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drivers/rtc/rtc-pcf8563.c: add RTC_VL_READ/RTC_VL_CLR ioctl feature 

Changes are based on arch/cris/arch-v10/drivers/pcf8563.c

[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Mikael Starvik <starvik@axis.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexander Stein 2012-05-29 15:07:36 -07:00 committed by Linus Torvalds
parent e311c92959
commit 0f20b767e2
1 changed files with 43 additions and 1 deletions
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44
drivers/rtc/rtc-pcf8563.c
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@ -64,6 +64,7 @@ struct pcf8563 {
* 1970...2069.
*/
int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
int voltage_low; /* incicates if a low_voltage was detected */
};
/*
@ -86,9 +87,11 @@ static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
return -EIO;
}
if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
pcf8563->voltage_low = 1;
dev_info(&client->dev,
"low voltage detected, date/time is not reliable.\n");
}
dev_dbg(&client->dev,
"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
@ -173,6 +176,44 @@ static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
return 0;
}
#ifdef CONFIG_RTC_INTF_DEV
static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
struct rtc_time tm;
switch (cmd) {
case RTC_VL_READ:
if (pcf8563->voltage_low)
dev_info(dev, "low voltage detected, date/time is not reliable.\n");
if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
sizeof(int)))
return -EFAULT;
return 0;
case RTC_VL_CLR:
/*
* Clear the VL bit in the seconds register in case
* the time has not been set already (which would
* have cleared it). This does not really matter
* because of the cached voltage_low value but do it
* anyway for consistency.
*/
if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
pcf8563_set_datetime(to_i2c_client(dev), &tm);
/* Clear the cached value. */
pcf8563->voltage_low = 0;
return 0;
default:
return -ENOIOCTLCMD;
}
}
#else
#define pcf8563_rtc_ioctl NULL
#endif
static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return pcf8563_get_datetime(to_i2c_client(dev), tm);
@ -184,6 +225,7 @@ static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
}
static const struct rtc_class_ops pcf8563_rtc_ops = {
.ioctl = pcf8563_rtc_ioctl,
.read_time = pcf8563_rtc_read_time,
.set_time = pcf8563_rtc_set_time,
};