling as there are package delays on both the processor and DDR
devices that can be de-skewed by performing Write Leveling. Therefore,
Freescale recommends determining Write Leveling calibration parameters
for all boards, regardless of topology used.'
That is why write level calibration is also done.

Signed-off-by: Ludwig Zenz <lzenz@dh-electronics.com>
This commit is contained in:
Ludwig Zenz 2019-04-15 11:13:08 +02:00 committed by Stefano Babic
parent a44ca1346d
commit aa34505653
1 changed files with 26 additions and 6 deletions
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32
board/dhelectronics/dh_imx6/dh_imx6_spl.c
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@ -482,6 +482,29 @@ static void setup_iomux_usb(void)
SETUP_IOMUX_PADS(usb_pads);
}
/* Perform DDR DRAM calibration */
static int spl_dram_perform_cal(struct mx6_ddr_sysinfo const *sysinfo)
{
int ret = 0;
#ifdef CONFIG_MX6_DDRCAL
udelay(100);
ret = mmdc_do_write_level_calibration(sysinfo);
if (ret) {
printf("DDR3: Write level calibration error [%d]\n", ret);
return ret;
}
ret = mmdc_do_dqs_calibration(sysinfo);
if (ret) {
printf("DDR3: DQS calibration error [%d]\n", ret);
return ret;
}
#endif /* CONFIG_MX6_DDRCAL */
return ret;
}
/* DRAM */
static void dhcom_spl_dram_init(void)
@ -509,8 +532,7 @@ static void dhcom_spl_dram_init(void)
}
/* Perform DDR DRAM calibration */
udelay(100);
mmdc_do_dqs_calibration(&dhcom_ddr_64bit);
spl_dram_perform_cal(&dhcom_ddr_64bit);
} else if (is_cpu_type(MXC_CPU_MX6DL)) {
mx6sdl_dram_iocfg(64, &dhcom6sdl_ddr_ioregs,
@ -528,8 +550,7 @@ static void dhcom_spl_dram_init(void)
}
/* Perform DDR DRAM calibration */
udelay(100);
mmdc_do_dqs_calibration(&dhcom_ddr_64bit);
spl_dram_perform_cal(&dhcom_ddr_64bit);
} else if (is_cpu_type(MXC_CPU_MX6SOLO)) {
mx6sdl_dram_iocfg(32, &dhcom6sdl_ddr_ioregs,
@ -552,8 +573,7 @@ static void dhcom_spl_dram_init(void)
}
/* Perform DDR DRAM calibration */
udelay(100);
mmdc_do_dqs_calibration(&dhcom_ddr_32bit);
spl_dram_perform_cal(&dhcom_ddr_32bit);
}
}