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References: <e7c061535f2dcca54d6498405fdd5ed7098b19f9.1539915051.git.baolin.wang@linaro.org>
 <2983281f449d180d008c2f49133088a12ea4046d.1539915051.git.baolin.wang@linaro.org>
 <20181021165201.wob4iar5sd263wkg@earth.universe> <CAMz4kuKt-=TGZGEr+n9d1yALhaRe1-_Da23QYojk_ZPmhzz9Vg@mail.gmail.com>
 <20181022104333.uakqxng7naf65d6m@earth.universe>
From:   Baolin Wang <baolin.wang@linaro.org>
Date:   Mon, 22 Oct 2018 18:49:17 +0800
Message-ID: <CAMz4kuKz3Esso_ZtcTJkMSQ9J3_gv9X5eqHb=W0pnQ4G7VYafg@mail.gmail.com>
Subject: Re: [PATCH v5 6/6] power: supply: Add Spreadtrum SC27XX fuel gauge
 unit driver
To:     Sebastian Reichel <sre@kernel.org>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Linux PM list <linux-pm@vger.kernel.org>,
        DTML <devicetree@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, yuanjiang.yu@unisoc.com,
        Mark Brown <broonie@kernel.org>,
        Craig Tatlor <ctatlor97@gmail.com>,
        Linus Walleij <linus.walleij@linaro.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 22 October 2018 at 18:43, Sebastian Reichel <sre@kernel.org> wrote:
> Hi,
>
> On Mon, Oct 22, 2018 at 01:54:50PM +0800, Baolin Wang wrote:
>> Hi Sebastian,
>>
>> On 22 October 2018 at 00:52, Sebastian Reichel <sre@kernel.org> wrote:
>> > Hi,
>> >
>> > On Fri, Oct 19, 2018 at 06:53:15PM +0800, Baolin Wang wrote:
>> >> This patch adds the Spreadtrum SC27XX serial PMICs fuel gauge support=
,
>> >> which is used to calculate the battery capacity.
>> >>
>> >> Original-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
>> >> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
>> >> Acked-by: Linus Walleij <linus.walleij@linaro.org>
>> >> ---
>> >
>> > Looks mostly good. I have a few comments still. My plan is to merge
>> > this early after the merge window, if the final version is finished
>> > at this point.
>> >
>> >> Changes from v4:
>> >>  - None.
>> >>
>> >> Changes from v3:
>> >>  - None.
>> >>
>> >> Changes from v2:
>> >>  - Use core helper functions to look up OCV capacity table.
>> >>  - Use device_property_read_u32() instead of of_property_read_u32().
>> >>  - Add acked tag from Linus.
>> >>
>> >> Changes from v1:
>> >>  - Use battery standard properties to get internal resistance and ocv=
 table.
>> >>  - Change devm_gpiod_get_optional() to devm_gpiod_get().
>> >>  - Add power_supply_changed() when detecting battery present change.
>> >>  - Return micro volts for sc27xx_fgu_get_vbat_ocv().
>> >> ---
>> >>  drivers/power/supply/Kconfig             |    7 +
>> >>  drivers/power/supply/Makefile            |    1 +
>> >>  drivers/power/supply/sc27xx_fuel_gauge.c |  661 ++++++++++++++++++++=
++++++++++
>> >>  3 files changed, 669 insertions(+)
>> >>  create mode 100644 drivers/power/supply/sc27xx_fuel_gauge.c
>> >>
>> >> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kcon=
fig
>> >> index f27cf07..917f4b7 100644
>> >> --- a/drivers/power/supply/Kconfig
>> >> +++ b/drivers/power/supply/Kconfig
>> >> @@ -652,4 +652,11 @@ config CHARGER_SC2731
>> >>        Say Y here to enable support for battery charging with SC2731
>> >>        PMIC chips.
>> >>
>> >> +config FUEL_GAUGE_SC27XX
>> >> +     tristate "Spreadtrum SC27XX fuel gauge driver"
>> >> +     depends on MFD_SC27XX_PMIC || COMPILE_TEST
>> >> +     help
>> >> +      Say Y here to enable support for fuel gauge with SC27XX
>> >> +      PMIC chips.
>> >> +
>> >>  endif # POWER_SUPPLY
>> >> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Mak=
efile
>> >> index 767105b..b731c2a 100644
>> >> --- a/drivers/power/supply/Makefile
>> >> +++ b/drivers/power/supply/Makefile
>> >> @@ -86,3 +86,4 @@ obj-$(CONFIG_AXP288_FUEL_GAUGE) +=3D axp288_fuel_ga=
uge.o
>> >>  obj-$(CONFIG_AXP288_CHARGER) +=3D axp288_charger.o
>> >>  obj-$(CONFIG_CHARGER_CROS_USBPD)     +=3D cros_usbpd-charger.o
>> >>  obj-$(CONFIG_CHARGER_SC2731) +=3D sc2731_charger.o
>> >> +obj-$(CONFIG_FUEL_GAUGE_SC27XX)      +=3D sc27xx_fuel_gauge.o
>> >> diff --git a/drivers/power/supply/sc27xx_fuel_gauge.c b/drivers/power=
/supply/sc27xx_fuel_gauge.c
>> >> new file mode 100644
>> >> index 0000000..1c0b856
>> >> --- /dev/null
>> >> +++ b/drivers/power/supply/sc27xx_fuel_gauge.c
>> >> @@ -0,0 +1,661 @@
>> >> +// SPDX-License-Identifier: GPL-2.0
>> >> +// Copyright (C) 2018 Spreadtrum Communications Inc.
>> >> +
>> >> +#include <linux/gpio/consumer.h>
>> >> +#include <linux/iio/consumer.h>
>> >> +#include <linux/interrupt.h>
>> >> +#include <linux/kernel.h>
>> >> +#include <linux/module.h>
>> >> +#include <linux/of.h>
>> >> +#include <linux/platform_device.h>
>> >> +#include <linux/power_supply.h>
>> >> +#include <linux/regmap.h>
>> >> +
>> >> +/* PMIC global control registers definition */
>> >> +#define SC27XX_MODULE_EN0            0xc08
>> >> +#define SC27XX_CLK_EN0                       0xc18
>> >> +#define SC27XX_FGU_EN                        BIT(7)
>> >> +#define SC27XX_FGU_RTC_EN            BIT(6)
>> >> +
>> >> +/* FGU registers definition */
>> >> +#define SC27XX_FGU_START             0x0
>> >> +#define SC27XX_FGU_CONFIG            0x4
>> >> +#define SC27XX_FGU_ADC_CONFIG                0x8
>> >> +#define SC27XX_FGU_STATUS            0xc
>> >> +#define SC27XX_FGU_INT_EN            0x10
>> >> +#define SC27XX_FGU_INT_CLR           0x14
>> >> +#define SC27XX_FGU_INT_STS           0x1c
>> >> +#define SC27XX_FGU_VOLTAGE           0x20
>> >> +#define SC27XX_FGU_OCV                       0x24
>> >> +#define SC27XX_FGU_POCV                      0x28
>> >> +#define SC27XX_FGU_CURRENT           0x2c
>> >> +#define SC27XX_FGU_CLBCNT_SETH               0x50
>> >> +#define SC27XX_FGU_CLBCNT_SETL               0x54
>> >> +#define SC27XX_FGU_CLBCNT_VALH               0x68
>> >> +#define SC27XX_FGU_CLBCNT_VALL               0x6c
>> >> +#define SC27XX_FGU_CLBCNT_QMAXL              0x74
>> >> +
>> >> +#define SC27XX_WRITE_SELCLB_EN               BIT(0)
>> >> +#define SC27XX_FGU_CLBCNT_MASK               GENMASK(15, 0)
>> >> +#define SC27XX_FGU_CLBCNT_SHIFT              16
>> >> +
>> >> +#define SC27XX_FGU_1000MV_ADC                686
>> >> +#define SC27XX_FGU_1000MA_ADC                1372
>> >> +#define SC27XX_FGU_CUR_BASIC_ADC     8192
>> >> +#define SC27XX_FGU_SAMPLE_HZ         2
>> >> +
>> >> +/*
>> >> + * struct sc27xx_fgu_data: describe the FGU device
>> >> + * @regmap: regmap for register access
>> >> + * @dev: platform device
>> >> + * @battery: battery power supply
>> >> + * @base: the base offset for the controller
>> >> + * @lock: protect the structure
>> >> + * @gpiod: GPIO for battery detection
>> >> + * @channel: IIO channel to get battery temperature
>> >> + * @internal_resist: the battery internal resistance in mOhm
>> >> + * @total_cap: the total capacity of the battery in mAh
>> >> + * @init_cap: the initial capacity of the battery in mAh
>> >> + * @init_clbcnt: the initial coulomb counter
>> >> + * @max_volt: the maximum constant input voltage in millivolt
>> >> + * @table_len: the capacity table length
>> >> + * @cap_table: capacity table with corresponding ocv
>> >> + */
>> >> +struct sc27xx_fgu_data {
>> >> +     struct regmap *regmap;
>> >> +     struct device *dev;
>> >> +     struct power_supply *battery;
>> >> +     u32 base;
>> >> +     struct mutex lock;
>> >> +     struct gpio_desc *gpiod;
>> >> +     struct iio_channel *channel;
>> >> +     bool bat_present;
>> >> +     int internal_resist;
>> >> +     int total_cap;
>> >> +     int init_cap;
>> >> +     int init_clbcnt;
>> >> +     int max_volt;
>> >> +     int table_len;
>> >> +     struct power_supply_battery_ocv_table *cap_table;
>> >> +};
>> >> +
>> >> +static const char * const sc27xx_charger_supply_name[] =3D {
>> >> +     "sc2731_charger",
>> >> +     "sc2720_charger",
>> >> +     "sc2721_charger",
>> >> +     "sc2723_charger",
>> >> +};
>> >> +
>> >> +static int sc27xx_fgu_adc_to_current(int adc)
>> >> +{
>> >> +     return (adc * 1000) / SC27XX_FGU_1000MA_ADC;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_adc_to_voltage(int adc)
>> >> +{
>> >> +     return (adc * 1000) / SC27XX_FGU_1000MV_ADC;
>> >> +}
>> >> +
>> >> +/*
>> >> + * When system boots on, we can not read battery capacity from coulo=
mb
>> >> + * registers, since now the coulomb registers are invalid. So we sho=
uld
>> >> + * calculate the battery open circuit voltage, and get current batte=
ry
>> >> + * capacity according to the capacity table.
>> >> + */
>> >> +static int sc27xx_fgu_get_boot_capacity(struct sc27xx_fgu_data *data=
, int *cap)
>> >> +{
>> >> +     int volt, cur, oci, ocv, ret;
>> >> +
>> >> +     /*
>> >> +      * After system booting on, the SC27XX_FGU_CLBCNT_QMAXL registe=
r saved
>> >> +      * the first sampled open circuit current.
>> >> +      */
>> >> +     ret =3D regmap_read(data->regmap, data->base + SC27XX_FGU_CLBCN=
T_QMAXL,
>> >> +                       &cur);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     cur <<=3D 1;
>> >> +     oci =3D sc27xx_fgu_adc_to_current(cur - SC27XX_FGU_CUR_BASIC_AD=
C);
>> >> +
>> >> +     /*
>> >> +      * Should get the OCV from SC27XX_FGU_POCV register at the syst=
em
>> >> +      * beginning. It is ADC values reading from registers which nee=
d to
>> >> +      * convert the corresponding voltage.
>> >> +      */
>> >> +     ret =3D regmap_read(data->regmap, data->base + SC27XX_FGU_POCV,=
 &volt);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     volt =3D sc27xx_fgu_adc_to_voltage(volt);
>> >> +     ocv =3D volt - (oci * data->internal_resist) / 1000;
>> >> +
>> >> +     /*
>> >> +      * Parse the capacity table to look up the correct capacity per=
cent
>> >> +      * according to current battery's corresponding OCV values.
>> >> +      */
>> >> +     *cap =3D power_supply_ocv2cap_simple(data->cap_table, data->tab=
le_len,
>> >> +                                        ocv);
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_set_clbcnt(struct sc27xx_fgu_data *data, int c=
lbcnt)
>> >> +{
>> >> +     int ret;
>> >> +
>> >> +     clbcnt *=3D SC27XX_FGU_SAMPLE_HZ;
>> >> +
>> >> +     ret =3D regmap_update_bits(data->regmap,
>> >> +                              data->base + SC27XX_FGU_CLBCNT_SETL,
>> >> +                              SC27XX_FGU_CLBCNT_MASK, clbcnt);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     ret =3D regmap_update_bits(data->regmap,
>> >> +                              data->base + SC27XX_FGU_CLBCNT_SETH,
>> >> +                              SC27XX_FGU_CLBCNT_MASK,
>> >> +                              clbcnt >> SC27XX_FGU_CLBCNT_SHIFT);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     return regmap_update_bits(data->regmap, data->base + SC27XX_FGU=
_START,
>> >> +                              SC27XX_WRITE_SELCLB_EN,
>> >> +                              SC27XX_WRITE_SELCLB_EN);
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_clbcnt(struct sc27xx_fgu_data *data, int *=
clb_cnt)
>> >> +{
>> >> +     int ccl, cch, ret;
>> >> +
>> >> +     ret =3D regmap_read(data->regmap, data->base + SC27XX_FGU_CLBCN=
T_VALL,
>> >> +                       &ccl);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     ret =3D regmap_read(data->regmap, data->base + SC27XX_FGU_CLBCN=
T_VALH,
>> >> +                       &cch);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     *clb_cnt =3D ccl & SC27XX_FGU_CLBCNT_MASK;
>> >> +     *clb_cnt |=3D (cch & SC27XX_FGU_CLBCNT_MASK) << SC27XX_FGU_CLBC=
NT_SHIFT;
>> >> +     *clb_cnt /=3D SC27XX_FGU_SAMPLE_HZ;
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_capacity(struct sc27xx_fgu_data *data, int=
 *cap)
>> >> +{
>> >> +     int ret, cur_clbcnt, delta_clbcnt, delta_cap, temp;
>> >> +
>> >> +     /* Get current coulomb counters firstly */
>> >> +     ret =3D sc27xx_fgu_get_clbcnt(data, &cur_clbcnt);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     delta_clbcnt =3D cur_clbcnt - data->init_clbcnt;
>> >> +
>> >> +     /*
>> >> +      * Convert coulomb counter to delta capacity (mAh), and set mul=
tiplier
>> >> +      * as 100 to improve the precision.
>> >> +      */
>> >> +     temp =3D DIV_ROUND_CLOSEST(delta_clbcnt, 360);
>> >> +     temp =3D sc27xx_fgu_adc_to_current(temp);
>> >> +
>> >> +     /*
>> >> +      * Convert to capacity percent of the battery total capacity,
>> >> +      * and multiplier is 100 too.
>> >> +      */
>> >> +     delta_cap =3D DIV_ROUND_CLOSEST(temp * 100, data->total_cap);
>> >> +     *cap =3D delta_cap + data->init_cap;
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_vbat_vol(struct sc27xx_fgu_data *data, int=
 *val)
>> >> +{
>> >> +     int ret, vol;
>> >> +
>> >> +     ret =3D regmap_read(data->regmap, data->base + SC27XX_FGU_VOLTA=
GE, &vol);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     /*
>> >> +      * It is ADC values reading from registers which need to conver=
t to
>> >> +      * corresponding voltage values.
>> >> +      */
>> >> +     *val =3D sc27xx_fgu_adc_to_voltage(vol);
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_current(struct sc27xx_fgu_data *data, int =
*val)
>> >> +{
>> >> +     int ret, cur;
>> >> +
>> >> +     ret =3D regmap_read(data->regmap, data->base + SC27XX_FGU_CURRE=
NT, &cur);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     /*
>> >> +      * It is ADC values reading from registers which need to conver=
t to
>> >> +      * corresponding current values.
>> >> +      */
>> >> +     *val =3D sc27xx_fgu_adc_to_current(cur - SC27XX_FGU_CUR_BASIC_A=
DC);
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_vbat_ocv(struct sc27xx_fgu_data *data, int=
 *val)
>> >> +{
>> >> +     int vol, cur, ret;
>> >> +
>> >> +     ret =3D sc27xx_fgu_get_vbat_vol(data, &vol);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     ret =3D sc27xx_fgu_get_current(data, &cur);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     /* Return the battery OCV in micro volts. */
>> >> +     *val =3D vol * 1000 - cur * data->internal_resist;
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_temp(struct sc27xx_fgu_data *data, int *te=
mp)
>> >> +{
>> >> +     return iio_read_channel_processed(data->channel, temp);
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_health(struct sc27xx_fgu_data *data, int *=
health)
>> >> +{
>> >> +     int ret, vol;
>> >> +
>> >> +     ret =3D sc27xx_fgu_get_vbat_vol(data, &vol);
>> >> +     if (ret)
>> >> +             return ret;
>> >> +
>> >> +     if (vol > data->max_volt)
>> >> +             *health =3D POWER_SUPPLY_HEALTH_OVERVOLTAGE;
>> >> +     else
>> >> +             *health =3D POWER_SUPPLY_HEALTH_GOOD;
>> >> +
>> >> +     return 0;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_status(struct sc27xx_fgu_data *data, int *=
status)
>> >> +{
>> >> +     union power_supply_propval val;
>> >> +     struct power_supply *psy;
>> >> +     int i, ret =3D -EINVAL;
>> >> +
>> >> +     for (i =3D 0; i < ARRAY_SIZE(sc27xx_charger_supply_name); i++) =
{
>> >> +             psy =3D power_supply_get_by_name(sc27xx_charger_supply_=
name[i]);
>> >> +             if (!psy)
>> >> +                     continue;
>> >> +
>> >> +             ret =3D power_supply_get_property(psy, POWER_SUPPLY_PRO=
P_STATUS,
>> >> +                                             &val);
>> >> +             power_supply_put(psy);
>> >> +             if (ret)
>> >> +                     return ret;
>> >> +
>> >> +             *status =3D val.intval;
>> >> +     }
>> >> +
>> >> +     return ret;
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_get_property(struct power_supply *psy,
>> >> +                                enum power_supply_property psp,
>> >> +                                union power_supply_propval *val)
>> >> +{
>> >> +     struct sc27xx_fgu_data *data =3D power_supply_get_drvdata(psy);
>> >> +     int ret =3D 0;
>> >> +     int value;
>> >> +
>> >> +     mutex_lock(&data->lock);
>> >> +
>> >> +     switch (psp) {
>> >> +     case POWER_SUPPLY_PROP_STATUS:
>> >> +             ret =3D sc27xx_fgu_get_status(data, &value);
>> >> +             if (ret)
>> >> +                     goto error;
>> >> +
>> >> +             val->intval =3D value;
>> >> +             break;
>> >> +
>> >> +     case POWER_SUPPLY_PROP_HEALTH:
>> >> +             ret =3D sc27xx_fgu_get_health(data, &value);
>> >> +             if (ret)
>> >> +                     goto error;
>> >> +
>> >> +             val->intval =3D value;
>> >> +             break;
>> >> +
>> >> +     case POWER_SUPPLY_PROP_PRESENT:
>> >> +             val->intval =3D data->bat_present;
>> >> +             break;
>> >> +
>> >> +     case POWER_SUPPLY_PROP_TEMP:
>> >> +             ret =3D sc27xx_fgu_get_temp(data, &value);
>> >> +             if (ret)
>> >> +                     goto error;
>> >> +
>> >> +             val->intval =3D value;
>> >> +             break;
>> >> +
>> >> +     case POWER_SUPPLY_PROP_TECHNOLOGY:
>> >> +             val->intval =3D POWER_SUPPLY_TECHNOLOGY_LION;
>> >> +             break;
>> >> +
>> >> +     case POWER_SUPPLY_PROP_CAPACITY:
>> >> +             ret =3D sc27xx_fgu_get_capacity(data, &value);
>> >> +             if (ret)
>> >> +                     goto error;
>> >> +
>> >> +             val->intval =3D value;
>> >> +             break;
>> >> +
>> >> +     case POWER_SUPPLY_PROP_VOLTAGE_NOW:
>> >> +             ret =3D sc27xx_fgu_get_vbat_vol(data, &value);
>> >> +             if (ret)
>> >> +                     goto error;
>> >> +
>> >> +             val->intval =3D value * 1000;
>> >> +             break;
>> >> +
>> >> +     case POWER_SUPPLY_PROP_VOLTAGE_OCV:
>> >> +             ret =3D sc27xx_fgu_get_vbat_ocv(data, &value);
>> >> +             if (ret)
>> >> +                     goto error;
>> >> +
>> >> +             val->intval =3D value;
>> >> +             break;
>> >> +
>> >> +     case POWER_SUPPLY_PROP_CURRENT_NOW:
>> >> +     case POWER_SUPPLY_PROP_CURRENT_AVG:
>> >> +             ret =3D sc27xx_fgu_get_current(data, &value);
>> >> +             if (ret)
>> >> +                     goto error;
>> >> +
>> >> +             val->intval =3D value * 1000;
>> >> +             break;
>> >> +
>> >> +     default:
>> >> +             ret =3D -EINVAL;
>> >> +             break;
>> >> +     }
>> >> +
>> >> +error:
>> >> +     mutex_unlock(&data->lock);
>> >> +     return ret;
>> >> +}
>> >> +
>> >> +static void sc27xx_fgu_external_power_changed(struct power_supply *p=
sy)
>> >> +{
>> >> +     struct sc27xx_fgu_data *data =3D power_supply_get_drvdata(psy);
>> >> +
>> >> +     power_supply_changed(data->battery);
>> >> +}
>> >> +
>> >> +static enum power_supply_property sc27xx_fgu_props[] =3D {
>> >> +     POWER_SUPPLY_PROP_STATUS,
>> >> +     POWER_SUPPLY_PROP_HEALTH,
>> >> +     POWER_SUPPLY_PROP_PRESENT,
>> >> +     POWER_SUPPLY_PROP_TEMP,
>> >> +     POWER_SUPPLY_PROP_TECHNOLOGY,
>> >> +     POWER_SUPPLY_PROP_CAPACITY,
>> >> +     POWER_SUPPLY_PROP_VOLTAGE_NOW,
>> >> +     POWER_SUPPLY_PROP_VOLTAGE_OCV,
>> >> +     POWER_SUPPLY_PROP_CURRENT_NOW,
>> >> +     POWER_SUPPLY_PROP_CURRENT_AVG,
>> >> +};
>> >> +
>> >> +static const struct power_supply_desc sc27xx_fgu_desc =3D {
>> >> +     .name                   =3D "sc27xx-fgu",
>> >> +     .type                   =3D POWER_SUPPLY_TYPE_BATTERY,
>> >> +     .properties             =3D sc27xx_fgu_props,
>> >> +     .num_properties         =3D ARRAY_SIZE(sc27xx_fgu_props),
>> >> +     .get_property           =3D sc27xx_fgu_get_property,
>> >> +     .external_power_changed =3D sc27xx_fgu_external_power_changed,
>> >> +};
>> >> +
>> >> +static irqreturn_t sc27xx_fgu_bat_detection(int irq, void *dev_id)
>> >> +{
>> >> +     struct sc27xx_fgu_data *data =3D dev_id;
>> >> +     int state;
>> >> +
>> >> +     mutex_lock(&data->lock);
>> >> +
>> >> +     state =3D gpiod_get_value_cansleep(data->gpiod);
>> >> +     if (state < 0) {
>> >> +             dev_err(data->dev, "failed to get gpio state\n");
>> >> +             mutex_unlock(&data->lock);
>> >> +             return IRQ_RETVAL(state);
>> >> +     }
>> >> +
>> >> +     data->bat_present =3D !!state;
>> >> +
>> >> +     mutex_unlock(&data->lock);
>> >> +
>> >> +     power_supply_changed(data->battery);
>> >> +     return IRQ_HANDLED;
>> >> +}
>> >> +
>> >> +static void sc27xx_fgu_disable(void *_data)
>> >> +{
>> >> +     struct sc27xx_fgu_data *data =3D _data;
>> >> +
>> >> +     regmap_update_bits(data->regmap, SC27XX_CLK_EN0, SC27XX_FGU_RTC=
_EN, 0);
>> >> +     regmap_update_bits(data->regmap, SC27XX_MODULE_EN0, SC27XX_FGU_=
EN, 0);
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_cap_to_clbcnt(struct sc27xx_fgu_data *data, in=
t capacity)
>> >> +{
>> >> +     /*
>> >> +      * Get current capacity (mAh) =3D battery total capacity (mAh) =
*
>> >> +      * current capacity percent (capacity / 100).
>> >> +      */
>> >> +     int cur_cap =3D DIV_ROUND_CLOSEST(data->total_cap * capacity, 1=
00);
>> >> +
>> >> +     /*
>> >> +      * Convert current capacity (mAh) to coulomb counter according =
to the
>> >> +      * formula: 1 mAh =3D3.6 coulomb.
>> >> +      */
>> >> +     return DIV_ROUND_CLOSEST(cur_cap * 36, 10);
>> >> +}
>> >> +
>> >> +static int sc27xx_fgu_hw_init(struct sc27xx_fgu_data *data)
>> >> +{
>> >> +     struct power_supply_battery_info info =3D { };
>> >> +     struct power_supply_battery_ocv_table *table;
>> >> +     int ret, i;
>> >> +
>> >> +     ret =3D power_supply_get_battery_info(data->battery, &info);
>> >> +     if (ret) {
>> >> +             dev_err(data->dev, "failed to get battery information\n=
");
>> >> +             return ret;
>> >> +     }
>> >> +
>> >> +     data->total_cap =3D info.charge_full_design_uah / 1000;
>> >> +     data->max_volt =3D info.constant_charge_voltage_max_uv / 1000;
>> >> +     data->internal_resist =3D info.factory_internal_resistance_uohm=
 / 1000;
>> >> +
>> >> +     /*
>> >> +      * For SC27XX fuel gauge device, we only use one ocv-capacity
>> >> +      * table in normal temperature 20 Celsius.
>> >> +      */
>> >> +     table =3D power_supply_find_ocv2cap_table(&info, 20, &data->tab=
le_len);
>> >> +     if (!table)
>> >> +             return -EINVAL;
>> >> +
>> >> +     data->cap_table =3D devm_kzalloc(data->dev,
>> >> +                                    data->table_len * sizeof(*table)=
,
>> >> +                                    GFP_KERNEL);
>> >> +     if (!data->cap_table) {
>> >> +             power_supply_put_battery_info(data->battery, &info);
>> >> +             return -ENOMEM;
>> >> +     }
>> >> +
>> >> +     for (i =3D 0; i < data->table_len; i++) {
>> >> +             data->cap_table[i].ocv =3D table[i].ocv / 1000;
>> >> +             data->cap_table[i].capacity =3D table[i].capacity;
>> >> +     }
>> >
>> > Don't divide the OCV by 1000. You feed this table into the
>> > generic power-supply function later, which should always
>> > get uV. Instead multiply the ocv parameter in your
>> > power_supply_ocv2cap_simple() call with 1000. This
>> > means you can just use devm_kmemdup() here.
>>
>> Good point. Will change it in next version.
>>
>> >
>> > Some ideas for later (I'm fine with merging the driver
>> > without these changes):
>> >
>> >  * Store battery_info directly in private driver data
>> >    instead of doing a copy of the temperature table.
>> >  * Call power_supply_ocv2cap() with current battery
>> >    temperature and let the power-supply core figure
>> >    out which ocv-to-capacity curve should be used.
>>
>> I should keep my original method, since we have no temperature table
>> now and only use one room temperature (20 degree). Thanks for your
>> useful comments.
>
> Which should work perfectly fine with power_supply_ocv2cap(). It
> will use the nearest curve, which is always the 20=C2=B0C one in your
> case. If you add a second temperature curve in the future (i.e.
> because of using the sc27xx fuel gauge with a different battery),
> it would just pick this up automatically. But I'm fine with doing
> this later.

Yes, it can work. But I'd like to do this fix when we need multiple
temperature values in future. Thanks for your understanding.

--=20
Baolin Wang
Best Regards