Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[cascardo/linux.git] / drivers / rtc / rtc-ds1307.c

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 821d9c0..8e1c5cb 100644 (file)
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -482,11 +482,6 @@ static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
        t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
        t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
        t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
-       t->time.tm_mon = -1;
-       t->time.tm_year = -1;
-       t->time.tm_wday = -1;
-       t->time.tm_yday = -1;
-       t->time.tm_isdst = -1;
 
        /* ... and status */
        t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
@@ -602,6 +597,8 @@ static const struct rtc_class_ops ds13xx_rtc_ops = {
  * Alarm support for mcp794xx devices.
  */
 
+#define MCP794XX_REG_WEEKDAY           0x3
+#define MCP794XX_REG_WEEKDAY_WDAY_MASK 0x7
 #define MCP794XX_REG_CONTROL           0x07
 #      define MCP794XX_BIT_ALM0_EN     0x10
 #      define MCP794XX_BIT_ALM1_EN     0x20
@@ -1231,13 +1228,16 @@ static int ds1307_probe(struct i2c_client *client,
 {
        struct ds1307           *ds1307;
        int                     err = -ENODEV;
-       int                     tmp;
+       int                     tmp, wday;
        struct chip_desc        *chip = &chips[id->driver_data];
        struct i2c_adapter      *adapter = to_i2c_adapter(client->dev.parent);
        bool                    want_irq = false;
        bool                    ds1307_can_wakeup_device = false;
        unsigned char           *buf;
        struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
+       struct rtc_time         tm;
+       unsigned long           timestamp;
+
        irq_handler_t   irq_handler = ds1307_irq;
 
        static const int        bbsqi_bitpos[] = {
@@ -1526,6 +1526,27 @@ read_rtc:
                                bin2bcd(tmp));
        }
 
+       /*
+        * Some IPs have weekday reset value = 0x1 which might not correct
+        * hence compute the wday using the current date/month/year values
+        */
+       ds1307_get_time(&client->dev, &tm);
+       wday = tm.tm_wday;
+       timestamp = rtc_tm_to_time64(&tm);
+       rtc_time64_to_tm(timestamp, &tm);
+
+       /*
+        * Check if reset wday is different from the computed wday
+        * If different then set the wday which we computed using
+        * timestamp
+        */
+       if (wday != tm.tm_wday) {
+               wday = i2c_smbus_read_byte_data(client, MCP794XX_REG_WEEKDAY);
+               wday = wday & ~MCP794XX_REG_WEEKDAY_WDAY_MASK;
+               wday = wday | (tm.tm_wday + 1);
+               i2c_smbus_write_byte_data(client, MCP794XX_REG_WEEKDAY, wday);
+       }
+
        if (want_irq) {
                device_set_wakeup_capable(&client->dev, true);
                set_bit(HAS_ALARM, &ds1307->flags);