]> www.infradead.org Git - linux.git/commitdiff
power: supply: Add driver for Pegatron Chagall battery
authorSvyatoslav Ryhel <clamor95@gmail.com>
Tue, 29 Apr 2025 06:18:01 +0000 (09:18 +0300)
committerSebastian Reichel <sebastian.reichel@collabora.com>
Tue, 29 Apr 2025 22:02:18 +0000 (00:02 +0200)
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 <clamor95@gmail.com>
Link: https://lore.kernel.org/r/20250429061803.9581-4-clamor95@gmail.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
drivers/power/supply/Kconfig
drivers/power/supply/Makefile
drivers/power/supply/chagall-battery.c [new file with mode: 0644]

index 8dbd39afa43cba67cddb0e8ca62e6e44d4864434..b756453ba424fd0f3646915de419a1e62d5046e6 100644 (file)
@@ -107,6 +107,18 @@ config BATTERY_ACT8945A
          Say Y here to enable support for power supply provided by
          Active-semi ActivePath ACT8945A charger.
 
+config BATTERY_CHAGALL
+       tristate "Pegatron Chagall battery driver"
+       depends on I2C
+       depends on LEDS_CLASS
+       help
+         Say Y to include support for Cypress CG7153AM IC based battery
+         fuel gauge with custom firmware found in Pegatron Chagall based
+         tablet line.
+
+         This driver can also be built as a module. If so, the module will be
+         called chagall-battery.
+
 config BATTERY_CPCAP
        tristate "Motorola CPCAP PMIC battery driver"
        depends on MFD_CPCAP && IIO
index 61677be328b0cb1d31440a54b06e201dadfcda7b..b723b1deceeabf146106c82c8ddd2982b2accc0f 100644 (file)
@@ -23,6 +23,7 @@ obj-$(CONFIG_CHARGER_ADP5061) += adp5061.o
 obj-$(CONFIG_BATTERY_ACT8945A) += act8945a_charger.o
 obj-$(CONFIG_BATTERY_AXP20X)   += axp20x_battery.o
 obj-$(CONFIG_CHARGER_AXP20X)   += axp20x_ac_power.o
+obj-$(CONFIG_BATTERY_CHAGALL)  += chagall-battery.o
 obj-$(CONFIG_BATTERY_CPCAP)    += cpcap-battery.o
 obj-$(CONFIG_BATTERY_CW2015)   += cw2015_battery.o
 obj-$(CONFIG_BATTERY_DS2760)   += ds2760_battery.o
diff --git a/drivers/power/supply/chagall-battery.c b/drivers/power/supply/chagall-battery.c
new file mode 100644 (file)
index 0000000..8b05422
--- /dev/null
@@ -0,0 +1,291 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/array_size.h>
+#include <linux/delay.h>
+#include <linux/devm-helpers.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/power_supply.h>
+#include <linux/regmap.h>
+
+#define CHAGALL_REG_LED_AMBER                          0x60
+#define CHAGALL_REG_LED_WHITE                          0x70
+#define CHAGALL_REG_BATTERY_TEMPERATURE                        0xa2
+#define CHAGALL_REG_BATTERY_VOLTAGE                    0xa4
+#define CHAGALL_REG_BATTERY_CURRENT                    0xa6
+#define CHAGALL_REG_BATTERY_CAPACITY                   0xa8
+#define CHAGALL_REG_BATTERY_CHARGING_CURRENT           0xaa
+#define CHAGALL_REG_BATTERY_CHARGING_VOLTAGE           0xac
+#define CHAGALL_REG_BATTERY_STATUS                     0xae
+#define   BATTERY_DISCHARGING                          BIT(6)
+#define   BATTERY_FULL_CHARGED                         BIT(5)
+#define   BATTERY_FULL_DISCHARGED                      BIT(4)
+#define CHAGALL_REG_BATTERY_REMAIN_CAPACITY            0xb0
+#define CHAGALL_REG_BATTERY_FULL_CAPACITY              0xb2
+#define CHAGALL_REG_MAX_COUNT                          0xb4
+
+#define CHAGALL_BATTERY_DATA_REFRESH                   5000
+#define TEMP_CELSIUS_OFFSET                            2731
+
+static const struct regmap_config chagall_battery_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+       .max_register = CHAGALL_REG_MAX_COUNT,
+       .reg_format_endian = REGMAP_ENDIAN_LITTLE,
+       .val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+struct chagall_battery_data {
+       struct regmap *regmap;
+       struct led_classdev amber_led;
+       struct led_classdev white_led;
+       struct power_supply *battery;
+       struct delayed_work poll_work;
+       u16 last_state;
+};
+
+static void chagall_led_set_brightness_amber(struct led_classdev *led,
+                                            enum led_brightness brightness)
+{
+       struct chagall_battery_data *cg =
+               container_of(led, struct chagall_battery_data, amber_led);
+
+       regmap_write(cg->regmap, CHAGALL_REG_LED_AMBER, brightness);
+}
+
+static void chagall_led_set_brightness_white(struct led_classdev *led,
+                                            enum led_brightness brightness)
+{
+       struct chagall_battery_data *cg =
+               container_of(led, struct chagall_battery_data, white_led);
+
+       regmap_write(cg->regmap, CHAGALL_REG_LED_WHITE, brightness);
+}
+
+static const enum power_supply_property chagall_battery_properties[] = {
+       POWER_SUPPLY_PROP_STATUS,
+       POWER_SUPPLY_PROP_PRESENT,
+       POWER_SUPPLY_PROP_VOLTAGE_NOW,
+       POWER_SUPPLY_PROP_VOLTAGE_MAX,
+       POWER_SUPPLY_PROP_CURRENT_NOW,
+       POWER_SUPPLY_PROP_CURRENT_MAX,
+       POWER_SUPPLY_PROP_CAPACITY,
+       POWER_SUPPLY_PROP_TEMP,
+       POWER_SUPPLY_PROP_CHARGE_FULL,
+       POWER_SUPPLY_PROP_CHARGE_NOW,
+};
+
+static const unsigned int chagall_battery_prop_offs[] = {
+       [POWER_SUPPLY_PROP_STATUS] = CHAGALL_REG_BATTERY_STATUS,
+       [POWER_SUPPLY_PROP_VOLTAGE_NOW] = CHAGALL_REG_BATTERY_VOLTAGE,
+       [POWER_SUPPLY_PROP_VOLTAGE_MAX] = CHAGALL_REG_BATTERY_CHARGING_VOLTAGE,
+       [POWER_SUPPLY_PROP_CURRENT_NOW] = CHAGALL_REG_BATTERY_CURRENT,
+       [POWER_SUPPLY_PROP_CURRENT_MAX] = CHAGALL_REG_BATTERY_CHARGING_CURRENT,
+       [POWER_SUPPLY_PROP_CAPACITY] = CHAGALL_REG_BATTERY_CAPACITY,
+       [POWER_SUPPLY_PROP_TEMP] = CHAGALL_REG_BATTERY_TEMPERATURE,
+       [POWER_SUPPLY_PROP_CHARGE_FULL] = CHAGALL_REG_BATTERY_FULL_CAPACITY,
+       [POWER_SUPPLY_PROP_CHARGE_NOW] = CHAGALL_REG_BATTERY_REMAIN_CAPACITY,
+};
+
+static int chagall_battery_get_value(struct chagall_battery_data *cg,
+                                    enum power_supply_property psp, u32 *val)
+{
+       if (psp >= ARRAY_SIZE(chagall_battery_prop_offs))
+               return -EINVAL;
+       if (!chagall_battery_prop_offs[psp])
+               return -EINVAL;
+
+       /* Battery data is stored in 2 consecutive registers with little-endian */
+       return regmap_bulk_read(cg->regmap, chagall_battery_prop_offs[psp], val, 2);
+}
+
+static int chagall_battery_get_status(u32 status_reg)
+{
+       if (status_reg & BATTERY_FULL_CHARGED)
+               return POWER_SUPPLY_STATUS_FULL;
+       else if (status_reg & BATTERY_DISCHARGING)
+               return POWER_SUPPLY_STATUS_DISCHARGING;
+       else
+               return POWER_SUPPLY_STATUS_CHARGING;
+}
+
+static int chagall_battery_get_property(struct power_supply *psy,
+                                       enum power_supply_property psp,
+                                       union power_supply_propval *val)
+{
+       struct chagall_battery_data *cg = power_supply_get_drvdata(psy);
+       int ret;
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_PRESENT:
+               val->intval = 1;
+               break;
+
+       default:
+               ret = chagall_battery_get_value(cg, psp, &val->intval);
+               if (ret)
+                       return ret;
+
+               switch (psp) {
+               case POWER_SUPPLY_PROP_TEMP:
+                       val->intval -= TEMP_CELSIUS_OFFSET;
+                       break;
+
+               case POWER_SUPPLY_PROP_VOLTAGE_MAX:
+               case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+               case POWER_SUPPLY_PROP_CURRENT_MAX:
+               case POWER_SUPPLY_PROP_CURRENT_NOW:
+               case POWER_SUPPLY_PROP_CHARGE_FULL:
+               case POWER_SUPPLY_PROP_CHARGE_NOW:
+                       val->intval *= 1000;
+                       break;
+
+               case POWER_SUPPLY_PROP_STATUS:
+                       val->intval = chagall_battery_get_status(val->intval);
+                       break;
+
+               default:
+                       break;
+               }
+
+               break;
+       }
+
+       return 0;
+}
+
+static void chagall_battery_poll_work(struct work_struct *work)
+{
+       struct chagall_battery_data *cg =
+               container_of(work, struct chagall_battery_data, poll_work.work);
+       u32 state;
+       int ret;
+
+       ret = chagall_battery_get_value(cg, POWER_SUPPLY_PROP_STATUS, &state);
+       if (ret)
+               return;
+
+       state = chagall_battery_get_status(state);
+
+       if (cg->last_state != state) {
+               cg->last_state = state;
+               power_supply_changed(cg->battery);
+       }
+
+       /* continuously send uevent notification */
+       schedule_delayed_work(&cg->poll_work,
+                             msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));
+}
+
+static const struct power_supply_desc chagall_battery_desc = {
+       .name = "chagall-battery",
+       .type = POWER_SUPPLY_TYPE_BATTERY,
+       .properties = chagall_battery_properties,
+       .num_properties = ARRAY_SIZE(chagall_battery_properties),
+       .get_property = chagall_battery_get_property,
+       .external_power_changed = power_supply_changed,
+};
+
+static int chagall_battery_probe(struct i2c_client *client)
+{
+       struct chagall_battery_data *cg;
+       struct device *dev = &client->dev;
+       struct power_supply_config cfg = { };
+       int ret;
+
+       cg = devm_kzalloc(dev, sizeof(*cg), GFP_KERNEL);
+       if (!cg)
+               return -ENOMEM;
+
+       cfg.drv_data = cg;
+       cfg.fwnode = dev_fwnode(dev);
+
+       i2c_set_clientdata(client, cg);
+
+       cg->regmap = devm_regmap_init_i2c(client, &chagall_battery_regmap_config);
+       if (IS_ERR(cg->regmap))
+               return dev_err_probe(dev, PTR_ERR(cg->regmap), "cannot allocate regmap\n");
+
+       cg->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
+       cg->battery = devm_power_supply_register(dev, &chagall_battery_desc, &cfg);
+       if (IS_ERR(cg->battery))
+               return dev_err_probe(dev, PTR_ERR(cg->battery),
+                                    "failed to register power supply\n");
+
+       cg->amber_led.name = "power::amber";
+       cg->amber_led.max_brightness = 1;
+       cg->amber_led.flags = LED_CORE_SUSPENDRESUME;
+       cg->amber_led.brightness_set = chagall_led_set_brightness_amber;
+       cg->amber_led.default_trigger = "chagall-battery-charging";
+
+       ret = devm_led_classdev_register(dev, &cg->amber_led);
+       if (ret)
+               return dev_err_probe(dev, ret, "failed to register amber LED\n");
+
+       cg->white_led.name = "power::white";
+       cg->white_led.max_brightness = 1;
+       cg->white_led.flags = LED_CORE_SUSPENDRESUME;
+       cg->white_led.brightness_set = chagall_led_set_brightness_white;
+       cg->white_led.default_trigger = "chagall-battery-full";
+
+       ret = devm_led_classdev_register(dev, &cg->white_led);
+       if (ret)
+               return dev_err_probe(dev, ret, "failed to register white LED\n");
+
+       led_set_brightness(&cg->amber_led, LED_OFF);
+       led_set_brightness(&cg->white_led, LED_OFF);
+
+       ret = devm_delayed_work_autocancel(dev, &cg->poll_work, chagall_battery_poll_work);
+       if (ret)
+               return ret;
+
+       schedule_delayed_work(&cg->poll_work, msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));
+
+       return 0;
+}
+
+static int __maybe_unused chagall_battery_suspend(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct chagall_battery_data *cg = i2c_get_clientdata(client);
+
+       cancel_delayed_work_sync(&cg->poll_work);
+
+       return 0;
+}
+
+static int __maybe_unused chagall_battery_resume(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       struct chagall_battery_data *cg = i2c_get_clientdata(client);
+
+       schedule_delayed_work(&cg->poll_work, msecs_to_jiffies(CHAGALL_BATTERY_DATA_REFRESH));
+
+       return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(chagall_battery_pm_ops,
+                        chagall_battery_suspend, chagall_battery_resume);
+
+static const struct of_device_id chagall_of_match[] = {
+       { .compatible = "pegatron,chagall-ec" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, chagall_of_match);
+
+static struct i2c_driver chagall_battery_driver = {
+       .driver = {
+               .name = "chagall-battery",
+               .pm = &chagall_battery_pm_ops,
+               .of_match_table = chagall_of_match,
+       },
+       .probe = chagall_battery_probe,
+};
+module_i2c_driver(chagall_battery_driver);
+
+MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
+MODULE_DESCRIPTION("Pegatron Chagall fuel gauge driver");
+MODULE_LICENSE("GPL");