Zephyr EC Charger

Overview

The charger chip enables an external power supply to provide power to the board's components.

The charger depends on having a battery, so both the charging subsystem and battery must be configured together in the same change.

Kconfig Options

CONFIG_PLATFORM_EC_CHARGER enables charging support in the EC application. Refer to Kconfig.charger for all sub-options controlling charging behavior.

Note: At least one charger IC must be enabled.

Note: The charger chip configuration serves a different role than the USB charging configuration found in Kconfig.usb_charger.

Example of enabled configs

Enable and disable charger configs in either the program.conf or project.conf file for your project.

# Charger
CONFIG_PLATFORM_EC_CHARGER=y
CONFIG_EC_CHARGER_ISL9237=y
# Charger sub-options
CONFIG_PLATFORM_EC_CHARGE_RAMP_HW=y
CONFIG_PLATFORM_EC_CHARGER_DISCHARGE_ON_AC=y
CONFIG_PLATFORM_EC_CHARGER_DISCHARGE_ON_AC_CHARGER=y
CONFIG_PLATFORM_EC_CHARGER_MIN_BAT_PCT_FOR_POWER_ON=2
CONFIG_PLATFORM_EC_CHARGER_MIN_POWER_MW_FOR_POWER_ON=10000
CONFIG_PLATFORM_EC_CHARGER_PROFILE_OVERRIDE=y
CONFIG_PLATFORM_EC_CHARGER_PSYS=y
CONFIG_PLATFORM_EC_CHARGER_PSYS_READ=y
CONFIG_PLATFORM_EC_CHARGER_SENSE_RESISTOR=10
CONFIG_PLATFORM_EC_CHARGER_SENSE_RESISTOR_AC=20
CONFIG_PLATFORM_EC_CONSOLE_CMD_CHARGER_ADC_AMON_BMON=y

Devicetree Nodes

How to add a charger devicetree node

Add charger node as child of `named-i2c-port`

Example:

named-i2c-ports {
   	compatible = "named-i2c-ports";
   	charger {
   		i2c-port = {ASSOCIATED PHANDLE};
		/* Could be any name, but must correlate to "Board Specific Code" */
		/* TODO(b/228237412): Update this comment once charger chg_chips[] is
		 * created by a shim driver.
		 */
   		enum-names = "I2C_PORT_CHARGER";
   	};
};

See the I2C doc on mapping legacy I2C port numbers to Zephyr devicetree nodes for more information on configuring the named-i2c-port node.

How to create a new charger

Add vendor,part.yaml to the charger bindings directory:

Example Template:

description: Vendor Part Charger IC

compatible: "vendor,part"

include: i2c-device.yaml

See the I2C doc for more information on configuring I2C device bindings.

Board Specific Code

Define or append to the charger_config_t global array

Example configuring an ISL923x charger chip:

const struct charger_config_t chg_chips[] = {
	{
		/* .i2c_port must match corresponding named-i2c-port child */
		.i2c_port = I2C_PORT_CHARGER,

		/* these may vary by vendor and part */
		.i2c_addr_flags = ISL923X_ADDR_FLAGS,
		.drv = &isl923x_drv,
	},
};

Threads

Enabling CONFIG_PLATFORM_EC_CHARGER also enables the charger thread described by Kconfig.tasks.

Testing and Debugging a Flashed Board

EC Console Commands

Use the charger EC console command to inspect the the chip's details and status.

Example output of uart:~$ charger:

charger
  Name:   ISL9241
  Option: 10100000110000000000000100 (0x2830004)
  Man id: 0x0049
  Dev id: 0x000e
  V_batt: 13152 (  64 - 18304,   8)
  I_batt:  2364 (   4 -  6140,   4)
  I_in:    3000 (   4 -  6140,   4)
  I_dptf: disabled

taskinfo

Use the taskinfo EC console command to inspect if the charging task was enabled.

Example output of uart:~$ taskinfo:

 Task Ready Name         Events      Time (s)  StkUsed
 0 R << idle >>       00000000 2055.869084   80/672
 1   HOOKS            00000000    5.215864  560/800
 2   CHG_RAMP         00000000    0.108705  424/672
 3   USB_CHG_P0       00000000    0.002139  368/672
 4   USB_CHG_P1       00000000    0.002132  368/672
 5   CHARGER          00000000   17.692626  488/928
 6 R MOTIONSENSE      80000002   50.203370  632/928
 7   KEYPROTO         00000000    0.008531  312/672
 8   CHIPSET          00000000    0.026394  528/800
 9   HOSTCMD          00000000    1.483327  600/800
10 R CONSOLE          00000000    0.101999  448/928
11   POWERBTN         00000000    0.001535  464/800
12   KEYSCAN          00000000    1.144058  328/672
13   PD_C0            00000000  176.510938  632/928
14   PD_C1            00000000   73.909944  624/928
15   PD_INT_C0        00000000    0.003969  472/672
16   PD_INT_C1        00000000    0.025180  512/672

pwr_avg

Use the pwr_avg EC console command to see battery charging rates.

chgstate

Use the chgstate EC console command to debug and manipulate machine charging state.

chgoverride

Use the chgoverride EC console command to disable or force charging from a specific charging enabled port. See Kconfig.charger for configuring multiple charging ports.

Use the chgsup command to view changes.

chglim

Use the chglim EC console command to set a max charger IC current and voltage charging limit.

Use the chgstate command to view changes.

chgsup

Use the chgsup EC console command to get the status of the port that is the chosen charge supplier.

Example output of uart:~$ chgsup:

port=1, type=0, cur=3000mA, vtg=15000mV, lsm=1

AP Console Commands (ectool)

chargecurrentlimit

Use the chargecurrentlimit ectool command to set the charge limit in milliamps.

Usage output of uart: # ectool chargecurrentlimit:

Usage: chargecurrentlimit <max_current_mA>

Use the chargestate ectool command to view changes.

chargecontrol

Use the chargecontrol ectool command to set whether the board is idle, discharging, or resume normal operation.

Usage output of uart: # ectool chargecontrol:

Usage: chargecontrol <normal | idle | discharge>