401 lines
10 KiB
C
401 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
|
|
* Driver for chargers which report their online status through a GPIO pin
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/init.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/power_supply.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/of.h>
|
|
#include <linux/gpio/consumer.h>
|
|
|
|
#include <linux/power/gpio-charger.h>
|
|
|
|
struct gpio_mapping {
|
|
u32 limit_ua;
|
|
u32 gpiodata;
|
|
} __packed;
|
|
|
|
struct gpio_charger {
|
|
struct device *dev;
|
|
unsigned int irq;
|
|
unsigned int charge_status_irq;
|
|
bool wakeup_enabled;
|
|
|
|
struct power_supply *charger;
|
|
struct power_supply_desc charger_desc;
|
|
struct gpio_desc *gpiod;
|
|
struct gpio_desc *charge_status;
|
|
|
|
struct gpio_descs *current_limit_gpios;
|
|
struct gpio_mapping *current_limit_map;
|
|
u32 current_limit_map_size;
|
|
u32 charge_current_limit;
|
|
};
|
|
|
|
static irqreturn_t gpio_charger_irq(int irq, void *devid)
|
|
{
|
|
struct power_supply *charger = devid;
|
|
|
|
power_supply_changed(charger);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
|
|
{
|
|
return power_supply_get_drvdata(psy);
|
|
}
|
|
|
|
static int set_charge_current_limit(struct gpio_charger *gpio_charger, int val)
|
|
{
|
|
struct gpio_mapping mapping;
|
|
int ndescs = gpio_charger->current_limit_gpios->ndescs;
|
|
struct gpio_desc **gpios = gpio_charger->current_limit_gpios->desc;
|
|
int i;
|
|
|
|
if (!gpio_charger->current_limit_map_size)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < gpio_charger->current_limit_map_size; i++) {
|
|
if (gpio_charger->current_limit_map[i].limit_ua <= val)
|
|
break;
|
|
}
|
|
mapping = gpio_charger->current_limit_map[i];
|
|
|
|
for (i = 0; i < ndescs; i++) {
|
|
bool val = (mapping.gpiodata >> i) & 1;
|
|
gpiod_set_value_cansleep(gpios[ndescs-i-1], val);
|
|
}
|
|
|
|
gpio_charger->charge_current_limit = mapping.limit_ua;
|
|
|
|
dev_dbg(gpio_charger->dev, "set charge current limit to %d (requested: %d)\n",
|
|
gpio_charger->charge_current_limit, val);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gpio_charger_get_property(struct power_supply *psy,
|
|
enum power_supply_property psp, union power_supply_propval *val)
|
|
{
|
|
struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
|
|
|
|
switch (psp) {
|
|
case POWER_SUPPLY_PROP_ONLINE:
|
|
val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
|
|
break;
|
|
case POWER_SUPPLY_PROP_STATUS:
|
|
if (gpiod_get_value_cansleep(gpio_charger->charge_status))
|
|
val->intval = POWER_SUPPLY_STATUS_CHARGING;
|
|
else
|
|
val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
|
|
break;
|
|
case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
|
|
val->intval = gpio_charger->charge_current_limit;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gpio_charger_set_property(struct power_supply *psy,
|
|
enum power_supply_property psp, const union power_supply_propval *val)
|
|
{
|
|
struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
|
|
|
|
switch (psp) {
|
|
case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
|
|
return set_charge_current_limit(gpio_charger, val->intval);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gpio_charger_property_is_writeable(struct power_supply *psy,
|
|
enum power_supply_property psp)
|
|
{
|
|
switch (psp) {
|
|
case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
|
|
return 1;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static enum power_supply_type gpio_charger_get_type(struct device *dev)
|
|
{
|
|
const char *chargetype;
|
|
|
|
if (!device_property_read_string(dev, "charger-type", &chargetype)) {
|
|
if (!strcmp("unknown", chargetype))
|
|
return POWER_SUPPLY_TYPE_UNKNOWN;
|
|
if (!strcmp("battery", chargetype))
|
|
return POWER_SUPPLY_TYPE_BATTERY;
|
|
if (!strcmp("ups", chargetype))
|
|
return POWER_SUPPLY_TYPE_UPS;
|
|
if (!strcmp("mains", chargetype))
|
|
return POWER_SUPPLY_TYPE_MAINS;
|
|
if (!strcmp("usb-sdp", chargetype))
|
|
return POWER_SUPPLY_TYPE_USB;
|
|
if (!strcmp("usb-dcp", chargetype))
|
|
return POWER_SUPPLY_TYPE_USB;
|
|
if (!strcmp("usb-cdp", chargetype))
|
|
return POWER_SUPPLY_TYPE_USB;
|
|
if (!strcmp("usb-aca", chargetype))
|
|
return POWER_SUPPLY_TYPE_USB;
|
|
}
|
|
dev_warn(dev, "unknown charger type %s\n", chargetype);
|
|
|
|
return POWER_SUPPLY_TYPE_UNKNOWN;
|
|
}
|
|
|
|
static int gpio_charger_get_irq(struct device *dev, void *dev_id,
|
|
struct gpio_desc *gpio)
|
|
{
|
|
int ret, irq = gpiod_to_irq(gpio);
|
|
|
|
if (irq > 0) {
|
|
ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq,
|
|
IRQF_TRIGGER_RISING |
|
|
IRQF_TRIGGER_FALLING,
|
|
dev_name(dev),
|
|
dev_id);
|
|
if (ret < 0) {
|
|
dev_warn(dev, "Failed to request irq: %d\n", ret);
|
|
irq = 0;
|
|
}
|
|
}
|
|
|
|
return irq;
|
|
}
|
|
|
|
static int init_charge_current_limit(struct device *dev,
|
|
struct gpio_charger *gpio_charger)
|
|
{
|
|
int i, len;
|
|
u32 cur_limit = U32_MAX;
|
|
|
|
gpio_charger->current_limit_gpios = devm_gpiod_get_array_optional(dev,
|
|
"charge-current-limit", GPIOD_OUT_LOW);
|
|
if (IS_ERR(gpio_charger->current_limit_gpios)) {
|
|
dev_err(dev, "error getting current-limit GPIOs\n");
|
|
return PTR_ERR(gpio_charger->current_limit_gpios);
|
|
}
|
|
|
|
if (!gpio_charger->current_limit_gpios)
|
|
return 0;
|
|
|
|
len = device_property_read_u32_array(dev, "charge-current-limit-mapping",
|
|
NULL, 0);
|
|
if (len < 0)
|
|
return len;
|
|
|
|
if (len == 0 || len % 2) {
|
|
dev_err(dev, "invalid charge-current-limit-mapping length\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
gpio_charger->current_limit_map = devm_kmalloc_array(dev,
|
|
len / 2, sizeof(*gpio_charger->current_limit_map), GFP_KERNEL);
|
|
if (!gpio_charger->current_limit_map)
|
|
return -ENOMEM;
|
|
|
|
gpio_charger->current_limit_map_size = len / 2;
|
|
|
|
len = device_property_read_u32_array(dev, "charge-current-limit-mapping",
|
|
(u32*) gpio_charger->current_limit_map, len);
|
|
if (len < 0)
|
|
return len;
|
|
|
|
for (i=0; i < gpio_charger->current_limit_map_size; i++) {
|
|
if (gpio_charger->current_limit_map[i].limit_ua > cur_limit) {
|
|
dev_err(dev, "charge-current-limit-mapping not sorted by current in descending order\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
cur_limit = gpio_charger->current_limit_map[i].limit_ua;
|
|
}
|
|
|
|
/* default to smallest current limitation for safety reasons */
|
|
len = gpio_charger->current_limit_map_size - 1;
|
|
set_charge_current_limit(gpio_charger,
|
|
gpio_charger->current_limit_map[len].limit_ua);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* The entries will be overwritten by driver's probe routine depending
|
|
* on the available features. This list ensures, that the array is big
|
|
* enough for all optional features.
|
|
*/
|
|
static enum power_supply_property gpio_charger_properties[] = {
|
|
POWER_SUPPLY_PROP_ONLINE,
|
|
POWER_SUPPLY_PROP_STATUS,
|
|
POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
|
|
};
|
|
|
|
static int gpio_charger_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
const struct gpio_charger_platform_data *pdata = dev->platform_data;
|
|
struct power_supply_config psy_cfg = {};
|
|
struct gpio_charger *gpio_charger;
|
|
struct power_supply_desc *charger_desc;
|
|
struct gpio_desc *charge_status;
|
|
int charge_status_irq;
|
|
int ret;
|
|
int num_props = 0;
|
|
|
|
if (!pdata && !dev->of_node) {
|
|
dev_err(dev, "No platform data\n");
|
|
return -ENOENT;
|
|
}
|
|
|
|
gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
|
|
if (!gpio_charger)
|
|
return -ENOMEM;
|
|
gpio_charger->dev = dev;
|
|
|
|
/*
|
|
* This will fetch a GPIO descriptor from device tree, ACPI or
|
|
* boardfile descriptor tables. It's good to try this first.
|
|
*/
|
|
gpio_charger->gpiod = devm_gpiod_get_optional(dev, NULL, GPIOD_IN);
|
|
if (IS_ERR(gpio_charger->gpiod)) {
|
|
/* Just try again if this happens */
|
|
return dev_err_probe(dev, PTR_ERR(gpio_charger->gpiod),
|
|
"error getting GPIO descriptor\n");
|
|
}
|
|
|
|
if (gpio_charger->gpiod) {
|
|
gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_ONLINE;
|
|
num_props++;
|
|
}
|
|
|
|
charge_status = devm_gpiod_get_optional(dev, "charge-status", GPIOD_IN);
|
|
if (IS_ERR(charge_status))
|
|
return PTR_ERR(charge_status);
|
|
if (charge_status) {
|
|
gpio_charger->charge_status = charge_status;
|
|
gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_STATUS;
|
|
num_props++;
|
|
}
|
|
|
|
ret = init_charge_current_limit(dev, gpio_charger);
|
|
if (ret < 0)
|
|
return ret;
|
|
if (gpio_charger->current_limit_map) {
|
|
gpio_charger_properties[num_props] =
|
|
POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX;
|
|
num_props++;
|
|
}
|
|
|
|
charger_desc = &gpio_charger->charger_desc;
|
|
charger_desc->properties = gpio_charger_properties;
|
|
charger_desc->num_properties = num_props;
|
|
charger_desc->get_property = gpio_charger_get_property;
|
|
charger_desc->set_property = gpio_charger_set_property;
|
|
charger_desc->property_is_writeable =
|
|
gpio_charger_property_is_writeable;
|
|
|
|
psy_cfg.of_node = dev->of_node;
|
|
psy_cfg.drv_data = gpio_charger;
|
|
|
|
if (pdata) {
|
|
charger_desc->name = pdata->name;
|
|
charger_desc->type = pdata->type;
|
|
psy_cfg.supplied_to = pdata->supplied_to;
|
|
psy_cfg.num_supplicants = pdata->num_supplicants;
|
|
} else {
|
|
charger_desc->name = dev->of_node->name;
|
|
charger_desc->type = gpio_charger_get_type(dev);
|
|
}
|
|
|
|
if (!charger_desc->name)
|
|
charger_desc->name = pdev->name;
|
|
|
|
gpio_charger->charger = devm_power_supply_register(dev, charger_desc,
|
|
&psy_cfg);
|
|
if (IS_ERR(gpio_charger->charger)) {
|
|
ret = PTR_ERR(gpio_charger->charger);
|
|
dev_err(dev, "Failed to register power supply: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
gpio_charger->irq = gpio_charger_get_irq(dev, gpio_charger->charger,
|
|
gpio_charger->gpiod);
|
|
|
|
charge_status_irq = gpio_charger_get_irq(dev, gpio_charger->charger,
|
|
gpio_charger->charge_status);
|
|
gpio_charger->charge_status_irq = charge_status_irq;
|
|
|
|
platform_set_drvdata(pdev, gpio_charger);
|
|
|
|
device_init_wakeup(dev, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int gpio_charger_suspend(struct device *dev)
|
|
{
|
|
struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
|
|
|
|
if (device_may_wakeup(dev))
|
|
gpio_charger->wakeup_enabled =
|
|
!enable_irq_wake(gpio_charger->irq);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gpio_charger_resume(struct device *dev)
|
|
{
|
|
struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
|
|
|
|
if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
|
|
disable_irq_wake(gpio_charger->irq);
|
|
power_supply_changed(gpio_charger->charger);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
|
|
gpio_charger_suspend, gpio_charger_resume);
|
|
|
|
static const struct of_device_id gpio_charger_match[] = {
|
|
{ .compatible = "gpio-charger" },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, gpio_charger_match);
|
|
|
|
static struct platform_driver gpio_charger_driver = {
|
|
.probe = gpio_charger_probe,
|
|
.driver = {
|
|
.name = "gpio-charger",
|
|
.pm = &gpio_charger_pm_ops,
|
|
.of_match_table = gpio_charger_match,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(gpio_charger_driver);
|
|
|
|
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
|
|
MODULE_DESCRIPTION("Driver for chargers only communicating via GPIO(s)");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:gpio-charger");
|