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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE96BC433EF for ; Tue, 16 Nov 2021 12:28:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA8D861284 for ; Tue, 16 Nov 2021 12:28:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236236AbhKPMbW (ORCPT ); Tue, 16 Nov 2021 07:31:22 -0500 Received: from mail-lf1-f52.google.com ([209.85.167.52]:37420 "EHLO mail-lf1-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236046AbhKPMbU (ORCPT ); Tue, 16 Nov 2021 07:31:20 -0500 Received: by mail-lf1-f52.google.com with SMTP id c32so52774373lfv.4; Tue, 16 Nov 2021 04:28:22 -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=x34Wmq5UEibmmAViM4h392AJ2nzdGPzrPviO8aZH958=; b=RwOnkK1kPcVYq9izUkfCVCAjSZcocSUFy1mdm97IYptjQNVBeZgBMFFOQdwPEdoWNb Rj7gTLVwhX6MbAdChSatP0cCAW+AHugAEs5SxShzzoEpQgrE8qBK2rbYDv0kIGvexQ65 KgfOAA4KjJKQsEyI/1wT1dLRi64d02Ad7LeKqJuby/MnOKgipHlijU0tWCwo1GUMSFaO N/Iye0+IRA41Y0c7BRl+4TW8VNXDPNYFtpQBwZde1z3jBHONB5pWHCf1iIMCIrcT+MhN 0+NtARSPV2xtYfnaF7OgalDUclcS+O4RTVXUC3oUuX9HYIL2S0FD4QJ7180uKQiMwFqZ aSsQ== X-Gm-Message-State: AOAM5334aRr3Mi10LT2cKeCbt2YQGVj3ll8os6hwUH+KSgcEAz+6Tqal jr7s8tPNQOKqmBAKcgLx7Mk= X-Google-Smtp-Source: ABdhPJwVMNPnMiTXtG4+v4jp8KH2KUUJQh74RZsmEtNcFkP9nF5YIgcmZRbfSW+pQvjDFhiAyMJbSQ== X-Received: by 2002:ac2:54b7:: with SMTP id w23mr6479169lfk.163.1637065701267; Tue, 16 Nov 2021 04:28:21 -0800 (PST) Received: from fedora (dc73szyyyyyyyyyyyyycy-3.rev.dnainternet.fi. [2001:14ba:16ee:fa00::4]) by smtp.gmail.com with ESMTPSA id k5sm1816451lja.34.2021.11.16.04.28.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Nov 2021 04:28:20 -0800 (PST) Date: Tue, 16 Nov 2021 14:28:13 +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 7/9] power: supply: add simple-gauge for SOC estimation and CC correction Message-ID: <26a80d9081382976cec58f9c3bc0ecb181c5836e.1637061794.git.matti.vaittinen@fi.rohmeurope.com> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="c73i0tdUUwqAJl/f" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --c73i0tdUUwqAJl/f Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Add generic 'simple gauge' helper for performing iterative SOC estimation and coulomb counter correction for devices with a (drifting) coulomb counter. This should allow few charger/fuel-gauge drivers to use generic loop instead of implementing their own. Charger/fuel-gauge drivers can register 'simple-gauge' which does periodically poll the driver and: - get battery state - adjust coulomb counter value (to fix drifting caused for example by ADC offset) if: - Battery is relaxed and OCV<=3D>SOC table is given - Battery is full charged - get battery age (cycles) from driver - get battery temperature - do battery capacity correction - by battery temperature - by battery age - by computed Vbat/OCV difference at low-battery condition if low-limit is set and OCV table given - by IC specific low-battery correction if provided - compute current State Of Charge (SOC) - do periodical calibration if IC supports that. (Many ICs do calibration of CC by shorting the ADC pins and getting the offset). - provide the user-space a consistent interface for getting/setting the battery-cycle information for ICs which can't store the battery aging information. Uses POWER_SUPPLY_PROP_CYCLE_COUNT for this. The simple gauge provides the last computed SOC as POWER_SUPPLY_PROP_CAPACITY to power_supply_class when requested. Things that should/could be added but are missing from this commit: - Support starting calibration in HW when entering to suspend. This is useful for ICs supporting delayed calibration to mitigate CC error during suspend - and to make periodical wake-up less critical. - periodical wake-up for performing SOC estimation computation (RTC integration) Signed-off-by: Matti Vaittinen --- RFCv3: - use devm_add_action_or_reset - Rename to simple_gauge - Limit access to power_supply parameters - Introduce simple_gauge_drvdata - no need to show simple_gauge at config menu. Users should just SELECT i= t. - allow tristate - Add blocking 'iteration run' - loop. - updated the comment section - Fixed clamped SOC which was not updated - Small comment improvements - Don't allow negative CC after computing capacity corrections - Fix gauge looping when last client exits --- drivers/power/supply/Kconfig | 3 + drivers/power/supply/Makefile | 1 + drivers/power/supply/simple-gauge.c | 1303 +++++++++++++++++++++++++++ include/linux/power/simple_gauge.h | 244 +++++ 4 files changed, 1551 insertions(+) create mode 100644 drivers/power/supply/simple-gauge.c create mode 100644 include/linux/power/simple_gauge.h diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig index 5cf5bb56d2e3..24a8d030a391 100644 --- a/drivers/power/supply/Kconfig +++ b/drivers/power/supply/Kconfig @@ -9,6 +9,9 @@ menuconfig POWER_SUPPLY =20 if POWER_SUPPLY =20 +config POWER_SIMPLE_GAUGE + tristate + config POWER_SUPPLY_DEBUG bool "Power supply debug" help diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile index 4e55a11aab79..8c8c5f6a6492 100644 --- a/drivers/power/supply/Makefile +++ b/drivers/power/supply/Makefile @@ -5,6 +5,7 @@ power_supply-y :=3D power_supply_core.o power_supply-$(CONFIG_SYSFS) +=3D power_supply_sysfs.o power_supply-$(CONFIG_LEDS_TRIGGERS) +=3D power_supply_leds.o =20 +obj-$(CONFIG_POWER_SIMPLE_GAUGE) +=3D simple-gauge.o obj-$(CONFIG_POWER_SUPPLY) +=3D power_supply.o obj-$(CONFIG_POWER_SUPPLY_HWMON) +=3D power_supply_hwmon.o obj-$(CONFIG_GENERIC_ADC_BATTERY) +=3D generic-adc-battery.o diff --git a/drivers/power/supply/simple-gauge.c b/drivers/power/supply/sim= ple-gauge.c new file mode 100644 index 000000000000..7bf96b4d35dd --- /dev/null +++ b/drivers/power/supply/simple-gauge.c @@ -0,0 +1,1303 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of some generic state-of-charge computations for devices + * with coulomb counter + * + * Copyright 2020 ROHM Semiconductors + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SWGAUGE_TIMEOUT_JITTER 100 +/* We add 0.5% of uAh to avoid rounding error */ +#define SOC_BY_CAP(uah, round, cap) ((uah + round) * 100 / (cap)) + +/* + * The idea here is to implement (typical?) periodical coulomb-counter pol= ling + * and adjusting. I know few ROHM ICs which do this in out-of-tree drivers= - + * and I think there is few drivers also in-tree doing something similar. I + * believe adding some SOC computation logic to core could benefit a few o= f the + * drivers. + * + * I selected the ROHM algorithm here because I know it better than others. + * + * So let's go explaining the logic pulled in here: + * + * Device drivers for (charger) ICs which contain a coulomb counter can + * register here and provide IC specific functions as listed in + * include/linux/power/simple_gauge.h struct simple_gauge_ops. Drivers can= also + * specify time interval the IC is polled. + * + * After registration the simple_gauge does periodically poll the driver a= nd: + * 1. get battery state + * 2. adjust coulomb counter value (to fix drifting caused for example by = ADC + * offset) if: + * - Battery is relaxed and OCV<=3D>SOC table is given + * - Battery is fully charged + * 3. get battery age (cycles) from driver + * 4. get battery temperature + * 5. do battery capacity correction + * - by battery temperature + * - by battery age + * - by computed Vbat/OCV difference at low-battery condition if + * low-limit is set and OCV table given + * - by IC specific low-battery correction if provided + * 6. compute current State Of Charge (SOC) based on corrected capacity + * 7. do periodical calibration if IC supports that. (Many ICs do calibrat= ion + * of CC by shorting the ADC pins and getting the offset). + * TODO: Support starting calibration in HW when entering to suspend. Th= is + * is useful for ICs supporting delayed calibration to mitigate CC error + * during suspend - and to make periodical wake-up less critical. + * + * The SW gauge provides the last computed SOC as POWER_SUPPLY_PROP_CAPACI= TY to + * power_supply_class when requested. + * + * Additionally the SW-gauge provides the user-space a consistent interfac= e for + * getting/setting the battery-cycle information for ICs which can't store= the + * battery aging information (like how many times battery has been charged= to + * full) over a reset. POWER_SUPPLY_PROP_CYCLE_COUNT is used for this. + * + * TODO: Some low-power devices which may spend long times suspended may p= refer + * periodical wake-up for performing SOC estimation/computation even at the + * cost of power-consumption caused by such a wake-up. So as a future + * improvement it would be nice to see a RTC integration which might allow= the + * periodic wake-up. (Or is there better ideas?). This could be useful for= the + * devices which do not support calibration when SOC is turned off and cur= rent + * consumption is minimal. + * + * If this is not seen as a complete waste of time - then I would like to = get + * suggestions and opinions :) Especially for following: + * 1. Should this be meld-in power_supply_class? I didn't go to that route= as I + * didn't want to obfuscate the power_supply registration with the item= s in + * the simple_gauge desc and ops. OTOH, the psy now has a pointer to sw= -gauge + * and sw-gauge to psy - which is a clear hint that the relation of them + * is quite tight. + */ + +static DEFINE_MUTEX(simple_gauge_lock); +static DEFINE_MUTEX(simple_gauge_start_lock); +static LIST_HEAD(simple_gauges); + +static int g_running; +static struct task_struct k; + +static int simple_gauge_set_cycle(struct simple_gauge *sw, int new_cycle) +{ + int ret =3D 0, old_cycle =3D sw->cycle; + + if (!sw->desc.allow_set_cycle && !sw->ops.set_cycle) + return -EINVAL; + + if (sw->ops.set_cycle) + ret =3D sw->ops.set_cycle(sw, old_cycle, &new_cycle); + + if (!ret) + sw->cycle =3D new_cycle; + + return ret; +} + +static int simple_gauge_set_property(struct power_supply *psy, + enum power_supply_property psp, + const union power_supply_propval *val) +{ + struct simple_gauge *sg =3D power_supply_get_drvdata(psy); + + if (!sg) { + WARN_ON(!sg); + return -EINVAL; + } + + if (psp =3D=3D POWER_SUPPLY_PROP_CYCLE_COUNT && sg->desc.allow_set_cycle) + return simple_gauge_set_cycle(sg, val->intval); + + if (sg->set_custom_property) + return sg->set_custom_property(sg, psp, val); + + return -EOPNOTSUPP; +} + +static int simple_gauge_get_property(struct power_supply *psy, + enum power_supply_property psp, + union power_supply_propval *val) +{ + struct simple_gauge *sg =3D power_supply_get_drvdata(psy); + + if (!sg) { + WARN_ON(!sg); + return -EINVAL; + } + /* + * We should ensure here is that the first iteration + * loop for SOC calculation must've been performed. TODO: + * How to ensure it? + * + * TODO: Add flags to advertice which properties can be computed by + * sw-gauge (with given call-backs) and only return those. Else + * default with driver get_property to allow the driver to compute + * and provide those w/o the SW-gauge. + * + * Or - we could first try calling the driver call-back and do these + * as a fall-back if driver returns an error? + */ + switch (psp) { + case POWER_SUPPLY_PROP_CAPACITY: + spin_lock(&sg->lock); + val->intval =3D sg->soc; + spin_unlock(&sg->lock); + return 0; + case POWER_SUPPLY_PROP_CYCLE_COUNT: + spin_lock(&sg->lock); + val->intval =3D sg->cycle; + spin_unlock(&sg->lock); + return 0; + case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: + /* uAh */ + val->intval =3D sg->designed_cap; + return 0; + case POWER_SUPPLY_PROP_CHARGE_FULL: + spin_lock(&sg->lock); + val->intval =3D sg->capacity_uah; + spin_unlock(&sg->lock); + return 0; + case POWER_SUPPLY_PROP_CHARGE_NOW: + spin_lock(&sg->lock); + val->intval =3D sg->cc_uah; + spin_unlock(&sg->lock); + return 0; + case POWER_SUPPLY_PROP_TEMP: + spin_lock(&sg->lock); + val->intval =3D sg->temp; + spin_unlock(&sg->lock); + return 0; + default: + break; + } + + if (sg->get_custom_property) + return sg->get_custom_property(sg, psp, val); + + return -EOPNOTSUPP; +} + +static void gauge_put(struct simple_gauge *sw) +{ + sw->refcount =3D 0; + if (!sw->refcount) + wake_up(&sw->wq); +} + +static void gauge_get(struct simple_gauge *sw) +{ + sw->refcount =3D 1; +} + +static int gauge_reserved(struct simple_gauge *sw) +{ + return sw->refcount; +} + +static int get_dsoc_from_ocv(struct simple_gauge *sw, int *dsoc, int temp,= int ocv) +{ + int ret; + + /* + * The OCV tables use degree C as units (if I did not misread the + * code - why?) - power_supply class user-space seems to mandate + * the tenths of a degree - so we require this from drivers and + * lose accuracy here :/ + */ + ret =3D power_supply_batinfo_ocv2cap(&sw->info, ocv, temp / 10); + if (ret > 0) { + *dsoc =3D ret * 10; + ret =3D 0; + } + + if (ret) { + if (!sw->ops.get_soc_by_ocv) + return ret; + /* For driver callbacks we use tenths of degree */ + ret =3D sw->ops.get_soc_by_ocv(sw, ocv, temp, dsoc); + } + return ret; +} + +static int simple_gauge_get_temp(struct simple_gauge *sw, int *temp) +{ + if (sw->ops.get_temp) + return sw->ops.get_temp(sw, temp); + + return -EINVAL; +} + +static int age_correct_cap(struct simple_gauge *sw, int *uah) +{ + int ret =3D 0; + + /* If IC provides more complex degradation computation - use it */ + if (sw->ops.age_correct_cap) { + int tmp =3D *uah; + + ret =3D sw->ops.age_correct_cap(sw, sw->cycle, &tmp); + if (!ret) { + *uah =3D tmp; + return 0; + } + } + /* Calculate constant uAh/cycle degradation */ + if (sw->desc.degrade_cycle_uah) { + int lost_cap; + + lost_cap =3D sw->desc.degrade_cycle_uah * sw->cycle; + if (lost_cap > sw->designed_cap) + *uah =3D 0; + else + *uah -=3D sw->desc.degrade_cycle_uah * sw->cycle; + + return 0; + } + + return ret; +} + +static int adjust_cc_relax(struct simple_gauge *sw, int rex_volt) +{ + int ret, temp, dsoc; + int full_uah =3D sw->designed_cap; + int uah_now; + + /* get temp */ + ret =3D simple_gauge_get_temp(sw, &temp); + if (ret) + return ret; + + /* get ocv */ + ret =3D get_dsoc_from_ocv(sw, &dsoc, temp, rex_volt); + if (ret) + return ret; + + /* + * Typically ROHM implemented drivers have kept the value CC in PMIC + * corresponding to IDEAL battery capacity and then substracted the + * lost capacity when converting CC value to uAh. I guess this prevents + * CC from hitting the floor. + */ + uah_now =3D full_uah * dsoc / 1000 + sw->soc_rounding; + if (uah_now > sw->designed_cap) + uah_now =3D sw->designed_cap; + + return sw->ops.update_cc_uah(sw, full_uah); +} + +static int get_state(struct simple_gauge *sw, int *state, int *rex_volt) +{ + int ret; + enum power_supply_property psp =3D POWER_SUPPLY_PROP_STATUS; + union power_supply_propval pstate; + + *state =3D 0; + + ret =3D power_supply_get_property(sw->psy, psp, &pstate); + if (ret) + return ret; + + if (pstate.intval =3D=3D POWER_SUPPLY_STATUS_FULL) + *state |=3D SW_GAUGE_FULL; + if (pstate.intval =3D=3D POWER_SUPPLY_STATUS_DISCHARGING || + pstate.intval =3D=3D POWER_SUPPLY_STATUS_NOT_CHARGING) { + *state |=3D SW_GAUGE_MAY_BE_LOW; + if (sw->desc.clamp_soc) + *state |=3D SW_GAUGE_CLAMP_SOC; + } + + if (sw->ops.is_relaxed) + if (sw->ops.is_relaxed(sw, rex_volt)) + *state |=3D SW_GAUGE_RELAX; + return ret; +} + +static int adjust_cc_full(struct simple_gauge *sw) +{ + int ret =3D 0, from_full_uah =3D 0; + int full_uah =3D sw->designed_cap; + + /* + * Some ICs are able to provide the uAh lost since the battery was + * fully charged. Decrease this from the designed capacity and set + * the CC value accordingly. + */ + if (sw->ops.get_uah_from_full) + ret =3D sw->ops.get_uah_from_full(sw, &from_full_uah); + + if (ret) + dev_warn(sw->dev, + "Failed to get capacity lost after fully charged\n"); + + full_uah -=3D from_full_uah; + + /* + * ROHM algorithm adjusts CC here based on designed capacity and not + * based on age/temperature corrected capacity. This helps avoiding + * CC dropping below zero when we estimate aging/temperature impact + * badly. It also allows to keep the estimated SOC in the sw-gauge + * so that all IC drivers do not need to care about it - at least + * in theory. But most importantly - this approach is tested on the + * field :) + */ + return sw->ops.update_cc_uah(sw, full_uah); +} + +/* + * Some charger ICs keep count of battery charge systems but can only store + * one or few cycles. They may need to clear the cycle counter and update + * counter in SW. This function fetches the counter from HW and allows HW = to + * clear IC counter if needed. + */ +static int update_cycle(struct simple_gauge *sw) +{ + int cycle, ret =3D -EINVAL; + + if (sw->ops.get_cycle) { + /* + * We provide old cycle value to driver so driver does not + * need to cache it + */ + cycle =3D sw->cycle; + ret =3D sw->ops.get_cycle(sw, &cycle); + if (ret) + return ret; + sw->cycle =3D cycle; + } else + sw->cycle++; + + return 0; +} + +static int simple_gauge_cap2ocv(struct simple_gauge *sw, int dsoc, int tem= p, int *ocv) +{ + int ret; + + if (sw->ops.get_ocv_by_soc) + return sw->ops.get_ocv_by_soc(sw, dsoc, temp, ocv); + + ret =3D power_supply_batinfo_dcap2ocv(&sw->info, dsoc, temp / 10); + if (ret > 0) { + *ocv =3D ret; + ret =3D 0; + } + + return ret; +} + +static int load_based_soc_zero_adjust(struct simple_gauge *sw, int *effect= ive_cap, + int cc_uah, int vsys, int temp) +{ + int dsoc, ocv_by_cap; + int ret, i; + int vdrop; + struct power_supply_battery_ocv_table *table; + int table_len; + int soc_adjust =3D 0; + + /* + * Get OCV for current estimated SOC - we use unit of 0.1% for SOC + * (dsoc) to improve accuracy. Note - batinfo expects 1% - should we + * introduce new DT entry of more accurate OCV table for improved SOC + * =3D> OCV where SOC was given using unit of 0.1% for improved internal + * calculation? User space should still only see 1% - but for "zero + * adjust" where we do SOC =3D> OCV =3D> drop-voltage =3D> SOC correction + * =3D> CC/capacity adjustment we would like to have more accurate SOC + * in these intermediate steps. + */ + dsoc =3D SOC_BY_CAP(cc_uah * 10, 0, *effective_cap); + ret =3D simple_gauge_cap2ocv(sw, dsoc, temp, &ocv_by_cap); + if (ret) { + dev_err(sw->dev, "Failed to convert cap to OCV\n"); + return ret; + } + /* Get the difference of OCV (no load) and VBAT (current load) */ + vdrop =3D ocv_by_cap - vsys; + dev_dbg(sw->dev, "Obtained OCV: %d, vsys %d, Computed Vdrop %d\n", + ocv_by_cap, vsys, vdrop); + if (vdrop <=3D 0) + return 0; + + /* + * We know that the SOC should be 0 at the moment when voltage with + * this load drops below system limit. So let's scan the OCV table + * and just assume the vdrop stays constant for the rest of the game. + * This way we can see what is the new 'zero adjusted capacity' for + * our battery. + * + * We don't support non DT originated OCV table here. + * + * I guess we could allow user to provide standard OCV tables in desc. + * Or the full batinfo for that matter. But for now we just force the + * drivers W/O OCV tables in DT to just provide whole low-voltage + * call-back. + */ + table =3D power_supply_find_ocv2cap_table(&sw->info, temp / 10, + &table_len); + if (!table) { + dev_warn(sw->dev, "No OCV table found\n"); + return -EINVAL; + } + + for (i =3D 0; i < table_len; i++) + if (table[i].ocv - vdrop <=3D sw->desc.system_min_voltage) + break; + + if (!i) + soc_adjust =3D table[0].capacity; + else if (i && i < table_len) { + int j; + int soc_range =3D table[i-1].capacity - table[i].capacity; + int volt_range =3D table[i-1].ocv - table[i].ocv; + int v_div =3D volt_range/soc_range; + + for (j =3D 0; j < soc_range; j++) + if (table[i].ocv + v_div * j - vdrop >=3D + sw->desc.system_min_voltage) + break; + soc_adjust =3D table[i].capacity + j; + } + if (soc_adjust) { + int new_full_cap; + + /* + * So we know that actually we will have SOC =3D 0 when capacity + * is soc_adjust. Lets compute new battery max capacity based + * on this. + */ + new_full_cap =3D *effective_cap * (100 - soc_adjust) / 100; + + *effective_cap =3D new_full_cap; + } + + return 0; +} + +static int simple_gauge_zero_cap_adjust(struct simple_gauge *sw, int *effe= ctive_cap, + int *cc_uah, int vsys, int temp) +{ + int ret, old_eff_cap =3D *effective_cap; + + if (sw->ops.zero_cap_adjust) + ret =3D sw->ops.zero_cap_adjust(sw, effective_cap, *cc_uah, vsys, + temp); + else + ret =3D load_based_soc_zero_adjust(sw, effective_cap, *cc_uah, + vsys, temp); + /* + * As we keep HW CC aligned to designed-cap - we need to + * also cancel this new offset from CC measured uAh + */ + if (!ret) + *cc_uah -=3D old_eff_cap - *effective_cap; + + return ret; +} + +static int find_dcap_change(struct simple_gauge *sw, int temp, int *delta_= cap) +{ + struct power_supply_temp_degr *dclosest =3D NULL, *d; + int i; + + for (i =3D 0; i < sw->amount_of_temp_dgr; i++) { + d =3D &sw->temp_dgr[i]; + if (!dclosest) { + dclosest =3D d; + continue; + } + if (abs(d->temp_set_point - temp) < + abs(dclosest->temp_set_point - temp)) + dclosest =3D d; + } + + if (!dclosest) + return -EINVAL; + + /* + * Temperaure range is in tenths of degrees and degrade value is for a + * degree =3D> divide by 10 after multiplication to fix the scale + */ + *delta_cap =3D (dclosest->temp_set_point - temp) * + dclosest->temp_degrade_1C / 10 + + dclosest->degrade_at_set; + + return 0; +} + +static int compute_temp_correct_uah(struct simple_gauge *sw, int *cap_uah,= int temp) +{ + int ret, uah_corr; + + ret =3D find_dcap_change(sw, temp, &uah_corr); + if (ret) + return ret; + + if (*cap_uah < -uah_corr) + *cap_uah =3D 0; + else + *cap_uah +=3D uah_corr; + + return 0; +} + +static int compute_soc_by_cc(struct simple_gauge *sw, int state) +{ + int cc_uah, ret; + int current_cap_uah; + int temp; + int new_soc; + bool do_zero_correct, changed =3D false; + + ret =3D sw->ops.get_uah(sw, &cc_uah); + /* The CC value should never exceed designed_cap as CC value. */ + if (cc_uah > sw->designed_cap) { + cc_uah =3D sw->designed_cap; + sw->ops.update_cc_uah(sw, sw->designed_cap); + } + + current_cap_uah =3D sw->designed_cap; + + dev_dbg(sw->dev, "iteration started - CC %u, cap %u (SOC %u)\n", + cc_uah, current_cap_uah, + SOC_BY_CAP(cc_uah, sw->soc_rounding, current_cap_uah)); + + ret =3D age_correct_cap(sw, ¤t_cap_uah); + if (ret) { + dev_err(sw->dev, "Age correction of battery failed\n"); + return ret; + } + + if (current_cap_uah =3D=3D 0) { + dev_warn(sw->dev, "Battery EOL\n"); + spin_lock(&sw->lock); + sw->capacity_uah =3D 0; + sw->soc =3D 0; + changed =3D true; + goto battery_eol_out; + } + + /* Do battery temperature compensation */ + ret =3D simple_gauge_get_temp(sw, &temp); + if (ret) { + dev_err(sw->dev, "Failed to get temperature\n"); + return ret; + } + + if (sw->ops.temp_correct_cap) + ret =3D sw->ops.temp_correct_cap(sw, ¤t_cap_uah, temp); + else if (sw->amount_of_temp_dgr) + ret =3D compute_temp_correct_uah(sw, ¤t_cap_uah, temp); + + if (ret) + dev_warn(sw->dev, + "Couldn't do temperature correction to battery cap\n"); + + /* + * We keep HW CC counter aligned to ideal battery CAP - EG, when + * battery is full, CC is set according to ideal battery capacity. + * Same when we set it based on OCV. Thus - when we compute SOC we will + * cancel this offset by decreasing the CC uah with the lost capacity + */ + cc_uah -=3D (sw->designed_cap - current_cap_uah); + + /* Only need zero correction when discharging */ + do_zero_correct =3D !!(state & SW_GAUGE_MAY_BE_LOW); + + /* + * Allow all ICs to have own adjustment functions for low Vsys to allow + * them tackle potential issues in capacity estimation at near + * depleted battery + */ + if (sw->desc.cap_adjust_volt_threshold && sw->ops.get_vsys && + do_zero_correct) { + int vsys; + + ret =3D sw->ops.get_vsys(sw, &vsys); + if (ret) { + dev_err(sw->dev, "Failed to get vsys\n"); + return ret; + } + + if (sw->desc.cap_adjust_volt_threshold >=3D vsys) + ret =3D simple_gauge_zero_cap_adjust(sw, ¤t_cap_uah, + &cc_uah, vsys, temp); + if (ret) + dev_warn(sw->dev, "Low voltage adjustment failed\n"); + } + + dev_dbg(sw->dev, "Corrected cap %u, designed-cap %u (SOC %u)\n", + current_cap_uah, sw->designed_cap, + SOC_BY_CAP(cc_uah, sw->soc_rounding, current_cap_uah)); + + if (cc_uah > sw->designed_cap) + cc_uah =3D sw->designed_cap; + + /* + * With badly behaving CC or wrong VDR values we may make the CC to go + * negative. Floor it to zero to avoid exhausting the battery W/O warning. + */ + if (cc_uah < 0) { + dev_warn(sw->dev, + "Bad battery capacity estimate\n"); + cc_uah =3D 0; + } + /* Store computed values */ + spin_lock(&sw->lock); + sw->cc_uah =3D cc_uah; + sw->temp =3D temp; + sw->capacity_uah =3D current_cap_uah; + new_soc =3D SOC_BY_CAP(cc_uah, sw->soc_rounding, current_cap_uah); + + /* + * Should we only ping user-space when SOC changes more than N%? + * Should the N be configurable (by user-space?) + */ + if (sw->soc !=3D new_soc) + changed =3D true; + + sw->soc =3D new_soc; + if (sw->clamped_soc >=3D 0 && state & SW_GAUGE_CLAMP_SOC) { + if (sw->clamped_soc < sw->soc) + sw->soc =3D sw->clamped_soc; + } + sw->clamped_soc =3D sw->soc; + +battery_eol_out: + spin_unlock(&sw->lock); + if (changed) + power_supply_changed(sw->psy); + + return ret; +} + +static void calibrate(struct simple_gauge *sw) +{ + if (sw->ops.calibrate) + sw->ops.calibrate(sw); +} + +static void iterate(struct simple_gauge *sw) +{ + int state, ret, rex_volt; + + /* Adjust battery aging information */ + ret =3D update_cycle(sw); + if (ret) { + dev_err(sw->dev, "Failed to update battery cycle\n"); + return; + } + + ret =3D get_state(sw, &state, &rex_volt); + if (ret) { + dev_err(sw->dev, "Failed to get state\n"); + return; + } + + /* Setting CC not possible? Omit CC adjustment */ + if (sw->ops.update_cc_uah) { + if (state & SW_GAUGE_FULL) { + ret =3D adjust_cc_full(sw); + if (ret) + dev_err(sw->dev, "Failed to do FULL adjust\n"); + } + if (state & SW_GAUGE_RELAX) { + ret =3D adjust_cc_relax(sw, rex_volt); + if (ret) + dev_err(sw->dev, "Failed to do RELAX adjust\n"); + } + } + + ret =3D compute_soc_by_cc(sw, state); + if (ret) + dev_err(sw->dev, "Failed to compute SOC for gauge\n"); +} + +static bool should_calibrate(struct simple_gauge *sw, u64 time) +{ + if (sw->desc.calibrate_interval && + sw->next_cal <=3D time + msecs_to_jiffies(SWGAUGE_TIMEOUT_JITTER)) { + sw->next_cal =3D time + + msecs_to_jiffies(sw->desc.calibrate_interval); + return true; + } + + return false; + +} + +static bool should_compute(struct simple_gauge *sw, u64 time) +{ + if (sw->next_iter <=3D time + msecs_to_jiffies(SWGAUGE_TIMEOUT_JITTER) || + sw->force_run) { + sw->force_run =3D 0; + sw->next_iter =3D time + + msecs_to_jiffies(sw->desc.poll_interval); + return true; + } + + return false; +} + +static void adjust_next_tmo(struct simple_gauge *sw, u64 *timeout, u64 now) +{ + u64 t =3D (sw->desc.calibrate_interval && sw->next_cal < sw->next_iter) ? + sw->next_cal : sw->next_iter; + + if (!*timeout || t - now < *timeout) + *timeout =3D t - now; + + if (*timeout < msecs_to_jiffies(SWGAUGE_TIMEOUT_JITTER)) + *timeout =3D msecs_to_jiffies(SWGAUGE_TIMEOUT_JITTER); +} + +static DECLARE_WAIT_QUEUE_HEAD(simple_gauge_thread_wait); +static DECLARE_WAIT_QUEUE_HEAD(simple_gauge_forced_wait); + +static int simple_gauge_forced_run; + +/** + * simple_gauge_run - force running the computation loop for gauge + * + * Drivers utilizing simple_gauge can trigger running the SOC computation = loop even + * prior the time-out occurs. This is usable for drivers with longish peri= od + * but which may get interrupts form device when some condition changes. N= ote, + * this function schedules the iteration but does not block. + * + * @sw: gauge fow which the computation should be ran. + */ +void simple_gauge_run(struct simple_gauge *sw) +{ + sw->force_run =3D 1; + simple_gauge_forced_run =3D 1; + barrier(); + wake_up(&simple_gauge_thread_wait); +} +EXPORT_SYMBOL_GPL(simple_gauge_run); + +static unsigned int g_iteration; + +static unsigned int simple_gauge_run_locked(struct simple_gauge *sg) +{ + unsigned int ctr; + + /* Wait for any ongoing iteration */ + mutex_lock(&simple_gauge_lock); + ctr =3D g_iteration; + simple_gauge_run(sg); + mutex_unlock(&simple_gauge_lock); + + return ctr; +} + +/** + * simple_gauge_run_blocking_timeout - Run gauge loop and block until ran + * + * Trigger simple-gauge to run. Wait until simple-gauge has been ran or ti= meout + * occurs. + * + * @sg: Pointer to gauge + * @timeout_ms: Timeout in milliseconds. + * + * Returns: 0 if gauge loop was ran. -EAGAIN if timeout occurred and + * -ERESTARTSYS if call was interrupted. + */ +int simple_gauge_run_blocking_timeout(struct simple_gauge *sg, + unsigned int timeout_ms) +{ + unsigned int ctr; + int ret; + + ctr =3D simple_gauge_run_locked(sg); + ret =3D wait_event_interruptible_timeout(simple_gauge_forced_wait, + g_iteration > ctr, + timeout_ms); + if (ret =3D=3D 1) + ret =3D 0; + else if (!ret) + ret =3D -EAGAIN; + + return ret; +} +EXPORT_SYMBOL_GPL(simple_gauge_run_blocking_timeout); + +/** + * simple_gauge_run_blocking - Run gauge loop and block until ran + * + * Trigger simple-gauge to run. Wait until simple-gauge has been ran. + * + * @sg: Pointer to gauge + * + * Returns: 0 on success. -ERESTARTSYS if call was interrupted. + */ +int simple_gauge_run_blocking(struct simple_gauge *sg) +{ + unsigned int ctr; + int ret; + + ctr =3D simple_gauge_run_locked(sg); + ret =3D wait_event_interruptible(simple_gauge_forced_wait, + g_iteration > ctr); + + return ret; +} +EXPORT_SYMBOL_GPL(simple_gauge_run_blocking); + +static int gauge_thread(void *data) +{ + + for (;;) { + u64 timeout =3D 0; + struct simple_gauge *sw; + u64 now =3D get_jiffies_64(); + + if (kthread_should_stop()) { + g_running =3D 0; + pr_info("gauge thread stopping...\n"); + /* + * Ensure the g_running is visible to all. OTOH - if + * thread stopping is not supported we can drop this + * clearing. + */ + smp_wmb(); + break; + } + + simple_gauge_forced_run =3D 0; + + mutex_lock(&simple_gauge_lock); + list_for_each_entry(sw, &simple_gauges, node) { + gauge_get(sw); + if (should_compute(sw, now)) + iterate(sw); + if (should_calibrate(sw, now)) + calibrate(sw); + adjust_next_tmo(sw, &timeout, now); + gauge_put(sw); + } + /* + * Increase iteration counter and wake up the waiters who have + * requested the blocking forced run. NOTE: We must increase + * iteration here inside the locking to avoid race. + */ + g_iteration++; + mutex_unlock(&simple_gauge_lock); + wake_up(&simple_gauge_forced_wait); + + /* + * If the last gauge exited we fall to sleep in order to not + * go lopoping with zero timeout. New client registration will + * wake us up. + */ + if (!timeout && list_empty(&simple_gauges)) { + pr_debug("No clients: going to sleep\n"); + wait_event_interruptible(simple_gauge_thread_wait, + simple_gauge_forced_run); + } else { + pr_debug("sleeping %u msec\n", + jiffies_to_msecs(timeout)); + wait_event_interruptible_timeout(simple_gauge_thread_wait, + simple_gauge_forced_run, timeout); + } + } + + return 0; +} + +static int start_gauge_thread(struct task_struct *k) +{ + int ret =3D 0; + + /* Ensure the running state is updated. Is this needed? How likely it is + * this would not be updated? Only reason why we have this first check + * is to avoid unnecessarily getting the lock when the thread is started + * - and it should always be except for the first caller. But does this + * memory barrier actually make this almost as heavy as getting the lock + * every time? Maybe we should just drop the barrier and let us hit the + * lock if g_running is in cache or some such (lots of hand waving to + * make it look like I knew what I was talking about :]). + */ + smp_rmb(); + if (g_running) + return 0; + + /* + * Would this be cleaner if we used schedule_delayed_work? rather than + * kthread? What I like is only one thread for sw-gauge, with + * not-so-high priority. What is the simplest way to achieve it? + */ + mutex_lock(&simple_gauge_start_lock); + if (!g_running) { + k =3D kthread_run(gauge_thread, NULL, "sw-gauge"); + if (IS_ERR(k)) + ret =3D PTR_ERR(k); + else + g_running =3D 1; + } + mutex_unlock(&simple_gauge_start_lock); + + return ret; +} + +/* + * I think this is unnecessary. If someone registers SW gauge to the system + * then we can probably leave this running even if the gauge was temporari= ly + * removed. So let's consider removing this and thus simplifying the desig= n. + * + * Perhaps even always launch the thread if SW-gauge is configured in? + */ +void stop_gauge_thread(struct task_struct *k); +void stop_gauge_thread(struct task_struct *k) +{ + kthread_stop(k); +} + +static bool is_needed_ops_given(struct simple_gauge_ops *ops) +{ + return (ops->get_uah && ops->get_temp && ops->update_cc_uah); +} + +static int simple_gauge_set_ops(struct simple_gauge *sw, struct simple_gau= ge_ops *ops) +{ + if (!is_needed_ops_given(ops)) + return -EINVAL; + + sw->ops =3D *ops; + + return 0; +} + +static int simple_gauge_is_writable(struct power_supply *psy, + enum power_supply_property psp) +{ + struct simple_gauge *sg =3D power_supply_get_drvdata(psy); + + if (!sg) { + WARN_ON(!sg); + return -EINVAL; + } + + if (psp =3D=3D POWER_SUPPLY_PROP_CYCLE_COUNT) + return sg->desc.allow_set_cycle; + + if (sg->custom_is_writable) + return sg->custom_is_writable(sg, psp); + + return 0; +} + +static int sgauge_config_check(struct device *dev, struct simple_gauge_psy= *pcfg) +{ + const char *errstr =3D NULL; + + if (!pcfg) { + errstr =3D "Missing config"; + } else { + if (!pcfg->psy_name) + errstr =3D "No power supply name"; + if (pcfg->num_additional_props) { + if (!pcfg->get_custom_property) + errstr =3D "property reader required"; + } + if (!pcfg->is_writable) { + if (pcfg->set_custom_property) + errstr =3D + "set_custom_property() but no is_writable()"; + } + } + if (!errstr) + return 0; + + dev_err(dev, "%s\n", errstr); + return -EINVAL; +} +static int simple_gauge_set_props(struct simple_gauge *new, + struct power_supply_desc *pd, + struct simple_gauge_psy *pcfg) +{ + int i, j; + + new->properties =3D kzalloc(sizeof(*pcfg->additional_props) * + pcfg->num_additional_props + SIMPLE_GAUGE_PROP_SIZE, + GFP_KERNEL); + if (!new->properties) + return -ENOMEM; + + for (i =3D 0; i < NUM_SIMPLE_GAUGE_PROPS; i++) + new->properties[i] =3D SIMPLE_GAUGE_PROPS[i]; + + for (j =3D 0; j < pcfg->num_additional_props; j++, i++) + new->properties[i] =3D pcfg->additional_props[j]; + + pd->properties =3D new->properties; + pd->num_properties =3D i; + new->get_custom_property =3D pcfg->get_custom_property; + new->set_custom_property =3D pcfg->set_custom_property; + + return 0; +} + +void *simple_gauge_get_drvdata(struct simple_gauge *sg) +{ + return sg->desc.drv_data; +} +EXPORT_SYMBOL_GPL(simple_gauge_get_drvdata); + +/** + * psy_register_simple_gauge - register driver to simple_gauge + * + * @parent: Parent device for power-supply class device. + * @psycfg: Confiurations for power-supply class. + * @ops: simple_gauge specific operations. + * @desc: simple_gauge configuration data. + * + * Return: pointer to simple_gauge on success, an ERR_PTR on failure. + * + * A power-supply driver for a device with drifting coulomb counter (CC) c= an + * register for periodical polling/CC correction. CC correction is done wh= en + * battery is reported to be FULL or relaxed. For FULL battery the CC is s= et + * based on designed capacity and for relaxed battery CC is set based on o= pen + * circuit voltage. The simple_gauge takes care of registering a power-sup= ply class + * and reporting a few power-supply properties to user-space. See + * SWGAUGE_PSY_PROPS. Swauge can also do battery capacity corretions based= on + * provided temperature/cycle degradation values and/or system voltage lim= it. + */ +struct simple_gauge *__must_check psy_register_simple_gauge(struct device = *parent, + struct simple_gauge_psy *pcfg, + struct simple_gauge_ops *ops, + struct simple_gauge_desc *desc) +{ + struct power_supply_desc *pd; + struct power_supply_config pg =3D { 0 }; + int ret; + struct simple_gauge *new; + + if (!parent) { + pr_err("no parent\n"); + return ERR_PTR(-EINVAL); + } + + if (!desc->poll_interval) { + dev_err(parent, "interval missing\n"); + return ERR_PTR(-EINVAL); + } + + if (sgauge_config_check(parent, pcfg)) + return ERR_PTR(-EINVAL); + + pd =3D kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) + return ERR_PTR(-ENOMEM); + + new =3D kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) { + ret =3D -ENOMEM; + goto free_out; + } + pd->name =3D pcfg->psy_name; + pd->type =3D POWER_SUPPLY_TYPE_BATTERY; + + pg.drv_data =3D new; + pg.of_node =3D pcfg->of_node; + pg.attr_grp =3D pcfg->attr_grp; + + ret =3D simple_gauge_set_props(new, pd, pcfg); + if (ret) { + ret =3D -ENOMEM; + goto free_out; + } + new->dev =3D parent; + new->custom_is_writable =3D pcfg->is_writable; + /* We don't want to clamp SOC before it is initialized */ + new->clamped_soc =3D -1; + + init_waitqueue_head(&new->wq); + + ret =3D simple_gauge_set_ops(new, ops); + if (ret) { + dev_err(new->dev, "bad ops\n"); + goto free_out; + } + new->desc =3D *desc; + + spin_lock_init(&new->lock); + pd->get_property =3D simple_gauge_get_property; + pd->set_property =3D simple_gauge_set_property; + if (pcfg->is_writable || desc->allow_set_cycle) + pd->property_is_writeable =3D simple_gauge_is_writable; + + /* Do we need power_supply_register_ws? */ + /* + * We should not return SOC to user-space before the first + * estimation iteration is ran. How should we sync this? Should we + * actually start the gauge thread and try getting SOC prior + * registering to psy class? That would require us to do the + * battery-info reading here. Or should we have some way of delaying + * sysfs creation from psy-class until first iteration is done? Kind + * of two-step power-supply class registration? Again, I am open to + * all suggestions! + * + * I don't know how this should be integrated to psy class. Should + * this sit between psy-class and driver? Should this be part of + * psy-class or ?? If this was meld in psy-class registration and + * the psy class registration was just given a new parameter for fuel + * gauge desc - then the synchronization between 1st iteration and + * sysfs creation might get more natural. + */ + new->psy =3D power_supply_register(parent, pd, &pg); + if (IS_ERR(new->psy)) { + dev_err(new->dev, "power supply registration failed\n"); + ret =3D PTR_ERR(new->psy); + goto free_out; + } + + ret =3D power_supply_get_battery_info(new->psy, &new->info); + if (ret && !new->ops.get_soc_by_ocv) { + dev_err(new->dev, "No OCV =3D> SoC conversion\n"); + goto info_out; + } + if (!ret) + new->batinfo_got =3D true; + + if (new->info.temp_dgrd_values) { + new->amount_of_temp_dgr =3D new->info.temp_dgrd_values; + new->temp_dgr =3D new->info.temp_dgrd; + } else { + new->amount_of_temp_dgr =3D new->desc.amount_of_temp_dgr; + new->temp_dgr =3D new->desc.temp_dgr; + } + + if (desc->designed_cap) { + new->designed_cap =3D desc->designed_cap; + } else if (ret || !new->info.charge_full_design_uah) { + dev_err(new->dev, "Unknown battery capacity\n"); + goto info_out; + } else { + new->designed_cap =3D new->info.charge_full_design_uah; + } + /* We add 0.5 % to soc uah in order to avoid flooring */ + new->soc_rounding =3D new->designed_cap / 200; + mutex_lock(&simple_gauge_lock); + list_add(&new->node, &simple_gauges); + mutex_unlock(&simple_gauge_lock); + ret =3D start_gauge_thread(&k); + if (ret) { + /* + * This error is not related to underlying device but to the + * simple_gauge itself. Thus don't print error using the parent + * device + */ + pr_err("Failed to start fuel-gauge thread\n"); + goto info_out; + } + dev_dbg(new->dev, "YaY! SW-gauge registered\n"); + + simple_gauge_run_blocking(new); + + return new; + +info_out: + if (new->batinfo_got) + power_supply_put_battery_info(new->psy, &new->info); + + power_supply_unregister(new->psy); +free_out: + if (new) { + kfree(new->properties); + kfree(new); + } + kfree(pd); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(psy_register_simple_gauge); + +/** + * psy_remove_simple_gauge - deregister driver from simple_gauge + * + * @sw: gauge driver to be deregistered. + */ +void psy_remove_simple_gauge(struct simple_gauge *sw) +{ + const struct power_supply_desc *desc; + + mutex_lock(&simple_gauge_lock); + list_del(&sw->node); + mutex_unlock(&simple_gauge_lock); + + wait_event(sw->wq, !gauge_reserved(sw)); + + if (sw->batinfo_got) + power_supply_put_battery_info(sw->psy, &sw->info); + + desc =3D sw->psy->desc; + power_supply_unregister(sw->psy); + + kfree(desc); + kfree(sw->properties); + kfree(sw); +} +EXPORT_SYMBOL_GPL(psy_remove_simple_gauge); + +static void devm_simple_gauge_release(void *res) +{ + psy_remove_simple_gauge(res); +} + +/** + * devm_psy_register_simple_gauge - managed register driver to simple_gauge + * + * @parent: Parent device for power-supply class device. Swgauge's lifetime + * is also bound to this device. + * @psycfg: Confiurations for power-supply class. + * @ops: simple_gauge specific operations. + * @desc: simple_gauge configuration data. + * + * Return: pointer to simple_gauge on success, an ERR_PTR on failure. + * + * A power-supply driver for a device with drifting coulomb counter (CC) c= an + * register for periodical polling/CC correction. CC correction is done wh= en + * battery is reported to be FULL or relaxed. For FULL battery the CC is s= et + * based on designed capacity and for relaxed battery CC is set based on o= pen + * circuit voltage. The simple_gauge takes care of registering a power-sup= ply class + * and reporting a few power-supply properties to user-space. See + * SWGAUGE_PSY_PROPS. Swauge can also do battery capacity corretions based= on + * provided temperature/cycle degradation values and/or system voltage lim= it. + */ +struct simple_gauge *__must_check +devm_psy_register_simple_gauge(struct device *parent, struct simple_gauge_= psy *psycfg, + struct simple_gauge_ops *ops, struct simple_gauge_desc *desc) +{ + struct simple_gauge *sw; + int ret; + + sw =3D psy_register_simple_gauge(parent, psycfg, ops, desc); + if (IS_ERR(sw)) + return sw; + + ret =3D devm_add_action_or_reset(parent, devm_simple_gauge_release, sw); + if (ret) + return ERR_PTR(ret); + + return sw; +} +EXPORT_SYMBOL_GPL(devm_psy_register_simple_gauge); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("generic fuel-gauge on coulomb counter"); +MODULE_AUTHOR("Matti Vaittinen "); diff --git a/include/linux/power/simple_gauge.h b/include/linux/power/simpl= e_gauge.h new file mode 100644 index 000000000000..cd085375ddec --- /dev/null +++ b/include/linux/power/simple_gauge.h @@ -0,0 +1,244 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2020 ROHM Semiconductors */ + +#ifndef POWER_SW_GAUGE_H +#define POWER_SW_GAUGE_H + +#include +#include +#include +#include +#include + +#define SW_GAUGE_FULL BIT(0) +#define SW_GAUGE_RELAX BIT(1) +#define SW_GAUGE_MAY_BE_LOW BIT(2) +#define SW_GAUGE_CLAMP_SOC BIT(3) + +/* Power supply properties handled by simple_gauge */ +static const enum power_supply_property SIMPLE_GAUGE_PROPS[] =3D { + POWER_SUPPLY_PROP_CAPACITY, + POWER_SUPPLY_PROP_CYCLE_COUNT, + POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, + POWER_SUPPLY_PROP_CHARGE_FULL, + POWER_SUPPLY_PROP_CHARGE_NOW, + POWER_SUPPLY_PROP_TEMP +}; +#define SIMPLE_GAUGE_PROP_SIZE (sizeof(SIMPLE_GAUGE_PROPS)) +#define NUM_SIMPLE_GAUGE_PROPS (ARRAY_SIZE(SIMPLE_GAUGE_PROPS)) + +struct simple_gauge; + +/** + * struct simple_gauge_ops - fuel-gauge operations + * + * @is_relaxed: return true if battery is at relaxed state. Update + * rex_volt to contain measured relaxed battery voltage. + * @get_temp: return the battery temperature in tenths of a degree C. + * @get_uah_from_full: some chargers can provide CC value change since bat= tery + * was last charged full. This value can be used by + * sw-gauge when correcting CC based on battery full + * status. This function should return charge lost since + * battery was last load full. Units in uAh. + * @get_uah: return current charge as measured by coulomb counter in + * uAh + * @update_cc_uah: Update CC by given charge in uAh + * @get_cycle: get battery cycle for age compensation + * @set_cycle: some batteries/chargers rely on user-space to store the + * cycle infomration over reset. Those drivers can + * implement the set_cycle callback which user-space can + * use to set the stored battery cycle after reset. + * @get_sys: get the current system voltage in uV. Used for + * IC specific low-voltage SOC correction. + * @get_soc_by_ocv: setups which do not store the OCV/SOC information in + * standard battery_info can implement this function to + * compute SOC based on OCV. SOC should be returned as + * units of 0.1% + * @get_ocv_by_soc: setups which do not store the OCV/SOC information in + * standard battery_info can implement this function to + * compute OCV based on SOC. NOTE: Soc is provided to + * the function in units of 0.1% to improve accuracy. + * @age_correct_cap: batteries/devices with more complicated aging + * correction than constant uAh times battery cycles + * can implement this to adjust capacity based on battery + * cycles. For constant aging use degrade_cycle_uah + * in desc. + * @temp_correct_cap: batteries/devices with more complicated temperature + * correction than ranges of temperatures with constant + * change uah/degree C can implement this to adjust + * capacity based on battery temperature. + * For temperature ranges with constant change uAh/degree + * use temp_dgr and amount_of_temp_dgr at desc. + * @calibrate: many devices implement coulomb counter calibration + * (for example by measuring ADC offset pins shorted). + * Such devices can implement this function for periodical + * calibration. + * @suspend_calibrate: Many small capacity battery devices or devices which + * spend long time MCU suspended can benefit from + * starting the calibration when entering to suspend. Such + * devices can implement this callback to initiaite + * calibration when entering to suspend + * @zero_cap_adjust: IC specific SOC estimation adjustment to be performed + * when battery is approaching empty. + */ +struct simple_gauge_ops { + /* + * Get battery relax - could probably also use PSY class state if + * it was extended with some properties like BATTERY_RELAXED to know + * if OCV can be used. + * + * Currently meaningfull states are charging/discharging/full/relaxed + * Full so we can correct battery capacity and/or CC + * Relax so we know we can use OCV + */ + bool (*is_relaxed)(struct simple_gauge *gauge, int *rex_volt); + int (*get_temp)(struct simple_gauge *gauge, int *temp); + int (*get_uah_from_full)(struct simple_gauge *gauge, int *uah); + int (*get_uah)(struct simple_gauge *gauge, int *uah); + int (*update_cc_uah)(struct simple_gauge *gauge, int bcap); + int (*get_cycle)(struct simple_gauge *gauge, int *cycle); + int (*set_cycle)(struct simple_gauge *gauge, int old, int *new_cycle); + int (*get_vsys)(struct simple_gauge *gauge, int *uv); + int (*get_soc_by_ocv)(struct simple_gauge *sw, int ocv, int temp, int *so= c); + int (*get_ocv_by_soc)(struct simple_gauge *sw, int soc, int temp, int *oc= v); + int (*age_correct_cap)(struct simple_gauge *gauge, int cycle, int *cap); + int (*temp_correct_cap)(struct simple_gauge *gauge, int *cap, int temp); + int (*calibrate)(struct simple_gauge *sw); + int (*suspend_calibrate)(struct simple_gauge *sw, bool start); + int (*zero_cap_adjust)(struct simple_gauge *sw, int *effective_cap, + int cc_uah, int vbat, int temp); +}; + +/** + * struct simple_gauge_desc - fuel gauge description + * + * The fuel gauges which benefit from generic computations (typically devi= ces + * with coulomb counter. OCV - SOC table and iterative polling / error + * correction) provided by the simple_gauge framework must be described by= the + * simple_gauge_desc prior registration to the simple_gauge framework. + * + * @name: Identifying name for gauge (Is this needed?) + * @degrade_cycle_uah: constant lost capacity / battery cycle in uAh. + * @amount_of_temp_dgr: amount of temperature ranges provided in temp_dgr + * @temp_dgr: ranges of constant lost capacity / temperature degree + * in uAh. Ranges should be sorted in asecnding order by + * temperature_floor. + * @poll_interval: time interval in mS at which this fuel gauge iteration + * loop for volage polling and coulomb counter corrections + * should be ran. + * @calibrate_interval: time interval in mS at which this IC should be + * calibrated. + * @designed_cap: designed battery capacity in uAh. Can be given here if + * not available via batinfo. + * @allow_set_cycle: Allow userspace to set cached battery cycle. If no HW + * access is required when new battery cycle value is set + * the driver can omit set_cycle callback and just set + * this to true. + * @clamp_soc: Set true tonot allow computed SOC to increase if state + * is discharging. + * @cap_adjust_volt_threshold: some systems want to apply extra computation + * to estimate battery capacity when voltage gets close + * to system limit in order to avoid shut-down for as long + * as possible. Such ICs can set this limit and optionally + * implement zero_cap_adjust callback. + * @system_min_voltage: ICs using the cap_adjust_volt_threshold and no + * zero_cap_adjust call-back should set this voltage + * to Vsys which correspond empty battery situation. + */ +struct simple_gauge_desc { + int degrade_cycle_uah; + int amount_of_temp_dgr; + struct power_supply_temp_degr *temp_dgr; + int poll_interval; + int calibrate_interval; + int designed_cap; /* This is also looked from batinfo (DT node) */ + int cap_adjust_volt_threshold; + int system_min_voltage; + bool allow_set_cycle; + bool clamp_soc; + void *drv_data; +}; + +/** + * struct simple_gauge_psy - power supply configuration + * + * configuration being further passed to power-supply registration. + */ +struct simple_gauge_psy { + const char *psy_name; + struct device_node *of_node; + /* Device specific sysfs attributes, delivered to power_supply */ + const struct attribute_group **attr_grp; + + enum power_supply_property *additional_props; + int num_additional_props; + + int (*is_writable)(struct simple_gauge *gauge, + enum power_supply_property psp); + int (*get_custom_property)(struct simple_gauge *gauge, + enum power_supply_property psp, + union power_supply_propval *val); + int (*set_custom_property)(struct simple_gauge *gauge, + enum power_supply_property psp, + const union power_supply_propval *val); +}; + +/** + * struct simple_gauge - simple_gauge runtime data + * + * Internal to sw-gauge. Should not be directly accessed/modified by drive= rs + */ +struct simple_gauge { + struct device *dev; + int designed_cap; /* This should be available for drivers */ + struct simple_gauge_desc desc; + int cycle; + u64 next_iter; /* Time of next iteration in jiffies64 */ + u64 next_cal; /* Time of next calibration in jiffies64 */ + int force_run; + int refcount; + struct power_supply *psy; + enum power_supply_property *properties; + + int (*get_custom_property)(struct simple_gauge *gauge, + enum power_supply_property psp, + union power_supply_propval *val); + int (*set_custom_property)(struct simple_gauge *gauge, + enum power_supply_property psp, + const union power_supply_propval *val); + int (*custom_is_writable)(struct simple_gauge *gauge, + enum power_supply_property psp); + struct power_supply_battery_info info; + struct simple_gauge_ops ops; + struct list_head node; + int amount_of_temp_dgr; + struct power_supply_temp_degr *temp_dgr; + spinlock_t lock; + bool batinfo_got; + wait_queue_head_t wq; + int soc_rounding; + int clamped_soc; + /* Cached values from prev iteration */ + int soc; /* SOC computed at previous iteration */ + int capacity_uah; /* CAP computed at previous iteration (uAh) */ + int cc_uah; /* uAh reported by CC at previous iteration */ + int temp; /* Temperature at previous iteration */ +}; + +struct simple_gauge *__must_check psy_register_simple_gauge(struct device = *parent, + struct simple_gauge_psy *psycfg, + struct simple_gauge_ops *ops, + struct simple_gauge_desc *desc); +void psy_remove_simple_gauge(struct simple_gauge *sw); + +struct simple_gauge *__must_check +devm_psy_register_simple_gauge(struct device *parent, struct simple_gauge_= psy *psycfg, + struct simple_gauge_ops *ops, + struct simple_gauge_desc *desc); +void simple_gauge_run(struct simple_gauge *sw); +int simple_gauge_run_blocking_timeout(struct simple_gauge *sg, + unsigned int timeout_ms); +int simple_gauge_run_blocking(struct simple_gauge *sg); +void *simple_gauge_get_drvdata(struct simple_gauge *sg); + +#endif /* POWER_SW_GAUGE_H */ --=20 2.31.1 --=20 Matti Vaittinen, Linux device drivers ROHM Semiconductors, Finland SWDC Kiviharjunlenkki 1E 90220 OULU FINLAND ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ Simon says - in Latin please. ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ Thanks to Simon Glass for the translation =3D]=20 --c73i0tdUUwqAJl/f Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEIx+f8wZb28fLKEhTeFA3/03aocUFAmGTo90ACgkQeFA3/03a ocVyAAf/fmRNl9/juc5789RuBVgYFnBL+t46yGm+P3n4LF2GNudG9Qa8N3CZ8LKH 8nPWCAvJrewBM/6TEaxDrzuK2jqZ5r5ZMWLDUYwrOPX8eCAkTPOPXJkswz3OJS4n uNb4It0560fVAoxiUlck5OTpehPYseycmIve/MP9q6FtVRh6UqQH6vhAHVZtFPCZ +JVo6xIq1Gu9XmzwuyhlfzWWFRU8Sdpn8VhmnJaFw/ORv8ruYQvdTzVskCPfgA3b 8wPV7I+ZhU9EJkCu7nd99yw2Uv4YojX5SzUk+i7CLwC4rMJLquDFWCvMR1bqte+Q HRdkgQeR/b82EqbjGJQDZzppfHBupw== =2BTS -----END PGP SIGNATURE----- --c73i0tdUUwqAJl/f--