From 0a1a588c0851736a4a8cb400e68e607455df0a65 Mon Sep 17 00:00:00 2001 From: Jesper Nilsson Date: Thu, 7 Feb 2013 12:27:43 +1100 Subject: [PATCH] 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. Signed-off-by: Jesper Nilsson Reviewed-by: Thierry Reding Signed-off-by: Andrew Morton --- drivers/rtc/rtc-pcf8523.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c index be05a645f99e..0696ab2b7c57 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 +251,35 @@ static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm) return pcf8523_start_rtc(client); } +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; + } +} + 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, -- 2.39.5