From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932884AbeEHO4g (ORCPT ); Tue, 8 May 2018 10:56:36 -0400 Received: from mail.micronovasrl.com ([212.103.203.10]:38028 "EHLO mail.micronovasrl.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932784AbeEHO40 (ORCPT ); Tue, 8 May 2018 10:56:26 -0400 Authentication-Results: mail.micronovasrl.com (amavisd-new); dkim=pass reason="pass (just generated, assumed good)" header.d=micronovasrl.com X-Spam-Flag: NO X-Spam-Score: -2.899 From: Giulio Benetti To: a.zummo@towertech.it Cc: alexandre.belloni@bootlin.com, robh+dt@kernel.org, mark.rutland@arm.com, linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Giulio Benetti Subject: [PATCH 4/4] rtc: ds1307: add frequency-test property to check calibration on m41txx Date: Tue, 8 May 2018 16:56:11 +0200 Message-Id: <20180508145611.49072-4-giulio.benetti@micronovasrl.com> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180508145611.49072-1-giulio.benetti@micronovasrl.com> References: <20180508145611.49072-1-giulio.benetti@micronovasrl.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On m41txx you can enable open-drain OUT pin to check if calibration is ok. Enabling OUT pin with frequency-test bool property, OUT pin will tick 512 times faster than 1s tick base. Enable FT bit on CONTROL register if calibration is active. Signed-off-by: Giulio Benetti --- Documentation/devicetree/bindings/rtc/rtc-ds1307.txt | 3 +++ drivers/rtc/rtc-ds1307.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt b/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt index d3d70a5495c5..72a5f8cdc306 100644 --- a/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt +++ b/Documentation/devicetree/bindings/rtc/rtc-ds1307.txt @@ -36,6 +36,9 @@ Optional properties: Should be given if internal trickle charger diode should be disabled - calibration: m41t0, m41t00, m41t11 only Set calibration value to correct external bias, ranging between (-31) and 31. +- frequency-test: m41t0, m41t00, m41t11 only + Enable open-drain OUT pin 512 times faster than 1 second tick. + This allows to check calibration value. Example: rtc1: ds1339@68 { diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 9cda52589c0f..a727ced157df 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -1485,6 +1485,10 @@ static int ds1307_probe(struct i2c_client *client, if (calib >= 0) out_byte |= M41TXX_BIT_CALIB_SIGN; + if (of_property_read_bool(client->dev.of_node, + "frequency-test")) + out_byte |= M41TXX_BIT_FT; + regmap_write(ds1307->regmap, M41TXX_REG_CONTROL, out_byte); } -- 2.17.0