From patchwork Mon Nov 22 23:41:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 12633131 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 2D918C433EF for ; Mon, 22 Nov 2021 23:44:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231601AbhKVXrM (ORCPT ); Mon, 22 Nov 2021 18:47:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60028 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230366AbhKVXrL (ORCPT ); Mon, 22 Nov 2021 18:47:11 -0500 Received: from mail-lj1-x22a.google.com (mail-lj1-x22a.google.com [IPv6:2a00:1450:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 528E4C061574 for ; Mon, 22 Nov 2021 15:44:04 -0800 (PST) Received: by mail-lj1-x22a.google.com with SMTP id 207so7272139ljf.10 for ; Mon, 22 Nov 2021 15:44:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=j3L8AKPmKrW1qhMXXFj7BV+nAdWI7YI0GdN2N1YN5R8=; b=JCR2PQ0oPUzShAhUzo6pCqyQwm5aNn34tTpMWsthX6jCMFFEiB1X7vC6CtSqBMRWJL ELnBEdHcPhcLJGoIQUX8dciVdHyCDZm03I2bwoBQUT+dCMKnNpid95sGlmjL0CWDpNXL NfzILg7nW/uslJHlIqS9oLPX9GnOg2AnTflcIHSH+UreKiZ/DB9NTk1LJHJE3wwQxhU/ bSNr7jyxdzBJ0NrwjxhERQ9Mu5BX0x0SbSZNLw1N9SJ00W9cwTyq5nRC4BWm+qDZVrla PwqiGSniAD0kXLN2yqHEq4iOtXgoQSerSbZ6+p9UY4rXVPlXxnqJtGWMnr7Gb1MZQMNk qyng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=j3L8AKPmKrW1qhMXXFj7BV+nAdWI7YI0GdN2N1YN5R8=; b=mGKb5TrRuR5z5gvDWxhs2Tm3JuIDXvLahyvRKPvY3Iwcq5pXpiUG3ESnwx/b1I3vFK QIxAEWgGu/rfgSHbQRGXBz/Stq74172LHaFML9pFy0DG4yiHo9bgGjxSAFKuNgu2KQMw Tgu9P+UN+ucYNcX0H9rVI3OJ1G83fsh159uQDInI248+AntheDfJbRALOGvQ/hkFlEjD rm/3utO3mfVxaU5MhUVrY55RAdfW4c3y9E8i2NJ6jaLGFhOAQc2HqoMSmaT/Gj4xBjqy HtuxYOJY58eR+68cYxC77VeYsZY0kxasqzFjaFrPRroKy6xRa/wTt5In5B1aOkInFLZu 1jtw== X-Gm-Message-State: AOAM533BxbJ21SlcYb7/8rru4LnWuCb+3Ta5mwxk3C5ouv6Q6puQk85I Bv+PSCCL8lfe3k4Pe2J72+ixdQ== X-Google-Smtp-Source: ABdhPJwxe2P8ijdDKGI5I2YwGtJXsWYEosAry7Kn2VLHDOJXjYN2pBKnJymT4xQUEjO7YZQJ6fN7uw== X-Received: by 2002:a2e:9708:: with SMTP id r8mr300465lji.36.1637624642423; Mon, 22 Nov 2021 15:44:02 -0800 (PST) Received: from localhost.localdomain (c-fdcc225c.014-348-6c756e10.bbcust.telenor.se. [92.34.204.253]) by smtp.gmail.com with ESMTPSA id b26sm1109311lff.148.2021.11.22.15.44.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Nov 2021 15:44:01 -0800 (PST) From: Linus Walleij To: Sebastian Reichel , Marcus Cooper , Jean Delvare , Guenter Roeck Cc: linux-pm@vger.kernel.org, linux-hwmon@vger.kernel.org, Linus Walleij Subject: [PATCH 1/2] power: supply: ab8500: Standardize NTC battery temp Date: Tue, 23 Nov 2021 00:41:40 +0100 Message-Id: <20211122234141.3356340-2-linus.walleij@linaro.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211122234141.3356340-1-linus.walleij@linaro.org> References: <20211122234141.3356340-1-linus.walleij@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org Several batteries monitor the temperature of the battery using an NTC resistor. Add an NTC resistor resistance to temperature look-up table to struct power_supply_battery_info and use this in the AB8500 battery temperature driver to look up the battery temperature. Add a helper function in the power supply core: power_supply_ntc_resist2temp_simple(), which can use the NTC resistance table to look up and interpolate a temperature from the table. Fix up some of the confusing wording on the temperature to internal resistance table, and clarify what each resistance table is for. The AB8500 default NTC resistor is 47KOhm at 25 degrees Celsius and serves as a good example of how this usually works. Signed-off-by: Linus Walleij --- drivers/power/supply/ab8500-bm.h | 16 -------- drivers/power/supply/ab8500_bmdata.c | 41 ++++++++++--------- drivers/power/supply/ab8500_btemp.c | 45 ++------------------ drivers/power/supply/power_supply_core.c | 52 ++++++++++++++++++++++++ include/linux/power_supply.h | 34 ++++++++++++++++ 5 files changed, 111 insertions(+), 77 deletions(-) diff --git a/drivers/power/supply/ab8500-bm.h b/drivers/power/supply/ab8500-bm.h index 57e1a8e27e51..90397f2a731f 100644 --- a/drivers/power/supply/ab8500-bm.h +++ b/drivers/power/supply/ab8500-bm.h @@ -272,18 +272,6 @@ enum ab8500_adc_therm { AB8500_ADC_THERM_BATTEMP, }; -/** - * struct ab8500_res_to_temp - defines one point in a temp to res curve. To - * be used in battery packs that combines the identification resistor with a - * NTC resistor. - * @temp: battery pack temperature in Celsius - * @resist: NTC resistor net total resistance - */ -struct ab8500_res_to_temp { - int temp; - int resist; -}; - /* Forward declaration */ struct ab8500_fg; @@ -363,8 +351,6 @@ struct ab8500_maxim_parameters { * @maint_b_chg_timer_h: charge time in maintenance B state * @low_high_cur_lvl: charger current in temp low/high state in mA * @low_high_vol_lvl: charger voltage in temp low/high state in mV' - * @n_r_t_tbl_elements: number of elements in r_to_t_tbl - * @r_to_t_tbl: table containing resistance to temp points */ struct ab8500_battery_type { int resis_high; @@ -377,8 +363,6 @@ struct ab8500_battery_type { int maint_b_chg_timer_h; int low_high_cur_lvl; int low_high_vol_lvl; - int n_temp_tbl_elements; - const struct ab8500_res_to_temp *r_to_t_tbl; }; /** diff --git a/drivers/power/supply/ab8500_bmdata.c b/drivers/power/supply/ab8500_bmdata.c index 62953f9cb85a..aba459393ee6 100644 --- a/drivers/power/supply/ab8500_bmdata.c +++ b/drivers/power/supply/ab8500_bmdata.c @@ -44,25 +44,25 @@ static struct power_supply_battery_ocv_table ocv_cap_tbl[] = { }; /* - * Note that the res_to_temp table must be strictly sorted by falling + * Note that the ntc_res_to_temp_tbl table must be strictly sorted by falling * resistance values to work. */ -static const struct ab8500_res_to_temp temp_tbl[] = { - {-5, 214834}, - { 0, 162943}, - { 5, 124820}, - {10, 96520}, - {15, 75306}, - {20, 59254}, - {25, 47000}, - {30, 37566}, - {35, 30245}, - {40, 24520}, - {45, 20010}, - {50, 16432}, - {55, 13576}, - {60, 11280}, - {65, 9425}, +static struct power_supply_ntc_resistance_temp_table ntc_res_to_temp_tbl[] = { + { .resistance_ohm = 214834, .temp = -5}, + { .resistance_ohm = 162943, .temp = 0}, + { .resistance_ohm = 124820, .temp = 5}, + { .resistance_ohm = 96520, .temp = 10}, + { .resistance_ohm = 75306, .temp = 15}, + { .resistance_ohm = 59254, .temp = 20}, + { .resistance_ohm = 47000, .temp = 25}, + { .resistance_ohm = 37566, .temp = 30}, + { .resistance_ohm = 30245, .temp = 35}, + { .resistance_ohm = 24520, .temp = 40}, + { .resistance_ohm = 20010, .temp = 45}, + { .resistance_ohm = 16432, .temp = 50}, + { .resistance_ohm = 13576, .temp = 55}, + { .resistance_ohm = 11280, .temp = 60}, + { .resistance_ohm = 9425, .temp = 65}, }; /* @@ -92,8 +92,6 @@ static struct ab8500_battery_type bat_type_thermistor_unknown = { .maint_b_chg_timer_h = 200, .low_high_cur_lvl = 300, .low_high_vol_lvl = 4000, - .n_temp_tbl_elements = ARRAY_SIZE(temp_tbl), - .r_to_t_tbl = temp_tbl, }; static const struct ab8500_bm_capacity_levels cap_levels = { @@ -217,6 +215,11 @@ int ab8500_bm_of_probe(struct power_supply *psy, bi->resist_table_size = ARRAY_SIZE(temp_to_batres_tbl_thermistor); } + if (!bi->ntc_resist_table) { + bi->ntc_resist_table = ntc_res_to_temp_tbl; + bi->ntc_resist_table_size = ARRAY_SIZE(ntc_res_to_temp_tbl); + } + if (!bi->ocv_table[0]) { /* Default capacity table at say 25 degrees Celsius */ bi->ocv_temp[0] = 25; diff --git a/drivers/power/supply/ab8500_btemp.c b/drivers/power/supply/ab8500_btemp.c index 20253b8a7fe9..79528c18618d 100644 --- a/drivers/power/supply/ab8500_btemp.c +++ b/drivers/power/supply/ab8500_btemp.c @@ -407,42 +407,6 @@ static int ab8500_btemp_get_batctrl_res(struct ab8500_btemp *di) return res; } -/** - * ab8500_btemp_res_to_temp() - resistance to temperature - * @di: pointer to the ab8500_btemp structure - * @tbl: pointer to the resiatance to temperature table - * @tbl_size: size of the resistance to temperature table - * @res: resistance to calculate the temperature from - * - * This function returns the battery temperature in degrees Celsius - * based on the NTC resistance. - */ -static int ab8500_btemp_res_to_temp(struct ab8500_btemp *di, - const struct ab8500_res_to_temp *tbl, int tbl_size, int res) -{ - int i; - /* - * Calculate the formula for the straight line - * Simple interpolation if we are within - * the resistance table limits, extrapolate - * if resistance is outside the limits. - */ - if (res > tbl[0].resist) - i = 0; - else if (res <= tbl[tbl_size - 1].resist) - i = tbl_size - 2; - else { - i = 0; - while (!(res <= tbl[i].resist && - res > tbl[i + 1].resist)) - i++; - } - - return fixp_linear_interpolate(tbl[i].resist, tbl[i].temp, - tbl[i + 1].resist, tbl[i + 1].temp, - res); -} - /** * ab8500_btemp_measure_temp() - measure battery temperature * @di: pointer to the ab8500_btemp structure @@ -451,6 +415,7 @@ static int ab8500_btemp_res_to_temp(struct ab8500_btemp *di, */ static int ab8500_btemp_measure_temp(struct ab8500_btemp *di) { + struct power_supply_battery_info *bi = &di->bm->bi; int temp, ret; static int prev; int rbat, rntc, vntc; @@ -469,9 +434,7 @@ static int ab8500_btemp_measure_temp(struct ab8500_btemp *di) return BTEMP_THERMAL_LOW_LIMIT; } - temp = ab8500_btemp_res_to_temp(di, - di->bm->bat_type->r_to_t_tbl, - di->bm->bat_type->n_temp_tbl_elements, rbat); + temp = power_supply_ntc_resist2temp_simple(bi, rbat); } else { ret = iio_read_channel_processed(di->btemp_ball, &vntc); if (ret < 0) { @@ -486,9 +449,7 @@ static int ab8500_btemp_measure_temp(struct ab8500_btemp *di) */ rntc = 230000 * vntc / (VTVOUT_V - vntc); - temp = ab8500_btemp_res_to_temp(di, - di->bm->bat_type->r_to_t_tbl, - di->bm->bat_type->n_temp_tbl_elements, rntc); + temp = power_supply_ntc_resist2temp_simple(bi, rntc); prev = temp; } dev_dbg(di->dev, "Battery temperature is %d\n", temp); diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index 2723d7d0ced3..a870c3fe032c 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -589,6 +589,7 @@ int power_supply_get_battery_info(struct power_supply *psy, info->temp_max = INT_MAX; info->factory_internal_resistance_uohm = -EINVAL; info->resist_table = NULL; + info->ntc_resist_table = NULL; for (index = 0; index < POWER_SUPPLY_OCV_TEMP_MAX; index++) { info->ocv_table[index] = NULL; @@ -806,6 +807,57 @@ int power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *t } EXPORT_SYMBOL_GPL(power_supply_temp2resist_simple); +/** + * power_supply_ntc_resist2temp_simple() - find the battery temperature + * @info: battery information + * @resistance_ohm: Current NTC resistance value in microohm + * + * This helper function is used to look up battery internal temperature + * according to current NTC resistance value from one NTC resistance table. + * The NTC resistance table must be ordered descending by resistance: + * largest resistance with lowest temperature first, lowest resistance with + * highest temperature last. The function will interpolate to find the + * corresponding temperature. + * + * Return: the battery temperature. + */ +int power_supply_ntc_resist2temp_simple(struct power_supply_battery_info *info, + int resistance_ohm) +{ + struct power_supply_ntc_resistance_temp_table *table; + int i, high, low; + int table_len; + + table = info->ntc_resist_table; + table_len = info->ntc_resist_table_size; + + if (!table || !table_len) { + pr_err("Empty battery NTC resistance table, assume 25 degrees\n"); + return 25; + } + if (!resistance_ohm) + pr_info("Battery NTC resistance 0, this is unlikely\n"); + + /* Break loop at table_len - 1 because that is the highest index */ + for (i = 0; i < table_len - 1; i++) + if (resistance_ohm > table[i].resistance_ohm) + break; + + /* The library function will deal with high == low */ + if ((i == 0) || (i == (table_len - 1))) + high = i; + else + high = i - 1; + low = i; + + return fixp_linear_interpolate(table[low].resistance_ohm, + table[low].temp, + table[high].resistance_ohm, + table[high].temp, + resistance_ohm); +} +EXPORT_SYMBOL_GPL(power_supply_ntc_resist2temp_simple); + /** * power_supply_ocv2cap_simple() - find the battery capacity * @table: Pointer to battery OCV lookup table diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index b5079109ac00..a0da806185b5 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -335,11 +335,29 @@ struct power_supply_battery_ocv_table { int capacity; /* percent */ }; +/** + * struct power_supply_resistance_temp_table - correlate temperature to resistance + * @temp: the internal temperature of the battery in degrees Celsius + * @resistance: the percentage of the factory internal resistance at this + * temperature, usually nomimal factory resistance is 100 percent at 25 + * degrees Celsius, lower at higher temperature and higher at lower + * temperature. + */ struct power_supply_resistance_temp_table { int temp; /* celsius */ int resistance; /* internal resistance percent */ }; +/** + * struct power_supply_ntc_resistance_temp_table - correlate NTC to temp + * @resistance: the NTC resistance in ohm + * @temp: the corresponding temperature in degrees Celsius + */ +struct power_supply_ntc_resistance_temp_table { + int resistance_ohm; + int temp; +}; + #define POWER_SUPPLY_OCV_TEMP_MAX 20 /** @@ -426,6 +444,18 @@ struct power_supply_resistance_temp_table { * by temperature: highest temperature with lowest resistance first, lowest * temperature with highest resistance last. * @resist_table_size: the number of items in the resist_table. + * @ntc_resist_table: this is a table that correlates a resistance of a negative + * temperature coefficient (NTC) resistor to an internal temperature of a + * battery. This can be achieved by a separate thermistor to + * supply voltage on a third terminal on a battery which is the most + * reliable. An external thermistor can also be used sometimes. Knowing the + * temperature of the battery is usually necessary to perform a lookup in the + * resist_table to determine the internal resistance of the battery, and + * to find the right ocv_table to determine the capacity of the battery. + * The NTC resistance table must be ordered descending by resistance: + * largest resistance with lowest temperature first, lowest resistance with + * highest temperature last. + * @ntc_resist_table_size: the number of items in the ntc_resist_table. * * This is the recommended struct to manage static battery parameters, * populated by power_supply_get_battery_info(). Most platform drivers should @@ -546,6 +576,8 @@ struct power_supply_battery_info { int ocv_table_size[POWER_SUPPLY_OCV_TEMP_MAX]; struct power_supply_resistance_temp_table *resist_table; int resist_table_size; + struct power_supply_ntc_resistance_temp_table *ntc_resist_table; + int ntc_resist_table_size; }; extern struct atomic_notifier_head power_supply_notifier; @@ -587,6 +619,8 @@ extern int power_supply_batinfo_ocv2cap(struct power_supply_battery_info *info, extern int power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *table, int table_len, int temp); +extern int power_supply_ntc_resist2temp_simple(struct power_supply_battery_info *info, + int resistance_ohm); extern void power_supply_changed(struct power_supply *psy); extern int power_supply_am_i_supplied(struct power_supply *psy); extern int power_supply_set_input_current_limit_from_supplier( From patchwork Mon Nov 22 23:41:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Linus Walleij X-Patchwork-Id: 12633133 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 41315C433FE for ; Mon, 22 Nov 2021 23:44:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231743AbhKVXrO (ORCPT ); Mon, 22 Nov 2021 18:47:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230366AbhKVXrO (ORCPT ); Mon, 22 Nov 2021 18:47:14 -0500 Received: from mail-lj1-x22a.google.com (mail-lj1-x22a.google.com [IPv6:2a00:1450:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A777BC061714 for ; Mon, 22 Nov 2021 15:44:06 -0800 (PST) Received: by mail-lj1-x22a.google.com with SMTP id d11so7272044ljg.8 for ; Mon, 22 Nov 2021 15:44:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=8mWWRHDRoQFVajzPe4x+gTl6ZLFecUeHwYt8iUOBunE=; b=KriieuwaKLXqOvZZj7TGQ/tsusT9Kt3lqrsWwP0GpIvHS8pJt5/NnFlPeJnO+g9PML Q/orJZW8CZzBQ1PRyIjgAUilmmxjjkBV46fkvQ1pS7cOCBHCKz9BaYhDWhMr28mry2SI I+XuVCQcEyjSgSt8wSmIV4ArFEVSamGXiaqpAOcuXy7jADNqDpK3m01Ax2+aZU5IkFx8 sfAX5vehzIm6OOnbD4+er/Ju6vMvKpcPKhJHHuAjbZip+TisUhJFi4VOK2cAVhu0ahZp pEbMWWm1I3OwZLeBlDKRAMpyYmrnL+ocJiJwNIvEfvEk7OY53Z4zlg8z1TeH8FVNeJxR 7Cbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=8mWWRHDRoQFVajzPe4x+gTl6ZLFecUeHwYt8iUOBunE=; b=BAhgiw5ebDNgaEU+oGD0kPHQmeqA722bPQz2GAMkA7WOLqicbC3NxwqiGJjMM0AIo9 EXm/ihnLiFQ5g7LazhxdsWii8P1AQP0kY+M+OZB4Xjd1zxV1GkPMzLsMU0I2Dkt05T72 5Bkv6uqfLSdUiEe0IJGr2GSYXyvWNLG+5sCJDTbsp270j28Hj6SatWpBj6HyEPoy63ml QSIvTK6k83JSjTXZ4p6inFLHPbpnGgX3f8zCyNwl/5zvYPaG1bvtmVyCQb0yhwJnxUyv O4nmzq6k6B4IEtSRuO3G03ntgb1FXuspXsycV0VYSjLrYhmlS04mwdmSlsz+uVHiRiPH v9SQ== X-Gm-Message-State: AOAM531z2pVj9uaJIy9cnvXtbE2DfLx8Q9XMEEKyI/XPjh7oJ03GBU0w ayuzqRJl3NmnsE366eWuOVxBkQ== X-Google-Smtp-Source: ABdhPJylgO9wYAne8/viO+flX+w24jPSmX2XHL7SU1OyxbxV1MfXhDG5nUpApmkOTm8nYavvCtR0tw== X-Received: by 2002:a05:651c:550:: with SMTP id q16mr190650ljp.371.1637624644831; Mon, 22 Nov 2021 15:44:04 -0800 (PST) Received: from localhost.localdomain (c-fdcc225c.014-348-6c756e10.bbcust.telenor.se. [92.34.204.253]) by smtp.gmail.com with ESMTPSA id b26sm1109311lff.148.2021.11.22.15.44.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Nov 2021 15:44:04 -0800 (PST) From: Linus Walleij To: Sebastian Reichel , Marcus Cooper , Jean Delvare , Guenter Roeck Cc: linux-pm@vger.kernel.org, linux-hwmon@vger.kernel.org, Linus Walleij Subject: [PATCH 2/2] power: supply: ab8500: Standardize maintenance charging Date: Tue, 23 Nov 2021 00:41:41 +0100 Message-Id: <20211122234141.3356340-3-linus.walleij@linaro.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211122234141.3356340-1-linus.walleij@linaro.org> References: <20211122234141.3356340-1-linus.walleij@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org Maintenance charging is the phase of keeping up the charge after the battery has charged fully using CC/CV charging. This can be done in many successive phases and is usually done with a slightly lower constant voltage than CV, and a slightly lower allowed current. Add an array of maintenance charging points each with a current, voltage and safety timer, and add helper functions to use these. Migrate the AB8500 code over. This is used in several Samsung products using the AB8500 and these batteries and their complete parameters will be added later as full examples, but the default battery in the AB8500 code serves as a reasonable example so far. Signed-off-by: Linus Walleij --- drivers/power/supply/ab8500-bm.h | 14 ------ drivers/power/supply/ab8500_bmdata.c | 27 +++++++--- drivers/power/supply/ab8500_chargalg.c | 41 +++++++++++---- drivers/power/supply/power_supply_core.c | 11 ++++ include/linux/power_supply.h | 64 ++++++++++++++++++++++++ 5 files changed, 126 insertions(+), 31 deletions(-) diff --git a/drivers/power/supply/ab8500-bm.h b/drivers/power/supply/ab8500-bm.h index 90397f2a731f..67acf4c72569 100644 --- a/drivers/power/supply/ab8500-bm.h +++ b/drivers/power/supply/ab8500-bm.h @@ -343,24 +343,12 @@ struct ab8500_maxim_parameters { * struct ab8500_battery_type - different batteries supported * @resis_high: battery upper resistance limit * @resis_low: battery lower resistance limit - * @maint_a_cur_lvl: charger current in maintenance A state in mA - * @maint_a_vol_lvl: charger voltage in maintenance A state in mV - * @maint_a_chg_timer_h: charge time in maintenance A state - * @maint_b_cur_lvl: charger current in maintenance B state in mA - * @maint_b_vol_lvl: charger voltage in maintenance B state in mV - * @maint_b_chg_timer_h: charge time in maintenance B state * @low_high_cur_lvl: charger current in temp low/high state in mA * @low_high_vol_lvl: charger voltage in temp low/high state in mV' */ struct ab8500_battery_type { int resis_high; int resis_low; - int maint_a_cur_lvl; - int maint_a_vol_lvl; - int maint_a_chg_timer_h; - int maint_b_cur_lvl; - int maint_b_vol_lvl; - int maint_b_chg_timer_h; int low_high_cur_lvl; int low_high_vol_lvl; }; @@ -405,7 +393,6 @@ struct ab8500_bm_charger_parameters { * @usb_safety_tmr_h safety timer for usb charger * @bkup_bat_v voltage which we charge the backup battery with * @bkup_bat_i current which we charge the backup battery with - * @no_maintenance indicates that maintenance charging is disabled * @capacity_scaling indicates whether capacity scaling is to be used * @ab8500_adc_therm placement of thermistor, batctrl or battemp adc * @chg_unknown_bat flag to enable charging of unknown batteries @@ -431,7 +418,6 @@ struct ab8500_bm_data { int usb_safety_tmr_h; int bkup_bat_v; int bkup_bat_i; - bool no_maintenance; bool capacity_scaling; bool chg_unknown_bat; bool enable_overshoot; diff --git a/drivers/power/supply/ab8500_bmdata.c b/drivers/power/supply/ab8500_bmdata.c index aba459393ee6..fe3a316ce643 100644 --- a/drivers/power/supply/ab8500_bmdata.c +++ b/drivers/power/supply/ab8500_bmdata.c @@ -80,16 +80,25 @@ static struct power_supply_resistance_temp_table temp_to_batres_tbl_thermistor[] { .temp = -20, .resistance = 198 /* 595 mOhm */ }, }; +struct power_supply_maintenance_charge_table maint_charge_table[] = { + { + /* Maintenance charging phase A, 60 hours */ + .charge_current_max_ua = 400000, + .charge_voltage_max_uv = 4050000, + .charge_safety_timer_minutes = 60*60, + }, + { + /* Maintenance charging phase B, 200 hours */ + .charge_current_max_ua = 400000, + .charge_voltage_max_uv = 4000000, + .charge_safety_timer_minutes = 200*60, + } +}; + /* Default battery type for reference designs is the unknown type */ static struct ab8500_battery_type bat_type_thermistor_unknown = { .resis_high = 0, .resis_low = 0, - .maint_a_cur_lvl = 400, - .maint_a_vol_lvl = 4050, - .maint_a_chg_timer_h = 60, - .maint_b_cur_lvl = 400, - .maint_b_vol_lvl = 4000, - .maint_b_chg_timer_h = 200, .low_high_cur_lvl = 300, .low_high_vol_lvl = 4000, }; @@ -146,7 +155,6 @@ struct ab8500_bm_data ab8500_bm_data = { .usb_safety_tmr_h = 4, .bkup_bat_v = BUP_VCH_SEL_2P6V, .bkup_bat_i = BUP_ICH_SEL_150UA, - .no_maintenance = false, .capacity_scaling = false, .adc_therm = AB8500_ADC_THERM_BATCTRL, .chg_unknown_bat = false, @@ -204,6 +212,11 @@ int ab8500_bm_of_probe(struct power_supply *psy, /* Charging stops when we drop below this current */ bi->charge_term_current_ua = 200000; + if (!bi->maintenance_charge || !bi->maintenance_charge_size) { + bi->maintenance_charge = maint_charge_table; + bi->maintenance_charge_size = ARRAY_SIZE(maint_charge_table); + } + /* * Internal resistance and factory resistance are tightly coupled * so both MUST be defined or we fall back to defaults. diff --git a/drivers/power/supply/ab8500_chargalg.c b/drivers/power/supply/ab8500_chargalg.c index 86d740ce3a63..a86b714d4f2c 100644 --- a/drivers/power/supply/ab8500_chargalg.c +++ b/drivers/power/supply/ab8500_chargalg.c @@ -484,7 +484,7 @@ static void ab8500_chargalg_stop_safety_timer(struct ab8500_chargalg *di) /** * ab8500_chargalg_start_maintenance_timer() - Start charging maintenance timer * @di: pointer to the ab8500_chargalg structure - * @duration: duration of ther maintenance timer in hours + * @duration: duration of ther maintenance timer in minutes * * The maintenance timer is used to maintain the charge in the battery once * the battery is considered full. These timers are chosen to match the @@ -493,9 +493,10 @@ static void ab8500_chargalg_stop_safety_timer(struct ab8500_chargalg *di) static void ab8500_chargalg_start_maintenance_timer(struct ab8500_chargalg *di, int duration) { + /* Set a timer in minutes with a 30 second range */ hrtimer_set_expires_range(&di->maintenance_timer, - ktime_set(duration * ONE_HOUR_IN_SECONDS, 0), - ktime_set(FIVE_MINUTES_IN_SECONDS, 0)); + ktime_set(duration * 60, 0), + ktime_set(30, 0)); di->events.maintenance_timer_expired = false; hrtimer_start_expires(&di->maintenance_timer, HRTIMER_MODE_REL); } @@ -1300,6 +1301,7 @@ static void ab8500_chargalg_external_power_changed(struct power_supply *psy) static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di) { struct power_supply_battery_info *bi = &di->bm->bi; + struct power_supply_maintenance_charge_table *mt; int charger_status; int ret; int curr_step_lvl_ua; @@ -1537,7 +1539,12 @@ static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di) handle_maxim_chg_curr(di); if (di->charge_status == POWER_SUPPLY_STATUS_FULL && di->maintenance_chg) { - if (di->bm->no_maintenance) + /* + * The battery is fully charged, check if we support + * maintenance charging else go back to waiting for + * the recharge voltage limit. + */ + if (power_supply_supports_maintenance_charging(bi)) ab8500_chargalg_state_to(di, STATE_WAIT_FOR_RECHARGE_INIT); else @@ -1558,12 +1565,19 @@ static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di) break; case STATE_MAINTENANCE_A_INIT: + mt = power_supply_get_maintenance_charging_setting(bi, 0); + if (!mt) { + /* No maintenance A state, go back to normal */ + ab8500_chargalg_state_to(di, STATE_NORMAL_INIT); + power_supply_changed(di->chargalg_psy); + break; + } ab8500_chargalg_stop_safety_timer(di); ab8500_chargalg_start_maintenance_timer(di, - di->bm->bat_type->maint_a_chg_timer_h); + mt->charge_safety_timer_minutes); ab8500_chargalg_start_charging(di, - di->bm->bat_type->maint_a_vol_lvl, - di->bm->bat_type->maint_a_cur_lvl); + mt->charge_voltage_max_uv, + mt->charge_current_max_ua); ab8500_chargalg_state_to(di, STATE_MAINTENANCE_A); power_supply_changed(di->chargalg_psy); fallthrough; @@ -1576,11 +1590,18 @@ static void ab8500_chargalg_algorithm(struct ab8500_chargalg *di) break; case STATE_MAINTENANCE_B_INIT: + mt = power_supply_get_maintenance_charging_setting(bi, 1); + if (!mt) { + /* No maintenance B state, go back to normal */ + ab8500_chargalg_state_to(di, STATE_NORMAL_INIT); + power_supply_changed(di->chargalg_psy); + break; + } ab8500_chargalg_start_maintenance_timer(di, - di->bm->bat_type->maint_b_chg_timer_h); + mt->charge_safety_timer_minutes); ab8500_chargalg_start_charging(di, - di->bm->bat_type->maint_b_vol_lvl, - di->bm->bat_type->maint_b_cur_lvl); + mt->charge_voltage_max_uv, + mt->charge_current_max_ua); ab8500_chargalg_state_to(di, STATE_MAINTENANCE_B); power_supply_changed(di->chargalg_psy); fallthrough; diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c index a870c3fe032c..b3820f087856 100644 --- a/drivers/power/supply/power_supply_core.c +++ b/drivers/power/supply/power_supply_core.c @@ -581,6 +581,7 @@ int power_supply_get_battery_info(struct power_supply *psy, info->charge_term_current_ua = -EINVAL; info->constant_charge_current_max_ua = -EINVAL; info->constant_charge_voltage_max_uv = -EINVAL; + info->maintenance_charge = NULL; info->temp_ambient_alert_min = INT_MIN; info->temp_ambient_alert_max = INT_MAX; info->temp_alert_min = INT_MIN; @@ -858,6 +859,16 @@ int power_supply_ntc_resist2temp_simple(struct power_supply_battery_info *info, } EXPORT_SYMBOL_GPL(power_supply_ntc_resist2temp_simple); +struct power_supply_maintenance_charge_table * +power_supply_get_maintenance_charging_setting(struct power_supply_battery_info *info, + int index) +{ + if (index >= info->maintenance_charge_size) + return NULL; + return &info->maintenance_charge[index]; +} +EXPORT_SYMBOL_GPL(power_supply_get_maintenance_charging_setting); + /** * power_supply_ocv2cap_simple() - find the battery capacity * @table: Pointer to battery OCV lookup table diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h index a0da806185b5..c6f379715cb1 100644 --- a/include/linux/power_supply.h +++ b/include/linux/power_supply.h @@ -358,6 +358,52 @@ struct power_supply_ntc_resistance_temp_table { int temp; }; +/** + * struct power_supply_maintenance_charge_table - setting for maintenace charging + * @charge_current_max_ua: maintenance charging current that is used to keep + * the charge of the battery full as current is consumed after full charging. + * The corresponding charge_voltage_max_uv is used as a safeguard: when we + * reach this voltage the maintenance charging current is turned off. It is + * turned back on if we fall below this voltage. + * @charge_voltage_max_uv: maintenance charging voltage that is usually a bit + * lower than the constant_charge_voltage_max_uv. We can apply this settings + * charge_current_max_ua until we get back up to this voltage. + * @safety_timer_minutes: maintenance charging safety timer, with an expiry + * time in minutes. We will only use maintenance charging in this setting + * for a certain amount of time, then we will first move to the next + * maintenance charge current and voltage pair in respective array and wait + * for the next safety timer timeout, or, if we reached the last maintencance + * charging setting, disable charging until we reach + * charge_restart_voltage_uv and restart ordinary CC/CV charging from there. + * These timers should be chosen to align with the typical discharge curve + * for the battery. + * + * When the main CC/CV charging is complete the battery can optionally be + * maintenance charged at the voltages from this table: a table of settings is + * traversed using a slightly lower current and voltage than what is used for + * CC/CV charging. The maintenance charging will for safety reasons not go on + * indefinately: we lower the current and voltage with successive maintenance + * settings, then disable charging completely after we reach the last one, + * and after that we do not restart charging until we reach + * charge_restart_voltage_uv (see struct power_supply_battery_info) and restart + * ordinary CC/CV charging from there. + * + * As an example, a Samsung EB425161LA Lithium-Ion battery is CC/CV charged + * at 900mA to 4340mV, then maintenance charged at 600mA and 4150mV for + * 60 hours, then maintenance charged at 600mA and 4100mV for 200 hours. + * After this the charge cycle is restarted waiting for + * charge_restart_voltage_uv. + * + * For most mobile electronics this type of maintenance charging is enough for + * the user to disconnect the device and make use of it before both maintenance + * charging cycles are complete. + */ +struct power_supply_maintenance_charge_table { + int charge_current_max_ua; + int charge_voltage_max_uv; + int charge_safety_timer_minutes; +}; + #define POWER_SUPPLY_OCV_TEMP_MAX 20 /** @@ -403,6 +449,10 @@ struct power_supply_ntc_resistance_temp_table { * @constant_charge_voltage_max_uv: voltage in microvolts signifying the end of * the CC (constant current) charging phase and the beginning of the CV * (constant voltage) charging phase. + * @maintenance_charge: an array of maintenance charging settings to be used + * after the main CC/CV charging phase is complete. + * @maintenance_charge_size: the number of maintenance charging settings in + * maintenance_charge. * @factory_internal_resistance_uohm: the internal resistance of the battery * at fabrication time, expressed in microohms. This resistance will vary * depending on the lifetime and charge of the battery, so this is just a @@ -564,6 +614,8 @@ struct power_supply_battery_info { int overvoltage_limit_uv; int constant_charge_current_max_ua; int constant_charge_voltage_max_uv; + struct power_supply_maintenance_charge_table *maintenance_charge; + int maintenance_charge_size; int factory_internal_resistance_uohm; int ocv_temp[POWER_SUPPLY_OCV_TEMP_MAX]; int temp_ambient_alert_min; @@ -621,12 +673,24 @@ power_supply_temp2resist_simple(struct power_supply_resistance_temp_table *table int table_len, int temp); extern int power_supply_ntc_resist2temp_simple(struct power_supply_battery_info *info, int resistance_ohm); +extern struct power_supply_maintenance_charge_table * +power_supply_get_maintenance_charging_setting(struct power_supply_battery_info *info, int index); extern void power_supply_changed(struct power_supply *psy); extern int power_supply_am_i_supplied(struct power_supply *psy); extern int power_supply_set_input_current_limit_from_supplier( struct power_supply *psy); extern int power_supply_set_battery_charged(struct power_supply *psy); +static inline bool +power_supply_supports_maintenance_charging(struct power_supply_battery_info *info) +{ + struct power_supply_maintenance_charge_table *mt; + + mt = power_supply_get_maintenance_charging_setting(info, 0); + + return (mt != NULL); +} + #ifdef CONFIG_POWER_SUPPLY extern int power_supply_is_system_supplied(void); #else