From patchwork Tue Nov 16 12:25:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Vaittinen, Matti" X-Patchwork-Id: 12622289 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43A7AC433F5 for ; Tue, 16 Nov 2021 12:25:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BF16619E1 for ; Tue, 16 Nov 2021 12:25:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232166AbhKPM2c (ORCPT ); Tue, 16 Nov 2021 07:28:32 -0500 Received: from mail-lf1-f42.google.com ([209.85.167.42]:45647 "EHLO mail-lf1-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236128AbhKPM2c (ORCPT ); Tue, 16 Nov 2021 07:28:32 -0500 Received: by mail-lf1-f42.google.com with SMTP id m27so28340076lfj.12; Tue, 16 Nov 2021 04:25:34 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=+WRFZ9VTjiWEB6JeEorrAKAYQgvA2HAsGTHlfXpHVoY=; b=P8XIKHkEG7wV7FH5SFlBLb2N/Hlm+AdDOhMdFF3Z2u9s+gg22UC7ygZGclKDhvTY2C oMatuZp/vjpgydbKducZIbd+Cjd3OeTOa1nim5ZSEwaiKpYGf7oleQ/7jQi6so0jlBCe TlbVrU7YGNrzq465vkpOlbOGwKxg66+zKeKVRdoJNSsS6tpAffjAW4dq3OpK1IURFlvL tsO+NCNSFIjabCfyKle3k2dc8Sxq3mA7b8vdWn4tDtUWck1CyI58ODiR60KiTwIdh/rs ng8O5Dy6hx/RLz8lshFxF7bjmHtDHs8qnnXLUd8mb3fW/3xLO5O/qy/FqVHlhO5hBk1b Iejg== X-Gm-Message-State: AOAM533gsu40xhLfuXQsjCT89KdHcIeBopgfyL/INQIL7KOc8RJB5t8G ioWelCHIlRRcWLTe+2tFqx/T86Dx2aM= X-Google-Smtp-Source: ABdhPJyr+pHVzUU8nxYhtR5y3GtUCUKJqDylMndPFm6NlnXqESbFAJ8Ri30tuv2QeT2WLX1z+5ABbQ== X-Received: by 2002:ac2:4c85:: with SMTP id d5mr6394851lfl.452.1637065533851; Tue, 16 Nov 2021 04:25:33 -0800 (PST) Received: from fedora (dc73szyyyyyyyyyyyyycy-3.rev.dnainternet.fi. [2001:14ba:16ee:fa00::4]) by smtp.gmail.com with ESMTPSA id x40sm1938781lfa.130.2021.11.16.04.25.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Nov 2021 04:25:33 -0800 (PST) Date: Tue, 16 Nov 2021 14:25:25 +0200 From: Matti Vaittinen To: Matti Vaittinen , Matti Vaittinen Cc: Sebastian Reichel , Rob Herring , Matti Vaittinen , Lee Jones , Linus Walleij , rostokus@gmail.com, fan.chen@mediatek.com, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-power@fi.rohmeurope.com Subject: [RFC PATCH v3 2/9] power: supply: add cap2ocv batinfo helper Message-ID: <20cfdc60b148646a0473640a8efdb056b207c56e.1637061794.git.matti.vaittinen@fi.rohmeurope.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The power-supply core supports concept of OCV (Open Circuit Voltage) => SOC (State Of Charge) conversion tables. Usually these tables are used to estimate SOC based on OCV. Some systems use so called "Zero Adjust" where at the near end-of-battery condition the SOC from coulomb counter is used to retrieve the OCV - and OCV and VSYS difference is used to re-estimate the battery capacity. Add helper to do look-up the other-way around and also get the OCV based on SOC Signed-off-by: Matti Vaittinen --- RFC v3: - Kerneldoc fixes --- drivers/power/supply/power_supply_core.c | 69 ++++++++++++++++++++++++ include/linux/power_supply.h | 5 ++ 2 files changed, 74 insertions(+) diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index fc12a4f407f4..295672165836 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -806,6 +806,48 @@ int power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *t } EXPORT_SYMBOL_GPL(power_supply_temp2resist_simple); +/** + * power_supply_dcap2ocv_simple() - find the battery OCV by capacity + * @table: Pointer to battery OCV/CAP lookup table + * @table_len: OCV/CAP table length + * @cap: Current cap value in units of 0.1% + * + * OCV (Open Circuit Voltage) is often used to estimate the battery SOC (State + * Of Charge). Usually conversion tables are used to store the corresponding + * OCV and SOC. Systems which use so called "Zero Adjust" where at the near + * end-of-battery condition the SOC from coulomb counter is used to retrieve + * the OCV - and OCV and VSYS difference is used to re-estimate the battery + * capacity. This helper function can be used to look up battery OCV according + * to current capacity value from one OCV table, and the OCV table must be + * ordered descending. + * + * Return: the battery OCV in uV. + */ +int power_supply_dcap2ocv_simple(struct power_supply_battery_ocv_table *table, + int table_len, int dcap) +{ + int i, ocv, tmp; + + for (i = 0; i < table_len; i++) + if (dcap > table[i].capacity * 10) + break; + + if (i > 0 && i < table_len) { + tmp = (table[i - 1].ocv - table[i].ocv) * + (dcap - table[i].capacity * 10); + + tmp /= (table[i - 1].capacity - table[i].capacity) * 10; + ocv = tmp + table[i].ocv; + } else if (i == 0) { + ocv = table[0].ocv; + } else { + ocv = table[table_len - 1].ocv; + } + + return ocv; +} +EXPORT_SYMBOL_GPL(power_supply_dcap2ocv_simple); + /** * power_supply_ocv2cap_simple() - find the battery capacity * @table: Pointer to battery OCV lookup table @@ -866,6 +908,33 @@ power_supply_find_ocv2cap_table(struct power_supply_battery_info *info, } EXPORT_SYMBOL_GPL(power_supply_find_ocv2cap_table); +/** + * power_supply_batinfo_dcap2ocv() - Compute OCV based on SOC + * @info: Pointer to battery information. + * @dcao: Battery capacity in units of 0.1% + * @temp: Temperatur in Celsius + * + * Compute the open circuit voltage at given temperature matching given + * capacity for a battery described by given battery info. Computation is + * done based on tables of known capacity - open circuit voltage value pairs. + * Requires the OCV tables being populated in the battery info. + * + * Return: The battery OCV in uV or -EINVAL if OCV table is not available. + */ +int power_supply_batinfo_dcap2ocv(struct power_supply_battery_info *info, + int dcap, int temp) +{ + struct power_supply_battery_ocv_table *table; + int table_len; + + table = power_supply_find_ocv2cap_table(info, temp, &table_len); + if (!table) + return -EINVAL; + + return power_supply_dcap2ocv_simple(table, table_len, dcap); +} +EXPORT_SYMBOL_GPL(power_supply_batinfo_dcap2ocv); + int power_supply_batinfo_ocv2cap(struct power_supply_battery_info *info, int ocv, int temp) { diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index 9ca1f120a211..fa8cf434f7e3 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -410,11 +410,16 @@ extern void power_supply_put_battery_info(struct power_supply *psy, struct power_supply_battery_info *info); extern int power_supply_ocv2cap_simple(struct power_supply_battery_ocv_table *table, int table_len, int ocv); +int power_supply_dcap2ocv_simple(struct power_supply_battery_ocv_table *table, + int table_len, int dcap); + extern struct power_supply_battery_ocv_table * power_supply_find_ocv2cap_table(struct power_supply_battery_info *info, int temp, int *table_len); extern int power_supply_batinfo_ocv2cap(struct power_supply_battery_info *info, int ocv, int temp); +int power_supply_batinfo_dcap2ocv(struct power_supply_battery_info *info, + int dcap, int temp); extern int power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *table, int table_len, int temp);