RTC v3020 fixes

Fix off-by-one in month calculations
Add delay for bus accesses to satisfy Tw > 500ns

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Acked-by: Raphael Assenat <raph@8d.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/rtc/rtc-v3020.c b/drivers/rtc/rtc-v3020.c
index 3b58d3d5d38a..a6b572978dc0 100644
--- a/drivers/rtc/rtc-v3020.c
+++ b/drivers/rtc/rtc-v3020.c
@@ -26,6 +26,7 @@
 #include <linux/types.h>
 #include <linux/bcd.h>
 #include <linux/rtc-v3020.h>
+#include <linux/delay.h>
 
 #include <asm/io.h>
 
@@ -47,6 +48,7 @@ static void v3020_set_reg(struct v3020 *chip, unsigned char address,
         for (i = 0; i < 4; i++) {
                 writel((tmp & 1) << chip->leftshift, chip->ioaddress);
                 tmp >>= 1;
+                udelay(1);
         }
 
         /* Commands dont have data */
@@ -54,6 +56,7 @@ static void v3020_set_reg(struct v3020 *chip, unsigned char address,
                 for (i = 0; i < 8; i++) {
                         writel((data & 1) << chip->leftshift, chip->ioaddress);
                         data >>= 1;
+                        udelay(1);
                 }
         }
 }
@@ -66,12 +69,14 @@ static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address)
         for (i = 0; i < 4; i++) {
                 writel((address & 1) << chip->leftshift, chip->ioaddress);
                 address >>= 1;
+                udelay(1);
         }
 
         for (i = 0; i < 8; i++) {
                 data >>= 1;
                 if (readl(chip->ioaddress) & (1 << chip->leftshift))
                         data |= 0x80;
+                udelay(1);
         }
 
         return data;
@@ -95,7 +100,7 @@ static int v3020_read_time(struct device *dev, struct rtc_time *dt)
         tmp = v3020_get_reg(chip, V3020_MONTH_DAY);
         dt->tm_mday     = BCD2BIN(tmp);
         tmp = v3020_get_reg(chip, V3020_MONTH);
-        dt->tm_mon      = BCD2BIN(tmp);
+        dt->tm_mon    = BCD2BIN(tmp) - 1;
         tmp = v3020_get_reg(chip, V3020_WEEK_DAY);
         dt->tm_wday     = BCD2BIN(tmp);
         tmp = v3020_get_reg(chip, V3020_YEAR);
@@ -135,7 +140,7 @@ static int v3020_set_time(struct device *dev, struct rtc_time *dt)
         v3020_set_reg(chip, V3020_MINUTES,      BIN2BCD(dt->tm_min));
         v3020_set_reg(chip, V3020_HOURS,        BIN2BCD(dt->tm_hour));
         v3020_set_reg(chip, V3020_MONTH_DAY,    BIN2BCD(dt->tm_mday));
-        v3020_set_reg(chip, V3020_MONTH,        BIN2BCD(dt->tm_mon));
+        v3020_set_reg(chip, V3020_MONTH,     BIN2BCD(dt->tm_mon + 1));
         v3020_set_reg(chip, V3020_WEEK_DAY,     BIN2BCD(dt->tm_wday));
         v3020_set_reg(chip, V3020_YEAR,         BIN2BCD(dt->tm_year % 100));