setalarm/getalarm functionalities for PCF823.

Ajit Kumar Jain

Hi,

We have NXP PCF8523 RTC sitting on i2c bus of AM335x.

The 'setalarm' and 'getalarm' support seems to be missing in pcf8523 driver(rtc-pcf8523.c).

Requesting help on getting some pointers/code references on supporting 'setalarm' and 'getalarm' in the existing pcf8523 driver.

Thanks

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

This is not a Sitara-related post, so I will move this to the Linux forum.

0 Titusrathinaraj Stalin over 8 years ago

TI__Guru** 116100 points

Hi Ajith,
You have to modify the driver to enable RTC alarm functionality.

You can refer to the following RTC drivers to implement.
lxr.free-electrons.com/.../rtc-isl1208.c

lxr.free-electrons.com/.../rtc-pcf8523.c

You have to use the following ops with updated structure members for RTC alarm read/write.
static const struct rtc_class_ops pcf8523_rtc_ops = {
.read_time = pcf8523_rtc_read_time,
.set_time = pcf8523_rtc_set_time,
.read_alarm = pcf8523_rtc_read_alarm,
.set_alarm = pcf8523_rtc_set_alarm,
.ioctl = pcf8523_rtc_ioctl,
};

Refer to the PCF8523 RTC data sheet for the register to read and write the RTC alarm time.
0x0A,0xB,0xC,0xD

www.nxp.com/documents/data_sheet/PCF8523.pdf

0 Ajit Kumar Jain over 8 years ago in reply to Titusrathinaraj Stalin

Prodigy 110 points

Hi,

Thanks for the details.

I coded both 'set_alarm' and 'get_alarm' entry points in rtc-pcf8523.c.

But, these entry points are not getting triggered upon ioctls(RTC_ALM_READ, RTC_ALM_SET) from user space.

Noticed that, pcf8523 alarm entry points are not called from rtc-dev.c and interface.c.

Requesting help on understanding the same and getting the rtc driver alarm entry points triggered.

Thanks

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setalarm/getalarm functionalities for PCF823.