rtc: m41t62: add compatible for m41t82

This adds a compatible string for m41t82. This ensures that this driver
can be used for m41t82 in DM mode, too (asit was usable for this model in
non-DM mode before).

In addition, the HT bit has to be reset during probe, since the m41t82
chip sets it when entering battery standby mode.

This patch ensures this driver works on socfpga_socrates.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>

diff --git a/drivers/rtc/m41t62.c b/drivers/rtc/m41t62.c
index 2ee7e00b021b5a268ca39aa1484fc0e4ddd95ff4..6161b7671284aaa0ae353e7642b00fb2f23170f6 100644 (file)
--- a/drivers/rtc/m41t62.c
+++ b/drivers/rtc/m41t62.c
@@ -155,6 +155,15 @@ static int m41t62_rtc_reset(struct udevice *dev)
        return ret;
 }
 
+/*
+ * Make sure HT bit is cleared. This bit is set on entering battery backup
+ * mode, so do this before the first read access.
+ */
+static int m41t62_rtc_probe(struct udevice *dev)
+{
+       return m41t62_rtc_reset(dev);
+}
+
 static const struct rtc_ops m41t62_rtc_ops = {
        .get = m41t62_rtc_get,
        .set = m41t62_rtc_set,
@@ -163,6 +172,7 @@ static const struct rtc_ops m41t62_rtc_ops = {
 
 static const struct udevice_id m41t62_rtc_ids[] = {
        { .compatible = "st,m41t62" },
+       { .compatible = "st,m41t82" },
        { .compatible = "microcrystal,rv4162" },
        { }
 };
@@ -172,6 +182,7 @@ U_BOOT_DRIVER(rtc_m41t62) = {
        .id     = UCLASS_RTC,
        .of_match = m41t62_rtc_ids,
        .ops    = &m41t62_rtc_ops,
+       .probe  = &m41t62_rtc_probe,
 };
 
 #else /* NON DM RTC code - will be removed */