From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BF13EB64DA for ; Thu, 22 Jun 2023 07:35:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230007AbjFVHfG (ORCPT ); Thu, 22 Jun 2023 03:35:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229595AbjFVHfD (ORCPT ); Thu, 22 Jun 2023 03:35:03 -0400 Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::223]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F02781992; Thu, 22 Jun 2023 00:35:00 -0700 (PDT) X-GND-Sasl: alexandre.belloni@bootlin.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1687419299; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=fjdI8hAWq8rRbopuLAzW8xGOPk9XesOe6kfQHrFp7GY=; b=BQE82NsrS8NeEQAYG+vpPyS2ZyKfdgdGzizBBatseeR6pqop6UvHtR3dRMldKcmwrRARvD HbU411bxng9hD83QWODyC9QFsvicyEANhFHHD6vY2rMn9jNxBpTzWCG7lovKfm9lYJ4PrC KEywegX+HSatfXBzzCeUmnTsaC9Ph0i8WlCYmSPC0GiDe0Dk43T9mvCIhLFsR1EifXPhLn vu76MMHxCSgp/+53+/Q5V1B2BL/7dSB1rwVQDAnSg5ZNo0mtNQi3ABKkiYatD85c4+vMkM VfYob9ubzxYkRzW/W/q0ghtxsP6S6D8wrc5S4idzYGNPgBbOqkYEgRQDbEIVUg== X-GND-Sasl: alexandre.belloni@bootlin.com X-GND-Sasl: alexandre.belloni@bootlin.com X-GND-Sasl: alexandre.belloni@bootlin.com X-GND-Sasl: alexandre.belloni@bootlin.com Received: by mail.gandi.net (Postfix) with ESMTPSA id 2A40860011; Thu, 22 Jun 2023 07:34:59 +0000 (UTC) Date: Thu, 22 Jun 2023 09:34:58 +0200 From: Alexandre Belloni To: Andrej Picej Cc: a.zummo@towertech.it, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, upstream@phytec.de Subject: Re: [PATCH v2] rtc: rv3028: Improve trickle charger logic Message-ID: <20230622073458dcd9f636@mail.local> References: <20230622071609.4032736-1-andrej.picej@norik.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230622071609.4032736-1-andrej.picej@norik.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/06/2023 09:16:09+0200, Andrej Picej wrote: > Property "trickle-resistor-ohms" allows us to set trickle charger > resistor. However there is no possibility to disable it afterwards. > > From now on, disable trickle charger circuit in case device-tree > property "trickle-resistor-ohms" is set to -1. > > Additionally, lets make sure we only update internal EEPROM in case of a > change. This prevents wear due to excessive EEPROM writes on each probe. > > Signed-off-by: Andrej Picej > --- > Changes in v2: > - disable trickle charger if device tree property trickle-resistor-ohms > is set to -1. What about using aux-voltage-chargeable which is the generic property for this? > --- > drivers/rtc/rtc-rv3028.c | 45 +++++++++++++++++++++++++++++----------- > 1 file changed, 33 insertions(+), 12 deletions(-) > > diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c > index ec5d7a614e2d..da2ae81fe7c8 100644 > --- a/drivers/rtc/rtc-rv3028.c > +++ b/drivers/rtc/rtc-rv3028.c > @@ -859,7 +859,8 @@ static int rv3028_probe(struct i2c_client *client) > { > struct rv3028_data *rv3028; > int ret, status; > - u32 ohms; > + s32 ohms; > + int val_old, val; > struct nvmem_config nvmem_cfg = { > .name = "rv3028_nvram", > .word_size = 1, > @@ -937,22 +938,42 @@ static int rv3028_probe(struct i2c_client *client) > if (ret) > return ret; > > - /* setup trickle charger */ > - if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms", > - &ohms)) { > - int i; > + ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &val_old); > + if (ret < 0) > + return ret; > + > + /* mask out only trickle charger bits */ > + val_old = val_old & (RV3028_BACKUP_TCE | RV3028_BACKUP_TCR_MASK); > > - for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++) > - if (ohms == rv3028_trickle_resistors[i]) > - break; > + /* setup trickle charger */ > + if (!of_property_read_s32(client->dev.of_node, "trickle-resistor-ohms", > + &ohms)) { > + /* disable trickle charger if trickle-resistor-ohms = <(-1)>; */ > + if (ohms == -1) { > + val = val_old & ~RV3028_BACKUP_TCE; > + } else { > + int i; > + > + for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++) > + if (ohms == rv3028_trickle_resistors[i]) > + break; > + > + if (i < ARRAY_SIZE(rv3028_trickle_resistors)) { > + /* enable trickle charger and its resistor */ > + val = RV3028_BACKUP_TCE | i; > + } else { > + dev_warn(&client->dev, "invalid trickle resistor value\n"); > + /* don't update the trickle charger regs */ > + val = val_old; > + } > + } > > - if (i < ARRAY_SIZE(rv3028_trickle_resistors)) { > + /* only update EEPROM if changes are necessary */ > + if (val_old != val) { > ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE | > - RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i); > + RV3028_BACKUP_TCR_MASK, val); > if (ret) > return ret; > - } else { > - dev_warn(&client->dev, "invalid trickle resistor value\n"); > } > } > > -- > 2.25.1 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com