The MAX14656 USB charger detector, also known as "AL32" is used to detect
the presence and capabilities of attached USB chargers. The device is
attached via I2C plus one interrupt line to signalize events.
The device can be found in LG smartphones like LS665 and LS770, compatible
devices are present in 4th/5th generation Amazon Kindle readers referenced
in source code packages as "Maxim AL32".
The initial version of this driver has been extracted from LG source code
package LGLS665_Android_Lollipop_LS665ZV3, enriched with information from
the Kindle_src_4.1.3 source code package and adapted to the current power
class sysfs interface. Non-Standard Apple chargers which the device may
detect are mapped to the USB Battery Charging Specification Revision 1.2
class USB_DCP.
Signed-off-by: Alexander Kurz <akurz@xxxxxxxx>
---
drivers/power/supply/Kconfig | 10 +
drivers/power/supply/Makefile | 1 +
drivers/power/supply/max14656_charger_detector.c | 326 +++++++++++++++++++++++
3 files changed, 337 insertions(+)
create mode 100644 drivers/power/supply/max14656_charger_detector.c
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 76806a0..58d5ec4 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -370,6 +370,16 @@ config CHARGER_MAX14577
Say Y to enable support for the battery charger control sysfs and
platform data of MAX14577/77836 MUICs.
+config CHARGER_DETECTOR_MAX14656
+ tristate "Maxim MAX14656 USB charger detector"
+ depends on I2C
+ depends on OF
+ help
+ Say Y to enable support for the Maxim MAX14656 USB charger detector.
+ The device is compliant with the USB Battery Charging Specification
+ Revision 1.2 and can be found e.g. in Kindle 4/5th generation
+ readers and certain LG devices.
+
config CHARGER_MAX77693
tristate "Maxim MAX77693 battery charger driver"
depends on MFD_MAX77693
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 36c599d..a703ef0 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_CHARGER_LP8788) += lp8788-charger.o
obj-$(CONFIG_CHARGER_GPIO) += gpio-charger.o
obj-$(CONFIG_CHARGER_MANAGER) += charger-manager.o
obj-$(CONFIG_CHARGER_MAX14577) += max14577_charger.o
+obj-$(CONFIG_CHARGER_DETECTOR_MAX14656) += max14656_charger_detector.o
obj-$(CONFIG_CHARGER_MAX77693) += max77693_charger.o
obj-$(CONFIG_CHARGER_MAX8997) += max8997_charger.o
obj-$(CONFIG_CHARGER_MAX8998) += max8998_charger.o
diff --git a/drivers/power/supply/max14656_charger_detector.c b/drivers/power/supply/max14656_charger_detector.c
new file mode 100644
index 0000000..2fd73e1
--- /dev/null
+++ b/drivers/power/supply/max14656_charger_detector.c
@@ -0,0 +1,326 @@
+/*
+ * Maxim MAX14656 / AL32 USB Charger Detector driver
+ *
+ * Copyright (C) 2014 LG Electronics, Inc
+ * Copyright (C) 2016 Alexander Kurz <akurz@xxxxxxxx>
+ *
+ * Components from Maxim AL32 Charger detection Driver for MX50 Yoshi Board
+ * Copyright (C) Amazon Technologies Inc. All rights reserved.
+ * Manish Lachwani (lachwani@xxxxxxxxxx)
+ *
+ * This package is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/of_device.h>
+#include <linux/workqueue.h>
+#include <linux/power_supply.h>
+
+#define MAX14656_MANUFACTURER "Maxim Integrated"
+#define MAX14656_NAME "max14656"
+
+#define MAX14656_DEVICE_ID 0x00
+#define MAX14656_INTERRUPT_1 0x01
+#define MAX14656_INTERRUPT_2 0x02
+#define MAX14656_STATUS_1 0x03
+#define MAX14656_STATUS_2 0x04
+#define MAX14656_INTMASK_1 0x05
+#define MAX14656_INTMASK_2 0x06
+#define MAX14656_CONTROL_1 0x07
+#define MAX14656_CONTROL_2 0x08
+#define MAX14656_CONTROL_3 0x09
+
+#define DEVICE_VENDOR_MASK 0xf0
+#define DEVICE_REV_MASK 0x0f
+#define INT_EN_REG_MASK BIT(4)
+#define CHG_TYPE_INT_MASK BIT(0)
+#define STATUS1_VB_VALID_MASK BIT(4)
+#define STATUS1_CHG_TYPE_MASK 0xf
+#define INT1_DCD_TIMEOUT_MASK BIT(7)
+#define CONTROL1_DEFAULT 0x0d
+#define CONTROL1_INT_EN BIT(4)
+#define CONTROL1_INT_ACTIVE_HIGH BIT(5)
+#define CONTROL1_EDGE BIT(7)
+#define CONTROL2_DEFAULT 0x8e
+#define CONTROL2_ADC_EN BIT(0)
+#define CONTROL3_DEFAULT 0x8d
+
+enum max14656_chg_type {
+ MAX14656_NO_CHARGER = 0,
+ MAX14656_SDP_CHARGER,
+ MAX14656_CDP_CHARGER,
+ MAX14656_DCP_CHARGER,
+ MAX14656_APPLE_500MA_CHARGER,
+ MAX14656_APPLE_1A_CHARGER,
+ MAX14656_APPLE_2A_CHARGER,
+ MAX14656_SPECIAL_500MA_CHARGER,
+ MAX14656_APPLE_12W,
+ MAX14656_CHARGER_LAST
+};
+
+static const struct max14656_chg_type_props {
+ enum power_supply_type type;
+} chg_type_props[] = {
+ { POWER_SUPPLY_TYPE_UNKNOWN },
+ { POWER_SUPPLY_TYPE_USB },
+ { POWER_SUPPLY_TYPE_USB_CDP },
+ { POWER_SUPPLY_TYPE_USB_DCP },
+ { POWER_SUPPLY_TYPE_USB_DCP },
+ { POWER_SUPPLY_TYPE_USB_DCP },
+ { POWER_SUPPLY_TYPE_USB_DCP },
+ { POWER_SUPPLY_TYPE_USB_DCP },
+ { POWER_SUPPLY_TYPE_USB },
+};
+
+struct max14656_chip {
+ struct i2c_client *client;
+ struct power_supply *detect_psy;
+ struct power_supply_desc psy_desc;
+ struct delayed_work irq_work;
+
+ int irq;
+ int online;
+};
+
+static int max14656_read_reg(struct i2c_client *client, int reg, u8 *val)
+{
+ s32 ret;
+
+ ret = i2c_smbus_read_byte_data(client, reg);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "i2c read fail: can't read from %02x: %d\n",
+ reg, ret);
+ return ret;
+ }
+ *val = ret;
+ return 0;
+}
+
+static int max14656_write_reg(struct i2c_client *client, int reg, u8 val)
+{
+ s32 ret;
+
+ ret = i2c_smbus_write_byte_data(client, reg, val);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "i2c write fail: can't write %02x to %02x: %d\n",
+ val, reg, ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int max14656_read_block_reg(struct i2c_client *client, u8 reg,
+ u8 length, u8 *val)
+{
+ int ret;
+
+ ret = i2c_smbus_read_i2c_block_data(client, reg, length, val);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to block read reg 0x%x: %d\n",
+ reg, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+#define REG_TOTAL_NUM 5
+static void max14656_irq_worker(struct work_struct *work)
+{
+ struct max14656_chip *chip =
+ container_of(work, struct max14656_chip, irq_work.work);
+
+ u8 buf[REG_TOTAL_NUM];
+ u8 chg_type;
+ int ret = 0;
+
+ ret = max14656_read_block_reg(chip->client, MAX14656_DEVICE_ID,
+ REG_TOTAL_NUM, buf);
+
+ if ((buf[MAX14656_STATUS_1] & STATUS1_VB_VALID_MASK) &&
+ (buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK)) {
+ chg_type = buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK;
+ if (chg_type < MAX14656_CHARGER_LAST)
+ chip->psy_desc.type = chg_type_props[chg_type].type;
+ else
+ chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
+ chip->online = 1;
+ } else {
+ chip->online = 0;
+ chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
+ }
+
+ power_supply_changed(chip->detect_psy);
+}
+
+static irqreturn_t max14656_irq(int irq, void *dev_id)
+{
+ struct max14656_chip *chip = dev_id;
+
+ schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(100));
+
+ return IRQ_HANDLED;
+}
+
+static int max14656_hw_init(struct max14656_chip *chip)
+{
+ uint8_t val = 0;
+ uint8_t rev;
+ struct i2c_client *client = chip->client;
+
+ if (max14656_read_reg(client, MAX14656_DEVICE_ID, &val))
+ return -ENODEV;
+
+ if ((val & DEVICE_VENDOR_MASK) != 0x20) {
+ dev_err(&client->dev, "wrong vendor ID %d\n",
+ ((val & DEVICE_VENDOR_MASK) >> 4));
+ return -ENODEV;
+ }
+ rev = val & DEVICE_REV_MASK;
+
+ /* Turn on ADC_EN */
+ if (max14656_write_reg(client, MAX14656_CONTROL_2, CONTROL2_ADC_EN))
+ return -EINVAL;
+
+ /* turn on interrupts and low power mode */
+ if (max14656_write_reg(client, MAX14656_CONTROL_1,
+ CONTROL1_DEFAULT |
+ CONTROL1_INT_EN |
+ CONTROL1_INT_ACTIVE_HIGH |
+ CONTROL1_EDGE))
+ return -EINVAL;
+
+ if (max14656_write_reg(client, MAX14656_INTMASK_1, 0x3))
+ return -EINVAL;
+
+ if (max14656_write_reg(client, MAX14656_INTMASK_2, 0x1))
+ return -EINVAL;
+
+ dev_info(&client->dev, "detected revision %d\n", rev);
+ return 0;
+}
+
+static int max14656_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct max14656_chip *chip = power_supply_get_drvdata(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_ONLINE:
+ val->intval = chip->online;
+ break;
+ case POWER_SUPPLY_PROP_MODEL_NAME:
+ val->strval = MAX14656_NAME;
+ break;
+ case POWER_SUPPLY_PROP_MANUFACTURER:
+ val->strval = MAX14656_MANUFACTURER;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static enum power_supply_property max14656_battery_props[] = {
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_MODEL_NAME,
+ POWER_SUPPLY_PROP_MANUFACTURER,
+};
+
+static int max14656_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+ struct device *dev = &client->dev;
+ struct power_supply_config psy_cfg = {};
+ struct max14656_chip *chip;
+ int irq = client->irq;
+ int ret = 0;
+
+ if (irq <= 0) {
+ dev_err(dev, "invalid irq number: %d\n", irq);
+ return -ENODEV;
+ }
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
+ dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
+ return -ENODEV;
+ }
+
+ chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ psy_cfg.drv_data = chip;
+ chip->client = client;
+ chip->online = 0;
+ chip->psy_desc.name = MAX14656_NAME;
+ chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
+ chip->psy_desc.properties = max14656_battery_props;
+ chip->psy_desc.num_properties = ARRAY_SIZE(max14656_battery_props);
+ chip->psy_desc.get_property = max14656_get_property;
+ chip->irq = irq;
+
+ ret = max14656_hw_init(chip);
+ if (ret)
+ return -ENODEV;
+
+ INIT_DELAYED_WORK(&chip->irq_work, max14656_irq_worker);
+
+ ret = devm_request_irq(dev, chip->irq, max14656_irq,
+ IRQF_TRIGGER_FALLING,
+ MAX14656_NAME, chip);
+ if (ret) {
+ dev_err(dev, "request_irq %d failed\n", chip->irq);
+ return -EINVAL;
+ }
+ enable_irq_wake(chip->irq);
+
+ chip->detect_psy = devm_power_supply_register(dev,
+ &chip->psy_desc, &psy_cfg);
+ if (IS_ERR(chip->detect_psy)) {
+ dev_err(dev, "power_supply_register failed\n");
+ return -EINVAL;
+ }
+
+ schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(2000));
+
+ return 0;
+}
+
+static const struct i2c_device_id max14656_id[] = {
+ { "max14656", 0 },
+ {}
+};
+
+static const struct of_device_id max14656_match_table[] = {
+ { .compatible = "maxim,max14656", },
+ {}
+};
+
+static struct i2c_driver max14656_i2c_driver = {
+ .driver = {
+ .name = "max14656",
+ .owner = THIS_MODULE,
+ .of_match_table = max14656_match_table,
+ },
+ .probe = max14656_probe,
+ .id_table = max14656_id,
+};
+module_i2c_driver(max14656_i2c_driver);
+
+MODULE_DESCRIPTION("MAX14656 USB charger detector");
+MODULE_LICENSE("GPL v2");
--
2.1.4
--
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