diff options
Diffstat (limited to 'drivers/rtc/rtc-m41t93.c')
| -rw-r--r-- | drivers/rtc/rtc-m41t93.c | 46 |
1 files changed, 27 insertions, 19 deletions
diff --git a/drivers/rtc/rtc-m41t93.c b/drivers/rtc/rtc-m41t93.c index 10f1c29436e..efab3d48cb1 100644 --- a/drivers/rtc/rtc-m41t93.c +++ b/drivers/rtc/rtc-m41t93.c @@ -48,6 +48,7 @@ static inline int m41t93_set_reg(struct spi_device *spi, u8 addr, u8 data) static int m41t93_set_time(struct device *dev, struct rtc_time *tm) { struct spi_device *spi = to_spi_device(dev); + int tmp; u8 buf[9] = {0x80}; /* write cmd + 8 data bytes */ u8 * const data = &buf[1]; /* ptr to first data byte */ @@ -62,6 +63,30 @@ static int m41t93_set_time(struct device *dev, struct rtc_time *tm) return -EINVAL; } + tmp = spi_w8r8(spi, M41T93_REG_FLAGS); + if (tmp < 0) + return tmp; + + if (tmp & M41T93_FLAG_OF) { + dev_warn(&spi->dev, "OF bit is set, resetting.\n"); + m41t93_set_reg(spi, M41T93_REG_FLAGS, tmp & ~M41T93_FLAG_OF); + + tmp = spi_w8r8(spi, M41T93_REG_FLAGS); + if (tmp < 0) { + return tmp; + } else if (tmp & M41T93_FLAG_OF) { + /* OF cannot be immediately reset: oscillator has to be + * restarted. */ + u8 reset_osc = buf[M41T93_REG_ST_SEC] | M41T93_FLAG_ST; + + dev_warn(&spi->dev, + "OF bit is still set, kickstarting clock.\n"); + m41t93_set_reg(spi, M41T93_REG_ST_SEC, reset_osc); + reset_osc &= ~M41T93_FLAG_ST; + m41t93_set_reg(spi, M41T93_REG_ST_SEC, reset_osc); + } + } + data[M41T93_REG_SSEC] = 0; data[M41T93_REG_ST_SEC] = bin2bcd(tm->tm_sec); data[M41T93_REG_MIN] = bin2bcd(tm->tm_min); @@ -89,10 +114,7 @@ static int m41t93_get_time(struct device *dev, struct rtc_time *tm) 1. halt bit (HT) is set: the clock is running but update of readout registers has been disabled due to power failure. This is normal case after poweron. Time is valid after resetting HT bit. - 2. oscillator fail bit (OF) is set. Oscillator has be stopped and - time is invalid: - a) OF can be immeditely reset. - b) OF cannot be immediately reset: oscillator has to be restarted. + 2. oscillator fail bit (OF) is set: time is invalid. */ tmp = spi_w8r8(spi, M41T93_REG_ALM_HOUR_HT); if (tmp < 0) @@ -110,21 +132,7 @@ static int m41t93_get_time(struct device *dev, struct rtc_time *tm) if (tmp & M41T93_FLAG_OF) { ret = -EINVAL; - dev_warn(&spi->dev, "OF bit is set, resetting.\n"); - m41t93_set_reg(spi, M41T93_REG_FLAGS, tmp & ~M41T93_FLAG_OF); - - tmp = spi_w8r8(spi, M41T93_REG_FLAGS); - if (tmp < 0) - return tmp; - else if (tmp & M41T93_FLAG_OF) { - u8 reset_osc = buf[M41T93_REG_ST_SEC] | M41T93_FLAG_ST; - - dev_warn(&spi->dev, - "OF bit is still set, kickstarting clock.\n"); - m41t93_set_reg(spi, M41T93_REG_ST_SEC, reset_osc); - reset_osc &= ~M41T93_FLAG_ST; - m41t93_set_reg(spi, M41T93_REG_ST_SEC, reset_osc); - } + dev_warn(&spi->dev, "OF bit is set, write time to restart.\n"); } if (tmp & M41T93_FLAG_BL) |