Commit 382099d6 authored by Hans de Goede's avatar Hans de Goede Committed by Greg Kroah-Hartman
Browse files

staging: typec: fusb302: Add support for USB2 charger detection through extcon 



The fusb302 port-controller relies on an external device doing USB2
charger-type detection.

The Intel Whiskey Cove PMIC with which the fusb302 is combined on some
X86/ACPI platforms already has a charger-type detection driver which
uses extcon to communicate the detected charger-type.

Rather then inventing a new API for USB2 charger-type detection
specifically for use with the tcpm code, this commit simply re-uses the
existing extcon API and uses that do USB2 charger detection.

Note that the "fcs,extcon-name" property name is only for kernel internal
use by X86/ACPI platform code and as such is NOT documented in
the fusb302 devicetree bindings.

Cc: "Yueyao (Nathan) Zhu" <yueyao@google.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4660e4ae

drivers/staging/typec/fusb302/fusb302.c

+49 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/debugfs.h>

#include <linux/delay.h>

#include <linux/errno.h>

#include <linux/extcon.h>

#include <linux/gpio.h>

#include <linux/i2c.h>

#include <linux/interrupt.h>
@@ -96,6 +97,7 @@ struct fusb302_chip { 


	int gpio_int_n;

	int gpio_int_n_irq;

	struct extcon_dev *extcon;



	struct workqueue_struct *wq;

	struct delayed_work bc_lvl_handler;
@@ -516,6 +518,38 @@ static int tcpm_get_vbus(struct tcpc_dev *dev) 
	return ret;

}



static int tcpm_get_current_limit(struct tcpc_dev *dev)

{

	struct fusb302_chip *chip = container_of(dev, struct fusb302_chip,

						 tcpc_dev);

	int current_limit = 0;

	unsigned long timeout;



	if (!chip->extcon)

		return 0;



	/*

	 * USB2 Charger detection may still be in progress when we get here,

	 * this can take upto 600ms, wait 800ms max.

	 */

	timeout = jiffies + msecs_to_jiffies(800);

	do {

		if (extcon_get_state(chip->extcon, EXTCON_CHG_USB_SDP) == 1)

			current_limit = 500;



		if (extcon_get_state(chip->extcon, EXTCON_CHG_USB_CDP) == 1 ||

		    extcon_get_state(chip->extcon, EXTCON_CHG_USB_ACA) == 1)

			current_limit = 1500;



		if (extcon_get_state(chip->extcon, EXTCON_CHG_USB_DCP) == 1)

			current_limit = 2000;



		msleep(50);

	} while (current_limit == 0 && time_before(jiffies, timeout));



	return current_limit;

}



static int fusb302_set_cc_pull(struct fusb302_chip *chip,

			       bool pull_up, bool pull_down)

{
@@ -1201,6 +1235,7 @@ static void init_tcpc_dev(struct tcpc_dev *fusb302_tcpc_dev) 
{

	fusb302_tcpc_dev->init = tcpm_init;

	fusb302_tcpc_dev->get_vbus = tcpm_get_vbus;

	fusb302_tcpc_dev->get_current_limit = tcpm_get_current_limit;

	fusb302_tcpc_dev->set_cc = tcpm_set_cc;

	fusb302_tcpc_dev->get_cc = tcpm_get_cc;

	fusb302_tcpc_dev->set_polarity = tcpm_set_polarity;
@@ -1685,6 +1720,7 @@ static int fusb302_probe(struct i2c_client *client, 
	struct fusb302_chip *chip;

	struct i2c_adapter *adapter;

	struct device *dev = &client->dev;

	const char *name;

	int ret = 0;

	u32 v;
@@ -1717,6 +1753,19 @@ static int fusb302_probe(struct i2c_client *client, 
	if (!device_property_read_u32(dev, "fcs,operating-sink-microwatt", &v))

		chip->tcpc_config.operating_snk_mw = v / 1000;



	/*

	 * Devicetree platforms should get extcon via phandle (not yet

	 * supported). On ACPI platforms, we get the name from a device prop.

	 * This device prop is for kernel internal use only and is expected

	 * to be set by the platform code which also registers the i2c client

	 * for the fusb302.

	 */

	if (device_property_read_string(dev, "fcs,extcon-name", &name) == 0) {

		chip->extcon = extcon_get_extcon_dev(name);

		if (!chip->extcon)

			return -EPROBE_DEFER;

	}



	ret = fusb302_debugfs_init(chip);

	if (ret < 0)

		return ret;

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