This patch makes the on-board RTC work on the socfpga_socrates board. This rtc is present on the board, but it does not work (fails with a timeout).
This patch adds a weak pull-up on the I2C0-SCL pin connected to the m41t82 RTC on this board. While the SDA line has a pull-up on the pcb, the pull-up on the SCL line seems to be missing. To work around this, enable the weak-pull-up feature on this pin.
After applying this patch, the rtc timeout is gone and the 'date' command can access the rtc chip.
Signed-off-by: Simon Goldschmidt simon.k.r.goldschmidt@gmail.com ---
Changes in v2: None
board/ebv/socrates/qts/iocsr_config.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/board/ebv/socrates/qts/iocsr_config.h b/board/ebv/socrates/qts/iocsr_config.h index 011fa2bac3..18b9c6ce4d 100644 --- a/board/ebv/socrates/qts/iocsr_config.h +++ b/board/ebv/socrates/qts/iocsr_config.h @@ -108,7 +108,7 @@ const unsigned long iocsr_scan_chain2_table[] = { 0x00018004, 0x06001209, 0x00004000, - 0x20002412, + 0x20042412, 0x00904800, 0x00000030, 0x80000000,