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@xxxxxxxxxx>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
> Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
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/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..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[] = {
> + "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 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 = power_supply_ocv2cap_simple(data->cap_table, data->table_len,
> + 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.factory_internal_resistance_uohm / 1000;
> +
> + /*
> + * For SC27XX fuel gauge device, we only use one ocv-capacity
> + * table in normal temperature 20 Celsius.
> + */
> + table = power_supply_find_ocv2cap_table(&info, 20, &data->table_len);
> + 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;
> + }
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.
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.
Thanks for your patience :)
-- Sebastian
> + 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;
> +}
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