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path: root/drivers/power/supply/gpio-charger.c
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-rw-r--r--drivers/power/supply/gpio-charger.c400
1 files changed, 400 insertions, 0 deletions
diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c
new file mode 100644
index 000000000..68212b397
--- /dev/null
+++ b/drivers/power/supply/gpio-charger.c
@@ -0,0 +1,400 @@
+// 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");