On Sun, 21 Jun 2020 02:02:20 +0200
Alexandre Belloni [off-list ref] wrote:

Hi,

On 21/06/2020 00:42:18+0200, Jonathan Neuschäfer wrote:

quoted

The Netronix EC implements an RTC with the following functionality:

- Calendar-based time keeping with single-second resolution
- Automatic power-on with single-minute resolution
- Alarm at single-second resolution

This binding only supports timekeeping for now.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
---
 .../bindings/mfd/netronix,ntxec.yaml          |  7 +++++
 .../bindings/rtc/netronix,ntxec-rtc.yaml      | 27 +++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/netronix,ntxec-rtc.yaml

diff --git a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
index 6562c41c5a9a9..f6a32f46f47bb 100644
--- a/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml
+++ b/Documentation/devicetree/bindings/mfd/netronix,ntxec.yaml

@@ -34,6 +34,9 @@ properties:
   pwm:
     $ref: ../pwm/netronix,ntxec-pwm.yaml

+  rtc:
+    $ref: ../rtc/netronix,ntxec-rtc.yaml
+  

Shouldn't the node simply be documented here?

Also, do you really need a compatible string to be able to proe the
driver? What are the chances that you'll get a similar EC without an
RTC?

Tolino Shine 2 HD has the mentioned EC but the vendor kernel does not use
its RTC (not checked whether it is present or functional).
As a key for grepping in the vendor sources: 
gptNtxHwCfg->m_val.bPCB = 0x50

Tolino Shine 3  and Kobo Clara HD do not have that EC.

Regrads,
Andreas