Change register values RK3399

Chip Platform Rockchip
1

Hi,

Following the Rockchip RK3399TRM datasheet, I’m looking to change the value of register 0xFF77E014 to a specific value (GRF in Address Mapping, offset 0xE014).
What are the possible ways to write to these registers?

2

If in uboot , use below

+    writel(0x10001, 0xff770000 + 0xe640);
+    reg = readl(0xff770000 + 0xe640);