diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-ds1307.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 821d9c089cdb..f25f7dce6e1f 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -602,6 +602,8 @@ 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 +1233,16 @@ 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 +1531,27 @@ 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); |