Date:   Tue, 23 May 2017 18:27:47 +0900
From:   Chanwoo Choi <cw00.choi@...sung.com>
To:     Hans de Goede <hdegoede@...hat.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>
Cc:     linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/5] extcon: Add FUSB302 USB TYPE-C controller support

Hi Hans,

I'm sorry for late reply.
I'll check this thread and then give you my opinion.

Regards,
Chanwoo Choi

On 2017년 04월 21일 22:01, Hans de Goede wrote:
> Add support for USB TYPE-C cable detection on systems using a
> FUSB302 USB TYPE-C controller.
> 
> Signed-off-by: Hans de Goede <hdegoede@...hat.com>
> ---
>  drivers/extcon/Kconfig          |   8 +
>  drivers/extcon/Makefile         |   1 +
>  drivers/extcon/extcon-fusb302.c | 782 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 791 insertions(+)
>  create mode 100644 drivers/extcon/extcon-fusb302.c
> 
> diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
> index 32f2dc8..562db5b 100644
> --- a/drivers/extcon/Kconfig
> +++ b/drivers/extcon/Kconfig
> @@ -35,6 +35,14 @@ config EXTCON_AXP288
>  	  Say Y here to enable support for USB peripheral detection
>  	  and USB MUX switching by X-Power AXP288 PMIC.
>  
> +config EXTCON_FUSB302
> +	tristate "FUSB302 USB TYPE-C controller support"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  Say Y here to enable support for USB TYPE-C cable detection using
> +	  a FUSB302 USB TYPE-C controller.
> +
>  config EXTCON_GPIO
>  	tristate "GPIO extcon support"
>  	depends on GPIOLIB || COMPILE_TEST
> diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
> index ecfa958..e5eb493 100644
> --- a/drivers/extcon/Makefile
> +++ b/drivers/extcon/Makefile
> @@ -7,6 +7,7 @@ extcon-core-objs		+= extcon.o devres.o
>  obj-$(CONFIG_EXTCON_ADC_JACK)	+= extcon-adc-jack.o
>  obj-$(CONFIG_EXTCON_ARIZONA)	+= extcon-arizona.o
>  obj-$(CONFIG_EXTCON_AXP288)	+= extcon-axp288.o
> +obj-$(CONFIG_EXTCON_FUSB302)	+= extcon-fusb302.o
>  obj-$(CONFIG_EXTCON_GPIO)	+= extcon-gpio.o
>  obj-$(CONFIG_EXTCON_INTEL_INT3496) += extcon-intel-int3496.o
>  obj-$(CONFIG_EXTCON_INTEL_CHT_WC) += extcon-intel-cht-wc.o
> diff --git a/drivers/extcon/extcon-fusb302.c b/drivers/extcon/extcon-fusb302.c
> new file mode 100644
> index 0000000..577adb9
> --- /dev/null
> +++ b/drivers/extcon/extcon-fusb302.c
> @@ -0,0 +1,782 @@
> +/*
> + * Extcon USB-C cable detection driver for FUSB302 USB TYPE-C controller
> + *
> + * Copyright (C) 2017 Hans de Goede <hdegoede@...hat.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/extcon.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +#include "extcon.h"
> +
> +#define REG_DEVICE_ID				0x01
> +#define DEVICE_ID_VER_MASK			GENMASK(7, 4)
> +#define DEVICE_ID_FUSB302_VER			0x80
> +
> +#define REG_SWITCHES0				0x02
> +#define SWITCHES0_PDWN1				BIT(0)
> +#define SWITCHES0_PDWN2				BIT(1)
> +#define SWITCHES0_PDWN				GENMASK(1, 0)
> +#define SWITCHES0_MEAS_CC1			BIT(2)
> +#define SWITCHES0_MEAS_CC2			BIT(3)
> +#define SWITCHES0_VCONN_CC1			BIT(4)
> +#define SWITCHES0_VCONN_CC2			BIT(5)
> +#define SWITCHES0_PU_EN1			BIT(6)
> +#define SWITCHES0_PU_EN2			BIT(7)
> +
> +#define REG_MEASURE				0x04
> +#define MEASURE_MDAC_MASK			GENMASK(5, 0)
> +/* Datasheet says MDAC must be set to 0x34 / 2226mV for vRd-3.0 detection */
> +#define MEASURE_MDAC_SNK_VRD30			0x34
> +/* MDAC must be set to 0x25 / 1600mV for disconnect det. with 80uA host-cur */
> +#define MEASURE_MDAC_SRC_80UA_HOST_CUR		0x25
> +
> +#define REG_CONTROL0				0x06
> +#define CONTROL0_HOST_CUR_MASK			GENMASK(3, 2)
> +#define CONTROL0_HOST_CUR_DISABLED		(0 << 2)
> +#define CONTROL0_HOST_CUR_80UA			(1 << 2)
> +#define CONTROL0_HOST_CUR_180UA			(2 << 2)
> +#define CONTROL0_HOST_CUR_330UA			(3 << 2)
> +#define CONTROL0_INT_MASK			BIT(5)
> +
> +#define REG_CONTROL2				0x08
> +#define CONTROL2_TOGGLE				BIT(0)
> +#define CONTROL2_MODE_MASK			GENMASK(2, 1)
> +#define CONTROL2_MODE_DRP			(1 << 1)
> +#define CONTROL2_MODE_SNK			(2 << 1)
> +#define CONTROL2_MODE_SRC			(3 << 1)
> +#define CONTROL2_SAVE_PWR_MASK			GENMASK(7, 6)
> +#define CONTROL2_SAVE_PWR_DISABLED		(0 << 6)
> +#define CONTROL2_SAVE_PWR_40MS			(1 << 6)
> +#define CONTROL2_SAVE_PWR_80MS			(2 << 6)
> +#define CONTROL2_SAVE_PWR_160MS			(3 << 6)
> +
> +#define REG_MASK1				0x0a
> +/* REG_MASK1 value for low-power / disabled state from datasheet */
> +#define MASK1_DISABLED				0xfe
> +#define MASK1_COMP_CHNG				BIT(5)
> +#define MASK1_VBUSOK				BIT(7)
> +
> +#define REG_POWER				0x0b
> +/* REG_POWER values for disabled and normal state from datasheet */
> +#define POWER_DISABLED				BIT(0)
> +#define POWER_NORMAL				GENMASK(2, 0)
> +
> +#define REG_RESET				0x0c
> +#define RESET_SW_RESET				BIT(0)
> +
> +#define REG_OCP					0x0d
> +
> +#define REG_MASKA				0x0e
> +/* REG_MASKA value for low-power / disabled state from datasheet */
> +#define MASKA_DISABLED				0xbf
> +
> +#define REG_MASKB				0x0f
> +/* REG_MASKB value for low-power / disabled state from datasheet */
> +#define MASKB_DISABLED				0x01
> +
> +#define REG_STATUS1A				0x3d
> +#define STATUS1A_TOGSS_MASK			GENMASK(5, 3)
> +#define STATUS1A_TOGSS_SRC_CC1			(1 << 3)
> +#define STATUS1A_TOGSS_SRC_CC2			(2 << 3)
> +#define STATUS1A_TOGSS_SNK_CC1			(5 << 3)
> +#define STATUS1A_TOGSS_SNK_CC2			(6 << 3)
> +
> +#define REG_INTERRUPTA				0x3e
> +#define INTERRUPTA_TOGDONE			BIT(6)
> +
> +#define REG_STATUS0				0x40
> +#define STATUS0_BC_LEVEL_MASK			GENMASK(1, 0)
> +#define STATUS0_BC_LEVEL_VRA			0
> +#define STATUS0_BC_LEVEL_VRDUSB			1
> +#define STATUS0_BC_LEVEL_VRD15			2
> +#define STATUS0_BC_LEVEL_VRD30			3
> +#define STATUS0_COMP				BIT(5)
> +#define STATUS0_VBUSOK				BIT(7)
> +
> +#define REG_INTERRUPT				0x42
> +#define INTERRUPT_BC_LVL			BIT(0)
> +#define INTERRUPT_COMP_CHNG			BIT(5)
> +#define INTERRUPT_VBUSOK			BIT(7)
> +
> +/* Timeouts from the FUSB302 datasheet */
> +#define TTOGCYCLE				msecs_to_jiffies(40 + 60 + 40)
> +
> +/* Timeouts from the USB-C specification */
> +#define TPDDEBOUNCE				msecs_to_jiffies(20)
> +#define TDRPTRY_MS				75
> +#define TDRPTRY					msecs_to_jiffies(TDRPTRY_MS)
> +#define TDRPTRYWAIT				msecs_to_jiffies(400)
> +#define TVBUSON					msecs_to_jiffies(275)
> +
> +enum typec_port_type {
> +	TYPEC_PORT_DFP,
> +	TYPEC_PORT_UFP,
> +	TYPEC_PORT_DRP,
> +};
> +
> +enum typec_role {
> +	TYPEC_SINK,
> +	TYPEC_SOURCE,
> +};
> +
> +enum fusb302_state {
> +	DISABLED_SNK, /* UFP */
> +	DISABLED_SRC, /* DFP */
> +	DISABLED_DRP,
> +	UNATTACHED_SNK,
> +	ATTACHED_SNK,
> +	UNATTACHED_SRC,
> +	ATTACHED_SRC,
> +};
> +/* For debugging */
> +static __maybe_unused const char *fusb302_state_str[] = {
> +	"DISABLED_SNK",
> +	"DISABLED_SRC",
> +	"DISABLED_DRP",
> +	"UNATTACHED_SNK",
> +	"ATTACHED_SNK",
> +	"UNATTACHED_SRC",
> +	"ATTACHED_SRC",
> +};
> +
> +enum fusb302_event {
> +	TOGGLE_DONE,
> +	BC_LVL_CHANGE,
> +	VBUS_VALID,
> +	VBUS_INVALID,
> +	COMP_LOW,
> +	COMP_HIGH,
> +	TIMEOUT,
> +	FALLBACK_TIMEOUT,
> +};
> +/* For debugging */
> +static __maybe_unused const char *fusb302_event_str[] = {
> +	"TOGGLE_DONE",
> +	"BC_LVL_CHANGE",
> +	"VBUS_VALID",
> +	"VBUS_INVALID",
> +	"COMP_LOW",
> +	"COMP_HIGH",
> +	"TIMEOUT",
> +	"FALLBACK_TIMEOUT",
> +};
> +
> +static const unsigned int fusb302_extcon_cables[] = {
> +	EXTCON_USB,
> +	EXTCON_USB_HOST,
> +	EXTCON_CHG_USB_SDP,
> +	EXTCON_CHG_USB_CDP,
> +	EXTCON_CHG_USB_FAST,
> +	EXTCON_NONE,
> +};
> +
> +struct fusb302_data {
> +	struct device *dev;
> +	struct regmap *regmap;
> +	struct extcon_dev *edev;
> +	struct mutex lock;
> +	struct delayed_work timeout;
> +	struct delayed_work fallback_timeout;
> +	struct delayed_work bc_work;
> +	enum fusb302_state state;
> +	enum typec_port_type port_type;
> +	enum typec_role preferred_role;
> +	int status0;
> +	int status1a;
> +	unsigned int snk_cable_id;
> +};
> +
> +static void fusb302_write_reg(struct fusb302_data *data, int reg, int val)
> +{
> +	int ret;
> +
> +	ret = regmap_write(data->regmap, reg, val);
> +	if (ret)
> +		dev_err(data->dev, "Error writing reg %02x: %d\n", reg, ret);
> +}
> +
> +static int fusb302_read_reg(struct fusb302_data *data, int reg)
> +{
> +	int ret, val;
> +
> +	ret = regmap_read(data->regmap, reg, &val);
> +	if (ret) {
> +		dev_err(data->dev, "Error reading reg %02x: %d\n", reg, ret);
> +		return 0;
> +	}
> +
> +	return val;
> +}
> +
> +static void fusb302_update_bits(struct fusb302_data *data, int reg,
> +				int mask, int val)
> +{
> +	int ret;
> +
> +	ret = regmap_update_bits(data->regmap, reg, mask, val);
> +	if (ret)
> +		dev_err(data->dev, "Error modifying reg %02x: %d\n", reg, ret);
> +}
> +
> +/* Small helper to sync EXTCON_CHG_USB_SDP and EXTCON_USB state */
> +static void fusb302_set_extcon_state(struct fusb302_data *data,
> +				     unsigned int cable, bool state)
> +{
> +	extcon_set_state_sync(data->edev, cable, state);
> +	if (cable == EXTCON_CHG_USB_SDP)
> +		extcon_set_state_sync(data->edev, EXTCON_USB, state);
> +}
> +
> +/* Helper for the disabled states */
> +static void fusb302_disable(struct fusb302_data *data)
> +{
> +	fusb302_write_reg(data, REG_POWER, POWER_DISABLED);
> +	fusb302_write_reg(data, REG_MASK1, MASK1_DISABLED);
> +	fusb302_write_reg(data, REG_MASKA, MASKA_DISABLED);
> +	fusb302_write_reg(data, REG_MASKB, MASKB_DISABLED);
> +	fusb302_update_bits(data, REG_CONTROL2, CONTROL2_TOGGLE, 0);
> +}
> +
> +/*
> + * fusb302_set_state() and fusb302_handle_event() implement the 3 state
> + * machines from the datasheet folded into 1 state-machine for code re-use.
> + */
> +static void fusb302_set_state(struct fusb302_data *data,
> +			      enum fusb302_state state)
> +{
> +	int status, switches0 = 0;
> +	enum fusb302_state old_state = data->state;
> +	union extcon_property_value prop;
> +
> +	/* Kill pending timeouts from previous state */
> +	cancel_delayed_work(&data->timeout);
> +	cancel_delayed_work(&data->fallback_timeout);
> +	cancel_delayed_work(&data->bc_work);
> +
> +	dev_dbg(data->dev, "New state %s\n", fusb302_state_str[state]);
> +
> +	switch (old_state) {
> +	case ATTACHED_SNK:
> +		fusb302_set_extcon_state(data, data->snk_cable_id, false);
> +		break;
> +	case ATTACHED_SRC:
> +		fusb302_set_extcon_state(data, EXTCON_USB_HOST, false);
> +		break;
> +	default:
> +		break; /* Do nothing */
> +	}
> +
> +	switch (state) {
> +	case DISABLED_SNK:
> +		fusb302_disable(data);
> +		fusb302_update_bits(data, REG_CONTROL2, CONTROL2_MODE_MASK,
> +				    CONTROL2_MODE_SNK);
> +		fusb302_update_bits(data, REG_CONTROL2, CONTROL2_TOGGLE,
> +				    CONTROL2_TOGGLE);
> +		break;
> +
> +	case DISABLED_SRC:
> +		fusb302_disable(data);
> +		fusb302_update_bits(data, REG_CONTROL2, CONTROL2_MODE_MASK,
> +				    CONTROL2_MODE_SRC);
> +		fusb302_update_bits(data, REG_CONTROL2, CONTROL2_TOGGLE,
> +				    CONTROL2_TOGGLE);
> +		break;
> +
> +	case DISABLED_DRP:
> +		fusb302_disable(data);
> +		fusb302_update_bits(data, REG_CONTROL2, CONTROL2_MODE_MASK,
> +				    CONTROL2_MODE_DRP);
> +		fusb302_update_bits(data, REG_CONTROL2, CONTROL2_TOGGLE,
> +				    CONTROL2_TOGGLE);
> +		break;
> +
> +	case UNATTACHED_SNK:
> +		fusb302_write_reg(data, REG_POWER, POWER_NORMAL);
> +
> +		/* Enable pull-down on CC1 / CC2 based on orientation */
> +		switch (data->status1a & STATUS1A_TOGSS_MASK) {
> +		case STATUS1A_TOGSS_SNK_CC1:
> +			switches0 = SWITCHES0_PDWN1 | SWITCHES0_MEAS_CC1;
> +			prop.intval = USB_TYPEC_POLARITY_NORMAL;
> +			break;
> +		case STATUS1A_TOGSS_SNK_CC2:
> +			switches0 = SWITCHES0_PDWN2 | SWITCHES0_MEAS_CC2;
> +			prop.intval = USB_TYPEC_POLARITY_FLIP;
> +			break;
> +		}
> +		fusb302_write_reg(data, REG_SWITCHES0, switches0);
> +		fusb302_update_bits(data, REG_CONTROL2, CONTROL2_TOGGLE, 0);
> +		extcon_set_property(data->edev, EXTCON_USB,
> +				    EXTCON_PROP_USB_TYPEC_POLARITY, prop);
> +
> +		/* Enable VBUSOK and COMP irq at 2.24V for BC detection */
> +		fusb302_update_bits(data, REG_MASK1,
> +				    MASK1_VBUSOK | MASK1_COMP_CHNG, 0);
> +		fusb302_update_bits(data, REG_MEASURE, MEASURE_MDAC_MASK,
> +				    MEASURE_MDAC_SNK_VRD30);
> +
> +		status = fusb302_read_reg(data, REG_STATUS0);
> +		if (status & STATUS0_VBUSOK) {
> +			/* Go straight to ATTACHED_SNK */
> +			fusb302_set_state(data, ATTACHED_SNK);
> +			return;
> +		}
> +
> +		mod_delayed_work(system_wq, &data->timeout, TVBUSON);
> +		break;
> +
> +	case ATTACHED_SNK:
> +		mod_delayed_work(system_wq, &data->bc_work, TPDDEBOUNCE);
> +		break;
> +
> +	case UNATTACHED_SRC:
> +		fusb302_write_reg(data, REG_POWER, POWER_NORMAL);
> +
> +		/* Enable pull-up / Vconn on CC1 / CC2 based on orientation */
> +		switch (data->status1a & STATUS1A_TOGSS_MASK) {
> +		case STATUS1A_TOGSS_SRC_CC1:
> +			switches0 = SWITCHES0_PU_EN1 | SWITCHES0_VCONN_CC2 |
> +				    SWITCHES0_MEAS_CC1;
> +			prop.intval = USB_TYPEC_POLARITY_NORMAL;
> +			break;
> +		case STATUS1A_TOGSS_SRC_CC2:
> +			switches0 = SWITCHES0_PU_EN2 | SWITCHES0_VCONN_CC1 |
> +				    SWITCHES0_MEAS_CC2;
> +			prop.intval = USB_TYPEC_POLARITY_FLIP;
> +			break;
> +		}
> +		fusb302_write_reg(data, REG_SWITCHES0, switches0);
> +		fusb302_update_bits(data, REG_CONTROL2, CONTROL2_TOGGLE, 0);
> +		extcon_set_property(data->edev, EXTCON_USB,
> +				    EXTCON_PROP_USB_TYPEC_POLARITY, prop);
> +
> +		/* Enable COMP irq at 1.6V for detach detection */
> +		fusb302_update_bits(data, REG_MASK1, MASK1_COMP_CHNG, 0);
> +		fusb302_update_bits(data, REG_MEASURE, MEASURE_MDAC_MASK,
> +				    MEASURE_MDAC_SRC_80UA_HOST_CUR);
> +
> +		status = fusb302_read_reg(data, REG_STATUS0);
> +		if (!(status & STATUS0_COMP)) {
> +			/* Go straight to ATTACHED_SRC */
> +			fusb302_set_state(data, ATTACHED_SRC);
> +			return;
> +		}
> +
> +		mod_delayed_work(system_wq, &data->timeout, TPDDEBOUNCE);
> +		break;
> +
> +	case ATTACHED_SRC:
> +		fusb302_set_extcon_state(data, EXTCON_USB_HOST, true);
> +		break;
> +	}
> +
> +	data->state = state;
> +}
> +
> +static void fusb302_set_state_disabled(struct fusb302_data *data)
> +{
> +
> +	switch (data->port_type) {
> +	case TYPEC_PORT_UFP:
> +		fusb302_set_state(data, DISABLED_SNK);
> +		break;
> +	case TYPEC_PORT_DFP:
> +		fusb302_set_state(data, DISABLED_SRC);
> +		break;
> +	case TYPEC_PORT_DRP:
> +		fusb302_set_state(data, DISABLED_DRP);
> +		break;
> +	}
> +}
> +
> +static void fusb302_handle_disabled_snk_event(struct fusb302_data *data,
> +					      int event)
> +{
> +	switch (event) {
> +	case TOGGLE_DONE:
> +		switch (data->status1a & STATUS1A_TOGSS_MASK) {
> +		case STATUS1A_TOGSS_SNK_CC1:
> +		case STATUS1A_TOGSS_SNK_CC2:
> +			fusb302_set_state(data, UNATTACHED_SNK);
> +			break;
> +		}
> +		break;
> +
> +	case TIMEOUT:
> +		/* Cannot become snk fallback to src */
> +		fusb302_set_state(data, DISABLED_SRC);
> +		mod_delayed_work(system_wq, &data->fallback_timeout,
> +				 TDRPTRYWAIT);
> +		break;
> +
> +	case FALLBACK_TIMEOUT:
> +		/* Both states failed return to disabled drp state */
> +		fusb302_set_state(data, DISABLED_DRP);
> +		break;
> +	}
> +}
> +
> +static void fusb302_handle_disabled_src_event(struct fusb302_data *data,
> +					      int event)
> +{
> +	switch (event) {
> +	case TOGGLE_DONE:
> +		switch (data->status1a & STATUS1A_TOGSS_MASK) {
> +		case STATUS1A_TOGSS_SRC_CC1:
> +		case STATUS1A_TOGSS_SRC_CC2:
> +			fusb302_set_state(data, UNATTACHED_SRC);
> +			break;
> +		}
> +		break;
> +
> +	case TIMEOUT:
> +		/* Cannot become src fallback to snk */
> +		fusb302_set_state(data, DISABLED_SNK);
> +		mod_delayed_work(system_wq, &data->fallback_timeout,
> +				 TDRPTRYWAIT);
> +		break;
> +
> +	case FALLBACK_TIMEOUT:
> +		/* Both states failed return to disabled drp state */
> +		fusb302_set_state(data, DISABLED_DRP);
> +		break;
> +	}
> +}
> +
> +static void fusb302_handle_disabled_drp_event(struct fusb302_data *data,
> +					      int event)
> +{
> +	switch (event) {
> +	case TOGGLE_DONE:
> +		switch (data->status1a & STATUS1A_TOGSS_MASK) {
> +		case STATUS1A_TOGSS_SNK_CC1:
> +		case STATUS1A_TOGSS_SNK_CC2:
> +			if (data->preferred_role == TYPEC_SINK) {
> +				/* Jump directly to UNATTACHED_SNK */
> +				fusb302_set_state(data, UNATTACHED_SNK);
> +			} else {
> +				/* Try to become src */
> +				fusb302_set_state(data, DISABLED_SNK);
> +				mod_delayed_work(system_wq, &data->timeout,
> +						 TDRPTRY);
> +			}
> +			break;
> +		case STATUS1A_TOGSS_SRC_CC1:
> +		case STATUS1A_TOGSS_SRC_CC2:
> +			if (data->preferred_role == TYPEC_SOURCE) {
> +				/* Jump directly to UNATTACHED_SRC */
> +				fusb302_set_state(data, UNATTACHED_SRC);
> +			} else {
> +				/*
> +				 * The USB-C spec says we must enable pull-downs
> +				 * and then wait tDRPTry before checking to
> +				 * avoid endless role-bouncing if both ends
> +				 * prefer the snk role.
> +				 */
> +				fusb302_write_reg(data, REG_SWITCHES0,
> +						  SWITCHES0_PDWN);
> +				fusb302_update_bits(data, REG_CONTROL2,
> +						    CONTROL2_TOGGLE, 0);
> +				msleep(TDRPTRY_MS);
> +				/*
> +				 * Use the toggle engine to do the src
> +				 * detection to keep things the same as for
> +				 * directly entering the src role.
> +				 */
> +				fusb302_set_state(data, DISABLED_SNK);
> +				mod_delayed_work(system_wq, &data->timeout,
> +						 TTOGCYCLE);
> +			}
> +			break;
> +		}
> +		break;
> +	}
> +}
> +
> +static void fusb302_handle_unattached_snk_event(struct fusb302_data *data,
> +					      int event)
> +{
> +	switch (event) {
> +	case VBUS_VALID: /* Cable attached */
> +		fusb302_set_state(data, ATTACHED_SNK);
> +		break;
> +	case TIMEOUT:
> +		fusb302_set_state_disabled(data);
> +		break;
> +	}
> +}
> +
> +static void fusb302_handle_attached_snk_event(struct fusb302_data *data,
> +					      int event)
> +{
> +	switch (event) {
> +	case BC_LVL_CHANGE:
> +	case COMP_LOW:
> +	case COMP_HIGH:
> +		mod_delayed_work(system_wq, &data->bc_work, TPDDEBOUNCE);
> +		break;
> +	case VBUS_INVALID: /* Cable detached */
> +		fusb302_set_state_disabled(data);
> +		break;
> +	}
> +}
> +
> +static void fusb302_handle_unattached_src_event(struct fusb302_data *data,
> +					      int event)
> +{
> +	switch (event) {
> +	case COMP_LOW: /* Cable attached */
> +		fusb302_set_state(data, ATTACHED_SRC);
> +		break;
> +	case TIMEOUT:
> +		fusb302_set_state_disabled(data);
> +		break;
> +	}
> +}
> +
> +static void fusb302_handle_attached_src_event(struct fusb302_data *data,
> +					      int event)
> +{
> +	switch (event) {
> +	case COMP_HIGH: /* Cable detached */
> +		fusb302_set_state_disabled(data);
> +		break;
> +	}
> +}
> +
> +static void fusb302_handle_event(struct fusb302_data *data, int event)
> +{
> +
> +	mutex_lock(&data->lock);
> +
> +	dev_dbg(data->dev, "Handling state %s event %s status %02x %02x\n",
> +		fusb302_state_str[data->state], fusb302_event_str[event],
> +		fusb302_read_reg(data, REG_STATUS0),
> +		fusb302_read_reg(data, REG_STATUS1A));
> +
> +	switch (data->state) {
> +	case DISABLED_SNK:
> +		fusb302_handle_disabled_snk_event(data, event);
> +		break;
> +	case DISABLED_SRC:
> +		fusb302_handle_disabled_src_event(data, event);
> +		break;
> +	case DISABLED_DRP:
> +		fusb302_handle_disabled_drp_event(data, event);
> +		break;
> +	case UNATTACHED_SNK:
> +		fusb302_handle_unattached_snk_event(data, event);
> +		break;
> +	case ATTACHED_SNK:
> +		fusb302_handle_attached_snk_event(data, event);
> +		break;
> +	case UNATTACHED_SRC:
> +		fusb302_handle_unattached_src_event(data, event);
> +		break;
> +	case ATTACHED_SRC:
> +		fusb302_handle_attached_src_event(data, event);
> +		break;
> +	}
> +	mutex_unlock(&data->lock);
> +}
> +
> +static void fusb302_timeout(struct work_struct *work)
> +{
> +	struct fusb302_data *data =
> +		container_of(work, struct fusb302_data, timeout.work);
> +
> +	fusb302_handle_event(data, TIMEOUT);
> +}
> +
> +static void fusb302_fallback_timeout(struct work_struct *work)
> +{
> +	struct fusb302_data *data =
> +		container_of(work, struct fusb302_data, fallback_timeout.work);
> +
> +	fusb302_handle_event(data, FALLBACK_TIMEOUT);
> +}
> +
> +static void fusb302_report_bc_level(struct work_struct *work)
> +{
> +	struct fusb302_data *data =
> +		container_of(work, struct fusb302_data, bc_work.work);
> +
> +	/* Clear old charger cable id */
> +	fusb302_set_extcon_state(data, data->snk_cable_id, false);
> +
> +	if (data->status0 & STATUS0_COMP) {
> +		dev_warn(data->dev, "vRd over maximum, assuming 500mA source\n");
> +		data->snk_cable_id = EXTCON_CHG_USB_SDP;
> +	} else {
> +		switch (data->status0 & STATUS0_BC_LEVEL_MASK) {
> +		case STATUS0_BC_LEVEL_VRA:
> +		case STATUS0_BC_LEVEL_VRDUSB:
> +			data->snk_cable_id = EXTCON_CHG_USB_SDP;
> +			break;
> +		case STATUS0_BC_LEVEL_VRD15:
> +			data->snk_cable_id = EXTCON_CHG_USB_CDP;
> +			break;
> +		case STATUS0_BC_LEVEL_VRD30:
> +			/* Use CHG_USB_FAST to indicate 3A capability */
> +			data->snk_cable_id = EXTCON_CHG_USB_FAST;
> +			break;
> +		}
> +	}
> +	fusb302_set_extcon_state(data, data->snk_cable_id, true);
> +}
> +
> +static irqreturn_t fusb302_irq_handler_thread(int irq, void *handler_data)
> +{
> +	struct fusb302_data *data = handler_data;
> +	int interrupt, interrupta;
> +
> +	interrupt = fusb302_read_reg(data, REG_INTERRUPT);
> +	interrupta = fusb302_read_reg(data, REG_INTERRUPTA);
> +
> +	if (interrupt)
> +		data->status0 = fusb302_read_reg(data, REG_STATUS0);
> +
> +	if (interrupta)
> +		data->status1a = fusb302_read_reg(data, REG_STATUS1A);
> +
> +	dev_dbg(data->dev, "Handling interrupt %02x %02x status %02x %02x\n",
> +		interrupt, interrupta, data->status0, data->status1a);
> +
> +	if (interrupt & INTERRUPT_BC_LVL)
> +		fusb302_handle_event(data, BC_LVL_CHANGE);
> +
> +	if (interrupt & INTERRUPT_COMP_CHNG) {
> +		if (data->status0 & STATUS0_COMP)
> +			fusb302_handle_event(data, COMP_HIGH);
> +		else
> +			fusb302_handle_event(data, COMP_LOW);
> +	}
> +
> +	if (interrupt & INTERRUPT_VBUSOK) {
> +		if (data->status0 & STATUS0_VBUSOK)
> +			fusb302_handle_event(data, VBUS_VALID);
> +		else
> +			fusb302_handle_event(data, VBUS_INVALID);
> +	}
> +
> +	if (interrupta & INTERRUPTA_TOGDONE)
> +		fusb302_handle_event(data, TOGGLE_DONE);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static const struct regmap_config fusb302_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.val_format_endian = REGMAP_ENDIAN_NATIVE,
> +};
> +
> +static int fusb302_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct fusb302_data *data;
> +	int ret;
> +
> +	if (!client->irq) {
> +		dev_err(dev, "Error irq not specified\n");
> +		return -EINVAL;
> +	}
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->dev = dev;
> +	/* TODO make these 2 configurable using device-properties */
> +	data->port_type = TYPEC_PORT_DRP;
> +	data->preferred_role = TYPEC_SINK;
> +
> +	data->regmap = devm_regmap_init_i2c(client, &fusb302_regmap_config);
> +	if (IS_ERR(data->regmap)) {
> +		ret = PTR_ERR(data->regmap);
> +		dev_err(dev, "Error to initializing regmap: %d\n", ret);
> +		return ret;
> +	}
> +
> +	mutex_init(&data->lock);
> +	INIT_DELAYED_WORK(&data->timeout, fusb302_timeout);
> +	INIT_DELAYED_WORK(&data->fallback_timeout, fusb302_fallback_timeout);
> +	INIT_DELAYED_WORK(&data->bc_work, fusb302_report_bc_level);
> +
> +	data->edev = devm_extcon_dev_allocate(dev, fusb302_extcon_cables);
> +	if (IS_ERR(data->edev))
> +		return PTR_ERR(data->edev);
> +
> +	data->edev->name = "fusb302";
> +
> +	ret = devm_extcon_dev_register(dev, data->edev);
> +	if (ret)
> +		return ret;
> +
> +	extcon_set_property_capability(data->edev, EXTCON_USB,
> +				       EXTCON_PROP_USB_TYPEC_POLARITY);
> +
> +	fusb302_write_reg(data, REG_RESET, RESET_SW_RESET);
> +	usleep_range(10000, 20000);
> +
> +	/* Enable power-saving */
> +	fusb302_update_bits(data, REG_CONTROL2, CONTROL2_SAVE_PWR_MASK,
> +			    CONTROL2_SAVE_PWR_40MS);
> +
> +	fusb302_set_state_disabled(data);
> +
> +	ret = devm_request_threaded_irq(dev, client->irq, NULL,
> +			fusb302_irq_handler_thread,
> +			IRQF_TRIGGER_LOW | IRQF_ONESHOT, "fusb302", data);
> +	if (ret) {
> +		dev_err(dev, "Error requesting irq: %d\n", ret);
> +		return ret;
> +	}
> +
> +	fusb302_update_bits(data, REG_CONTROL0, CONTROL0_INT_MASK, 0);
> +
> +	i2c_set_clientdata(client, data);
> +	return 0;
> +}
> +
> +static int fusb302_remove(struct i2c_client *client)
> +{
> +	struct fusb302_data *data = i2c_get_clientdata(client);
> +
> +	devm_free_irq(data->dev, client->irq, data);
> +	cancel_delayed_work_sync(&data->timeout);
> +	cancel_delayed_work_sync(&data->fallback_timeout);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id fusb302_i2c_ids[] = {
> +	{ "fusb302" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(i2c, fusb302_i2c_ids);
> +
> +static struct i2c_driver fusb302_driver = {
> +	.probe_new = fusb302_probe,
> +	.remove = fusb302_remove,
> +	.id_table = fusb302_i2c_ids,
> +	.driver = {
> +		.name = "fusb302",
> +	},
> +};
> +module_i2c_driver(fusb302_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Hans de Goede <hdegoede@...hat.com>");
> +MODULE_DESCRIPTION("FUSB302 USB TYPE-C controller Driver");
> 

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