diff options
| author | Jesper Nilsson <jesper.nilsson@axis.com> | 2013-02-21 16:44:27 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-21 17:22:27 -0800 |
| commit | f32bc70d5f938cfef3e534c9db6d38a3759eac6d (patch) | |
| tree | 2b3772a6c6923871136d6285bb28e3898c6fea42 | |
| parent | fca1dd031a28da74db3df4921dc36fa78941c99f (diff) | |
rtc-pcf8523: add low battery voltage support
Implement reading of the battery voltage low signal for rtc-pcf8523.
The bit is read-only and cannot be cleared by software, so no
clear function is implemented.
[akpm@linux-foundation.org: omit pcf8563_rtc_ioctl() if CONFIG_RTC_INTF_DEV=n]
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/rtc/rtc-pcf8523.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c index be05a645f99..889e3160e70 100644 --- a/drivers/rtc/rtc-pcf8523.c +++ b/drivers/rtc/rtc-pcf8523.c @@ -23,6 +23,7 @@ #define REG_CONTROL3_PM_VDD (1 << 6) /* switch-over disabled */ #define REG_CONTROL3_PM_DSM (1 << 5) /* direct switching mode */ #define REG_CONTROL3_PM_MASK 0xe0 +#define REG_CONTROL3_BLF (1 << 2) /* battery low bit, read-only */ #define REG_SECONDS 0x03 #define REG_SECONDS_OS (1 << 7) @@ -250,9 +251,39 @@ static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm) return pcf8523_start_rtc(client); } +#ifdef CONFIG_RTC_INTF_DEV +static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd, + unsigned long arg) +{ + struct i2c_client *client = to_i2c_client(dev); + u8 value; + int ret = 0, err; + + switch (cmd) { + case RTC_VL_READ: + err = pcf8523_read(client, REG_CONTROL3, &value); + if (err < 0) + return err; + + if (value & REG_CONTROL3_BLF) + ret = 1; + + if (copy_to_user((void __user *)arg, &ret, sizeof(int))) + return -EFAULT; + + return 0; + default: + return -ENOIOCTLCMD; + } +} +#else +#define pcf8523_rtc_ioctl NULL +#endif + static const struct rtc_class_ops pcf8523_rtc_ops = { .read_time = pcf8523_rtc_read_time, .set_time = pcf8523_rtc_set_time, + .ioctl = pcf8523_rtc_ioctl, }; static int pcf8523_probe(struct i2c_client *client, |