// SPDX-License-Identifier: GPL-2.0-or-later
/*
* max8903_charger.c - Maxim 8903 USB/Adapter Charger Driver
*
* Copyright (C) 2011 Samsung Electronics
* MyungJoo Ham <[email protected]>
*/
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/power_supply.h>
#include <linux/platform_device.h>
struct max8903_data {
struct device *dev;
struct power_supply *psy;
struct power_supply_desc psy_desc;
/*
* GPIOs
* chg, flt, dcm and usus are optional.
* dok or uok must be present.
* If dok is present, cen must be present.
*/
struct gpio_desc *cen; /* Charger Enable input */
struct gpio_desc *dok; /* DC (Adapter) Power OK output */
struct gpio_desc *uok; /* USB Power OK output */
struct gpio_desc *chg; /* Charger status output */
struct gpio_desc *flt; /* Fault output */
struct gpio_desc *dcm; /* Current-Limit Mode input (1: DC, 2: USB) */
struct gpio_desc *usus; /* USB Suspend Input (1: suspended) */
bool fault;
bool usb_in;
bool ta_in;
};
static enum power_supply_property max8903_charger_props[] = {
POWER_SUPPLY_PROP_STATUS, /* Charger status output */
POWER_SUPPLY_PROP_ONLINE, /* External power source */
POWER_SUPPLY_PROP_HEALTH, /* Fault or OK */
};
static int max8903_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct max8903_data *data = power_supply_get_drvdata(psy);
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
if (data->chg) {
if (gpiod_get_value(data->chg))
/* CHG asserted */
val->intval = POWER_SUPPLY_STATUS_CHARGING;
else if (data->usb_in || data->ta_in)
val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
else
val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
}
break;
case POWER_SUPPLY_PROP_ONLINE:
val->intval = 0;
if (data->usb_in || data->ta_in)
val->intval = 1;
break;
case POWER_SUPPLY_PROP_HEALTH:
val->intval = POWER_SUPPLY_HEALTH_GOOD;
if (data->fault)
val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
break;
default:
return -EINVAL;
}
return 0;
}
static irqreturn_t max8903_dcin(int irq, void *_data)
{
struct max8903_data *data = _data;
bool ta_in;
enum power_supply_type old_type;
/*
* This means the line is asserted.
*
* The signal is active low, but the inversion is handled in the GPIO
* library as the line should be flagged GPIO_ACTIVE_LOW in the device
* tree.
*/
ta_in = gpiod_get_value(data->dok);
if (ta_in == data->ta_in)
return IRQ_HANDLED;
data->ta_in = ta_in;
/* Set Current-Limit-Mode 1:DC 0:USB */
if (data->dcm)
gpiod_set_value(data->dcm, ta_in);
/* Charger Enable / Disable */
if (data->cen) {
int val;
if (ta_in)
/* Certainly enable if DOK is asserted */
val = 1;
else if (data->usb_in)
/* Enable if the USB charger is enabled */
val = 1;
else
/* Else default-disable */
val = 0;
gpiod_set_value(data->cen, val);
}
dev_dbg(data->dev, "TA(DC-IN) Charger %s.\n", ta_in ?
"Connected" : "Disconnected");
old_type = data->psy_desc.type;
if (data->ta_in)
data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
else if (data->usb_in)
data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
else
data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
if (old_type != data->psy_desc.type)
power_supply_changed(data->psy);
return IRQ_HANDLED;
}
static irqreturn_t max8903_usbin(int irq, void *_data)
{
struct max8903_data *data = _data;
bool usb_in;
enum power_supply_type old_type;
/*
* This means the line is asserted.
*
* The signal is active low, but the inversion is handled in the GPIO
* library as the line should be flagged GPIO_ACTIVE_LOW in the device
* tree.
*/
usb_in = gpiod_get_value(data->uok);
if (usb_in == data->usb_in)
return IRQ_HANDLED;
data->usb_in = usb_in;
/* Do not touch Current-Limit-Mode */
/* Charger Enable / Disable */
if (data->cen) {
int val;
if (usb_in)
/* Certainly enable if UOK is asserted */
val = 1;
else if (data->ta_in)
/* Enable if the DC charger is enabled */
val = 1;
else
/* Else default-disable */
val = 0;
gpiod_set_value(data->cen, val);
}
dev_dbg(data->dev, "USB Charger %s.\n", usb_in ?
"Connected" : "Disconnected");
old_type = data->psy_desc.type;
if (data->ta_in)
data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
else if (data->usb_in)
data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
else
data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
if (old_type != data->psy_desc.type)
power_supply_changed(data->psy);
return IRQ_HANDLED;
}
static irqreturn_t max8903_fault(int irq, void *_data)
{
struct max8903_data *data = _data;
bool fault;
/*
* This means the line is asserted.
*
* The signal is active low, but the inversion is handled in the GPIO
* library as the line should be flagged GPIO_ACTIVE_LOW in the device
* tree.
*/
fault = gpiod_get_value(data->flt);
if (fault == data->fault)
return IRQ_HANDLED;
data->fault = fault;
if (fault)
dev_err(data->dev, "Charger suffers a fault and stops.\n");
else
dev_err(data->dev, "Charger recovered from a fault.\n");
return IRQ_HANDLED;
}
static int max8903_setup_gpios(struct platform_device *pdev)
{
struct max8903_data *data = platform_get_drvdata(pdev);
struct device *dev = &pdev->dev;
bool ta_in = false;
bool usb_in = false;
enum gpiod_flags flags;
data->dok = devm_gpiod_get_optional(dev, "dok", GPIOD_IN);
if (IS_ERR(data->dok))
return dev_err_probe(dev, PTR_ERR(data->dok),
"failed to get DOK GPIO");
if (data->dok) {
gpiod_set_consumer_name(data->dok, data->psy_desc.name);
/*
* The DC OK is pulled up to 1 and goes low when a charger
* is plugged in (active low) but in the device tree the
* line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
* here if the DC charger is plugged in.
*/
ta_in = gpiod_get_value(data->dok);
}
data->uok = devm_gpiod_get_optional(dev, "uok", GPIOD_IN);
if (IS_ERR(data->uok))
return dev_err_probe(dev, PTR_ERR(data->uok),
"failed to get UOK GPIO");
if (data->uok) {
gpiod_set_consumer_name(data->uok, data->psy_desc.name);
/*
* The USB OK is pulled up to 1 and goes low when a USB charger
* is plugged in (active low) but in the device tree the
* line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
* here if the USB charger is plugged in.
*/
usb_in = gpiod_get_value(data->uok);
}
/* Either DC OK or USB OK must be provided */
if (!data->dok && !data->uok) {
dev_err(dev, "no valid power source\n");
return -EINVAL;
}
/*
* If either charger is already connected at this point,
* assert the CEN line and enable charging from the start.
*
* The line is active low but also marked with GPIO_ACTIVE_LOW
* in the device tree, so when we assert the line with
* GPIOD_OUT_HIGH the line will be driven low.
*/
flags = (ta_in || usb_in) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
/*
* If DC OK is provided, Charger Enable CEN is compulsory
* so this is not optional here.
*/
data->cen = devm_gpiod_get(dev, "cen", flags);
if (IS_ERR(data->cen))
return dev_err_probe(dev, PTR_ERR(data->cen),
"failed to get CEN GPIO");
gpiod_set_consumer_name(data->cen, data->psy_desc.name);
/*
* If the DC charger is connected, then select it.
*
* The DCM line should be marked GPIO_ACTIVE_HIGH in the
* device tree. Driving it high will enable the DC charger
* input over the USB charger input.
*/
flags = ta_in ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
data->dcm = devm_gpiod_get_optional(dev, "dcm", flags);
if (IS_ERR(data->dcm))
return dev_err_probe(dev, PTR_ERR(data->dcm),
"failed to get DCM GPIO");
gpiod_set_consumer_name(data->dcm, data->psy_desc.name);
data->chg = devm_gpiod_get_optional(dev, "chg", GPIOD_IN);
if (IS_ERR(data->chg))
return dev_err_probe(dev, PTR_ERR(data->chg),
"failed to get CHG GPIO");
gpiod_set_consumer_name(data->chg, data->psy_desc.name);
data->flt = devm_gpiod_get_optional(dev, "flt", GPIOD_IN);
if (IS_ERR(data->flt))
return dev_err_probe(dev, PTR_ERR(data->flt),
"failed to get FLT GPIO");
gpiod_set_consumer_name(data->flt, data->psy_desc.name);
data->usus = devm_gpiod_get_optional(dev, "usus", GPIOD_IN);
if (IS_ERR(data->usus))
return dev_err_probe(dev, PTR_ERR(data->usus),
"failed to get USUS GPIO");
gpiod_set_consumer_name(data->usus, data->psy_desc.name);
data->fault = false;
data->ta_in = ta_in;
data->usb_in = usb_in;
return 0;
}
static int max8903_probe(struct platform_device *pdev)
{
struct max8903_data *data;
struct device *dev = &pdev->dev;
struct power_supply_config psy_cfg = {};
int ret = 0;
data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->dev = dev;
platform_set_drvdata(pdev, data);
ret = max8903_setup_gpios(pdev);
if (ret)
return ret;
data->psy_desc.name = "max8903_charger";
data->psy_desc.type = (data->ta_in) ? POWER_SUPPLY_TYPE_MAINS :
((data->usb_in) ? POWER_SUPPLY_TYPE_USB :
POWER_SUPPLY_TYPE_BATTERY);
data->psy_desc.get_property = max8903_get_property;
data->psy_desc.properties = max8903_charger_props;
data->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props);
psy_cfg.of_node = dev->of_node;
psy_cfg.drv_data = data;
data->psy = devm_power_supply_register(dev, &data->psy_desc, &psy_cfg);
if (IS_ERR(data->psy)) {
dev_err(dev, "failed: power supply register.\n");
return PTR_ERR(data->psy);
}
if (data->dok) {
ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->dok),
NULL, max8903_dcin,
IRQF_TRIGGER_FALLING |
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
"MAX8903 DC IN", data);
if (ret) {
dev_err(dev, "Cannot request irq %d for DC (%d)\n",
gpiod_to_irq(data->dok), ret);
return ret;
}
}
if (data->uok) {
ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->uok),
NULL, max8903_usbin,
IRQF_TRIGGER_FALLING |
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
"MAX8903 USB IN", data);
if (ret) {
dev_err(dev, "Cannot request irq %d for USB (%d)\n",
gpiod_to_irq(data->uok), ret);
return ret;
}
}
if (data->flt) {
ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->flt),
NULL, max8903_fault,
IRQF_TRIGGER_FALLING |
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
"MAX8903 Fault", data);
if (ret) {
dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
gpiod_to_irq(data->flt), ret);
return ret;
}
}
return 0;
}
static const struct of_device_id max8903_match_ids[] = {
{ .compatible = "maxim,max8903", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, max8903_match_ids);
static struct platform_driver max8903_driver = {
.probe = max8903_probe,
.driver = {
.name = "max8903-charger",
.of_match_table = max8903_match_ids
},
};
module_platform_driver(max8903_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MAX8903 Charger Driver");
MODULE_AUTHOR("MyungJoo Ham <[email protected]>");
MODULE_ALIAS("platform:max8903-charger");
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