Re: [RFC 6/6] power: supply: Ettus Research E31x battery driver

From: Sebastian Reichel
Date: Tue Feb 12 2019 - 17:27:07 EST


Hi,

On Mon, Feb 11, 2019 at 07:01:43PM -0600, Virendra Kakade wrote:
> Add support for E31x devices battery which is a sub-device of E31X-PMU.
> Enables query of battery properties from device tree.
>
> Signed-off-by: Virendra Kakade <virendra.kakade@xxxxxx>
> ---
> drivers/power/supply/Kconfig | 6 +
> drivers/power/supply/Makefile | 1 +
> drivers/power/supply/e31x-battery.c | 357 ++++++++++++++++++++++++++++
> include/linux/mfd/e31x-pmu.h | 15 +-
> 4 files changed, 377 insertions(+), 2 deletions(-)
> create mode 100644 drivers/power/supply/e31x-battery.c
>
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index 3d043b8fd49c..e05e02dffc49 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -666,4 +666,10 @@ config E31X_CHARGER
> help
> This adds support for the battery charger in Ettus Research E31x PMU.
>
> +config E31X_BATTERY
> + tristate "Ettus Research E31x battery support"
> + depends on MFD_E31X_PMU
> + help
> + This adds support for the battery in Ettus Research E31x PMU.
> +
> endif # POWER_SUPPLY
> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
> index 6f4f8ca5484e..3850d08db942 100644
> --- a/drivers/power/supply/Makefile
> +++ b/drivers/power/supply/Makefile
> @@ -88,3 +88,4 @@ obj-$(CONFIG_CHARGER_CROS_USBPD) += cros_usbpd-charger.o
> obj-$(CONFIG_CHARGER_SC2731) += sc2731_charger.o
> obj-$(CONFIG_FUEL_GAUGE_SC27XX) += sc27xx_fuel_gauge.o
> obj-$(CONFIG_E31X_CHARGER) += e31x-charger.o
> +obj-$(CONFIG_E31X_BATTERY) += e31x-battery.o
> diff --git a/drivers/power/supply/e31x-battery.c b/drivers/power/supply/e31x-battery.c
> new file mode 100644
> index 000000000000..d44a639e8bc2
> --- /dev/null
> +++ b/drivers/power/supply/e31x-battery.c
> @@ -0,0 +1,357 @@
> +// SPDX-License-Identifier: GPL-2.0

same issue as in charger driver.

> +/*
> + * Copyright (c) 2018 National Instruments Corp
> + * Author: Virendra Kakade <virendra.kakade@xxxxxx>
> + *
> + * Ettus Research E31x battery driver
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/mutex.h>
> +#include <linux/regmap.h>
> +#include <linux/string.h>
> +#include <linux/slab.h>
> +#include <linux/power_supply.h>
> +#include <linux/delay.h>
> +#include <linux/mfd/e31x-pmu.h>

I also believe a few of those includes are unused.

> +#define E31X_PMU_BATTERY_VOLTAGE_MASK GENMASK(23, 8)
> +#define E31X_PMU_BATTERY_VOLTAGE_SHIFT 8
> +#define E31X_PMU_BATTERY_TEMP_ALERT_MASK GENMASK(7, 6)
> +#define E31X_PMU_BATTERY_TEMP_ALERT_SHIFT 6
> +#define E31X_PMU_BATTERY_ONLINE_MASK BIT(5)
> +#define E31X_PMU_BATTERY_ONLINE_SHIFT 5
> +#define E31X_PMU_BATTERY_HEALTH_MASK GENMASK(4, 2)
> +#define E31X_PMU_BATTERY_HEALTH_SHIFT 2
> +#define E31X_PMU_BATTERY_STATUS_MASK GENMASK(1, 0)
> +#define E31X_PMU_BATTERY_STATUS_SHIFT 0
> +
> +#define E31X_PMU_GAUGE_TEMP_MASK GENMASK(31, 16)
> +#define E31X_PMU_GAUGE_TEMP_SHIFT 16
> +#define E31X_PMU_GAUGE_CHARGE_MASK GENMASK(15, 0)
> +#define E31X_PMU_GAUGE_CHARGE_SHIFT 0
> +
> +#define E31X_PMU_GAUGE_VOLTAGE_MASK GENMASK(15, 0)
> +#define E31X_PMU_GAUGE_VOLTAGE_SHIFT 0
> +
> +#define E31X_PMU_GAUGE_CHARGE_LAST_FULL_MASK GENMASK(15, 0)
> +#define E31X_PMU_GAUGE_CHARGE_LAST_FULL_SHIFT 0
> +
> +#define E31X_BATTERY_CHARGE_DESIGN_FULL (3200000)
> +#define E31X_PMU_VSENSE (6000)
> +
> +struct e31x_battery_dev {
> + struct regmap *regmap;
> + struct power_supply *supply;
> +};
> +
> +static int e31x_battery_set_prop(struct power_supply *psy,
> + enum power_supply_property psp,
> + const union power_supply_propval *val)
> +{
> + return 0;
> +}

If you don't have writable properties you do not have to
specify any handler.

> +static int e31x_battery_get_status(struct e31x_battery_dev *bat,
> + union power_supply_propval *val)
> +{
> + u32 value;
> + int err;
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_CHARGER, &value);
> + if (err)
> + return err;
> +
> + value = E31X_PMU_GET_FIELD(CHARGER_ONLINE, value);
> +
> + /* if charger is offline, we're discharging, period */
> + if (!value) {
> + val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
> + return 0;
> + }
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_BATTERY, &value);
> + if (err)
> + return err;
> +
> + value &= E31X_PMU_BATTERY_STATUS_MASK;
> +
> + switch (value) {
> + case 0x0:
> + val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> + break;
> + case 0x1:
> + val->intval = POWER_SUPPLY_STATUS_CHARGING;
> + break;
> + case 0x2:
> + val->intval = POWER_SUPPLY_STATUS_FULL;
> + break;
> + case 0x3:
> + val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
> + break;
> + default:
> + return -EIO;
> + };
> +
> + return 0;
> +}
> +
> +static int e31x_battery_get_health(struct e31x_battery_dev *bat,
> + union power_supply_propval *val)
> +{
> + u32 value;
> + int err;
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_BATTERY, &value);
> + if (err)
> + return err;
> +
> + value = E31X_PMU_GET_FIELD(BATTERY_HEALTH, value);
> +
> + switch (value) {
> + case 0x00:
> + val->intval = POWER_SUPPLY_HEALTH_GOOD;
> + break;
> + case 0x01:
> + val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
> + break;
> + case 0x02:
> + val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
> + break;
> + case 0x03:
> + val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
> + break;
> + case 0x04:
> + val->intval = POWER_SUPPLY_HEALTH_COLD;
> + break;
> + default:
> + val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static int e31x_battery_get_online(struct e31x_battery_dev *bat,
> + union power_supply_propval *val)
> +{
> + u32 value;
> + int err;
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_BATTERY, &value);
> + if (err)
> + return err;
> +
> + val->intval = !!(value & E31X_PMU_BATTERY_ONLINE_MASK);
> +
> + return 0;
> +}
> +
> +static int e31x_battery_get_voltage_now(struct e31x_battery_dev *bat,
> + union power_supply_propval *val)
> +{
> + u32 value;
> + int err;
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_BATTERY, &value);
> +
> + if (err)
> + return err;
> +
> + value = E31X_PMU_GET_FIELD(BATTERY_VOLTAGE, value);
> +
> + val->intval = 10000 * (value * E31X_PMU_VSENSE / GENMASK(15, 0));
> +
> + return 0;
> +}
> +
> +#define E31X_PMU_BIN_TO_UAH(x) ((x) * 53)
> +#define E31X_PMU_UAH_TO_BIN(x) ((x) / 53)
> +
> +static int e31x_battery_get_charge_now(struct e31x_battery_dev *bat,
> + union power_supply_propval *val)
> +{
> + u32 value;
> + int err;
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_GAUGE, &value);
> + if (err)
> + return err;
> +
> + value = E31X_PMU_GET_FIELD(GAUGE_CHARGE, value);
> + val->intval = E31X_PMU_BIN_TO_UAH(value);
> +
> + return 0;
> +}
> +
> +static int e31x_battery_get_temp(struct e31x_battery_dev *bat,
> + union power_supply_propval *val)
> +{
> + u32 value;
> + int err;
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_GAUGE, &value);
> + if (err)
> + return err;
> +
> + value = E31X_PMU_GET_FIELD(GAUGE_TEMP, value);
> + val->intval = 10 * (((600 * value) / 0xffff) - 273);
> +
> + return 0;
> +}
> +
> +static int e31x_battery_get_charge_full(struct e31x_battery_dev *bat,
> + union power_supply_propval *val)
> +{
> + u32 value;
> + int err;
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_LAST, &value);
> + if (err)
> + return err;
> +
> + value = E31X_PMU_GET_FIELD(GAUGE_CHARGE_LAST_FULL, value);
> + val->intval = E31X_PMU_BIN_TO_UAH(value);
> +
> + return 0;
> +}
> +
> +static const int e31x_pmu_temp_values[] = {
> + 600, 800, 1000, 1200
> +};
> +
> +static int e31x_battery_get_temp_alert_max(struct e31x_battery_dev *bat,
> + union power_supply_propval *val)
> +{
> + u32 value;
> + int err;
> + int i;
> +
> + err = regmap_read(bat->regmap, E31X_PMU_REG_BATTERY, &value);
> + if (err)
> + return err;
> +
> + value = E31X_PMU_GET_FIELD(BATTERY_TEMP_ALERT, value);
> + for (i = 1; i < ARRAY_SIZE(e31x_pmu_temp_values); i++)
> + if (e31x_pmu_temp_values[i] > value)
> + break;
> +
> + val->intval = e31x_pmu_temp_values[i - 1];
> +
> + return 0;
> +}
> +
> +static int e31x_battery_get_prop(struct power_supply *psy,
> + enum power_supply_property psp,
> + union power_supply_propval *val)
> +{
> + struct e31x_battery_dev *battery = power_supply_get_drvdata(psy);
> +
> + switch (psp) {
> + case POWER_SUPPLY_PROP_STATUS:
> + return e31x_battery_get_status(battery, val);
> + case POWER_SUPPLY_PROP_HEALTH:
> + return e31x_battery_get_health(battery, val);
> + case POWER_SUPPLY_PROP_ONLINE:
> + return e31x_battery_get_online(battery, val);
> + case POWER_SUPPLY_PROP_TECHNOLOGY:
> + val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
> + break;
> + case POWER_SUPPLY_PROP_TEMP:
> + return e31x_battery_get_temp(battery, val);
> + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> + return e31x_battery_get_voltage_now(battery, val);
> + case POWER_SUPPLY_PROP_CHARGE_NOW:
> + return e31x_battery_get_charge_now(battery, val);
> + case POWER_SUPPLY_PROP_CHARGE_FULL:
> + return e31x_battery_get_charge_full(battery, val);
> + case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
> + val->intval = E31X_BATTERY_CHARGE_DESIGN_FULL;
> + return 0;
> + case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
> + return e31x_battery_get_temp_alert_max(battery, val);
> + default:
> + break;
> + };
> +
> + return 0;
> +}
> +
> +static enum power_supply_property e31x_battery_props[] = {
> + POWER_SUPPLY_PROP_STATUS,
> + POWER_SUPPLY_PROP_HEALTH,
> + POWER_SUPPLY_PROP_ONLINE,
> + POWER_SUPPLY_PROP_TECHNOLOGY,
> + POWER_SUPPLY_PROP_TEMP,
> + POWER_SUPPLY_PROP_VOLTAGE_NOW,
> + POWER_SUPPLY_PROP_CHARGE_NOW,
> + POWER_SUPPLY_PROP_CHARGE_FULL,
> + POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
> + POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
> +};
> +
> +static int e31x_battery_prop_writeable(struct power_supply *psy,
> + enum power_supply_property psp)
> +{
> + return psp == POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN ||
> + psp == POWER_SUPPLY_PROP_SCOPE;
> +}

You'r e31x_battery_set_prop() is empty and you do not even
expose POWER_SUPPLY_PROP_SCOPE.

> +static const struct power_supply_desc e31x_battery_desc = {
> + .name = "e31x-battery",
> + .type = POWER_SUPPLY_TYPE_BATTERY,
> + .properties = e31x_battery_props,
> + .num_properties = ARRAY_SIZE(e31x_battery_props),
> + .property_is_writeable = e31x_battery_prop_writeable,
> + .get_property = e31x_battery_get_prop,
> + .set_property = e31x_battery_set_prop,
> +};
> +
> +static const struct of_device_id e31x_battery_id[] = {
> + { .compatible = "ni,e31x-battery" },
> + { },
> +};
> +
> +static int e31x_battery_probe(struct platform_device *pdev)
> +{
> + struct power_supply_config psy_cfg = {};
> + struct e31x_battery_dev *battery;
> +
> + if (!of_device_is_available(pdev->dev.of_node))
> + return -ENODEV;

Why is this needed? I would expect, that the driver is not being
probed for a disabled node.

> + battery = devm_kzalloc(&pdev->dev, sizeof(*battery), GFP_KERNEL);
> + if (!battery)
> + return -ENOMEM;
> +
> + battery->regmap = syscon_regmap_lookup_by_phandle(\

useless \

> + pdev->dev.parent->of_node, "regmap");
> +
> + psy_cfg.of_node = pdev->dev.of_node;
> + psy_cfg.drv_data = battery;
> +
> + battery->supply = devm_power_supply_register(&pdev->dev,
> + &e31x_battery_desc,
> + &psy_cfg);
> + if (IS_ERR(battery->supply))
> + return PTR_ERR(battery->supply);
> + return 0;
> +}
> +
> +static struct platform_driver e31x_battery_driver = {
> + .driver = {
> + .name = "e31x-battery",
> + .of_match_table = e31x_battery_id,
> + },
> + .probe = e31x_battery_probe,
> +};
> +module_platform_driver(e31x_battery_driver);
> +
> +MODULE_AUTHOR("Virendra Kakade <virendra.kakade@xxxxxx>");
> +MODULE_DESCRIPTION("E31x battery driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/mfd/e31x-pmu.h b/include/linux/mfd/e31x-pmu.h
> index e0649845fe4d..0441f8f896ca 100644
> --- a/include/linux/mfd/e31x-pmu.h
> +++ b/include/linux/mfd/e31x-pmu.h
> @@ -11,13 +11,24 @@
>
> #include <linux/bitops.h>
>
> -#define E31X_PMU_REG_MISC 0x04
> -#define E31X_PMU_REG_CHARGER 0x0c
> +#define E31X_PMU_REG_MISC 0x04
> +#define E31X_PMU_REG_BATTERY 0x08
> +#define E31X_PMU_REG_CHARGER 0x0c
> +#define E31X_PMU_REG_GAUGE 0x10
> +#define E31X_PMU_REG_STATUS 0x14
> +#define E31X_PMU_REG_LAST 0x18
> +#define E31X_PMU_REG_EEPROM 0x1c
>
> #define E31X_PMU_GET_FIELD(name, reg) \
> (((reg) & E31X_PMU_## name ##_MASK) >> \
> E31X_PMU_## name ##_SHIFT)
>
> +/* the eeprom register */
> +static const u32 E31X_PMU_EEPROM_AUTOBOOT_MASK = BIT(0);
> +static const u32 E31X_PMU_EEPROM_AUTOBOOT_SHIFT;
> +static const u32 E31X_PMU_EEPROM_DB_POWER_MASK = BIT(1);
> +static const u32 E31X_PMU_EEPROM_DB_POWER_SHIFT = 1;
> +
> #define E31X_PMU_CHARGER_ONLINE_MASK BIT(2)
> #define E31X_PMU_CHARGER_ONLINE_SHIFT 2

Otherwise looks good.

-- Sebastian

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