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power: supply: Add driver for Pegatron Chagall battery
The Pegatron Chagall is an Android tablet utilizing a customized Cypress CG7153AM microcontroller (MCU) as its battery fuel gauge. It supports a single-cell battery and features a dual-color charging LED. Signed-off-by: Svyatoslav Ryhel <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sebastian Reichel <[email protected]>
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‎drivers/power/supply/Kconfig

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@@ -107,6 +107,18 @@ config BATTERY_ACT8945A
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Say Y here to enable support for power supply provided by
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Active-semi ActivePath ACT8945A charger.
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config BATTERY_CHAGALL
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tristate "Pegatron Chagall battery driver"
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depends on I2C
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depends on LEDS_CLASS
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help
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Say Y to include support for Cypress CG7153AM IC based battery
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fuel gauge with custom firmware found in Pegatron Chagall based
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tablet line.
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This driver can also be built as a module. If so, the module will be
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called chagall-battery.
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config BATTERY_CPCAP
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tristate "Motorola CPCAP PMIC battery driver"
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depends on MFD_CPCAP && IIO

‎drivers/power/supply/Makefile

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@@ -23,6 +23,7 @@ obj-$(CONFIG_CHARGER_ADP5061) += adp5061.o
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obj-$(CONFIG_BATTERY_ACT8945A) += act8945a_charger.o
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obj-$(CONFIG_BATTERY_AXP20X) += axp20x_battery.o
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obj-$(CONFIG_CHARGER_AXP20X) += axp20x_ac_power.o
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obj-$(CONFIG_BATTERY_CHAGALL) += chagall-battery.o
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obj-$(CONFIG_BATTERY_CPCAP) += cpcap-battery.o
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obj-$(CONFIG_BATTERY_CW2015) += cw2015_battery.o
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obj-$(CONFIG_BATTERY_DS2760) += ds2760_battery.o

‎drivers/power/supply/chagall-battery.c

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// SPDX-License-Identifier: GPL-2.0-or-later
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#include <linux/array_size.h>
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#include <linux/delay.h>
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#include <linux/devm-helpers.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/leds.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/power_supply.h>
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#include <linux/regmap.h>
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#define CHAGALL_REG_LED_AMBER 0x60
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#define CHAGALL_REG_LED_WHITE 0x70
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#define CHAGALL_REG_BATTERY_TEMPERATURE 0xa2
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#define CHAGALL_REG_BATTERY_VOLTAGE 0xa4
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#define CHAGALL_REG_BATTERY_CURRENT 0xa6
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#define CHAGALL_REG_BATTERY_CAPACITY 0xa8
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#define CHAGALL_REG_BATTERY_CHARGING_CURRENT 0xaa
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#define CHAGALL_REG_BATTERY_CHARGING_VOLTAGE 0xac
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#define CHAGALL_REG_BATTERY_STATUS 0xae
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#define BATTERY_DISCHARGING BIT(6)
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#define BATTERY_FULL_CHARGED BIT(5)
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#define BATTERY_FULL_DISCHARGED BIT(4)
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#define CHAGALL_REG_BATTERY_REMAIN_CAPACITY 0xb0
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#define CHAGALL_REG_BATTERY_FULL_CAPACITY 0xb2
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#define CHAGALL_REG_MAX_COUNT 0xb4
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#define CHAGALL_BATTERY_DATA_REFRESH 5000
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#define TEMP_CELSIUS_OFFSET 2731
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static const struct regmap_config chagall_battery_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = CHAGALL_REG_MAX_COUNT,
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.reg_format_endian = REGMAP_ENDIAN_LITTLE,
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.val_format_endian = REGMAP_ENDIAN_LITTLE,
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};
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struct chagall_battery_data {
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struct regmap *regmap;
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struct led_classdev amber_led;
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struct led_classdev white_led;
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struct power_supply *battery;
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struct delayed_work poll_work;
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u16 last_state;
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};
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static void chagall_led_set_brightness_amber(struct led_classdev *led,
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enum led_brightness brightness)
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{
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struct chagall_battery_data *cg =
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container_of(led, struct chagall_battery_data, amber_led);
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regmap_write(cg->regmap, CHAGALL_REG_LED_AMBER, brightness);
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}
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static void chagall_led_set_brightness_white(struct led_classdev *led,
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enum led_brightness brightness)
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{
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struct chagall_battery_data *cg =
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container_of(led, struct chagall_battery_data, white_led);
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regmap_write(cg->regmap, CHAGALL_REG_LED_WHITE, brightness);
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}
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static const enum power_supply_property chagall_battery_properties[] = {
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POWER_SUPPLY_PROP_STATUS,
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POWER_SUPPLY_PROP_PRESENT,
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POWER_SUPPLY_PROP_VOLTAGE_NOW,
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POWER_SUPPLY_PROP_VOLTAGE_MAX,
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POWER_SUPPLY_PROP_CURRENT_NOW,
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POWER_SUPPLY_PROP_CURRENT_MAX,
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POWER_SUPPLY_PROP_CAPACITY,
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POWER_SUPPLY_PROP_TEMP,
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POWER_SUPPLY_PROP_CHARGE_FULL,
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POWER_SUPPLY_PROP_CHARGE_NOW,
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};
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static const unsigned int chagall_battery_prop_offs[] = {
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[POWER_SUPPLY_PROP_STATUS] = CHAGALL_REG_BATTERY_STATUS,
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[POWER_SUPPLY_PROP_VOLTAGE_NOW] = CHAGALL_REG_BATTERY_VOLTAGE,
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[POWER_SUPPLY_PROP_VOLTAGE_MAX] = CHAGALL_REG_BATTERY_CHARGING_VOLTAGE,
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[POWER_SUPPLY_PROP_CURRENT_NOW] = CHAGALL_REG_BATTERY_CURRENT,
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[POWER_SUPPLY_PROP_CURRENT_MAX] = CHAGALL_REG_BATTERY_CHARGING_CURRENT,
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[POWER_SUPPLY_PROP_CAPACITY] = CHAGALL_REG_BATTERY_CAPACITY,
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[POWER_SUPPLY_PROP_TEMP] = CHAGALL_REG_BATTERY_TEMPERATURE,
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[POWER_SUPPLY_PROP_CHARGE_FULL] = CHAGALL_REG_BATTERY_FULL_CAPACITY,
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[POWER_SUPPLY_PROP_CHARGE_NOW] = CHAGALL_REG_BATTERY_REMAIN_CAPACITY,
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};
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static int chagall_battery_get_value(struct chagall_battery_data *cg,
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enum power_supply_property psp, u32 *val)
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{
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if (psp >= ARRAY_SIZE(chagall_battery_prop_offs))
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return -EINVAL;
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if (!chagall_battery_prop_offs[psp])
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return -EINVAL;
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/* Battery data is stored in 2 consecutive registers with little-endian */
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return regmap_bulk_read(cg->regmap, chagall_battery_prop_offs[psp], val, 2);
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}
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static int chagall_battery_get_status(u32 status_reg)
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{
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if (status_reg & BATTERY_FULL_CHARGED)
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return POWER_SUPPLY_STATUS_FULL;
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else if (status_reg & BATTERY_DISCHARGING)
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return POWER_SUPPLY_STATUS_DISCHARGING;
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else
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return POWER_SUPPLY_STATUS_CHARGING;
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}
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static int chagall_battery_get_property(struct power_supply *psy,
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enum power_supply_property psp,
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union power_supply_propval *val)
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{
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struct chagall_battery_data *cg = power_supply_get_drvdata(psy);
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int ret;
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switch (psp) {
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case POWER_SUPPLY_PROP_PRESENT:
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val->intval = 1;
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break;
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default:
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ret = chagall_battery_get_value(cg, psp, &val->intval);
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if (ret)
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return ret;
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switch (psp) {
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case POWER_SUPPLY_PROP_TEMP:
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val->intval -= TEMP_CELSIUS_OFFSET;
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break;
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case POWER_SUPPLY_PROP_VOLTAGE_MAX:
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case POWER_SUPPLY_PROP_VOLTAGE_NOW:
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case POWER_SUPPLY_PROP_CURRENT_MAX:
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case POWER_SUPPLY_PROP_CURRENT_NOW:
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case POWER_SUPPLY_PROP_CHARGE_FULL:
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case POWER_SUPPLY_PROP_CHARGE_NOW:
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val->intval *= 1000;
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break;
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case POWER_SUPPLY_PROP_STATUS:
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val->intval = chagall_battery_get_status(val->intval);
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break;
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default:
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break;
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}
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break;
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}
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return 0;
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}
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static void chagall_battery_poll_work(struct work_struct *work)
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{
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struct chagall_battery_data *cg =
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container_of(work, struct chagall_battery_data, poll_work.work);
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u32 state;
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int ret;
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ret = chagall_battery_get_value(cg, POWER_SUPPLY_PROP_STATUS, &state);
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if (ret)
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return;
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state = chagall_battery_get_status(state);
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if (cg->last_state != state) {
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cg->last_state = state;
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power_supply_changed(cg->battery);
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}
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/* continuously send uevent notification */
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schedule_delayed_work(&cg->poll_work,
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msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));
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}
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static const struct power_supply_desc chagall_battery_desc = {
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.name = "chagall-battery",
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.type = POWER_SUPPLY_TYPE_BATTERY,
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.properties = chagall_battery_properties,
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.num_properties = ARRAY_SIZE(chagall_battery_properties),
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.get_property = chagall_battery_get_property,
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.external_power_changed = power_supply_changed,
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};
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static int chagall_battery_probe(struct i2c_client *client)
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{
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struct chagall_battery_data *cg;
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struct device *dev = &client->dev;
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struct power_supply_config cfg = { };
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int ret;
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cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
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if (!cg)
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return -ENOMEM;
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cfg.drv_data = cg;
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cfg.fwnode = dev_fwnode(dev);
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i2c_set_clientdata(client, cg);
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cg->regmap = devm_regmap_init_i2c(client, &chagall_battery_regmap_config);
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if (IS_ERR(cg->regmap))
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return dev_err_probe(dev, PTR_ERR(cg->regmap), "cannot allocate regmap\n");
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cg->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
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cg->battery = devm_power_supply_register(dev, &chagall_battery_desc, &cfg);
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if (IS_ERR(cg->battery))
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return dev_err_probe(dev, PTR_ERR(cg->battery),
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"failed to register power supply\n");
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cg->amber_led.name = "power::amber";
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cg->amber_led.max_brightness = 1;
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cg->amber_led.flags = LED_CORE_SUSPENDRESUME;
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cg->amber_led.brightness_set = chagall_led_set_brightness_amber;
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cg->amber_led.default_trigger = "chagall-battery-charging";
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ret = devm_led_classdev_register(dev, &cg->amber_led);
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if (ret)
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return dev_err_probe(dev, ret, "failed to register amber LED\n");
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cg->white_led.name = "power::white";
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cg->white_led.max_brightness = 1;
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cg->white_led.flags = LED_CORE_SUSPENDRESUME;
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cg->white_led.brightness_set = chagall_led_set_brightness_white;
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cg->white_led.default_trigger = "chagall-battery-full";
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ret = devm_led_classdev_register(dev, &cg->white_led);
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if (ret)
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return dev_err_probe(dev, ret, "failed to register white LED\n");
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led_set_brightness(&cg->amber_led, LED_OFF);
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led_set_brightness(&cg->white_led, LED_OFF);
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ret = devm_delayed_work_autocancel(dev, &cg->poll_work, chagall_battery_poll_work);
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if (ret)
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return ret;
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schedule_delayed_work(&cg->poll_work, msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));
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return 0;
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}
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static int __maybe_unused chagall_battery_suspend(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct chagall_battery_data *cg = i2c_get_clientdata(client);
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cancel_delayed_work_sync(&cg->poll_work);
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return 0;
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}
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static int __maybe_unused chagall_battery_resume(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct chagall_battery_data *cg = i2c_get_clientdata(client);
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schedule_delayed_work(&cg->poll_work, msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(chagall_battery_pm_ops,
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chagall_battery_suspend, chagall_battery_resume);
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static const struct of_device_id chagall_of_match[] = {
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{ .compatible = "pegatron,chagall-ec" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, chagall_of_match);
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static struct i2c_driver chagall_battery_driver = {
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.driver = {
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.name = "chagall-battery",
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.pm = &chagall_battery_pm_ops,
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.of_match_table = chagall_of_match,
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},
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.probe = chagall_battery_probe,
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};
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module_i2c_driver(chagall_battery_driver);
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MODULE_AUTHOR("Svyatoslav Ryhel <[email protected]>");
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MODULE_DESCRIPTION("Pegatron Chagall fuel gauge driver");
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MODULE_LICENSE("GPL");

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