[PATCH 0/2] pcf85363: support for quartz-load-femtofarads

From: Javier Carrasco
Date: Mon Feb 13 2023 - 04:51:17 EST


These patches add support for the quartz-load-femtofarads property in
the pcf85363 device driver and a description of the property's possible
values.

The driver has been tested with a PCF85263ATT RTC and a CTS3-32.768-12.5-20
oscillator that needs a 12.5 pF load capacitor. With no property
support the 7 pF default value leads to at least 2 Hz output frequency
deviations, while setting the right value the deviation decreased to
0.15 Hz. These measurements were made with a high precision oscilloscope
(SIGLENT SDS5104X).

This modification does not affect existing designs where the
quartz-load-femtofarads is not defined because in that case the default
value is used.

Javier Carrasco (2):
rtc: pcf85363: add support for the quartz-load-femtofarads property
dt-bindings: rtc: nxp,pcf8563: add quartz-load-femtofarads for
pcf85263 and pcf85363

.../devicetree/bindings/rtc/nxp,pcf8563.yaml | 20 ++++++++--
drivers/rtc/rtc-pcf85363.c | 37 ++++++++++++++++++-
2 files changed, 53 insertions(+), 4 deletions(-)

--
2.37.2


Javier Carrasco
Research and Development

Wolfvision GmbH
Oberes Ried 14 | 6833 Klaus | Austria
Tel: +43 5523 52250 <tel:+43552352250> | Mail: javier.carrasco@xxxxxxxxxxxxxx <mailto:javier.carrasco@xxxxxxxxxxxxxx>

Website: wolfvision.com <www.wolfvision.com>
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