power: supply: bq24190_charger: Use extcon to determine ilimit, 5v boost

Add support for monitoring an extcon device with USB SDP/CDP/DCP and HOST
cables and adjust ilimit and enable/disable the 5V boost converter
accordingly. This is necessary on systems where the PSEL pin is hardwired
high and ILIM needs to be set by software based on the detected charger
type, as well as on systems where the 5V boost converter is used, as
that always needs to be enabled from software.

Cc: Liam Breck <kernel@networkimprov.net>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/supply/Kconfig

@@ -438,6 +438,7 @@ config CHARGER_BQ2415X
 config CHARGER_BQ24190
 	tristate "TI BQ24190 battery charger driver"
 	depends on I2C
+	depends on EXTCON
 	depends on GPIOLIB || COMPILE_TEST
 	help
 	  Say Y to enable support for the TI BQ24190 battery charger.

drivers/power/supply/bq24190_charger.c

@@ -11,10 +11,12 @@
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
+#include <linux/extcon.h>
 #include <linux/of_irq.h>
 #include <linux/of_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/power_supply.h>
+#include <linux/workqueue.h>
 #include <linux/gpio.h>
 #include <linux/i2c.h>
 
@@ -36,6 +38,8 @@
 #define BQ24190_REG_POC_WDT_RESET_SHIFT		6
 #define BQ24190_REG_POC_CHG_CONFIG_MASK		(BIT(5) | BIT(4))
 #define BQ24190_REG_POC_CHG_CONFIG_SHIFT	4
+#define BQ24190_REG_POC_CHG_CONFIG_CHARGE	1
+#define BQ24190_REG_POC_CHG_CONFIG_OTG		2
 #define BQ24190_REG_POC_SYS_MIN_MASK		(BIT(3) | BIT(2) | BIT(1))
 #define BQ24190_REG_POC_SYS_MIN_SHIFT		1
 #define BQ24190_REG_POC_BOOST_LIM_MASK		BIT(0)
@@ -148,6 +152,9 @@ struct bq24190_dev_info {
 	struct device			*dev;
 	struct power_supply		*charger;
 	struct power_supply		*battery;
+	struct extcon_dev		*extcon;
+	struct notifier_block		extcon_nb;
+	struct delayed_work		extcon_work;
 	char				model_name[I2C_NAME_SIZE];
 	bool				initialized;
 	bool				irq_event;
@@ -164,6 +171,11 @@ struct bq24190_dev_info {
  * number at that index in the array is the real-world value that it
  * represents.
  */
+
+/* REG00[2:0] (IINLIM) in uAh */
+static const int bq24190_iinlim_values[] = {
+	100000, 150000, 500000, 900000, 1200000, 1500000, 2000000, 3000000 };
+
 /* REG02[7:2] (ICHG) in uAh */
 static const int bq24190_ccc_ichg_values[] = {
 	 512000,  576000,  640000,  704000,  768000,  832000,  896000,  960000,
@@ -1277,6 +1289,78 @@ static irqreturn_t bq24190_irq_handler_thread(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static void bq24190_extcon_work(struct work_struct *work)
+{
+	struct bq24190_dev_info *bdi =
+		container_of(work, struct bq24190_dev_info, extcon_work.work);
+	int ret, iinlim = 0;
+
+	ret = pm_runtime_get_sync(bdi->dev);
+	if (ret < 0) {
+		dev_err(bdi->dev, "Error getting runtime-pm ref: %d\n", ret);
+		return;
+	}
+
+	if (extcon_get_state(bdi->extcon, EXTCON_CHG_USB_SDP) == 1)
+		iinlim = 500000;
+	else if (extcon_get_state(bdi->extcon, EXTCON_CHG_USB_CDP) == 1 ||
+		 extcon_get_state(bdi->extcon, EXTCON_CHG_USB_ACA) == 1)
+		iinlim = 1500000;
+	else if (extcon_get_state(bdi->extcon, EXTCON_CHG_USB_DCP) == 1)
+		iinlim = 2000000;
+
+	if (iinlim) {
+		ret = bq24190_set_field_val(bdi, BQ24190_REG_ISC,
+				BQ24190_REG_ISC_IINLIM_MASK,
+				BQ24190_REG_ISC_IINLIM_SHIFT,
+				bq24190_iinlim_values,
+				ARRAY_SIZE(bq24190_iinlim_values),
+				iinlim);
+		if (ret)
+			dev_err(bdi->dev, "Can't set IINLIM: %d\n", ret);
+	}
+
+	/*
+	 * If no charger has been detected and host mode is requested, activate
+	 * the 5V boost converter, otherwise deactivate it.
+	 */
+	if (!iinlim && extcon_get_state(bdi->extcon, EXTCON_USB_HOST) == 1) {
+		ret = bq24190_write_mask(bdi, BQ24190_REG_POC,
+					 BQ24190_REG_POC_CHG_CONFIG_MASK,
+					 BQ24190_REG_POC_CHG_CONFIG_SHIFT,
+					 BQ24190_REG_POC_CHG_CONFIG_OTG);
+	} else {
+		ret = bq24190_write_mask(bdi, BQ24190_REG_POC,
+					 BQ24190_REG_POC_CHG_CONFIG_MASK,
+					 BQ24190_REG_POC_CHG_CONFIG_SHIFT,
+					 BQ24190_REG_POC_CHG_CONFIG_CHARGE);
+	}
+	if (ret)
+		dev_err(bdi->dev, "Can't set CHG_CONFIG: %d\n", ret);
+
+	pm_runtime_mark_last_busy(bdi->dev);
+	pm_runtime_put_autosuspend(bdi->dev);
+}
+
+static int bq24190_extcon_event(struct notifier_block *nb, unsigned long event,
+				void *param)
+{
+	struct bq24190_dev_info *bdi =
+		container_of(nb, struct bq24190_dev_info, extcon_nb);
+
+	/*
+	 * The Power-Good detection may take up to 220ms, sometimes
+	 * the external charger detection is quicker, and the bq24190 will
+	 * reset to iinlim based on its own charger detection (which is not
+	 * hooked up when using external charger detection) resulting in
+	 * a too low default 500mA iinlim. Delay applying the extcon value
+	 * for 300ms to avoid this.
+	 */
+	queue_delayed_work(system_wq, &bdi->extcon_work, msecs_to_jiffies(300));
+
+	return NOTIFY_OK;
+}
+
 static int bq24190_hw_init(struct bq24190_dev_info *bdi)
 {
 	u8 v;
@@ -1314,6 +1398,7 @@ static int bq24190_probe(struct i2c_client *client,
 	struct device *dev = &client->dev;
 	struct power_supply_config charger_cfg = {}, battery_cfg = {};
 	struct bq24190_dev_info *bdi;
+	const char *name;
 	int ret;
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
@@ -1341,6 +1426,18 @@ static int bq24190_probe(struct i2c_client *client,
 		return -EINVAL;
 	}
 
+	/*
+	 * The extcon-name property is purely an in kernel interface for
+	 * x86/ACPI use, DT platforms should get extcon via phandle.
+	 */
+	if (device_property_read_string(dev, "extcon-name", &name) == 0) {
+		bdi->extcon = extcon_get_extcon_dev(name);
+		if (!bdi->extcon)
+			return -EPROBE_DEFER;
+
+		dev_info(bdi->dev, "using extcon device %s\n", name);
+	}
+
 	pm_runtime_enable(dev);
 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_set_autosuspend_delay(dev, 600);
@@ -1391,6 +1488,18 @@ static int bq24190_probe(struct i2c_client *client,
 		goto out5;
 	}
 
+	if (bdi->extcon) {
+		INIT_DELAYED_WORK(&bdi->extcon_work, bq24190_extcon_work);
+		bdi->extcon_nb.notifier_call = bq24190_extcon_event;
+		ret = devm_extcon_register_notifier(dev, bdi->extcon, -1,
+						    &bdi->extcon_nb);
+		if (ret)
+			goto out5;
+
+		/* Sync initial cable state */
+		queue_delayed_work(system_wq, &bdi->extcon_work, 0);
+	}
+
 	enable_irq_wake(client->irq);
 
 	pm_runtime_mark_last_busy(dev);