[PATCH 1/4] rtc: mcp795: fix invalid month setting.

From: Emil Bartczak
Date: Mon Dec 05 2016 - 08:12:12 EST


The 10 month register was always set to value 0 in the RTC hardware.
Due to the bug month November or December became February.
---
drivers/rtc/rtc-mcp795.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c
index 4021fd0..266328b 100644
--- a/drivers/rtc/rtc-mcp795.c
+++ b/drivers/rtc/rtc-mcp795.c
@@ -29,7 +29,7 @@
#define MCP795_EEWREN 0x06
#define MCP795_SRREAD 0x05
#define MCP795_SRWRITE 0x01
-#define MCP795_READ 0x13
+#define MCP795_READ 0x13
#define MCP795_WRITE 0x12
#define MCP795_UNLOCK 0x14
#define MCP795_IDWRITE 0x32
@@ -39,6 +39,7 @@

#define MCP795_ST_BIT 0x80
#define MCP795_24_BIT 0x40
+#define MCP795_LP_BIT 0x20

static int mcp795_rtcc_read(struct device *dev, u8 addr, u8 *buf, u8 count)
{
@@ -108,7 +109,8 @@ static int mcp795_set_time(struct device *dev, struct rtc_time *tim)
data[1] = (data[1] & 0x80) | ((tim->tm_min / 10) << 4) | (tim->tm_min % 10);
data[2] = ((tim->tm_hour / 10) << 4) | (tim->tm_hour % 10);
data[4] = ((tim->tm_mday / 10) << 4) | ((tim->tm_mday) % 10);
- data[5] = (data[5] & 0x10) | (tim->tm_mon / 10) | (tim->tm_mon % 10);
+ data[5] = (data[5] & MCP795_LP_BIT) |
+ ((tim->tm_mon / 10) << 4) | (tim->tm_mon % 10);

if (tim->tm_year > 100)
tim->tm_year -= 100;
@@ -137,11 +139,11 @@ static int mcp795_read_time(struct device *dev, struct rtc_time *tim)
if (ret)
return ret;

- tim->tm_sec = ((data[0] & 0x70) >> 4) * 10 + (data[0] & 0x0f);
- tim->tm_min = ((data[1] & 0x70) >> 4) * 10 + (data[1] & 0x0f);
+ tim->tm_sec = ((data[0] & 0x70) >> 4) * 10 + (data[0] & 0x0f);
+ tim->tm_min = ((data[1] & 0x70) >> 4) * 10 + (data[1] & 0x0f);
tim->tm_hour = ((data[2] & 0x30) >> 4) * 10 + (data[2] & 0x0f);
tim->tm_mday = ((data[4] & 0x30) >> 4) * 10 + (data[4] & 0x0f);
- tim->tm_mon = ((data[5] & 0x10) >> 4) * 10 + (data[5] & 0x0f);
+ tim->tm_mon = ((data[5] & 0x10) >> 4) * 10 + (data[5] & 0x0f);
tim->tm_year = ((data[6] & 0xf0) >> 4) * 10 + (data[6] & 0x0f) + 100; /* Assume we are in 20xx */

dev_dbg(dev, "Read from mcp795: %04d-%02d-%02d %02d:%02d:%02d\n",
--
2.7.4