diff options
| author | Mylène Josserand <mylene.josserand@free-electrons.com> | 2016-03-21 18:06:10 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-03-25 02:41:13 +0100 |
| commit | ee087744247c421c83abea7f01217bfd39b8f5a9 (patch) | |
| tree | 19addc9c871e45976fec758034e4a5b407fb8daa /drivers/rtc | |
| parent | 59a8383adb75459c9d6766656bccc05950b783ea (diff) | |
| download | linux-ee087744247c421c83abea7f01217bfd39b8f5a9.tar.bz2 | |
rtc: abx80x: handle the oscillator failure bit
Handle the Oscillator Failure ('OF') bit from Oscillator Status register
(0x1D). This bit is cleared on set_time function and is read each time the
date/time is read, but only in case of XT Oscillator selection.
In RC mode, this bit is always set.
Signed-off-by: Mylène Josserand <mylene.josserand@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-abx80x.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c index 0e4c9a0989d1..ba0d61934d35 100644 --- a/drivers/rtc/rtc-abx80x.c +++ b/drivers/rtc/rtc-abx80x.c @@ -58,6 +58,7 @@ #define ABX8XX_OSC_OSEL BIT(7) #define ABX8XX_REG_OSS 0x1d +#define ABX8XX_OSS_OF BIT(1) #define ABX8XX_OSS_OMODE BIT(4) #define ABX8XX_REG_CFG_KEY 0x1f @@ -138,7 +139,23 @@ static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char buf[8]; - int err; + int err, flags, rc_mode = 0; + + /* Read the Oscillator Failure only in XT mode */ + rc_mode = abx80x_is_rc_mode(client); + if (rc_mode < 0) + return rc_mode; + + if (!rc_mode) { + flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS); + if (flags < 0) + return flags; + + if (flags & ABX8XX_OSS_OF) { + dev_err(dev, "Oscillator failure, data is invalid.\n"); + return -EINVAL; + } + } err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH, sizeof(buf), buf); @@ -166,7 +183,7 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct i2c_client *client = to_i2c_client(dev); unsigned char buf[8]; - int err; + int err, flags; if (tm->tm_year < 100) return -EINVAL; @@ -187,6 +204,18 @@ static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm) return -EIO; } + /* Clear the OF bit of Oscillator Status Register */ + flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS); + if (flags < 0) + return flags; + + err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS, + flags & ~ABX8XX_OSS_OF); + if (err < 0) { + dev_err(&client->dev, "Unable to write oscillator status register\n"); + return err; + } + return 0; } |