ARM: imx: Force DRAM regulators into FPWM mode on DH i.MX8MP DHCOM SoM

In case the Buck5 and Buck6 regulators which supply DRAM Vdd1 and Vdd2/Vddq
respectively operate in automatic PWM/PFM mode, the DRAM EDAC detects more
correctable errors than if the regulators operate in forced PWM only mode.
Force DRAM regulators to forced PWM mode only to stop tempting the DRAM.

Signed-off-by: Marek Vasut <marex@denx.de>

diff --git a/board/dhelectronics/dh_imx8mp/spl.c b/board/dhelectronics/dh_imx8mp/spl.c
index 1b05da53c352d7cc2889a085cf927f29113aca64..21b12a70c8ea775541195168423ed1e667388425 100644 (file)
--- a/board/dhelectronics/dh_imx8mp/spl.c
+++ b/board/dhelectronics/dh_imx8mp/spl.c
@@ -94,6 +94,11 @@ static int dh_imx8mp_board_power_init(void)
        /* To avoid timing risk from SoC to ARM, increase VDD_ARM to OD voltage 0.95V */
        pmic_reg_write(dev, PCA9450_BUCK2OUT_DVS0, 0x1c);
 
+       /* DRAM Vdd1 always FPWM */
+       pmic_reg_write(dev, PCA9450_BUCK5CTRL, 0x0d);
+       /* DRAM Vdd2/Vddq always FPWM */
+       pmic_reg_write(dev, PCA9450_BUCK6CTRL, 0x0d);
+
        /* Set LDO4 and CONFIG2 to enable the I2C level translator. */
        pmic_reg_write(dev, PCA9450_LDO4CTRL, 0x59);
        pmic_reg_write(dev, PCA9450_CONFIG2, 0x1);