On 26 September 2018 at 20:45, Sebastian Reichel <[email protected]> wrote:
> Hi,
>
> On Wed, Sep 26, 2018 at 04:30:39PM +0800, Baolin Wang wrote:
>> Hi Linus,
>>
>> On 26 September 2018 at 16:00, Linus Walleij <[email protected]> wrote:
>> > On Wed, Sep 26, 2018 at 4:59 AM Baolin Wang <[email protected]> wrote:
>> >
>> >> Introduce one property to present the battery internal resistance for battery
>> >> information.
>> >>
>> >> Signed-off-by: Baolin Wang <[email protected]>
>> >> ---
>> >> Changes from v1:
>> >> - New patch in v2.
>> >
>> > I'm a bit confused by the physics in this patch.
>> >
>> > The internal resistance of a battery is not a constant in its life cycle,
>> > this varies over the age of the battery, and the reason I thing is
>> > chemical residuals accumulating on the anode and cathode inside
>> > the battery and the energy storage medium aging. (Plus/minus my
>> > ignorance about how batteries actually work.)
>>
>> Yes, you are right. The internal resistance can be affected by
>> temperature or battery age or other factors. But our solution just
>> uses one constant internal resistance to calculate OCV value to look
>> up the capacity table when system boots on, in this case we do not
>> need one more accuracy OCV, since we will calculate the battery
>> capacity in future. So we just introduce one estimation constant
>> internal resistance.
>>
>> >
>> > AFAIK the fact that the internal resistance varies is of high
>> > importance for people developing algorithms of battery capacity
>> > and longevity. Such that some (hardware) capacity monitors go
>> > to great lengths to measure with high precision the current
>> > internal resistance of the battery for their algorithms.
>> >
>> > Sorry for making things more complex, but should it be named
>> > "factory-internal-resistance-micro-ohms" or
>> > "typical-internal-resistance-micro-ohms"?
>>
>> I am fine with this change. If Sebastian also agree with this change,
>> I will fix. Thanks for your reviewing and comments.
>
> Ack.
>
> FWIW for proper battery status you need to collect battery specific
> statistics, that is the reason fuel gauge chip providers recommend to
> combine the chip with the battery cells into a "smart battery".

OK. I will rename it as "factory-internal-resistance-micro-ohms" in
next version. Thanks.

--
Baolin Wang
Best Regards

2018-09-27 01:10:34

by Baolin Wang

[permalink] [raw]

Subject: Re: [PATCH v2 2/4] power: supply: core: Introduce properties to present the battery OCV table

On 26 September 2018 at 21:51, Sebastian Reichel <[email protected]> wrote:
> Hi,
>
> On Wed, Sep 26, 2018 at 10:59:12AM +0800, Baolin Wang wrote:
>> Some battery driver will use the open circuit voltage (OCV) value to look
>> up the corresponding battery capacity percent in one certain degree Celsius.
>> Thus this patch provides some battery properties to present the OCV table
>> temperatures and OCV capacity table values.
>>
>> Suggested-by: Sebastian Reichel <[email protected]>
>> Signed-off-by: Baolin Wang <[email protected]>
>> ---
>> Changes from v1:
>> - New patch in v2.
>> ---
>> .../devicetree/bindings/power/supply/battery.txt | 14 +++++
>> drivers/power/supply/power_supply_core.c | 63 +++++++++++++++++++-
>> include/linux/power_supply.h | 11 ++++
>> 3 files changed, 87 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/power/supply/battery.txt b/Documentation/devicetree/bindings/power/supply/battery.txt
>> index 25b9d2e..ac2b303 100644
>> --- a/Documentation/devicetree/bindings/power/supply/battery.txt
>> +++ b/Documentation/devicetree/bindings/power/supply/battery.txt
>> @@ -23,6 +23,16 @@ Optional Properties:
>> - constant-charge-current-max-microamp: maximum constant input current
>> - constant-charge-voltage-max-microvolt: maximum constant input voltage
>> - internal-resistance-micro-ohms: battery internal resistance
>> + - ocv-capacity-table-0: An array providing the battery capacity percent
>> + with corresponding open circuit voltage (OCV) of the battery, which
>> + is used to look up battery capacity according to current OCV value.
>> + - ocv-capacity-table-1: Same as ocv-capacity-table-0
>> + ......
>> + - ocv-capacity-table-n: Same as ocv-capacity-table-0
>> + - ocv-capacity-table-temperatures: An array containing the temperature
>> + in degree Celsius, for each of the battery capacity lookup table.
>> + The first temperature value specifies the OCV table 0, and the second
>> + temperature value specifies the OCV table 1, and so on.
>>
>> Battery properties are named, where possible, for the corresponding
>> elements in enum power_supply_property, defined in
>> @@ -44,6 +54,10 @@ Example:
>> constant-charge-current-max-microamp = <900000>;
>> constant-charge-voltage-max-microvolt = <4200000>;
>> internal-resistance-micro-ohms = <250000>;
>> + ocv-capacity-table-temperatures = <(-10) 0 10>;
>> + ocv-capacity-table-0 = <4185000 100>, <4113000 95>, <4066000 90>, ...;
>> + ocv-capacity-table-1 = <4200000 100>, <4185000 95>, <4113000 90>, ...;
>> + ocv-capacity-table-2 = <4250000 100>, <4200000 95>, <4185000 90>, ...;
>> };
>>
>> charger: charger@11 {
>> diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
>> index 9f3452f..151ff03 100644
>> --- a/drivers/power/supply/power_supply_core.c
>> +++ b/drivers/power/supply/power_supply_core.c
>> @@ -570,7 +570,7 @@ int power_supply_get_battery_info(struct power_supply *psy,
>> {
>> struct device_node *battery_np;
>> const char *value;
>> - int err;
>> + int err, len, index;
>>
>> info->energy_full_design_uwh = -EINVAL;
>> info->charge_full_design_uah = -EINVAL;
>> @@ -581,6 +581,12 @@ int power_supply_get_battery_info(struct power_supply *psy,
>> info->constant_charge_voltage_max_uv = -EINVAL;
>> info->internal_resistance_uohm = -EINVAL;
>>
>> + for (index = 0; index < POWER_SUPPLY_OCV_TEMP_MAX; index++) {
>> + info->ocv_table[index] = NULL;
>> + info->ocv_temp[index] = -EINVAL;
>> + info->ocv_table_size[index] = -EINVAL;
>> + }
>> +
>> if (!psy->of_node) {
>> dev_warn(&psy->dev, "%s currently only supports devicetree\n",
>> __func__);
>> @@ -620,10 +626,65 @@ int power_supply_get_battery_info(struct power_supply *psy,
>> of_property_read_u32(battery_np, "internal-resistance-micro-ohms",
>> &info->internal_resistance_uohm);
>>
>> + len = of_property_count_u32_elems(battery_np,
>> + "ocv-capacity-table-temperatures");
>> + if (len < 0 && len != -EINVAL) {
>> + return len;
>> + } else if (len > POWER_SUPPLY_OCV_TEMP_MAX) {
>> + dev_err(&psy->dev, "Too many temperature values\n");
>> + return -EINVAL;
>> + } else if (len > 0) {
>> + of_property_read_u32_array(battery_np,
>> + "ocv-capacity-table-temperatures",
>> + info->ocv_temp, len);
>> + }
>> +
>> + for (index = 0; index < len; index++) {
>> + struct power_supply_battery_ocv_table *table;
>> + char *propname;
>> + const __be32 *list;
>> + int i, tab_len, size;
>> +
>> + propname = kasprintf(GFP_KERNEL, "ocv-capacity-table-%d", index);
>> + list = of_get_property(battery_np, propname, &size);
>> + kfree(propname);
>> + if (!list || !size) {
>> + dev_err(&psy->dev, "failed to get ocv capacity table\n");
>
> I think it's better to replace "ocv capacity table" with %s / propname.

Yes.

>
>> + power_supply_put_battery_info(psy, info);
>> + return -EINVAL;
>> + }
>> +
>> + tab_len = size / sizeof(*table);
>
> I think this should be
>
> tab_len = size / (2 * sizeof(__be32));
>
> which decouples DT memory layout from kernel memory layout.

Sure.

>
>> + info->ocv_table_size[index] = tab_len;
>> +
>> + table = info->ocv_table[index] = devm_kzalloc(&psy->dev,
>> + tab_len * sizeof(*table),
>> + GFP_KERNEL);
>> + if (!info->ocv_table[index]) {
>> + power_supply_put_battery_info(psy, info);
>> + return -ENOMEM;
>> + }
>> +
>> + for (i = 0; i < tab_len; i++) {
>> + table[i].ocv = be32_to_cpu(*list++);
>> + table[i].capacity = be32_to_cpu(*list++);
>> + }
>> + }
>> +
>> return 0;
>> }
>> EXPORT_SYMBOL_GPL(power_supply_get_battery_info);
>>
>> +void power_supply_put_battery_info(struct power_supply *psy,
>> + struct power_supply_battery_info *info)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < POWER_SUPPLY_OCV_TEMP_MAX; i++)
>> + kfree(info->ocv_table[i]);
>> +}
>> +EXPORT_SYMBOL_GPL(power_supply_put_battery_info);
>> +
>> int power_supply_get_property(struct power_supply *psy,
>> enum power_supply_property psp,
>> union power_supply_propval *val)
>> diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
>> index 019452d..b0a2768 100644
>> --- a/include/linux/power_supply.h
>> +++ b/include/linux/power_supply.h
>> @@ -309,6 +309,12 @@ struct power_supply_info {
>> int use_for_apm;
>> };
>>
>> +struct power_supply_battery_ocv_table {
>> + int ocv; /* microVolts */
>> + int capacity; /* percent */
>> +};
>> +
>> +#define POWER_SUPPLY_OCV_TEMP_MAX 20
>> /*
>> * This is the recommended struct to manage static battery parameters,
>> * populated by power_supply_get_battery_info(). Most platform drivers should
>> @@ -327,6 +333,9 @@ struct power_supply_battery_info {
>> int constant_charge_current_max_ua; /* microAmps */
>> int constant_charge_voltage_max_uv; /* microVolts */
>> int internal_resistance_uohm; /* microOhms */
>> + int ocv_temp[POWER_SUPPLY_OCV_TEMP_MAX]; /* celsius */
>> + struct power_supply_battery_ocv_table *ocv_table[POWER_SUPPLY_OCV_TEMP_MAX];
>> + int ocv_table_size[POWER_SUPPLY_OCV_TEMP_MAX];
>> };
>>
>> extern struct atomic_notifier_head power_supply_notifier;
>> @@ -350,6 +359,8 @@ extern struct power_supply *devm_power_supply_get_by_phandle(
>>
>> extern int power_supply_get_battery_info(struct power_supply *psy,
>> struct power_supply_battery_info *info);
>> +extern void power_supply_put_battery_info(struct power_supply *psy,
>> + struct power_supply_battery_info *info);
>> 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(
>
> Looks good to me. Technically this can result in existing users of
> power_supply_get_battery_info leaking memory, if they have an OCV
> table in DT.

Fortunately existing users did not have an OCV table. Moreover once
this patch merged, I will send patches to add
power_supply_put_battery_info() for existing users of battery info.

--
Baolin Wang
Best Regards

2018-09-27 05:17:51

by Baolin Wang

[permalink] [raw]

Subject: Re: [PATCH v2 4/4] power: supply: Add Spreadtrum SC27XX fuel gauge unit driver

On 26 September 2018 at 23:30, Sebastian Reichel <[email protected]> wrote:
> Hi,
>
> On Wed, Sep 26, 2018 at 10:59:14AM +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 <[email protected]>
>> Signed-off-by: Baolin Wang <[email protected]>
>> ---
>> 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 | 691 ++++++++++++++++++++++++++++++
>> 3 files changed, 699 insertions(+)
>> create mode 100644 drivers/power/supply/sc27xx_fuel_gauge.c
>>
>> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
>> 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/Makefile
>> index 767105b..b731c2a 100644
>> --- a/drivers/power/supply/Makefile
>> +++ b/drivers/power/supply/Makefile
>> @@ -86,3 +86,4 @@ obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
>> obj-$(CONFIG_AXP288_CHARGER) += axp288_charger.o
>> obj-$(CONFIG_CHARGER_CROS_USBPD) += cros_usbpd-charger.o
>> obj-$(CONFIG_CHARGER_SC2731) += sc2731_charger.o
>> +obj-$(CONFIG_FUEL_GAUGE_SC27XX) += 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..d3422cf
>> --- /dev/null
>> +++ b/drivers/power/supply/sc27xx_fuel_gauge.c
>> @@ -0,0 +1,691 @@
>> +// 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[] = {
>> + "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;
>> +}
>> +
>> +static int sc27xx_fgu_ocv_to_capacity(struct sc27xx_fgu_data *data, int ocv)
>> +{
>> + struct power_supply_battery_ocv_table *tab = data->cap_table;
>> + int n = data->table_len;
>> + int i, cap, tmp;
>> +
>> + /*
>> + * Find the position in the table for current battery OCV value,
>> + * then use these two points to calculate battery capacity
>> + * according to the linear method.
>> + */
>> + for (i = 0; i < n; i++)
>> + if (ocv > tab[i].ocv)
>> + break;
>> +
>> + if (i > 0 && i < n) {
>> + tmp = (tab[i - 1].capacity - tab[i].capacity) *
>> + (ocv - tab[i].ocv) * 2;
>> + tmp /= tab[i - 1].ocv - tab[i].ocv;
>> + tmp = (tmp + 1) / 2;
>> + cap = tmp + tab[i].capacity;
>> + } else if (i == 0) {
>> + cap = tab[0].capacity;
>> + } else {
>> + cap = tab[n - 1].capacity;
>> + }
>> +
>> + return cap;
>> +}
>
> We should have a function working on the table(s) from battery_info
> instead, which can be shared by drivers. Maybe something like this:
>
> int ocv2cap_simple(struct power_supply_battery_ocv_table *table, int ocv)
> {
> // basically your code but working with the common table
> }
>
> struct power_supply_battery_ocv_table *find_ocv2cap_table(struct power_supply_battery_info *info, int temp)
> {
> int best_temp_diff, temp_diff = INT_MAX;
> int best_index = 0;
>
> for (int i=0; i < POWER_SUPPLY_OCV_TEMP_MAX; i++) {
> temp_diff = abs(info->ocv_temp[i] - temp);
> if (temp_diff < best_temp_diff) {
> best_temp_diff = temp_diff;
> best_index = i;
> }
> }
>
> return &info->ocv_table[i];
> }
>
> int batinfo_ocv2cap(struct power_supply_battery_info *info, int ocv, int temp)
> {
> struct power_supply_battery_ocv_table *table = find_ocv2cap_table(battery_info, temp);
> return ocv2cap_simple(table, ocv);
> }

OK. Will add these helpers in next version.

>> +
>> +/*
>> + * When system boots on, we can not read battery capacity from coulomb
>> + * registers, since now the coulomb registers are invalid. So we should
>> + * calculate the battery open circuit voltage, and get current battery
>> + * 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 register saved
>> + * the first sampled open circuit current.
>> + */
>> + ret = regmap_read(data->regmap, data->base + SC27XX_FGU_CLBCNT_QMAXL,
>> + &cur);
>> + if (ret)
>> + return ret;
>> +
>> + cur <<= 1;
>> + oci = sc27xx_fgu_adc_to_current(cur - SC27XX_FGU_CUR_BASIC_ADC);
>> +
>> + /*
>> + * Should get the OCV from SC27XX_FGU_POCV register at the system
>> + * beginning. It is ADC values reading from registers which need to
>> + * convert the corresponding voltage.
>> + */
>> + ret = regmap_read(data->regmap, data->base + SC27XX_FGU_POCV, &volt);
>> + if (ret)
>> + return ret;
>> +
>> + volt = sc27xx_fgu_adc_to_voltage(volt);
>> + ocv = volt - (oci * data->internal_resist) / 1000;
>> +
>> + /*
>> + * Parse the capacity table to look up the correct capacity percent
>> + * according to current battery's corresponding OCV values.
>> + */
>> + *cap = sc27xx_fgu_ocv_to_capacity(data, ocv);
>> +
>> + return 0;
>> +}
>> +
>> +static int sc27xx_fgu_set_clbcnt(struct sc27xx_fgu_data *data, int clbcnt)
>> +{
>> + int ret;
>> +
>> + clbcnt *= SC27XX_FGU_SAMPLE_HZ;
>> +
>> + ret = regmap_update_bits(data->regmap,
>> + data->base + SC27XX_FGU_CLBCNT_SETL,
>> + SC27XX_FGU_CLBCNT_MASK, clbcnt);
>> + if (ret)
>> + return ret;
>> +
>> + ret = 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 = regmap_read(data->regmap, data->base + SC27XX_FGU_CLBCNT_VALL,
>> + &ccl);
>> + if (ret)
>> + return ret;
>> +
>> + ret = regmap_read(data->regmap, data->base + SC27XX_FGU_CLBCNT_VALH,
>> + &cch);
>> + if (ret)
>> + return ret;
>> +
>> + *clb_cnt = ccl & SC27XX_FGU_CLBCNT_MASK;
>> + *clb_cnt |= (cch & SC27XX_FGU_CLBCNT_MASK) << SC27XX_FGU_CLBCNT_SHIFT;
>> + *clb_cnt /= 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 = sc27xx_fgu_get_clbcnt(data, &cur_clbcnt);
>> + if (ret)
>> + return ret;
>> +
>> + delta_clbcnt = cur_clbcnt - data->init_clbcnt;
>> +
>> + /*
>> + * Convert coulomb counter to delta capacity (mAh), and set multiplier
>> + * as 100 to improve the precision.
>> + */
>> + temp = DIV_ROUND_CLOSEST(delta_clbcnt, 360);
>> + temp = sc27xx_fgu_adc_to_current(temp);
>> +
>> + /*
>> + * Convert to capacity percent of the battery total capacity,
>> + * and multiplier is 100 too.
>> + */
>> + delta_cap = DIV_ROUND_CLOSEST(temp * 100, data->total_cap);
>> + *cap = 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 = regmap_read(data->regmap, data->base + SC27XX_FGU_VOLTAGE, &vol);
>> + if (ret)
>> + return ret;
>> +
>> + /*
>> + * It is ADC values reading from registers which need to convert to
>> + * corresponding voltage values.
>> + */
>> + *val = 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 = regmap_read(data->regmap, data->base + SC27XX_FGU_CURRENT, &cur);
>> + if (ret)
>> + return ret;
>> +
>> + /*
>> + * It is ADC values reading from registers which need to convert to
>> + * corresponding current values.
>> + */
>> + *val = sc27xx_fgu_adc_to_current(cur - SC27XX_FGU_CUR_BASIC_ADC);
>> +
>> + return 0;
>> +}
>> +
>> +static int sc27xx_fgu_get_vbat_ocv(struct sc27xx_fgu_data *data, int *val)
>> +{
>> + int vol, cur, ret;
>> +
>> + ret = sc27xx_fgu_get_vbat_vol(data, &vol);
>> + if (ret)
>> + return ret;
>> +
>> + ret = sc27xx_fgu_get_current(data, &cur);
>> + if (ret)
>> + return ret;
>> +
>> + /* Return the battery OCV in micro volts. */
>> + *val = vol * 1000 - cur * data->internal_resist;
>> +
>> + return 0;
>> +}
>> +
>> +static int sc27xx_fgu_get_temp(struct sc27xx_fgu_data *data, int *temp)
>> +{
>> + 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 = sc27xx_fgu_get_vbat_vol(data, &vol);
>> + if (ret)
>> + return ret;
>> +
>> + if (vol > data->max_volt)
>> + *health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
>> + else
>> + *health = 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 = -EINVAL;
>> +
>> + for (i = 0; i < ARRAY_SIZE(sc27xx_charger_supply_name); i++) {
>> + psy = power_supply_get_by_name(sc27xx_charger_supply_name[i]);
>> + if (!psy)
>> + continue;
>> +
>> + ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_STATUS,
>> + &val);
>> + power_supply_put(psy);
>> + if (ret)
>> + return ret;
>> +
>> + *status = 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 = power_supply_get_drvdata(psy);
>> + int ret = 0;
>> + int value;
>> +
>> + mutex_lock(&data->lock);
>> +
>> + switch (psp) {
>> + case POWER_SUPPLY_PROP_STATUS:
>> + ret = sc27xx_fgu_get_status(data, &value);
>> + if (ret)
>> + goto error;
>> +
>> + val->intval = value;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_HEALTH:
>> + ret = sc27xx_fgu_get_health(data, &value);
>> + if (ret)
>> + goto error;
>> +
>> + val->intval = value;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_PRESENT:
>> + val->intval = data->bat_present;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_TEMP:
>> + ret = sc27xx_fgu_get_temp(data, &value);
>> + if (ret)
>> + goto error;
>> +
>> + val->intval = value;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_TECHNOLOGY:
>> + val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_CAPACITY:
>> + ret = sc27xx_fgu_get_capacity(data, &value);
>> + if (ret)
>> + goto error;
>> +
>> + val->intval = value;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
>> + ret = sc27xx_fgu_get_vbat_vol(data, &value);
>> + if (ret)
>> + goto error;
>> +
>> + val->intval = value * 1000;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_VOLTAGE_OCV:
>> + ret = sc27xx_fgu_get_vbat_ocv(data, &value);
>> + if (ret)
>> + goto error;
>> +
>> + val->intval = value;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_CURRENT_NOW:
>> + case POWER_SUPPLY_PROP_CURRENT_AVG:
>> + ret = sc27xx_fgu_get_current(data, &value);
>> + if (ret)
>> + goto error;
>> +
>> + val->intval = value * 1000;
>> + break;
>> +
>> + default:
>> + ret = -EINVAL;
>> + break;
>> + }
>> +
>> +error:
>> + mutex_unlock(&data->lock);
>> + return ret;
>> +}
>> +
>> +static void sc27xx_fgu_external_power_changed(struct power_supply *psy)
>> +{
>> + struct sc27xx_fgu_data *data = power_supply_get_drvdata(psy);
>> +
>> + power_supply_changed(data->battery);
>> +}
>> +
>> +static enum power_supply_property sc27xx_fgu_props[] = {
>> + 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 = {
>> + .name = "sc27xx-fgu",
>> + .type = POWER_SUPPLY_TYPE_BATTERY,
>> + .properties = sc27xx_fgu_props,
>> + .num_properties = ARRAY_SIZE(sc27xx_fgu_props),
>> + .get_property = sc27xx_fgu_get_property,
>> + .external_power_changed = sc27xx_fgu_external_power_changed,
>> +};
>> +
>> +static irqreturn_t sc27xx_fgu_bat_detection(int irq, void *dev_id)
>> +{
>> + struct sc27xx_fgu_data *data = dev_id;
>> + int state;
>> +
>> + mutex_lock(&data->lock);
>> +
>> + state = 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 = !!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 = _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, int capacity)
>> +{
>> + /*
>> + * Get current capacity (mAh) = battery total capacity (mAh) *
>> + * current capacity percent (capacity / 100).
>> + */
>> + int cur_cap = DIV_ROUND_CLOSEST(data->total_cap * capacity, 100);
>> +
>> + /*
>> + * Convert current capacity (mAh) to coulomb counter according to the
>> + * formula: 1 mAh =3.6 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 = { };
>> + struct power_supply_battery_ocv_table *table;
>> + int ret, i;
>> +
>> + ret = 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 = info.charge_full_design_uah / 1000;
>> + data->max_volt = info.constant_charge_voltage_max_uv / 1000;
>> + data->internal_resist = info.internal_resistance_uohm / 1000;
>> + data->table_len = info.ocv_table_size[0];
>> +
>> + /*
>> + * For SC27XX fuel gauge device, we only need one ocv-capacity
>> + * table in normal temperature.
>> + */
>> + table = info.ocv_table[0];
>> + if (!table)
>> + return -EINVAL;
>> +
>> + data->cap_table = 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 = 0; i < data->table_len; i++) {
>> + data->cap_table[i].ocv = table[i].ocv / 1000;
>> + data->cap_table[i].capacity = table[i].capacity;
>> + }
>> +
>> + power_supply_put_battery_info(data->battery, &info);
>> +
>> + /* Enable the FGU module */
>> + ret = regmap_update_bits(data->regmap, SC27XX_MODULE_EN0,
>> + SC27XX_FGU_EN, SC27XX_FGU_EN);
>> + if (ret) {
>> + dev_err(data->dev, "failed to enable fgu\n");
>> + return ret;
>> + }
>> +
>> + /* Enable the FGU RTC clock to make it work */
>> + ret = regmap_update_bits(data->regmap, SC27XX_CLK_EN0,
>> + SC27XX_FGU_RTC_EN, SC27XX_FGU_RTC_EN);
>> + if (ret) {
>> + dev_err(data->dev, "failed to enable fgu RTC clock\n");
>> + goto disable_fgu;
>> + }
>> +
>> + /*
>> + * Get the boot battery capacity when system powers on, which is used to
>> + * initialize the coulomb counter. After that, we can read the coulomb
>> + * counter to measure the battery capacity.
>> + */
>> + ret = sc27xx_fgu_get_boot_capacity(data, &data->init_cap);
>> + if (ret) {
>> + dev_err(data->dev, "failed to get boot capacity\n");
>> + goto disable_clk;
>> + }
>> +
>> + /*
>> + * Convert battery capacity to the corresponding initial coulomb counter
>> + * and set into coulomb counter registers.
>> + */
>> + data->init_clbcnt = sc27xx_fgu_cap_to_clbcnt(data, data->init_cap);
>> + ret = sc27xx_fgu_set_clbcnt(data, data->init_clbcnt);
>> + if (ret) {
>> + dev_err(data->dev, "failed to initialize coulomb counter\n");
>> + goto disable_clk;
>> + }
>> +
>> + return 0;
>> +
>> +disable_clk:
>> + regmap_update_bits(data->regmap, SC27XX_CLK_EN0, SC27XX_FGU_RTC_EN, 0);
>> +disable_fgu:
>> + regmap_update_bits(data->regmap, SC27XX_MODULE_EN0, SC27XX_FGU_EN, 0);
>> +
>> + return ret;
>> +}
>> +
>> +static int sc27xx_fgu_probe(struct platform_device *pdev)
>> +{
>> + struct device_node *np = pdev->dev.of_node;
>> + struct power_supply_config fgu_cfg = { };
>> + struct sc27xx_fgu_data *data;
>> + int ret, irq;
>> +
>> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + data->regmap = dev_get_regmap(pdev->dev.parent, NULL);
>> + if (!data->regmap) {
>> + dev_err(&pdev->dev, "failed to get regmap\n");
>> + return -ENODEV;
>> + }
>> +
>> + ret = of_property_read_u32(np, "reg", &data->base);
>> + if (ret) {
>> + dev_err(&pdev->dev, "failed to get fgu address\n");
>> + return ret;
>> + }
>
> Can you please use device_property_read_u32() instead.
> If I didn't miss anything you can drop #include <linux/of.h> afterwards.

Sure. Thanks.

>
> -- Sebastian
>
>> + data->channel = devm_iio_channel_get(&pdev->dev, "bat-temp");
>> + if (IS_ERR(data->channel)) {
>> + dev_err(&pdev->dev, "failed to get IIO channel\n");
>> + return PTR_ERR(data->channel);
>> + }
>> +
>> + data->gpiod = devm_gpiod_get(&pdev->dev, "bat-detect", GPIOD_IN);
>> + if (IS_ERR(data->gpiod)) {
>> + dev_err(&pdev->dev, "failed to get battery detection GPIO\n");
>> + return PTR_ERR(data->gpiod);
>> + }
>> +
>> + ret = gpiod_get_value_cansleep(data->gpiod);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "failed to get gpio state\n");
>> + return ret;
>> + }
>> +
>> + data->bat_present = !!ret;
>> + mutex_init(&data->lock);
>> + data->dev = &pdev->dev;
>> +
>> + fgu_cfg.drv_data = data;
>> + fgu_cfg.of_node = np;
>> + data->battery = devm_power_supply_register(&pdev->dev, &sc27xx_fgu_desc,
>> + &fgu_cfg);
>> + if (IS_ERR(data->battery)) {
>> + dev_err(&pdev->dev, "failed to register power supply\n");
>> + return PTR_ERR(data->battery);
>> + }
>> +
>> + ret = sc27xx_fgu_hw_init(data);
>> + if (ret) {
>> + dev_err(&pdev->dev, "failed to initialize fgu hardware\n");
>> + return ret;
>> + }
>> +
>> + ret = devm_add_action(&pdev->dev, sc27xx_fgu_disable, data);
>> + if (ret) {
>> + sc27xx_fgu_disable(data);
>> + dev_err(&pdev->dev, "failed to add fgu disable action\n");
>> + return ret;
>> + }
>> +
>> + irq = gpiod_to_irq(data->gpiod);
>> + if (irq < 0) {
>> + dev_err(&pdev->dev, "failed to translate GPIO to IRQ\n");
>> + return irq;
>> + }
>> +
>> + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
>> + sc27xx_fgu_bat_detection,
>> + IRQF_ONESHOT | IRQF_TRIGGER_RISING |
>> + IRQF_TRIGGER_FALLING,
>> + pdev->name, data);
>> + if (ret) {
>> + dev_err(&pdev->dev, "failed to request IRQ\n");
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id sc27xx_fgu_of_match[] = {
>> + { .compatible = "sprd,sc2731-fgu", },
>> + { }
>> +};
>> +
>> +static struct platform_driver sc27xx_fgu_driver = {
>> + .probe = sc27xx_fgu_probe,
>> + .driver = {
>> + .name = "sc27xx-fgu",
>> + .of_match_table = sc27xx_fgu_of_match,
>> + }
>> +};
>> +
>> +module_platform_driver(sc27xx_fgu_driver);
>> +
>> +MODULE_DESCRIPTION("Spreadtrum SC27XX PMICs Fual Gauge Unit Driver");
>> +MODULE_LICENSE("GPL v2");

--
Baolin Wang
Best Regards

2018-09-27 06:41:15

by Sebastian Reichel

[permalink] [raw]

Subject: Re: [PATCH v2 2/4] power: supply: core: Introduce properties to present the battery OCV table

Hi,

On Thu, Sep 27, 2018 at 09:10:05AM +0800, Baolin Wang wrote:
> On 26 September 2018 at 21:51, Sebastian Reichel <[email protected]> wrote:
> > Looks good to me. Technically this can result in existing users of
> > power_supply_get_battery_info leaking memory, if they have an OCV
> > table in DT.
>
> Fortunately existing users did not have an OCV table.

Right. I was just talking about potential memory leak, if the DT
file of these boards has the OCV table defined. I don't think
that this will be a problem in real life.

> Moreover once this patch merged, I will send patches to add
> power_supply_put_battery_info() for existing users of battery
> info.

Thanks.

-- Sebastian

Attachments:

(No filename) (707.00 B)
signature.asc (849.00 B)
Download all attachments