3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Keerthy <j-keerthy@xxxxxx> commit e29385fab0bf94017fac130ee32f5bb2daf74417 upstream. The reset value of weekday is 0x1. This is wrong since the reset values of the day/month/year make up to Jan 1 2001. When computed weekday comes out to be Monday. On a scale of 1-7(Sunday - Saturday) it should be 0x2. So we should not be relying on the reset value. Hence compute the wday using the current date/month/year values. Check if reset wday is any different from the computed wday, If different then set the wday which we computed using date/month/year values. Document Referred: http://ww1.microchip.com/downloads/en/DeviceDoc/20002266F.pdf Fixes: 1d1945d261a2af "drivers/rtc/rtc-ds1307.c: add alarm support for mcp7941x chips" Signed-off-by: Keerthy <j-keerthy@xxxxxx> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> [bwh: Backported to 3.16: - No 64-time rtc_time functions available - Adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- drivers/rtc/rtc-ds1307.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -611,6 +611,8 @@ static const struct rtc_class_ops ds13xx * Alarm support for mcp7941x devices. */ +#define MCP794XX_REG_WEEKDAY 0x3 +#define MCP794XX_REG_WEEKDAY_WDAY_MASK 0x7 #define MCP7941X_REG_CONTROL 0x07 # define MCP7941X_BIT_ALM0_EN 0x10 # define MCP7941X_BIT_ALM1_EN 0x20 @@ -840,12 +842,15 @@ static int ds1307_probe(struct i2c_clien { struct ds1307 *ds1307; int err = -ENODEV; - int tmp; + int tmp, wday; const struct chip_desc *chip = &chips[id->driver_data]; struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); bool want_irq = false; unsigned char *buf; struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev); + struct rtc_time tm; + unsigned long timestamp; + static const int bbsqi_bitpos[] = { [ds_1337] = 0, [ds_1339] = DS1339_BIT_BBSQI, @@ -1115,6 +1120,27 @@ read_rtc: return PTR_ERR(ds1307->rtc); } + /* + * 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; + rtc_tm_to_time(&tm, ×tamp); + rtc_time_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) { err = request_irq(client->irq, ds1307_irq, IRQF_SHARED, ds1307->rtc->name, client); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html