aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm2708/patches-4.19/950-0165-Revert-rtc-pcf8523-properly-handle-oscillator-stop-b.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0165-Revert-rtc-pcf8523-properly-handle-oscillator-stop-b.patch')
-rw-r--r--target/linux/brcm2708/patches-4.19/950-0165-Revert-rtc-pcf8523-properly-handle-oscillator-stop-b.patch56
1 files changed, 56 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0165-Revert-rtc-pcf8523-properly-handle-oscillator-stop-b.patch b/target/linux/brcm2708/patches-4.19/950-0165-Revert-rtc-pcf8523-properly-handle-oscillator-stop-b.patch
new file mode 100644
index 0000000000..b9a4f52e5a
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.19/950-0165-Revert-rtc-pcf8523-properly-handle-oscillator-stop-b.patch
@@ -0,0 +1,56 @@
+From 0557d41d861b8c214b3472749482efdc71363dbb Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Mon, 29 Oct 2018 14:45:45 +0000
+Subject: [PATCH] Revert "rtc: pcf8523: properly handle oscillator stop
+ bit"
+
+This reverts commit ede44c908d44b166a5b6bd7caacd105c2ff5a70f.
+
+See: https://github.com/raspberrypi/firmware/issues/1065
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+---
+ drivers/rtc/rtc-pcf8523.c | 25 ++++++++++++++++++++++---
+ 1 file changed, 22 insertions(+), 3 deletions(-)
+
+--- a/drivers/rtc/rtc-pcf8523.c
++++ b/drivers/rtc/rtc-pcf8523.c
+@@ -212,8 +212,28 @@ static int pcf8523_rtc_read_time(struct
+ if (err < 0)
+ return err;
+
+- if (regs[0] & REG_SECONDS_OS)
+- return -EINVAL;
++ if (regs[0] & REG_SECONDS_OS) {
++ /*
++ * If the oscillator was stopped, try to clear the flag. Upon
++ * power-up the flag is always set, but if we cannot clear it
++ * the oscillator isn't running properly for some reason. The
++ * sensible thing therefore is to return an error, signalling
++ * that the clock cannot be assumed to be correct.
++ */
++
++ regs[0] &= ~REG_SECONDS_OS;
++
++ err = pcf8523_write(client, REG_SECONDS, regs[0]);
++ if (err < 0)
++ return err;
++
++ err = pcf8523_read(client, REG_SECONDS, &regs[0]);
++ if (err < 0)
++ return err;
++
++ if (regs[0] & REG_SECONDS_OS)
++ return -EAGAIN;
++ }
+
+ tm->tm_sec = bcd2bin(regs[0] & 0x7f);
+ tm->tm_min = bcd2bin(regs[1] & 0x7f);
+@@ -249,7 +269,6 @@ static int pcf8523_rtc_set_time(struct d
+ return err;
+
+ regs[0] = REG_SECONDS;
+- /* This will purposely overwrite REG_SECONDS_OS */
+ regs[1] = bin2bcd(tm->tm_sec);
+ regs[2] = bin2bcd(tm->tm_min);
+ regs[3] = bin2bcd(tm->tm_hour);