target/linux/bcm27xx/patches-5.15/950-0529-rtc-pcf85063-Always-clear-EXT_TEST-from-set_time.patch

   1 From c3cfd27eb16d2fc12cfa77e6cd5f9eb352403c16 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.com>
   3 Date: Fri, 15 Oct 2021 11:45:36 +0100
   4 Subject: [PATCH] rtc: pcf85063: Always clear EXT_TEST from set_time
   5
   6 Power-on reset after the insertion of a battery does not always complete
   7 successfully, leading to corrupted register content. The EXT_TEST bit
   8 will stop the clock from running, but currently the driver will never
   9 recover.
  10
  11 Safely handle the erroneous state by clearing EXT_TEST as part of the
  12 usual set_time method.
  13
  14 Signed-off-by: Phil Elwell <phil@raspberrypi.com>
  15 ---
  16  drivers/rtc/rtc-pcf85063.c | 2 ++
  17  1 file changed, 2 insertions(+)
  18
  19 --- a/drivers/rtc/rtc-pcf85063.c
  20 +++ b/drivers/rtc/rtc-pcf85063.c
  21 @@ -34,6 +34,7 @@
  22  #define PCF85063_REG_CTRL1             0x00 /* status */
  23  #define PCF85063_REG_CTRL1_CAP_SEL     BIT(0)
  24  #define PCF85063_REG_CTRL1_STOP                BIT(5)
  25 +#define PCF85063_REG_CTRL1_EXT_TEST    BIT(7)
  26
  27  #define PCF85063_REG_CTRL2             0x01
  28  #define PCF85063_CTRL2_AF              BIT(6)
  29 @@ -117,6 +118,7 @@ static int pcf85063_rtc_set_time(struct
  30          * reset state until all time/date registers are written
  31          */
  32         rc = regmap_update_bits(pcf85063->regmap, PCF85063_REG_CTRL1,
  33 +                               PCF85063_REG_CTRL1_EXT_TEST |
  34                                 PCF85063_REG_CTRL1_STOP,
  35                                 PCF85063_REG_CTRL1_STOP);
  36         if (rc)