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path: root/drivers/power/supply/ltc3651-charger.c
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Diffstat (limited to 'drivers/power/supply/ltc3651-charger.c')
-rw-r--r--drivers/power/supply/ltc3651-charger.c210
1 files changed, 210 insertions, 0 deletions
diff --git a/drivers/power/supply/ltc3651-charger.c b/drivers/power/supply/ltc3651-charger.c
new file mode 100644
index 000000000000..eea63ff211c4
--- /dev/null
+++ b/drivers/power/supply/ltc3651-charger.c
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2017, Topic Embedded Products
+ * Driver for LTC3651 charger IC.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/gpio/consumer.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>
+
+struct ltc3651_charger {
+ struct power_supply *charger;
+ struct power_supply_desc charger_desc;
+ struct gpio_desc *acpr_gpio;
+ struct gpio_desc *fault_gpio;
+ struct gpio_desc *chrg_gpio;
+};
+
+static irqreturn_t ltc3651_charger_irq(int irq, void *devid)
+{
+ struct power_supply *charger = devid;
+
+ power_supply_changed(charger);
+
+ return IRQ_HANDLED;
+}
+
+static inline struct ltc3651_charger *psy_to_ltc3651_charger(
+ struct power_supply *psy)
+{
+ return power_supply_get_drvdata(psy);
+}
+
+static int ltc3651_charger_get_property(struct power_supply *psy,
+ enum power_supply_property psp, union power_supply_propval *val)
+{
+ struct ltc3651_charger *ltc3651_charger = psy_to_ltc3651_charger(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ if (!ltc3651_charger->chrg_gpio) {
+ val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+ break;
+ }
+ if (gpiod_get_value(ltc3651_charger->chrg_gpio))
+ val->intval = POWER_SUPPLY_STATUS_CHARGING;
+ else
+ val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+ break;
+ case POWER_SUPPLY_PROP_ONLINE:
+ val->intval = gpiod_get_value(ltc3651_charger->acpr_gpio);
+ break;
+ case POWER_SUPPLY_PROP_HEALTH:
+ if (!ltc3651_charger->fault_gpio) {
+ val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
+ break;
+ }
+ if (!gpiod_get_value(ltc3651_charger->fault_gpio)) {
+ val->intval = POWER_SUPPLY_HEALTH_GOOD;
+ break;
+ }
+ /*
+ * If the fault pin is active, the chrg pin explains the type
+ * of failure.
+ */
+ if (!ltc3651_charger->chrg_gpio) {
+ val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+ break;
+ }
+ val->intval = gpiod_get_value(ltc3651_charger->chrg_gpio) ?
+ POWER_SUPPLY_HEALTH_OVERHEAT :
+ POWER_SUPPLY_HEALTH_DEAD;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static enum power_supply_property ltc3651_charger_properties[] = {
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_HEALTH,
+};
+
+static int ltc3651_charger_probe(struct platform_device *pdev)
+{
+ struct power_supply_config psy_cfg = {};
+ struct ltc3651_charger *ltc3651_charger;
+ struct power_supply_desc *charger_desc;
+ int ret;
+
+ ltc3651_charger = devm_kzalloc(&pdev->dev, sizeof(*ltc3651_charger),
+ GFP_KERNEL);
+ if (!ltc3651_charger)
+ return -ENOMEM;
+
+ ltc3651_charger->acpr_gpio = devm_gpiod_get(&pdev->dev,
+ "lltc,acpr", GPIOD_IN);
+ if (IS_ERR(ltc3651_charger->acpr_gpio)) {
+ ret = PTR_ERR(ltc3651_charger->acpr_gpio);
+ dev_err(&pdev->dev, "Failed to acquire acpr GPIO: %d\n", ret);
+ return ret;
+ }
+ ltc3651_charger->fault_gpio = devm_gpiod_get_optional(&pdev->dev,
+ "lltc,fault", GPIOD_IN);
+ if (IS_ERR(ltc3651_charger->fault_gpio)) {
+ ret = PTR_ERR(ltc3651_charger->fault_gpio);
+ dev_err(&pdev->dev, "Failed to acquire fault GPIO: %d\n", ret);
+ return ret;
+ }
+ ltc3651_charger->chrg_gpio = devm_gpiod_get_optional(&pdev->dev,
+ "lltc,chrg", GPIOD_IN);
+ if (IS_ERR(ltc3651_charger->chrg_gpio)) {
+ ret = PTR_ERR(ltc3651_charger->chrg_gpio);
+ dev_err(&pdev->dev, "Failed to acquire chrg GPIO: %d\n", ret);
+ return ret;
+ }
+
+ charger_desc = &ltc3651_charger->charger_desc;
+ charger_desc->name = pdev->dev.of_node->name;
+ charger_desc->type = POWER_SUPPLY_TYPE_MAINS;
+ charger_desc->properties = ltc3651_charger_properties;
+ charger_desc->num_properties = ARRAY_SIZE(ltc3651_charger_properties);
+ charger_desc->get_property = ltc3651_charger_get_property;
+ psy_cfg.of_node = pdev->dev.of_node;
+ psy_cfg.drv_data = ltc3651_charger;
+
+ ltc3651_charger->charger = devm_power_supply_register(&pdev->dev,
+ charger_desc, &psy_cfg);
+ if (IS_ERR(ltc3651_charger->charger)) {
+ ret = PTR_ERR(ltc3651_charger->charger);
+ dev_err(&pdev->dev, "Failed to register power supply: %d\n",
+ ret);
+ return ret;
+ }
+
+ /*
+ * Acquire IRQs for the GPIO pins if possible. If the system does not
+ * support IRQs on these pins, userspace will have to poll the sysfs
+ * files manually.
+ */
+ if (ltc3651_charger->acpr_gpio) {
+ ret = gpiod_to_irq(ltc3651_charger->acpr_gpio);
+ if (ret >= 0)
+ ret = devm_request_any_context_irq(&pdev->dev, ret,
+ ltc3651_charger_irq,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ dev_name(&pdev->dev), ltc3651_charger->charger);
+ if (ret < 0)
+ dev_warn(&pdev->dev, "Failed to request acpr irq\n");
+ }
+ if (ltc3651_charger->fault_gpio) {
+ ret = gpiod_to_irq(ltc3651_charger->fault_gpio);
+ if (ret >= 0)
+ ret = devm_request_any_context_irq(&pdev->dev, ret,
+ ltc3651_charger_irq,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ dev_name(&pdev->dev), ltc3651_charger->charger);
+ if (ret < 0)
+ dev_warn(&pdev->dev, "Failed to request fault irq\n");
+ }
+ if (ltc3651_charger->chrg_gpio) {
+ ret = gpiod_to_irq(ltc3651_charger->chrg_gpio);
+ if (ret >= 0)
+ ret = devm_request_any_context_irq(&pdev->dev, ret,
+ ltc3651_charger_irq,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ dev_name(&pdev->dev), ltc3651_charger->charger);
+ if (ret < 0)
+ dev_warn(&pdev->dev, "Failed to request chrg irq\n");
+ }
+
+ platform_set_drvdata(pdev, ltc3651_charger);
+
+ return 0;
+}
+
+static const struct of_device_id ltc3651_charger_match[] = {
+ { .compatible = "lltc,ltc3651-charger" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ltc3651_charger_match);
+
+static struct platform_driver ltc3651_charger_driver = {
+ .probe = ltc3651_charger_probe,
+ .driver = {
+ .name = "ltc3651-charger",
+ .of_match_table = ltc3651_charger_match,
+ },
+};
+
+module_platform_driver(ltc3651_charger_driver);
+
+MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
+MODULE_DESCRIPTION("Driver for LTC3651 charger");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ltc3651-charger");