// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2020 Google LLC
 *
 * This driver provides the ability to view and manage Type C ports through the
 * Chrome OS EC.
 */

#include <linux/acpi.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_data/cros_usbpd_notify.h>
#include <linux/platform_device.h>
#include <linux/usb/pd.h>
#include <linux/usb/pd_vdo.h>
#include <linux/usb/typec.h>
#include <linux/usb/typec_altmode.h>
#include <linux/usb/typec_dp.h>
#include <linux/usb/typec_mux.h>
#include <linux/usb/typec_tbt.h>
#include <linux/usb/role.h>

#define DRV_NAME "cros-ec-typec"

/* Supported alt modes. */
enum {
	CROS_EC_ALTMODE_DP = 0,
	CROS_EC_ALTMODE_TBT,
	CROS_EC_ALTMODE_MAX,
};

/* Container for altmode pointer nodes. */
struct cros_typec_altmode_node {
	struct typec_altmode *amode;
	struct list_head list;
};

/* Per port data. */
struct cros_typec_port {
	struct typec_port *port;
	/* Initial capabilities for the port. */
	struct typec_capability caps;
	struct typec_partner *partner;
	struct typec_cable *cable;
	/* SOP' plug. */
	struct typec_plug *plug;
	/* Port partner PD identity info. */
	struct usb_pd_identity p_identity;
	/* Port cable PD identity info. */
	struct usb_pd_identity c_identity;
	struct typec_switch *ori_sw;
	struct typec_mux *mux;
	struct usb_role_switch *role_sw;

	/* Variables keeping track of switch state. */
	struct typec_mux_state state;
	uint8_t mux_flags;

	/* Port alt modes. */
	struct typec_altmode p_altmode[CROS_EC_ALTMODE_MAX];

	/* Flag indicating that PD partner discovery data parsing is completed. */
	bool sop_disc_done;
	bool sop_prime_disc_done;
	struct ec_response_typec_discovery *disc_data;
	struct list_head partner_mode_list;
	struct list_head plug_mode_list;
};

/* Platform-specific data for the Chrome OS EC Type C controller. */
struct cros_typec_data {
	struct device *dev;
	struct cros_ec_device *ec;
	int num_ports;
	unsigned int pd_ctrl_ver;
	/* Array of ports, indexed by port number. */
	struct cros_typec_port *ports[EC_USB_PD_MAX_PORTS];
	struct notifier_block nb;
	struct work_struct port_work;
	bool typec_cmd_supported;
	bool needs_mux_ack;
};

static int cros_typec_parse_port_props(struct typec_capability *cap,
				       struct fwnode_handle *fwnode,
				       struct device *dev)
{
	const char *buf;
	int ret;

	memset(cap, 0, sizeof(*cap));
	ret = fwnode_property_read_string(fwnode, "power-role", &buf);
	if (ret) {
		dev_err(dev, "power-role not found: %d\n", ret);
		return ret;
	}

	ret = typec_find_port_power_role(buf);
	if (ret < 0)
		return ret;
	cap->type = ret;

	ret = fwnode_property_read_string(fwnode, "data-role", &buf);
	if (ret) {
		dev_err(dev, "data-role not found: %d\n", ret);
		return ret;
	}

	ret = typec_find_port_data_role(buf);
	if (ret < 0)
		return ret;
	cap->data = ret;

	ret = fwnode_property_read_string(fwnode, "try-power-role", &buf);
	if (ret) {
		dev_err(dev, "try-power-role not found: %d\n", ret);
		return ret;
	}

	ret = typec_find_power_role(buf);
	if (ret < 0)
		return ret;
	cap->prefer_role = ret;

	cap->fwnode = fwnode;

	return 0;
}

static int cros_typec_get_switch_handles(struct cros_typec_port *port,
					 struct fwnode_handle *fwnode,
					 struct device *dev)
{
	port->mux = fwnode_typec_mux_get(fwnode, NULL);
	if (IS_ERR(port->mux)) {
		dev_dbg(dev, "Mux handle not found.\n");
		goto mux_err;
	}

	port->ori_sw = fwnode_typec_switch_get(fwnode);
	if (IS_ERR(port->ori_sw)) {
		dev_dbg(dev, "Orientation switch handle not found.\n");
		goto ori_sw_err;
	}

	port->role_sw = fwnode_usb_role_switch_get(fwnode);
	if (IS_ERR(port->role_sw)) {
		dev_dbg(dev, "USB role switch handle not found.\n");
		goto role_sw_err;
	}

	return 0;

role_sw_err:
	usb_role_switch_put(port->role_sw);
ori_sw_err:
	typec_switch_put(port->ori_sw);
mux_err:
	typec_mux_put(port->mux);

	return -ENODEV;
}

static int cros_typec_add_partner(struct cros_typec_data *typec, int port_num,
				  bool pd_en)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct typec_partner_desc p_desc = {
		.usb_pd = pd_en,
	};
	int ret = 0;

	/*
	 * Fill an initial PD identity, which will then be updated with info
	 * from the EC.
	 */
	p_desc.identity = &port->p_identity;

	port->partner = typec_register_partner(port->port, &p_desc);
	if (IS_ERR(port->partner)) {
		ret = PTR_ERR(port->partner);
		port->partner = NULL;
	}

	return ret;
}

static void cros_typec_unregister_altmodes(struct cros_typec_data *typec, int port_num,
					   bool is_partner)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct cros_typec_altmode_node *node, *tmp;
	struct list_head *head;

	head = is_partner ? &port->partner_mode_list : &port->plug_mode_list;
	list_for_each_entry_safe(node, tmp, head, list) {
		list_del(&node->list);
		typec_unregister_altmode(node->amode);
		devm_kfree(typec->dev, node);
	}
}

static int cros_typec_usb_disconnect_state(struct cros_typec_port *port)
{
	port->state.alt = NULL;
	port->state.mode = TYPEC_STATE_USB;
	port->state.data = NULL;

	usb_role_switch_set_role(port->role_sw, USB_ROLE_NONE);
	typec_switch_set(port->ori_sw, TYPEC_ORIENTATION_NONE);

	return typec_mux_set(port->mux, &port->state);
}

static void cros_typec_remove_partner(struct cros_typec_data *typec,
				      int port_num)
{
	struct cros_typec_port *port = typec->ports[port_num];

	cros_typec_unregister_altmodes(typec, port_num, true);

	cros_typec_usb_disconnect_state(port);

	typec_unregister_partner(port->partner);
	port->partner = NULL;
	memset(&port->p_identity, 0, sizeof(port->p_identity));
	port->sop_disc_done = false;
}

static void cros_typec_remove_cable(struct cros_typec_data *typec,
				    int port_num)
{
	struct cros_typec_port *port = typec->ports[port_num];

	cros_typec_unregister_altmodes(typec, port_num, false);

	typec_unregister_plug(port->plug);
	port->plug = NULL;
	typec_unregister_cable(port->cable);
	port->cable = NULL;
	memset(&port->c_identity, 0, sizeof(port->c_identity));
	port->sop_prime_disc_done = false;
}

static void cros_unregister_ports(struct cros_typec_data *typec)
{
	int i;

	for (i = 0; i < typec->num_ports; i++) {
		if (!typec->ports[i])
			continue;

		if (typec->ports[i]->partner)
			cros_typec_remove_partner(typec, i);

		if (typec->ports[i]->cable)
			cros_typec_remove_cable(typec, i);

		usb_role_switch_put(typec->ports[i]->role_sw);
		typec_switch_put(typec->ports[i]->ori_sw);
		typec_mux_put(typec->ports[i]->mux);
		typec_unregister_port(typec->ports[i]->port);
	}
}

/*
 * Fake the alt mode structs until we actually start registering Type C port
 * and partner alt modes.
 */
static void cros_typec_register_port_altmodes(struct cros_typec_data *typec,
					      int port_num)
{
	struct cros_typec_port *port = typec->ports[port_num];

	/* All PD capable CrOS devices are assumed to support DP altmode. */
	port->p_altmode[CROS_EC_ALTMODE_DP].svid = USB_TYPEC_DP_SID;
	port->p_altmode[CROS_EC_ALTMODE_DP].mode = USB_TYPEC_DP_MODE;

	/*
	 * Register TBT compatibility alt mode. The EC will not enter the mode
	 * if it doesn't support it, so it's safe to register it unconditionally
	 * here for now.
	 */
	port->p_altmode[CROS_EC_ALTMODE_TBT].svid = USB_TYPEC_TBT_SID;
	port->p_altmode[CROS_EC_ALTMODE_TBT].mode = TYPEC_ANY_MODE;

	port->state.alt = NULL;
	port->state.mode = TYPEC_STATE_USB;
	port->state.data = NULL;
}

static int cros_typec_init_ports(struct cros_typec_data *typec)
{
	struct device *dev = typec->dev;
	struct typec_capability *cap;
	struct fwnode_handle *fwnode;
	struct cros_typec_port *cros_port;
	const char *port_prop;
	int ret;
	int nports;
	u32 port_num = 0;

	nports = device_get_child_node_count(dev);
	if (nports == 0) {
		dev_err(dev, "No port entries found.\n");
		return -ENODEV;
	}

	if (nports > typec->num_ports) {
		dev_err(dev, "More ports listed than can be supported.\n");
		return -EINVAL;
	}

	/* DT uses "reg" to specify port number. */
	port_prop = dev->of_node ? "reg" : "port-number";
	device_for_each_child_node(dev, fwnode) {
		if (fwnode_property_read_u32(fwnode, port_prop, &port_num)) {
			ret = -EINVAL;
			dev_err(dev, "No port-number for port, aborting.\n");
			goto unregister_ports;
		}

		if (port_num >= typec->num_ports) {
			dev_err(dev, "Invalid port number.\n");
			ret = -EINVAL;
			goto unregister_ports;
		}

		dev_dbg(dev, "Registering port %d\n", port_num);

		cros_port = devm_kzalloc(dev, sizeof(*cros_port), GFP_KERNEL);
		if (!cros_port) {
			ret = -ENOMEM;
			goto unregister_ports;
		}

		typec->ports[port_num] = cros_port;
		cap = &cros_port->caps;

		ret = cros_typec_parse_port_props(cap, fwnode, dev);
		if (ret < 0)
			goto unregister_ports;

		cros_port->port = typec_register_port(dev, cap);
		if (IS_ERR(cros_port->port)) {
			dev_err(dev, "Failed to register port %d\n", port_num);
			ret = PTR_ERR(cros_port->port);
			goto unregister_ports;
		}

		ret = cros_typec_get_switch_handles(cros_port, fwnode, dev);
		if (ret)
			dev_dbg(dev, "No switch control for port %d\n",
				port_num);

		cros_typec_register_port_altmodes(typec, port_num);

		cros_port->disc_data = devm_kzalloc(dev, EC_PROTO2_MAX_RESPONSE_SIZE, GFP_KERNEL);
		if (!cros_port->disc_data) {
			ret = -ENOMEM;
			goto unregister_ports;
		}

		INIT_LIST_HEAD(&cros_port->partner_mode_list);
		INIT_LIST_HEAD(&cros_port->plug_mode_list);
	}

	return 0;

unregister_ports:
	cros_unregister_ports(typec);
	return ret;
}

static int cros_typec_ec_command(struct cros_typec_data *typec,
				 unsigned int version,
				 unsigned int command,
				 void *outdata,
				 unsigned int outsize,
				 void *indata,
				 unsigned int insize)
{
	struct cros_ec_command *msg;
	int ret;

	msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
	if (!msg)
		return -ENOMEM;

	msg->version = version;
	msg->command = command;
	msg->outsize = outsize;
	msg->insize = insize;

	if (outsize)
		memcpy(msg->data, outdata, outsize);

	ret = cros_ec_cmd_xfer_status(typec->ec, msg);
	if (ret >= 0 && insize)
		memcpy(indata, msg->data, insize);

	kfree(msg);
	return ret;
}

static int cros_typec_usb_safe_state(struct cros_typec_port *port)
{
	port->state.mode = TYPEC_STATE_SAFE;

	return typec_mux_set(port->mux, &port->state);
}

/*
 * Spoof the VDOs that were likely communicated by the partner for TBT alt
 * mode.
 */
static int cros_typec_enable_tbt(struct cros_typec_data *typec,
				 int port_num,
				 struct ec_response_usb_pd_control_v2 *pd_ctrl)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct typec_thunderbolt_data data;
	int ret;

	if (typec->pd_ctrl_ver < 2) {
		dev_err(typec->dev,
			"PD_CTRL version too old: %d\n", typec->pd_ctrl_ver);
		return -ENOTSUPP;
	}

	/* Device Discover Mode VDO */
	data.device_mode = TBT_MODE;

	if (pd_ctrl->control_flags & USB_PD_CTRL_TBT_LEGACY_ADAPTER)
		data.device_mode = TBT_SET_ADAPTER(TBT_ADAPTER_TBT3);

	/* Cable Discover Mode VDO */
	data.cable_mode = TBT_MODE;
	data.cable_mode |= TBT_SET_CABLE_SPEED(pd_ctrl->cable_speed);

	if (pd_ctrl->control_flags & USB_PD_CTRL_OPTICAL_CABLE)
		data.cable_mode |= TBT_CABLE_OPTICAL;

	if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_LINK_UNIDIR)
		data.cable_mode |= TBT_CABLE_LINK_TRAINING;

	data.cable_mode |= TBT_SET_CABLE_ROUNDED(pd_ctrl->cable_gen);

	/* Enter Mode VDO */
	data.enter_vdo = TBT_SET_CABLE_SPEED(pd_ctrl->cable_speed);

	if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_CABLE)
		data.enter_vdo |= TBT_ENTER_MODE_ACTIVE_CABLE;

	if (!port->state.alt) {
		port->state.alt = &port->p_altmode[CROS_EC_ALTMODE_TBT];
		ret = cros_typec_usb_safe_state(port);
		if (ret)
			return ret;
	}

	port->state.data = &data;
	port->state.mode = TYPEC_TBT_MODE;

	return typec_mux_set(port->mux, &port->state);
}

/* Spoof the VDOs that were likely communicated by the partner. */
static int cros_typec_enable_dp(struct cros_typec_data *typec,
				int port_num,
				struct ec_response_usb_pd_control_v2 *pd_ctrl)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct typec_displayport_data dp_data;
	int ret;

	if (typec->pd_ctrl_ver < 2) {
		dev_err(typec->dev,
			"PD_CTRL version too old: %d\n", typec->pd_ctrl_ver);
		return -ENOTSUPP;
	}

	/* Status VDO. */
	dp_data.status = DP_STATUS_ENABLED;
	if (port->mux_flags & USB_PD_MUX_HPD_IRQ)
		dp_data.status |= DP_STATUS_IRQ_HPD;
	if (port->mux_flags & USB_PD_MUX_HPD_LVL)
		dp_data.status |= DP_STATUS_HPD_STATE;

	/* Configuration VDO. */
	dp_data.conf = DP_CONF_SET_PIN_ASSIGN(pd_ctrl->dp_mode);
	if (!port->state.alt) {
		port->state.alt = &port->p_altmode[CROS_EC_ALTMODE_DP];
		ret = cros_typec_usb_safe_state(port);
		if (ret)
			return ret;
	}

	port->state.data = &dp_data;
	port->state.mode = TYPEC_MODAL_STATE(ffs(pd_ctrl->dp_mode));

	return typec_mux_set(port->mux, &port->state);
}

static int cros_typec_enable_usb4(struct cros_typec_data *typec,
				  int port_num,
				  struct ec_response_usb_pd_control_v2 *pd_ctrl)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct enter_usb_data data;

	data.eudo = EUDO_USB_MODE_USB4 << EUDO_USB_MODE_SHIFT;

	/* Cable Speed */
	data.eudo |= pd_ctrl->cable_speed << EUDO_CABLE_SPEED_SHIFT;

	/* Cable Type */
	if (pd_ctrl->control_flags & USB_PD_CTRL_OPTICAL_CABLE)
		data.eudo |= EUDO_CABLE_TYPE_OPTICAL << EUDO_CABLE_TYPE_SHIFT;
	else if (pd_ctrl->control_flags & USB_PD_CTRL_ACTIVE_CABLE)
		data.eudo |= EUDO_CABLE_TYPE_RE_TIMER << EUDO_CABLE_TYPE_SHIFT;

	data.active_link_training = !!(pd_ctrl->control_flags &
				       USB_PD_CTRL_ACTIVE_LINK_UNIDIR);

	port->state.alt = NULL;
	port->state.data = &data;
	port->state.mode = TYPEC_MODE_USB4;

	return typec_mux_set(port->mux, &port->state);
}

static int cros_typec_configure_mux(struct cros_typec_data *typec, int port_num,
				uint8_t mux_flags,
				struct ec_response_usb_pd_control_v2 *pd_ctrl)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct ec_params_usb_pd_mux_ack mux_ack;
	enum typec_orientation orientation;
	int ret;

	if (mux_flags == USB_PD_MUX_NONE) {
		ret = cros_typec_usb_disconnect_state(port);
		goto mux_ack;
	}

	if (mux_flags & USB_PD_MUX_POLARITY_INVERTED)
		orientation = TYPEC_ORIENTATION_REVERSE;
	else
		orientation = TYPEC_ORIENTATION_NORMAL;

	ret = typec_switch_set(port->ori_sw, orientation);
	if (ret)
		return ret;

	ret = usb_role_switch_set_role(typec->ports[port_num]->role_sw,
					pd_ctrl->role & PD_CTRL_RESP_ROLE_DATA
					? USB_ROLE_HOST : USB_ROLE_DEVICE);
	if (ret)
		return ret;

	if (mux_flags & USB_PD_MUX_USB4_ENABLED) {
		ret = cros_typec_enable_usb4(typec, port_num, pd_ctrl);
	} else if (mux_flags & USB_PD_MUX_TBT_COMPAT_ENABLED) {
		ret = cros_typec_enable_tbt(typec, port_num, pd_ctrl);
	} else if (mux_flags & USB_PD_MUX_DP_ENABLED) {
		ret = cros_typec_enable_dp(typec, port_num, pd_ctrl);
	} else if (mux_flags & USB_PD_MUX_SAFE_MODE) {
		ret = cros_typec_usb_safe_state(port);
	} else if (mux_flags & USB_PD_MUX_USB_ENABLED) {
		port->state.alt = NULL;
		port->state.mode = TYPEC_STATE_USB;
		ret = typec_mux_set(port->mux, &port->state);
	} else {
		dev_dbg(typec->dev,
			"Unrecognized mode requested, mux flags: %x\n",
			mux_flags);
	}

mux_ack:
	if (!typec->needs_mux_ack)
		return ret;

	/* Sending Acknowledgment to EC */
	mux_ack.port = port_num;

	if (cros_typec_ec_command(typec, 0, EC_CMD_USB_PD_MUX_ACK, &mux_ack,
				  sizeof(mux_ack), NULL, 0) < 0)
		dev_warn(typec->dev,
			 "Failed to send Mux ACK to EC for port: %d\n",
			 port_num);

	return ret;
}

static void cros_typec_set_port_params_v0(struct cros_typec_data *typec,
		int port_num, struct ec_response_usb_pd_control *resp)
{
	struct typec_port *port = typec->ports[port_num]->port;
	enum typec_orientation polarity;

	if (!resp->enabled)
		polarity = TYPEC_ORIENTATION_NONE;
	else if (!resp->polarity)
		polarity = TYPEC_ORIENTATION_NORMAL;
	else
		polarity = TYPEC_ORIENTATION_REVERSE;

	typec_set_pwr_role(port, resp->role ? TYPEC_SOURCE : TYPEC_SINK);
	typec_set_orientation(port, polarity);
}

static void cros_typec_set_port_params_v1(struct cros_typec_data *typec,
		int port_num, struct ec_response_usb_pd_control_v1 *resp)
{
	struct typec_port *port = typec->ports[port_num]->port;
	enum typec_orientation polarity;
	bool pd_en;
	int ret;

	if (!(resp->enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
		polarity = TYPEC_ORIENTATION_NONE;
	else if (!resp->polarity)
		polarity = TYPEC_ORIENTATION_NORMAL;
	else
		polarity = TYPEC_ORIENTATION_REVERSE;
	typec_set_orientation(port, polarity);
	typec_set_data_role(port, resp->role & PD_CTRL_RESP_ROLE_DATA ?
			TYPEC_HOST : TYPEC_DEVICE);
	typec_set_pwr_role(port, resp->role & PD_CTRL_RESP_ROLE_POWER ?
			TYPEC_SOURCE : TYPEC_SINK);
	typec_set_vconn_role(port, resp->role & PD_CTRL_RESP_ROLE_VCONN ?
			TYPEC_SOURCE : TYPEC_SINK);

	/* Register/remove partners when a connect/disconnect occurs. */
	if (resp->enabled & PD_CTRL_RESP_ENABLED_CONNECTED) {
		if (typec->ports[port_num]->partner)
			return;

		pd_en = resp->enabled & PD_CTRL_RESP_ENABLED_PD_CAPABLE;
		ret = cros_typec_add_partner(typec, port_num, pd_en);
		if (ret)
			dev_warn(typec->dev,
				 "Failed to register partner on port: %d\n",
				 port_num);
	} else {
		if (typec->ports[port_num]->partner)
			cros_typec_remove_partner(typec, port_num);

		if (typec->ports[port_num]->cable)
			cros_typec_remove_cable(typec, port_num);
	}
}

static int cros_typec_get_mux_info(struct cros_typec_data *typec, int port_num,
				   struct ec_response_usb_pd_mux_info *resp)
{
	struct ec_params_usb_pd_mux_info req = {
		.port = port_num,
	};

	return cros_typec_ec_command(typec, 0, EC_CMD_USB_PD_MUX_INFO, &req,
				     sizeof(req), resp, sizeof(*resp));
}

/*
 * Helper function to register partner/plug altmodes.
 */
static int cros_typec_register_altmodes(struct cros_typec_data *typec, int port_num,
					bool is_partner)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct ec_response_typec_discovery *sop_disc = port->disc_data;
	struct cros_typec_altmode_node *node;
	struct typec_altmode_desc desc;
	struct typec_altmode *amode;
	int num_altmodes = 0;
	int ret = 0;
	int i, j;

	for (i = 0; i < sop_disc->svid_count; i++) {
		for (j = 0; j < sop_disc->svids[i].mode_count; j++) {
			memset(&desc, 0, sizeof(desc));
			desc.svid = sop_disc->svids[i].svid;
			desc.mode = j;
			desc.vdo = sop_disc->svids[i].mode_vdo[j];

			if (is_partner)
				amode = typec_partner_register_altmode(port->partner, &desc);
			else
				amode = typec_plug_register_altmode(port->plug, &desc);

			if (IS_ERR(amode)) {
				ret = PTR_ERR(amode);
				goto err_cleanup;
			}

			/* If no memory is available we should unregister and exit. */
			node = devm_kzalloc(typec->dev, sizeof(*node), GFP_KERNEL);
			if (!node) {
				ret = -ENOMEM;
				typec_unregister_altmode(amode);
				goto err_cleanup;
			}

			node->amode = amode;

			if (is_partner)
				list_add_tail(&node->list, &port->partner_mode_list);
			else
				list_add_tail(&node->list, &port->plug_mode_list);
			num_altmodes++;
		}
	}

	if (is_partner)
		ret = typec_partner_set_num_altmodes(port->partner, num_altmodes);
	else
		ret = typec_plug_set_num_altmodes(port->plug, num_altmodes);

	if (ret < 0) {
		dev_err(typec->dev, "Unable to set %s num_altmodes for port: %d\n",
			is_partner ? "partner" : "plug", port_num);
		goto err_cleanup;
	}

	return 0;

err_cleanup:
	cros_typec_unregister_altmodes(typec, port_num, is_partner);
	return ret;
}

/*
 * Parse the PD identity data from the EC PD discovery responses and copy that to the supplied
 * PD identity struct.
 */
static void cros_typec_parse_pd_identity(struct usb_pd_identity *id,
					 struct ec_response_typec_discovery *disc)
{
	int i;

	/* First, update the PD identity VDOs for the partner. */
	if (disc->identity_count > 0)
		id->id_header = disc->discovery_vdo[0];
	if (disc->identity_count > 1)
		id->cert_stat = disc->discovery_vdo[1];
	if (disc->identity_count > 2)
		id->product = disc->discovery_vdo[2];

	/* Copy the remaining identity VDOs till a maximum of 6. */
	for (i = 3; i < disc->identity_count && i < VDO_MAX_OBJECTS; i++)
		id->vdo[i - 3] = disc->discovery_vdo[i];
}

static int cros_typec_handle_sop_prime_disc(struct cros_typec_data *typec, int port_num, u16 pd_revision)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct ec_response_typec_discovery *disc = port->disc_data;
	struct typec_cable_desc c_desc = {};
	struct typec_plug_desc p_desc;
	struct ec_params_typec_discovery req = {
		.port = port_num,
		.partner_type = TYPEC_PARTNER_SOP_PRIME,
	};
	u32 cable_plug_type;
	int ret = 0;

	memset(disc, 0, EC_PROTO2_MAX_RESPONSE_SIZE);
	ret = cros_typec_ec_command(typec, 0, EC_CMD_TYPEC_DISCOVERY, &req, sizeof(req),
				    disc, EC_PROTO2_MAX_RESPONSE_SIZE);
	if (ret < 0) {
		dev_err(typec->dev, "Failed to get SOP' discovery data for port: %d\n", port_num);
		goto sop_prime_disc_exit;
	}

	/* Parse the PD identity data, even if only 0s were returned. */
	cros_typec_parse_pd_identity(&port->c_identity, disc);

	if (disc->identity_count != 0) {
		cable_plug_type = VDO_TYPEC_CABLE_TYPE(port->c_identity.vdo[0]);
		switch (cable_plug_type) {
		case CABLE_ATYPE:
			c_desc.type = USB_PLUG_TYPE_A;
			break;
		case CABLE_BTYPE:
			c_desc.type = USB_PLUG_TYPE_B;
			break;
		case CABLE_CTYPE:
			c_desc.type = USB_PLUG_TYPE_C;
			break;
		case CABLE_CAPTIVE:
			c_desc.type = USB_PLUG_CAPTIVE;
			break;
		default:
			c_desc.type = USB_PLUG_NONE;
		}
		c_desc.active = PD_IDH_PTYPE(port->c_identity.id_header) == IDH_PTYPE_ACABLE;
	}

	c_desc.identity = &port->c_identity;
	c_desc.pd_revision = pd_revision;

	port->cable = typec_register_cable(port->port, &c_desc);
	if (IS_ERR(port->cable)) {
		ret = PTR_ERR(port->cable);
		port->cable = NULL;
		goto sop_prime_disc_exit;
	}

	p_desc.index = TYPEC_PLUG_SOP_P;
	port->plug = typec_register_plug(port->cable, &p_desc);
	if (IS_ERR(port->plug)) {
		ret = PTR_ERR(port->plug);
		port->plug = NULL;
		goto sop_prime_disc_exit;
	}

	ret = cros_typec_register_altmodes(typec, port_num, false);
	if (ret < 0) {
		dev_err(typec->dev, "Failed to register plug altmodes, port: %d\n", port_num);
		goto sop_prime_disc_exit;
	}

	return 0;

sop_prime_disc_exit:
	cros_typec_remove_cable(typec, port_num);
	return ret;
}

static int cros_typec_handle_sop_disc(struct cros_typec_data *typec, int port_num, u16 pd_revision)
{
	struct cros_typec_port *port = typec->ports[port_num];
	struct ec_response_typec_discovery *sop_disc = port->disc_data;
	struct ec_params_typec_discovery req = {
		.port = port_num,
		.partner_type = TYPEC_PARTNER_SOP,
	};
	int ret = 0;

	if (!port->partner) {
		dev_err(typec->dev,
			"SOP Discovery received without partner registered, port: %d\n",
			port_num);
		ret = -EINVAL;
		goto disc_exit;
	}

	typec_partner_set_pd_revision(port->partner, pd_revision);

	memset(sop_disc, 0, EC_PROTO2_MAX_RESPONSE_SIZE);
	ret = cros_typec_ec_command(typec, 0, EC_CMD_TYPEC_DISCOVERY, &req, sizeof(req),
				    sop_disc, EC_PROTO2_MAX_RESPONSE_SIZE);
	if (ret < 0) {
		dev_err(typec->dev, "Failed to get SOP discovery data for port: %d\n", port_num);
		goto disc_exit;
	}

	cros_typec_parse_pd_identity(&port->p_identity, sop_disc);

	ret = typec_partner_set_identity(port->partner);
	if (ret < 0) {
		dev_err(typec->dev, "Failed to update partner PD identity, port: %d\n", port_num);
		goto disc_exit;
	}

	ret = cros_typec_register_altmodes(typec, port_num, true);
	if (ret < 0) {
		dev_err(typec->dev, "Failed to register partner altmodes, port: %d\n", port_num);
		goto disc_exit;
	}

disc_exit:
	return ret;
}

static int cros_typec_send_clear_event(struct cros_typec_data *typec, int port_num, u32 events_mask)
{
	struct ec_params_typec_control req = {
		.port = port_num,
		.command = TYPEC_CONTROL_COMMAND_CLEAR_EVENTS,
		.clear_events_mask = events_mask,
	};

	return cros_typec_ec_command(typec, 0, EC_CMD_TYPEC_CONTROL, &req,
				     sizeof(req), NULL, 0);
}

static void cros_typec_handle_status(struct cros_typec_data *typec, int port_num)
{
	struct ec_response_typec_status resp;
	struct ec_params_typec_status req = {
		.port = port_num,
	};
	int ret;

	ret = cros_typec_ec_command(typec, 0, EC_CMD_TYPEC_STATUS, &req, sizeof(req),
				    &resp, sizeof(resp));
	if (ret < 0) {
		dev_warn(typec->dev, "EC_CMD_TYPEC_STATUS failed for port: %d\n", port_num);
		return;
	}

	/* Handle any events appropriately. */
	if (resp.events & PD_STATUS_EVENT_SOP_DISC_DONE && !typec->ports[port_num]->sop_disc_done) {
		u16 sop_revision;

		/* Convert BCD to the format preferred by the TypeC framework */
		sop_revision = (le16_to_cpu(resp.sop_revision) & 0xff00) >> 4;
		ret = cros_typec_handle_sop_disc(typec, port_num, sop_revision);
		if (ret < 0)
			dev_err(typec->dev, "Couldn't parse SOP Disc data, port: %d\n", port_num);
		else {
			typec->ports[port_num]->sop_disc_done = true;
			ret = cros_typec_send_clear_event(typec, port_num,
							  PD_STATUS_EVENT_SOP_DISC_DONE);
			if (ret < 0)
				dev_warn(typec->dev,
					 "Failed SOP Disc event clear, port: %d\n", port_num);
		}
		if (resp.sop_connected)
			typec_set_pwr_opmode(typec->ports[port_num]->port, TYPEC_PWR_MODE_PD);
	}

	if (resp.events & PD_STATUS_EVENT_SOP_PRIME_DISC_DONE &&
	    !typec->ports[port_num]->sop_prime_disc_done) {
		u16 sop_prime_revision;

		/* Convert BCD to the format preferred by the TypeC framework */
		sop_prime_revision = (le16_to_cpu(resp.sop_prime_revision) & 0xff00) >> 4;
		ret = cros_typec_handle_sop_prime_disc(typec, port_num, sop_prime_revision);
		if (ret < 0)
			dev_err(typec->dev, "Couldn't parse SOP' Disc data, port: %d\n", port_num);
		else {
			typec->ports[port_num]->sop_prime_disc_done = true;
			ret = cros_typec_send_clear_event(typec, port_num,
							  PD_STATUS_EVENT_SOP_PRIME_DISC_DONE);
			if (ret < 0)
				dev_warn(typec->dev,
					 "Failed SOP Disc event clear, port: %d\n", port_num);
		}
	}
}

static int cros_typec_port_update(struct cros_typec_data *typec, int port_num)
{
	struct ec_params_usb_pd_control req;
	struct ec_response_usb_pd_control_v2 resp;
	struct ec_response_usb_pd_mux_info mux_resp;
	int ret;

	if (port_num < 0 || port_num >= typec->num_ports) {
		dev_err(typec->dev, "cannot get status for invalid port %d\n",
			port_num);
		return -EINVAL;
	}

	req.port = port_num;
	req.role = USB_PD_CTRL_ROLE_NO_CHANGE;
	req.mux = USB_PD_CTRL_MUX_NO_CHANGE;
	req.swap = USB_PD_CTRL_SWAP_NONE;

	ret = cros_typec_ec_command(typec, typec->pd_ctrl_ver,
				    EC_CMD_USB_PD_CONTROL, &req, sizeof(req),
				    &resp, sizeof(resp));
	if (ret < 0)
		return ret;

	dev_dbg(typec->dev, "Enabled %d: 0x%hhx\n", port_num, resp.enabled);
	dev_dbg(typec->dev, "Role %d: 0x%hhx\n", port_num, resp.role);
	dev_dbg(typec->dev, "Polarity %d: 0x%hhx\n", port_num, resp.polarity);
	dev_dbg(typec->dev, "State %d: %s\n", port_num, resp.state);

	if (typec->pd_ctrl_ver != 0)
		cros_typec_set_port_params_v1(typec, port_num,
			(struct ec_response_usb_pd_control_v1 *)&resp);
	else
		cros_typec_set_port_params_v0(typec, port_num,
			(struct ec_response_usb_pd_control *) &resp);

	if (typec->typec_cmd_supported)
		cros_typec_handle_status(typec, port_num);

	/* Update the switches if they exist, according to requested state */
	ret = cros_typec_get_mux_info(typec, port_num, &mux_resp);
	if (ret < 0) {
		dev_warn(typec->dev,
			 "Failed to get mux info for port: %d, err = %d\n",
			 port_num, ret);
		return 0;
	}

	/* No change needs to be made, let's exit early. */
	if (typec->ports[port_num]->mux_flags == mux_resp.flags)
		return 0;

	typec->ports[port_num]->mux_flags = mux_resp.flags;
	ret = cros_typec_configure_mux(typec, port_num, mux_resp.flags, &resp);
	if (ret)
		dev_warn(typec->dev, "Configure muxes failed, err = %d\n", ret);

	return ret;
}

static int cros_typec_get_cmd_version(struct cros_typec_data *typec)
{
	struct ec_params_get_cmd_versions_v1 req_v1;
	struct ec_response_get_cmd_versions resp;
	int ret;

	/* We're interested in the PD control command version. */
	req_v1.cmd = EC_CMD_USB_PD_CONTROL;
	ret = cros_typec_ec_command(typec, 1, EC_CMD_GET_CMD_VERSIONS,
				    &req_v1, sizeof(req_v1), &resp,
				    sizeof(resp));
	if (ret < 0)
		return ret;

	if (resp.version_mask & EC_VER_MASK(2))
		typec->pd_ctrl_ver = 2;
	else if (resp.version_mask & EC_VER_MASK(1))
		typec->pd_ctrl_ver = 1;
	else
		typec->pd_ctrl_ver = 0;

	dev_dbg(typec->dev, "PD Control has version mask 0x%hhx\n",
		typec->pd_ctrl_ver);

	return 0;
}

/* Check the EC feature flags to see if TYPEC_* features are supported. */
static int cros_typec_feature_supported(struct cros_typec_data *typec, enum ec_feature_code feature)
{
	struct ec_response_get_features resp = {};
	int ret;

	ret = cros_typec_ec_command(typec, 0, EC_CMD_GET_FEATURES, NULL, 0,
				    &resp, sizeof(resp));
	if (ret < 0) {
		dev_warn(typec->dev,
			 "Failed to get features, assuming typec feature=%d unsupported.\n",
			 feature);
		return 0;
	}

	return resp.flags[feature / 32] & EC_FEATURE_MASK_1(feature);
}

static void cros_typec_port_work(struct work_struct *work)
{
	struct cros_typec_data *typec = container_of(work, struct cros_typec_data, port_work);
	int ret, i;

	for (i = 0; i < typec->num_ports; i++) {
		ret = cros_typec_port_update(typec, i);
		if (ret < 0)
			dev_warn(typec->dev, "Update failed for port: %d\n", i);
	}
}

static int cros_ec_typec_event(struct notifier_block *nb,
			       unsigned long host_event, void *_notify)
{
	struct cros_typec_data *typec = container_of(nb, struct cros_typec_data, nb);

	flush_work(&typec->port_work);
	schedule_work(&typec->port_work);

	return NOTIFY_OK;
}

#ifdef CONFIG_ACPI
static const struct acpi_device_id cros_typec_acpi_id[] = {
	{ "GOOG0014", 0 },
	{}
};
MODULE_DEVICE_TABLE(acpi, cros_typec_acpi_id);
#endif

#ifdef CONFIG_OF
static const struct of_device_id cros_typec_of_match[] = {
	{ .compatible = "google,cros-ec-typec", },
	{}
};
MODULE_DEVICE_TABLE(of, cros_typec_of_match);
#endif

static int cros_typec_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct cros_typec_data *typec;
	struct ec_response_usb_pd_ports resp;
	int ret, i;

	typec = devm_kzalloc(dev, sizeof(*typec), GFP_KERNEL);
	if (!typec)
		return -ENOMEM;

	typec->dev = dev;
	typec->ec = dev_get_drvdata(pdev->dev.parent);
	platform_set_drvdata(pdev, typec);

	ret = cros_typec_get_cmd_version(typec);
	if (ret < 0) {
		dev_err(dev, "failed to get PD command version info\n");
		return ret;
	}

	typec->typec_cmd_supported = !!cros_typec_feature_supported(typec,
					EC_FEATURE_TYPEC_CMD);
	typec->needs_mux_ack = !!cros_typec_feature_supported(typec,
					EC_FEATURE_TYPEC_MUX_REQUIRE_AP_ACK);

	ret = cros_typec_ec_command(typec, 0, EC_CMD_USB_PD_PORTS, NULL, 0,
				    &resp, sizeof(resp));
	if (ret < 0)
		return ret;

	typec->num_ports = resp.num_ports;
	if (typec->num_ports > EC_USB_PD_MAX_PORTS) {
		dev_warn(typec->dev,
			 "Too many ports reported: %d, limiting to max: %d\n",
			 typec->num_ports, EC_USB_PD_MAX_PORTS);
		typec->num_ports = EC_USB_PD_MAX_PORTS;
	}

	ret = cros_typec_init_ports(typec);
	if (ret < 0)
		return ret;

	INIT_WORK(&typec->port_work, cros_typec_port_work);

	/*
	 * Safe to call port update here, since we haven't registered the
	 * PD notifier yet.
	 */
	for (i = 0; i < typec->num_ports; i++) {
		ret = cros_typec_port_update(typec, i);
		if (ret < 0)
			goto unregister_ports;
	}

	typec->nb.notifier_call = cros_ec_typec_event;
	ret = cros_usbpd_register_notify(&typec->nb);
	if (ret < 0)
		goto unregister_ports;

	return 0;

unregister_ports:
	cros_unregister_ports(typec);
	return ret;
}

static int __maybe_unused cros_typec_suspend(struct device *dev)
{
	struct cros_typec_data *typec = dev_get_drvdata(dev);

	cancel_work_sync(&typec->port_work);

	return 0;
}

static int __maybe_unused cros_typec_resume(struct device *dev)
{
	struct cros_typec_data *typec = dev_get_drvdata(dev);

	/* Refresh port state. */
	schedule_work(&typec->port_work);

	return 0;
}

static const struct dev_pm_ops cros_typec_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(cros_typec_suspend, cros_typec_resume)
};

static struct platform_driver cros_typec_driver = {
	.driver	= {
		.name = DRV_NAME,
		.acpi_match_table = ACPI_PTR(cros_typec_acpi_id),
		.of_match_table = of_match_ptr(cros_typec_of_match),
		.pm = &cros_typec_pm_ops,
	},
	.probe = cros_typec_probe,
};

module_platform_driver(cros_typec_driver);

MODULE_AUTHOR("Prashant Malani <pmalani@chromium.org>");
MODULE_DESCRIPTION("Chrome OS EC Type C control");
MODULE_LICENSE("GPL");