imx8mn: Add low drive mode support for DDR4/LPDDR4 EVK
Add dedicated defconfigs for iMX8MN low drive mode which set the VDD_SOC
and VDD_DRAM to 0.8v, DDR at 1600MTS (800Mhz clock) and GPU at 200Mhz.
Signed-off-by: Ye Li <ye.li@nxp.com>
Acked-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/board/freescale/imx8mn_evk/spl.c b/board/freescale/imx8mn_evk/spl.c
index 5d4c2ac..03f2a56 100644
--- a/board/freescale/imx8mn_evk/spl.c
+++ b/board/freescale/imx8mn_evk/spl.c
@@ -75,10 +75,15 @@
/* BUCKxOUT_DVS0/1 control BUCK123 output */
pmic_reg_write(dev, PCA9450_BUCK123_DVS, 0x29);
+#ifdef CONFIG_IMX8MN_LOW_DRIVE_MODE
+ /* Set VDD_SOC/VDD_DRAM to 0.8v for low drive mode */
+ pmic_reg_write(dev, PCA9450_BUCK1OUT_DVS0, 0x10);
+#else
/* increase VDD_SOC/VDD_DRAM to typical value 0.95V before first DRAM access */
+ pmic_reg_write(dev, PCA9450_BUCK1OUT_DVS0, 0x1C);
+#endif
/* Set DVS1 to 0.85v for suspend */
/* Enable DVS control through PMIC_STBY_REQ and set B1_ENMODE=1 (ON by PMIC_ON_REQ=H) */
- pmic_reg_write(dev, PCA9450_BUCK1OUT_DVS0, 0x1C);
pmic_reg_write(dev, PCA9450_BUCK1OUT_DVS1, 0x14);
pmic_reg_write(dev, PCA9450_BUCK1CTRL, 0x59);