// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
 */

#include <linux/slab.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/soc/qcom/altmode-glink.h>
#include <linux/usb/dwc3-msm.h>
#include <linux/usb/pd_vdo.h>

#include "dp_altmode.h"
#include "dp_debug.h"
#include "sde_dbg.h"


#define ALTMODE_CONFIGURE_MASK (0x3f)
#define ALTMODE_HPD_STATE_MASK (0x40)
#define ALTMODE_HPD_IRQ_MASK (0x80)

struct dp_altmode_private {
	bool forced_disconnect;
	struct device *dev;
	struct dp_hpd_cb *dp_cb;
	struct dp_altmode dp_altmode;
	struct altmode_client *amclient;
	struct altmode_client_data altmode;
	const char *parent_name;
	bool connected;
	struct notifier_block nb;
};

enum dp_altmode_pin_assignment {
	DPAM_HPD_OUT,
	DPAM_HPD_A,
	DPAM_HPD_B,
	DPAM_HPD_C,
	DPAM_HPD_D,
	DPAM_HPD_E,
	DPAM_HPD_F,
};

static int dp_altmode_release_ss_lanes(struct dp_altmode_private *altmode)
{
	int rc;
	struct device_node *np;
	struct device_node *usb_node;
	struct platform_device *usb_pdev;
	int timeout = 250;

	if (!altmode || !altmode->dev) {
		DP_ERR("invalid args\n");
		return -EINVAL;
	}

	np = altmode->dev->of_node;

	usb_node = of_parse_phandle(np, "usb-controller", 0);
	if (!usb_node) {
		DP_ERR("unable to get usb node\n");
		return -EINVAL;
	}

	usb_pdev = of_find_device_by_node(usb_node);
	if (!usb_pdev) {
		of_node_put(usb_node);
		DP_ERR("unable to get usb pdev\n");
		return -EINVAL;
	}

	while (timeout) {
		rc = dwc3_msm_release_ss_lane(&usb_pdev->dev);
		if (rc != -EBUSY)
			break;

		DP_WARN("USB busy, retry\n");

		/* wait for hw recommended delay for usb */
		msleep(20);
		timeout--;
	}
	of_node_put(usb_node);
	platform_device_put(usb_pdev);

	if (rc)
		DP_ERR("Error releasing SS lanes: %d\n", rc);

	return rc;
}

static void dp_altmode_send_pan_ack(struct altmode_client *amclient,
		u8 port_index)
{
	int rc;
	struct altmode_pan_ack_msg ack;

	ack.cmd_type = ALTMODE_PAN_ACK;
	ack.port_index = port_index;

	rc = altmode_send_data(amclient, &ack, sizeof(ack));
	if (rc < 0) {
		DP_ERR("failed: %d\n", rc);
		return;
	}

	DP_DEBUG("port=%d\n", port_index);
}

static int dp_altmode_notify(void *priv, void *data, size_t len)
{
	int rc = 0;
	struct dp_altmode_private *altmode =
			(struct dp_altmode_private *) priv;
	u8 port_index, dp_data, orientation;
	u8 *payload = (u8 *) data;
	u8 pin, hpd_state, hpd_irq;
	bool force_multi_func = altmode->dp_altmode.base.force_multi_func;

	port_index = payload[0];
	orientation = payload[1];
	dp_data = payload[8];

	pin = dp_data & ALTMODE_CONFIGURE_MASK;
	hpd_state = (dp_data & ALTMODE_HPD_STATE_MASK) >> 6;
	hpd_irq = (dp_data & ALTMODE_HPD_IRQ_MASK) >> 7;

	altmode->dp_altmode.base.hpd_high = !!hpd_state;
	altmode->dp_altmode.base.hpd_irq = !!hpd_irq;
	altmode->dp_altmode.base.multi_func = force_multi_func ? true :
		!(pin == DPAM_HPD_C || pin == DPAM_HPD_E);

	DP_DEBUG("payload=0x%x\n", dp_data);
	DP_DEBUG("port_index=%d, orientation=%d, pin=%d, hpd_state=%d\n",
			port_index, orientation, pin, hpd_state);
	DP_DEBUG("multi_func=%d, hpd_high=%d, hpd_irq=%d\n",
			altmode->dp_altmode.base.multi_func,
			altmode->dp_altmode.base.hpd_high,
			altmode->dp_altmode.base.hpd_irq);
	DP_DEBUG("connected=%d\n", altmode->connected);
	SDE_EVT32_VERBOSE(dp_data, port_index, orientation, pin, hpd_state,
			altmode->dp_altmode.base.multi_func,
			altmode->dp_altmode.base.hpd_high,
			altmode->dp_altmode.base.hpd_irq, altmode->connected);

	if (!pin) {
		/* Cable detach */
		if (altmode->connected) {
			altmode->connected = false;
			altmode->dp_altmode.base.alt_mode_cfg_done = false;
			altmode->dp_altmode.base.orientation = ORIENTATION_NONE;
			if (altmode->dp_cb && altmode->dp_cb->disconnect)
				altmode->dp_cb->disconnect(altmode->dev);
		}
		goto ack;
	}

	/* Configure */
	if (!altmode->connected) {
		altmode->connected = true;
		altmode->dp_altmode.base.alt_mode_cfg_done = true;

		switch (orientation) {
		case 0:
			orientation = ORIENTATION_CC1;
			break;
		case 1:
			orientation = ORIENTATION_CC2;
			break;
		case 2:
			orientation = ORIENTATION_NONE;
			break;
		default:
			orientation = ORIENTATION_NONE;
			break;
		}

		altmode->dp_altmode.base.orientation = orientation;

		if (!altmode->dp_altmode.base.multi_func) {
			rc = dp_altmode_release_ss_lanes(altmode);
			if (rc)
				goto ack;
		}

		if (altmode->dp_cb && altmode->dp_cb->configure)
			altmode->dp_cb->configure(altmode->dev);
		goto ack;
	}

	/* Attention */
	if (altmode->forced_disconnect)
		goto ack;

	if (altmode->dp_cb && altmode->dp_cb->attention)
		altmode->dp_cb->attention(altmode->dev);
ack:
	dp_altmode_send_pan_ack(altmode->amclient, port_index);
	return rc;
}

static int dp_altmode_register(struct notifier_block *nb, unsigned long ebt,
		void *pdev)
{
	int rc;
	struct platform_device *altmode_pdev = pdev;
	struct dp_altmode_private *altmode = container_of(nb,
			struct dp_altmode_private, nb);

	altmode->amclient = altmode_register_client(&altmode_pdev->dev,
			&altmode->altmode);
	if (IS_ERR_OR_NULL(altmode->amclient)) {
		rc = PTR_ERR(altmode->amclient);
		DP_ERR("failed to register dp altmode client: %d\n", rc);
		return -EINVAL;
	}

	DP_DEBUG("success\n");

	return 0;
}

static int dp_altmode_simulate_connect(struct dp_hpd *dp_hpd, bool hpd)
{
	struct dp_altmode *dp_altmode;
	struct dp_altmode_private *altmode;

	dp_altmode = container_of(dp_hpd, struct dp_altmode, base);
	altmode = container_of(dp_altmode, struct dp_altmode_private,
			dp_altmode);

	dp_altmode->base.hpd_high = hpd;
	altmode->forced_disconnect = !hpd;
	altmode->dp_altmode.base.alt_mode_cfg_done = hpd;

	if (hpd)
		altmode->dp_cb->configure(altmode->dev);
	else
		altmode->dp_cb->disconnect(altmode->dev);

	return 0;
}

static int dp_altmode_simulate_attention(struct dp_hpd *dp_hpd, int vdo)
{
	struct dp_altmode *dp_altmode;
	struct dp_altmode_private *altmode;
	struct dp_altmode *status;

	dp_altmode = container_of(dp_hpd, struct dp_altmode, base);
	altmode = container_of(dp_altmode, struct dp_altmode_private,
			dp_altmode);

	status = &altmode->dp_altmode;

	status->base.hpd_high  = (vdo & BIT(7)) ? true : false;
	status->base.hpd_irq   = (vdo & BIT(8)) ? true : false;

	if (altmode->dp_cb && altmode->dp_cb->attention)
		altmode->dp_cb->attention(altmode->dev);

	return 0;
}

struct dp_hpd *dp_altmode_get(struct device *dev, struct dp_hpd_cb *cb)
{
	int rc = 0;
	struct dp_altmode_private *altmode;
	struct dp_altmode *dp_altmode;
	const char *altmode_str = "qcom,altmode-parent";
	struct altmode_client_data client_data = {
		.callback	= &dp_altmode_notify,
	};

	if (!cb) {
		DP_ERR("invalid cb data\n");
		return ERR_PTR(-EINVAL);
	}

	altmode = kzalloc(sizeof(*altmode), GFP_KERNEL);
	if (!altmode)
		return ERR_PTR(-ENOMEM);

	altmode->dev = dev;
	altmode->dp_cb = cb;

	client_data.name = "displayport";
	client_data.svid = USB_SID_DISPLAYPORT;
	client_data.priv = altmode;

	altmode->altmode = client_data;

	dp_altmode = &altmode->dp_altmode;
	dp_altmode->base.register_hpd = NULL;
	dp_altmode->base.simulate_connect = dp_altmode_simulate_connect;
	dp_altmode->base.simulate_attention = dp_altmode_simulate_attention;

	rc = of_property_read_string(altmode->dev->of_node, altmode_str,
			&altmode->parent_name);
	if (rc < 0) {
		DP_ERR("No altmode parent device specified\n");
		goto error;
	}

	DP_DEBUG("parent_name=%s\n", altmode->parent_name);

	altmode->nb.notifier_call = dp_altmode_register;
	rc = altmode_register_notifier(altmode->parent_name, &altmode->nb);
	if (rc < 0) {
		DP_ERR("altmode probe notifier registration failed: %d\n", rc);
		goto error;
	}

	DP_DEBUG("success\n");

	return &dp_altmode->base;
error:
	kfree(altmode);
	return ERR_PTR(rc);
}

void dp_altmode_put(struct dp_hpd *dp_hpd)
{
	struct dp_altmode *dp_altmode;
	struct dp_altmode_private *altmode;

	dp_altmode = container_of(dp_hpd, struct dp_altmode, base);
	if (!dp_altmode)
		return;

	altmode = container_of(dp_altmode, struct dp_altmode_private,
			dp_altmode);

	altmode_deregister_client(altmode->amclient);

	kfree(altmode);
}