// SPDX-License-Identifier: GPL-2.0
|
/*
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* USB Typec-C DisplayPort Alternate Mode driver
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*
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* Copyright (C) 2018 Intel Corporation
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* Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
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*
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* DisplayPort is trademark of VESA (www.vesa.org)
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*/
|
|
#include <linux/delay.h>
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/property.h>
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#include <linux/usb/pd_vdo.h>
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#include <linux/usb/typec_dp.h>
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#include <drm/drm_connector.h>
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#include "displayport.h"
|
|
#define DP_HEADER(_dp, ver, cmd) (VDO((_dp)->alt->svid, 1, ver, cmd) \
|
| VDO_OPOS(USB_TYPEC_DP_MODE))
|
|
enum {
|
DP_CONF_USB,
|
DP_CONF_DFP_D,
|
DP_CONF_UFP_D,
|
DP_CONF_DUAL_D,
|
};
|
|
/* Pin assignments that use USB3.1 Gen2 signaling to carry DP protocol */
|
#define DP_PIN_ASSIGN_GEN2_BR_MASK (BIT(DP_PIN_ASSIGN_A) | \
|
BIT(DP_PIN_ASSIGN_B))
|
|
/* Pin assignments that use DP v1.3 signaling to carry DP protocol */
|
#define DP_PIN_ASSIGN_DP_BR_MASK (BIT(DP_PIN_ASSIGN_C) | \
|
BIT(DP_PIN_ASSIGN_D) | \
|
BIT(DP_PIN_ASSIGN_E) | \
|
BIT(DP_PIN_ASSIGN_F))
|
|
/* DP only pin assignments */
|
#define DP_PIN_ASSIGN_DP_ONLY_MASK (BIT(DP_PIN_ASSIGN_A) | \
|
BIT(DP_PIN_ASSIGN_C) | \
|
BIT(DP_PIN_ASSIGN_E))
|
|
/* Pin assignments where one channel is for USB */
|
#define DP_PIN_ASSIGN_MULTI_FUNC_MASK (BIT(DP_PIN_ASSIGN_B) | \
|
BIT(DP_PIN_ASSIGN_D) | \
|
BIT(DP_PIN_ASSIGN_F))
|
|
/*
|
* A UFP_U that uses a USB Type-C plug describes the pin assignments supported
|
* for the corresponding receptacle. (i.e., a UFP_D will describe the DFP_D pin
|
* assignments to which it connects), whereas a UFP_U that uses a USB Type-C
|
* receptacle describes its pin assignments directly (i.e., a UFP_D will
|
* describe its own UFP_D pin assignments).
|
*/
|
#define DP_CAP_PIN_ASSIGN(_cap_) (((_cap_) & DP_CAP_RECEPTACLE) ? \
|
DP_CAP_UFP_D_PIN_ASSIGN(_cap_) : \
|
DP_CAP_DFP_D_PIN_ASSIGN(_cap_))
|
|
enum dp_state {
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DP_STATE_IDLE,
|
DP_STATE_ENTER,
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DP_STATE_UPDATE,
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DP_STATE_CONFIGURE,
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DP_STATE_EXIT,
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};
|
|
struct dp_altmode {
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struct typec_displayport_data data;
|
|
enum dp_state state;
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bool hpd;
|
|
struct mutex lock; /* device lock */
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struct work_struct work;
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struct typec_altmode *alt;
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const struct typec_altmode *port;
|
struct fwnode_handle *connector_fwnode;
|
};
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|
static int dp_altmode_notify(struct dp_altmode *dp)
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{
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u8 state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
|
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return typec_altmode_notify(dp->alt, TYPEC_MODAL_STATE(state),
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&dp->data);
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}
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static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
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{
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u32 conf = DP_CONF_SIGNALING_DP; /* Only DP signaling supported */
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u8 pin_assign = 0;
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switch (con) {
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case DP_STATUS_CON_DISABLED:
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return 0;
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case DP_STATUS_CON_DFP_D:
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conf |= DP_CONF_UFP_U_AS_DFP_D;
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break;
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case DP_STATUS_CON_UFP_D:
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case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
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conf |= DP_CONF_UFP_U_AS_UFP_D;
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break;
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default:
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break;
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}
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/* Determining the initial pin assignment. */
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if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
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pin_assign = DP_CAP_PIN_ASSIGN(dp->alt->vdo);
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/* Is USB together with DP preferred */
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if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
|
pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
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pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
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else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) {
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pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
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/* Default to pin assign C if available */
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if (pin_assign & BIT(DP_PIN_ASSIGN_C))
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pin_assign = BIT(DP_PIN_ASSIGN_C);
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}
|
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/*
|
* DFP_U never selects Pin Assignment E when Pin Assignment C
|
* and possibly Pin Assignment D are offered by the UFP_U.
|
*/
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if (pin_assign & (BIT(DP_PIN_ASSIGN_C) | BIT(DP_PIN_ASSIGN_D)))
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pin_assign &= ~BIT(DP_PIN_ASSIGN_E);
|
|
if (!pin_assign)
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return -EINVAL;
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|
conf |= DP_CONF_SET_PIN_ASSIGN(pin_assign);
|
}
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|
dp->data.conf = conf;
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|
return 0;
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}
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static int dp_altmode_status_update(struct dp_altmode *dp)
|
{
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bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
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bool hpd = !!(dp->data.status & DP_STATUS_HPD_STATE);
|
u8 con = DP_STATUS_CONNECTION(dp->data.status);
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int ret = 0;
|
|
if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
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dp->data.conf = 0;
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dp->state = DP_STATE_CONFIGURE;
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} else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
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dp->state = DP_STATE_EXIT;
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} else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
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ret = dp_altmode_configure(dp, con);
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if (!ret)
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dp->state = DP_STATE_CONFIGURE;
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} else {
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if (dp->hpd != hpd) {
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drm_connector_oob_hotplug_event(dp->connector_fwnode);
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dp->hpd = hpd;
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}
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}
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|
return ret;
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}
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static int dp_altmode_configured(struct dp_altmode *dp)
|
{
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int ret;
|
|
sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");
|
|
if (!dp->data.conf)
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return typec_altmode_notify(dp->alt, TYPEC_STATE_USB,
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&dp->data);
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ret = dp_altmode_notify(dp);
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if (ret)
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return ret;
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sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
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return 0;
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}
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static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
|
{
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int svdm_version = typec_altmode_get_svdm_version(dp->alt);
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u32 header;
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int ret;
|
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if (svdm_version < 0)
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return svdm_version;
|
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header = DP_HEADER(dp, svdm_version, DP_CMD_CONFIGURE);
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ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE, &dp->data);
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if (ret) {
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dev_err(&dp->alt->dev,
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"unable to put to connector to safe mode\n");
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return ret;
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}
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ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
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if (ret) {
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if (DP_CONF_GET_PIN_ASSIGN(dp->data.conf))
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dp_altmode_notify(dp);
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else
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typec_altmode_notify(dp->alt, TYPEC_STATE_USB,
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&dp->data);
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}
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return ret;
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}
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static void dp_altmode_work(struct work_struct *work)
|
{
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struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
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int svdm_version;
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u32 header;
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u32 vdo;
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int ret;
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mutex_lock(&dp->lock);
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|
switch (dp->state) {
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case DP_STATE_ENTER:
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ret = typec_altmode_enter(dp->alt, NULL);
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if (ret && ret != -EBUSY)
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dev_err(&dp->alt->dev, "failed to enter mode\n");
|
break;
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case DP_STATE_UPDATE:
|
svdm_version = typec_altmode_get_svdm_version(dp->alt);
|
if (svdm_version < 0)
|
break;
|
header = DP_HEADER(dp, svdm_version, DP_CMD_STATUS_UPDATE);
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vdo = 1;
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ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
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if (ret)
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dev_err(&dp->alt->dev,
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"unable to send Status Update command (%d)\n",
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ret);
|
break;
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case DP_STATE_CONFIGURE:
|
ret = dp_altmode_configure_vdm(dp, dp->data.conf);
|
if (ret)
|
dev_err(&dp->alt->dev,
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"unable to send Configure command (%d)\n", ret);
|
break;
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case DP_STATE_EXIT:
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if (typec_altmode_exit(dp->alt))
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dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
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break;
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default:
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break;
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}
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dp->state = DP_STATE_IDLE;
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|
mutex_unlock(&dp->lock);
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}
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static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
|
{
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struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
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u8 old_state;
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mutex_lock(&dp->lock);
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old_state = dp->state;
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dp->data.status = vdo;
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if (old_state != DP_STATE_IDLE)
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dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
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old_state);
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if (dp_altmode_status_update(dp))
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dev_warn(&alt->dev, "%s: status update failed\n", __func__);
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|
if (dp_altmode_notify(dp))
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dev_err(&alt->dev, "%s: notification failed\n", __func__);
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|
if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
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schedule_work(&dp->work);
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|
mutex_unlock(&dp->lock);
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}
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|
static int dp_altmode_vdm(struct typec_altmode *alt,
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const u32 hdr, const u32 *vdo, int count)
|
{
|
struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
|
int cmd_type = PD_VDO_CMDT(hdr);
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int cmd = PD_VDO_CMD(hdr);
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int ret = 0;
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|
mutex_lock(&dp->lock);
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|
if (dp->state != DP_STATE_IDLE) {
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ret = -EBUSY;
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goto err_unlock;
|
}
|
|
switch (cmd_type) {
|
case CMDT_RSP_ACK:
|
switch (cmd) {
|
case CMD_ENTER_MODE:
|
dp->state = DP_STATE_UPDATE;
|
break;
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case CMD_EXIT_MODE:
|
dp->data.status = 0;
|
dp->data.conf = 0;
|
break;
|
case DP_CMD_STATUS_UPDATE:
|
dp->data.status = *vdo;
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ret = dp_altmode_status_update(dp);
|
break;
|
case DP_CMD_CONFIGURE:
|
ret = dp_altmode_configured(dp);
|
break;
|
default:
|
break;
|
}
|
break;
|
case CMDT_RSP_NAK:
|
switch (cmd) {
|
case DP_CMD_CONFIGURE:
|
dp->data.conf = 0;
|
ret = dp_altmode_configured(dp);
|
break;
|
default:
|
break;
|
}
|
break;
|
default:
|
break;
|
}
|
|
if (dp->state != DP_STATE_IDLE)
|
schedule_work(&dp->work);
|
|
err_unlock:
|
mutex_unlock(&dp->lock);
|
return ret;
|
}
|
|
static int dp_altmode_activate(struct typec_altmode *alt, int activate)
|
{
|
return activate ? typec_altmode_enter(alt, NULL) :
|
typec_altmode_exit(alt);
|
}
|
|
static const struct typec_altmode_ops dp_altmode_ops = {
|
.attention = dp_altmode_attention,
|
.vdm = dp_altmode_vdm,
|
.activate = dp_altmode_activate,
|
};
|
|
static const char * const configurations[] = {
|
[DP_CONF_USB] = "USB",
|
[DP_CONF_DFP_D] = "source",
|
[DP_CONF_UFP_D] = "sink",
|
};
|
|
static ssize_t
|
configuration_store(struct device *dev, struct device_attribute *attr,
|
const char *buf, size_t size)
|
{
|
struct dp_altmode *dp = dev_get_drvdata(dev);
|
u32 conf;
|
u32 cap;
|
int con;
|
int ret = 0;
|
|
con = sysfs_match_string(configurations, buf);
|
if (con < 0)
|
return con;
|
|
mutex_lock(&dp->lock);
|
|
if (dp->state != DP_STATE_IDLE) {
|
ret = -EBUSY;
|
goto err_unlock;
|
}
|
|
cap = DP_CAP_CAPABILITY(dp->alt->vdo);
|
|
if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) ||
|
(con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D))) {
|
ret = -EINVAL;
|
goto err_unlock;
|
}
|
|
conf = dp->data.conf & ~DP_CONF_DUAL_D;
|
conf |= con;
|
|
if (dp->alt->active) {
|
ret = dp_altmode_configure_vdm(dp, conf);
|
if (ret)
|
goto err_unlock;
|
}
|
|
dp->data.conf = conf;
|
|
err_unlock:
|
mutex_unlock(&dp->lock);
|
|
return ret ? ret : size;
|
}
|
|
static ssize_t configuration_show(struct device *dev,
|
struct device_attribute *attr, char *buf)
|
{
|
struct dp_altmode *dp = dev_get_drvdata(dev);
|
int len;
|
u8 cap;
|
u8 cur;
|
int i;
|
|
mutex_lock(&dp->lock);
|
|
cap = DP_CAP_CAPABILITY(dp->alt->vdo);
|
cur = DP_CONF_CURRENTLY(dp->data.conf);
|
|
len = sprintf(buf, "%s ", cur ? "USB" : "[USB]");
|
|
for (i = 1; i < ARRAY_SIZE(configurations); i++) {
|
if (i == cur)
|
len += sprintf(buf + len, "[%s] ", configurations[i]);
|
else if ((i == DP_CONF_DFP_D && cap & DP_CAP_DFP_D) ||
|
(i == DP_CONF_UFP_D && cap & DP_CAP_UFP_D))
|
len += sprintf(buf + len, "%s ", configurations[i]);
|
}
|
|
mutex_unlock(&dp->lock);
|
|
buf[len - 1] = '\n';
|
return len;
|
}
|
static DEVICE_ATTR_RW(configuration);
|
|
static const char * const pin_assignments[] = {
|
[DP_PIN_ASSIGN_A] = "A",
|
[DP_PIN_ASSIGN_B] = "B",
|
[DP_PIN_ASSIGN_C] = "C",
|
[DP_PIN_ASSIGN_D] = "D",
|
[DP_PIN_ASSIGN_E] = "E",
|
[DP_PIN_ASSIGN_F] = "F",
|
};
|
|
/*
|
* Helper function to extract a peripheral's currently supported
|
* Pin Assignments from its DisplayPort alternate mode state.
|
*/
|
static u8 get_current_pin_assignments(struct dp_altmode *dp)
|
{
|
if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
|
return DP_CAP_PIN_ASSIGN_DFP_D(dp->alt->vdo);
|
else
|
return DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo);
|
}
|
|
static ssize_t
|
pin_assignment_store(struct device *dev, struct device_attribute *attr,
|
const char *buf, size_t size)
|
{
|
struct dp_altmode *dp = dev_get_drvdata(dev);
|
u8 assignments;
|
u32 conf;
|
int ret;
|
|
ret = sysfs_match_string(pin_assignments, buf);
|
if (ret < 0)
|
return ret;
|
|
conf = DP_CONF_SET_PIN_ASSIGN(BIT(ret));
|
ret = 0;
|
|
mutex_lock(&dp->lock);
|
|
if (conf & dp->data.conf)
|
goto out_unlock;
|
|
if (dp->state != DP_STATE_IDLE) {
|
ret = -EBUSY;
|
goto out_unlock;
|
}
|
|
assignments = get_current_pin_assignments(dp);
|
|
if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
|
ret = -EINVAL;
|
goto out_unlock;
|
}
|
|
conf |= dp->data.conf & ~DP_CONF_PIN_ASSIGNEMENT_MASK;
|
|
/* Only send Configure command if a configuration has been set */
|
if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
|
ret = dp_altmode_configure_vdm(dp, conf);
|
if (ret)
|
goto out_unlock;
|
}
|
|
dp->data.conf = conf;
|
|
out_unlock:
|
mutex_unlock(&dp->lock);
|
|
return ret ? ret : size;
|
}
|
|
static ssize_t pin_assignment_show(struct device *dev,
|
struct device_attribute *attr, char *buf)
|
{
|
struct dp_altmode *dp = dev_get_drvdata(dev);
|
u8 assignments;
|
int len = 0;
|
u8 cur;
|
int i;
|
|
mutex_lock(&dp->lock);
|
|
cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
|
|
assignments = get_current_pin_assignments(dp);
|
|
for (i = 0; assignments; assignments >>= 1, i++) {
|
if (assignments & 1) {
|
if (i == cur)
|
len += sprintf(buf + len, "[%s] ",
|
pin_assignments[i]);
|
else
|
len += sprintf(buf + len, "%s ",
|
pin_assignments[i]);
|
}
|
}
|
|
mutex_unlock(&dp->lock);
|
|
/* get_current_pin_assignments can return 0 when no matching pin assignments are found */
|
if (len == 0)
|
len++;
|
|
buf[len - 1] = '\n';
|
return len;
|
}
|
static DEVICE_ATTR_RW(pin_assignment);
|
|
static struct attribute *dp_altmode_attrs[] = {
|
&dev_attr_configuration.attr,
|
&dev_attr_pin_assignment.attr,
|
NULL
|
};
|
|
static const struct attribute_group dp_altmode_group = {
|
.name = "displayport",
|
.attrs = dp_altmode_attrs,
|
};
|
|
int dp_altmode_probe(struct typec_altmode *alt)
|
{
|
const struct typec_altmode *port = typec_altmode_get_partner(alt);
|
struct fwnode_handle *fwnode;
|
struct dp_altmode *dp;
|
int ret;
|
|
/* FIXME: Port can only be DFP_U. */
|
|
/* Make sure we have compatiple pin configurations */
|
if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
|
DP_CAP_PIN_ASSIGN_UFP_D(alt->vdo)) &&
|
!(DP_CAP_PIN_ASSIGN_UFP_D(port->vdo) &
|
DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo)))
|
return -ENODEV;
|
|
ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group);
|
if (ret)
|
return ret;
|
|
dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
|
if (!dp)
|
return -ENOMEM;
|
|
INIT_WORK(&dp->work, dp_altmode_work);
|
mutex_init(&dp->lock);
|
dp->port = port;
|
dp->alt = alt;
|
|
alt->desc = "DisplayPort";
|
alt->ops = &dp_altmode_ops;
|
|
fwnode = dev_fwnode(alt->dev.parent->parent); /* typec_port fwnode */
|
dp->connector_fwnode = fwnode_find_reference(fwnode, "displayport", 0);
|
if (IS_ERR(dp->connector_fwnode))
|
dp->connector_fwnode = NULL;
|
|
typec_altmode_set_drvdata(alt, dp);
|
|
dp->state = DP_STATE_ENTER;
|
schedule_work(&dp->work);
|
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(dp_altmode_probe);
|
|
void dp_altmode_remove(struct typec_altmode *alt)
|
{
|
struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
|
|
sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
|
cancel_work_sync(&dp->work);
|
|
if (dp->connector_fwnode) {
|
if (dp->hpd)
|
drm_connector_oob_hotplug_event(dp->connector_fwnode);
|
|
fwnode_handle_put(dp->connector_fwnode);
|
}
|
}
|
EXPORT_SYMBOL_GPL(dp_altmode_remove);
|
|
static const struct typec_device_id dp_typec_id[] = {
|
{ USB_TYPEC_DP_SID, USB_TYPEC_DP_MODE },
|
{ },
|
};
|
MODULE_DEVICE_TABLE(typec, dp_typec_id);
|
|
static struct typec_altmode_driver dp_altmode_driver = {
|
.id_table = dp_typec_id,
|
.probe = dp_altmode_probe,
|
.remove = dp_altmode_remove,
|
.driver = {
|
.name = "typec_displayport",
|
.owner = THIS_MODULE,
|
},
|
};
|
module_typec_altmode_driver(dp_altmode_driver);
|
|
MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
|
MODULE_LICENSE("GPL v2");
|
MODULE_DESCRIPTION("DisplayPort Alternate Mode");
|
