Hi Alexandre, thanks a lot!! On 05.02.19 22:55, Alexandre Belloni wrote: > Hi, > > On 11/01/2019 13:15:39+0000, Oliver.Rohe@xxxxxxxx wrote: >> When the oscillator of the rtc gets interrupted, >> e.g. due to an empty battery, reading from the rtc will now return an error >> and the oscillator bit will be cleared, once the rtc is successfully reset. >> >> Signed-off-by: Oliver Rohe <oliver.rohe@xxxxxxxx> >> --- >> drivers/rtc/rtc-rs5c372.c | 60 ++++++++++++++++++++++++++++++++++++++++------- >> 1 file changed, 52 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c >> index ff35dce..91d1475 100644 >> --- a/drivers/rtc/rtc-rs5c372.c >> +++ b/drivers/rtc/rtc-rs5c372.c >> @@ -52,8 +52,10 @@ >> # define RS5C_CTRL1_CT4 (4 << 0) /* 1 Hz level irq */ >> #define RS5C_REG_CTRL2 15 >> # define RS5C372_CTRL2_24 (1 << 5) >> -# define R2x2x_CTRL2_XSTP (1 << 5) /* only if R2x2x */ >> -# define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2x2x */ >> +# define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2x2x */ > > This should probably use tabs instead of spaces :) >> +# define R2x2x_CTRL2_VDET (1 << 6) /* only if R2x2x */ >> +# define R2x2x_CTRL2_XSTP (1 << 5) /* only if R2x2x */ >> +# define R2x2x_CTRL2_PON (1 << 4) /* only if R2x2x */ >> # define RS5C_CTRL2_CTFG (1 << 2) >> # define RS5C_CTRL2_AAFG (1 << 1) /* or WAFG */ >> # define RS5C_CTRL2_BAFG (1 << 0) /* or DAFG */ >> @@ -212,10 +214,31 @@ static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm) >> struct i2c_client *client = to_i2c_client(dev); >> struct rs5c372 *rs5c = i2c_get_clientdata(client); >> int status = rs5c_get_regs(rs5c); >> + unsigned char ctrl2 = rs5c->regs[RS5C_REG_CTRL2]; >> >> if (status < 0) >> return status; >> >> + switch (rs5c->type) { >> + case rtc_r2025sd: >> + case rtc_r2221tl: >> + if (ctrl2 & R2x2x_CTRL2_VDET) >> + dev_warn(&client->dev, "rtc battery voltage drop below threshold detected.\n"); > > VDET doesn't mean anything specific regarding timekeeping so I wouldn't warn here. VDET means in case the chip is powered by a battery, that is about to die sometime soon, it gives you heads up. > >> + if (ctrl2 & R2x2x_CTRL2_PON) >> + dev_warn(&client->dev, "rtc battery voltage drop to zero detected.\n"); > > You should return -EINVAL directly here The PON implies the XSTP bit, so I only return from there, just to print all the warning messages, but I can return directly from here if you want. > >> + if ((rs5c->type == rtc_r2025sd && !(ctrl2 & R2x2x_CTRL2_XSTP)) || >> + (rs5c->type == rtc_r2221tl && (ctrl2 & R2x2x_CTRL2_XSTP))) { >> + dev_warn(&client->dev, "rtc oscillator interruption detected. Please reset the rtc clock.\n"); >> + return -EIO; > > -EINVAL is the correct error code here. Ok > >> + } >> + break; >> + default: >> + if (ctrl2 & RS5C_CTRL2_XSTP) { >> + dev_warn(&client->dev, "rtc oscillator interruption detected. Please reset the rtc clock.\n"); >> + return -EIO; > > and here. OK > >