Rtc - Cherry PUMA SOM-RK3399-Q7 User Manual

The kernel devicetree defines the used display configuration. Example device trees for various output configu-
rations are provided with the EVK software package.
To configure the bootloader which devicetree to load, edit the configuration variable fdtfile in the file /boot/
puma_rk3399/userEnv.txt. For example to enable DisplayPort write:
fdtfile=rk3399-puma-edp.dtb
Filename
rk3399-puma.dtb
rk3399-puma-edp.dtb
rk3399-puma-mipidsi.dtb
rk3399-puma-hdmi+edp.dtb
rk3399-puma-hdmi+mipidsi.dtb
See https://git.embedded.cherry.de/som-hardware.git/ for video adapter reference designs.

3.12 RTC

the RK3399-Q7 contain a real-time clock (RTC) on-module. The RTC is read by the kernel on bootup and used
to set the system clock.
To check the RTC value, use hwclock:
hwclock
Thu 30 Apr 2015 03:51:20
The RTC will be set automatically to the system clock on shutdown, so you can set the system clock using the
date command and reboot to update the RTC:
date --set 2015-04-20
date --set 03:51:30
v1.6
Page 12
Qseven Port Function
LVDS A MIPI-DSI
LVDS B MIPI-DSI
Fig. 3.12: Display connector pinout
Display 1
HDMI
Display Port on LVDS A
MIPI-DSI on LVDS A
HDMI
HDMI
PM CEST -0.826662 seconds
Alternate Function
eDP
MIPI-CSI
NC GND
GND LVDS_B_CLK_N
LVDS_A3_N LVDS_B_CLK_P
LVDS_A3_P GND
GND LVDS_B3_N
GND LVDS_B3_P
LVDS_A2_N GND
LVDS_A2_P GND
GND
LVDS_B2_N
GND LVDS_B2_P
LVDS_A1_N GND
LVDS_A1_P GND
GND LVDS_B1_N
NC LVDS_B1_P
GND GND
LVDS_A0_N DP_HPD#
LVDS_A0_P GND
GND LVDS_B0_N
LVDS_A_CLK_N LVDS_B0_P
LVDS_A_CLK_P GND
GND NC
LVDS_PPEN LVDS_BLC_DAT
3V3 NC
3V3 LVDS_BLC_CLK
LVDS_BLT_CTRL 3V3
LVDS_BLEN GND
NC LVDS_DID_DAT
GPO0 LVDS_DID_CLK
GND GND
12V 12V
12V 12V
GND 12V
Display 2
Display Port on LVDS A
MIPI-DSI on LVDS A