linux/drivers/usb/typec/ucsi/displayport.c

// SPDX-License-Identifier: GPL-2.0
/*
 * UCSI DisplayPort Alternate Mode Support
 *
 * Copyright (C) 2018, Intel Corporation
 * Author: Heikki Krogerus <[email protected]>
 */

#include <linux/usb/typec_dp.h>
#include <linux/usb/pd_vdo.h>

#include "ucsi.h"

#define UCSI_CMD_SET_NEW_CAM(_con_num_, _enter_, _cam_, _am_) …

struct ucsi_dp { … };

/*
 * Note. Alternate mode control is optional feature in UCSI. It means that even
 * if the system supports alternate modes, the OS may not be aware of them.
 *
 * In most cases however, the OS will be able to see the supported alternate
 * modes, but it may still not be able to configure them, not even enter or exit
 * them. That is because UCSI defines alt mode details and alt mode "overriding"
 * as separate options.
 *
 * In case alt mode details are supported, but overriding is not, the driver
 * will still display the supported pin assignments and configuration, but any
 * changes the user attempts to do will lead into failure with return value of
 * -EOPNOTSUPP.
 */

static int ucsi_displayport_enter(struct typec_altmode *alt, u32 *vdo)
{ … }

static int ucsi_displayport_exit(struct typec_altmode *alt)
{ … }

/*
 * We do not actually have access to the Status Update VDO, so we have to guess
 * things.
 */
static int ucsi_displayport_status_update(struct ucsi_dp *dp)
{ … }

static int ucsi_displayport_configure(struct ucsi_dp *dp)
{ … }

static int ucsi_displayport_vdm(struct typec_altmode *alt,
				u32 header, const u32 *data, int count)
{ … }

static const struct typec_altmode_ops ucsi_displayport_ops = …;

static void ucsi_displayport_work(struct work_struct *work)
{ … }

void ucsi_displayport_remove_partner(struct typec_altmode *alt)
{ … }

struct typec_altmode *ucsi_register_displayport(struct ucsi_connector *con,
						bool override, int offset,
						struct typec_altmode_desc *desc)
{ … }