[U-Boot] [PATCH v2 3/4] arm: socfpga: socrates: make rtc work

Simon Goldschmidt simon.k.r.goldschmidt at gmail.com
Wed Mar 13 16:48:38 UTC 2019


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 at 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,
-- 
2.17.1



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