Re: [PATCH 2/2] power: supply: Add Spreadtrum SC27XX fuel gauge unit driver
From: Baolin Wang
Date: Mon Sep 17 2018 - 00:01:58 EST
Hi Sebastian,
On 16 September 2018 at 22:35, Sebastian Reichel
<sebastian.reichel@xxxxxxxxxxxxx> wrote:
> Hi,
>
> Looks mostly good. I have a couple of comments in addition to the
> ones from the binding about using battery_info for the OCV ->
> capacity mapping.
OK.
>> +
>> +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;
>> +
>> + *val = vol - (cur * data->inner_resist) / 1000;
>
> You multiply this with 1000 directly after this function to get back
> to uV. Just drop the division and the multiplication.
But the vol's unit is mV, so I can change to:
*val = vol * 1000 - cur * data->inner_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 * 1000;
>> + 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);
>> + }
>> +
>> + if (state)
>> + data->bat_present = true;
>> + else
>> + data->bat_present = false;
>> +
>> + mutex_unlock(&data->lock);
>
> You want to call power_supply_changed() here.
Ah, right. Missed this.
>
>> + 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 = { };
>> + int ret;
>> +
>> + 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;
>> +
>> + /* 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_parse_dt(struct sc27xx_fgu_data *data,
>> + struct device_node *np)
>> +{
>> + const __be32 *list;
>> + int i, len, size, ret;
>> +
>> + ret = of_property_read_u32(np, "reg", &data->base);
>> + if (ret) {
>> + dev_err(data->dev, "failed to get fgu address\n");
>> + return ret;
>> + }
>> +
>> + data->gpiod = devm_gpiod_get_optional(data->dev, "bat-detect", GPIOD_IN);
>> + if (IS_ERR(data->gpiod)) {
>> + dev_err(data->dev, "failed to get battery detection GPIO\n");
>> + return PTR_ERR(data->gpiod);
>> + }
>
> According to the binding (and the remaining code!) this gpio is not
> optional.
Yes, they are not optional. If we can not get the detection GPIO, we
will return errors. So am I missing something else?
Thanks for your comments.
>
> -- Sebastian
>
>> + data->channel = devm_iio_channel_get(data->dev, "bat-temp");
>> + if (IS_ERR(data->channel)) {
>> + dev_err(data->dev, "failed to get IIO channel\n");
>> + return PTR_ERR(data->channel);
>> + }
>> +
>> + /* Get the battery inner resistance */
>> + ret = of_property_read_u32(np, "sprd,inner-resist", &data->inner_resist);
>> + if (ret) {
>> + dev_err(data->dev, "failed to get battery inner resistance\n");
>> + return ret;
>> + }
>> +
>> + /* Get battery ocv-capacity table */
>> + list = of_get_property(np, "sprd,ocv-cap-table", &size);
>> + if (!list || !size) {
>> + dev_err(data->dev, "failed to get ocv-capacity table\n");
>> + return -EINVAL;
>> + }
>> +
>> + len = size / 8;
>> + data->table_len = len;
>> + data->cap_table = devm_kzalloc(data->dev,
>> + sizeof(struct sc27xx_fgu_capacity_table) * len,
>> + GFP_KERNEL);
>> + if (!data->cap_table)
>> + return -ENOMEM;
>> +
>> + for (i = 0; i < len; i++) {
>> + data->cap_table[i].ocv = be32_to_cpu(*list++);
>> + data->cap_table[i].capacity = be32_to_cpu(*list++);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +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;
>> + }
>> +
>> + mutex_init(&data->lock);
>> + data->dev = &pdev->dev;
>> + data->bat_present = true;
>> +
>> + ret = sc27xx_fgu_parse_dt(data, np);
>> + if (ret)
>> + return ret;
>> +
>> + 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");
>> --
>> 1.7.9.5
>>
--
Baolin Wang
Best Regards