[linux-block.git] / drivers / usb / typec / altmodes / displayport.c

// SPDX-License-Identifier: GPL-2.0
/**
 * USB Typec-C DisplayPort Alternate Mode driver
 *
 * Copyright (C) 2018 Intel Corporation
 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
 *
 * DisplayPort is trademark of VESA (www.vesa.org)
 */

#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/usb/pd_vdo.h>
#include <linux/usb/typec_dp.h>

#define DP_HEADER(_dp, cmd)		(VDO((_dp)->alt->svid, 1, 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))

enum dp_state {
	DP_STATE_IDLE,
	DP_STATE_ENTER,
	DP_STATE_UPDATE,
	DP_STATE_CONFIGURE,
	DP_STATE_EXIT,
};

struct dp_altmode {
	struct typec_displayport_data data;

	enum dp_state state;

	struct mutex lock; /* device lock */
	struct work_struct work;
	struct typec_altmode *alt;
	const struct typec_altmode *port;
};

static int dp_altmode_notify(struct dp_altmode *dp)
{
	u8 state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));

	return typec_altmode_notify(dp->alt, TYPEC_MODAL_STATE(state),
				   &dp->data);
}

static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
{
	u32 conf = DP_CONF_SIGNALING_DP; /* Only DP signaling supported */
	u8 pin_assign = 0;

	switch (con) {
	case DP_STATUS_CON_DISABLED:
		return 0;
	case DP_STATUS_CON_DFP_D:
		conf |= DP_CONF_UFP_U_AS_DFP_D;
		pin_assign = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo) &
			     DP_CAP_DFP_D_PIN_ASSIGN(dp->port->vdo);
		break;
	case DP_STATUS_CON_UFP_D:
	case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
		conf |= DP_CONF_UFP_U_AS_UFP_D;
		pin_assign = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo) &
			     DP_CAP_UFP_D_PIN_ASSIGN(dp->port->vdo);
		break;
	default:
		break;
	}

	/* Determining the initial pin assignment. */
	if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
		/* Is USB together with DP preferred */
		if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
		    pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
			pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
		else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK)
			pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;

		if (!pin_assign)
			return -EINVAL;

		conf |= DP_CONF_SET_PIN_ASSIGN(pin_assign);
	}

	dp->data.conf = conf;

	return 0;
}

static int dp_altmode_status_update(struct dp_altmode *dp)
{
	bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
	u8 con = DP_STATUS_CONNECTION(dp->data.status);
	int ret = 0;

	if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
		dp->data.conf = 0;
		dp->state = DP_STATE_CONFIGURE;
	} else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
		dp->state = DP_STATE_EXIT;
	} else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
		ret = dp_altmode_configure(dp, con);
		if (!ret)
			dp->state = DP_STATE_CONFIGURE;
	}

	return ret;
}

static int dp_altmode_configured(struct dp_altmode *dp)
{
	int ret;

	sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");

	if (!dp->data.conf)
		return typec_altmode_notify(dp->alt, TYPEC_STATE_USB,
					    &dp->data);

	ret = dp_altmode_notify(dp);
	if (ret)
		return ret;

	sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");

	return 0;
}

static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
{
	u32 header = DP_HEADER(dp, DP_CMD_CONFIGURE);
	int ret;

	ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE, &dp->data);
	if (ret) {
		dev_err(&dp->alt->dev,
			"unable to put to connector to safe mode\n");
		return ret;
	}

	ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
	if (ret) {
		if (DP_CONF_GET_PIN_ASSIGN(dp->data.conf))
			dp_altmode_notify(dp);
		else
			typec_altmode_notify(dp->alt, TYPEC_STATE_USB,
					     &dp->data);
	}

	return ret;
}

static void dp_altmode_work(struct work_struct *work)
{
	struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
	u32 header;
	u32 vdo;
	int ret;

	mutex_lock(&dp->lock);

	switch (dp->state) {
	case DP_STATE_ENTER:
		ret = typec_altmode_enter(dp->alt);
		if (ret)
			dev_err(&dp->alt->dev, "failed to enter mode\n");
		break;
	case DP_STATE_UPDATE:
		header = DP_HEADER(dp, DP_CMD_STATUS_UPDATE);
		vdo = 1;
		ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
		if (ret)
			dev_err(&dp->alt->dev,
				"unable to send Status Update command (%d)\n",
				ret);
		break;
	case DP_STATE_CONFIGURE:
		ret = dp_altmode_configure_vdm(dp, dp->data.conf);
		if (ret)
			dev_err(&dp->alt->dev,
				"unable to send Configure command (%d)\n", ret);
		break;
	case DP_STATE_EXIT:
		if (typec_altmode_exit(dp->alt))
			dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
		break;
	default:
		break;
	}

	dp->state = DP_STATE_IDLE;

	mutex_unlock(&dp->lock);
}

static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
{
	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
	u8 old_state;

	mutex_lock(&dp->lock);

	old_state = dp->state;
	dp->data.status = vdo;

	if (old_state != DP_STATE_IDLE)
		dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
			 old_state);

	if (dp_altmode_status_update(dp))
		dev_warn(&alt->dev, "%s: status update failed\n", __func__);

	if (dp_altmode_notify(dp))
		dev_err(&alt->dev, "%s: notification failed\n", __func__);

	if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
		schedule_work(&dp->work);

	mutex_unlock(&dp->lock);
}

static int dp_altmode_vdm(struct typec_altmode *alt,
			  const u32 hdr, const u32 *vdo, int count)
{
	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
	int cmd_type = PD_VDO_CMDT(hdr);
	int cmd = PD_VDO_CMD(hdr);
	int ret = 0;

	mutex_lock(&dp->lock);

	if (dp->state != DP_STATE_IDLE) {
		ret = -EBUSY;
		goto err_unlock;
	}

	switch (cmd_type) {
	case CMDT_RSP_ACK:
		switch (cmd) {
		case CMD_ENTER_MODE:
			dp->state = DP_STATE_UPDATE;
			break;
		case CMD_EXIT_MODE:
			dp->data.status = 0;
			dp->data.conf = 0;
			break;
		case DP_CMD_STATUS_UPDATE:
			dp->data.status = *vdo;
			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) : 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",
};

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;
	}

	if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
		assignments = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
	else
		assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);

	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));

	if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
		assignments = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
	else
		assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);

	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);

	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 dp_altmode *dp;
	int ret;

	/* FIXME: Port can only be DFP_U. */

	/* Make sure we have compatiple pin configurations */
	if (!(DP_CAP_DFP_D_PIN_ASSIGN(port->vdo) &
	      DP_CAP_UFP_D_PIN_ASSIGN(alt->vdo)) &&
	    !(DP_CAP_UFP_D_PIN_ASSIGN(port->vdo) &
	      DP_CAP_DFP_D_PIN_ASSIGN(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;

	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);
}
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");
Commit	Line	Data
0e3bb7d6 HK	1	// SPDX-License-Identifier: GPL-2.0
	2	/**
	3	* USB Typec-C DisplayPort Alternate Mode driver
	4	*
	5	* Copyright (C) 2018 Intel Corporation
	6	* Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
	7	*
	8	* DisplayPort is trademark of VESA (www.vesa.org)
	9	*/
	10
	11	#include <linux/delay.h>
	12	#include <linux/mutex.h>
	13	#include <linux/module.h>
	14	#include <linux/usb/pd_vdo.h>
	15	#include <linux/usb/typec_dp.h>
	16
d266e968	17	#define DP_HEADER(_dp, cmd) (VDO((_dp)->alt->svid, 1, cmd) \| \
0e3bb7d6 HK	18	VDO_OPOS(USB_TYPEC_DP_MODE))
	19
	20	enum {
	21	DP_CONF_USB,
	22	DP_CONF_DFP_D,
	23	DP_CONF_UFP_D,
	24	DP_CONF_DUAL_D,
	25	};
	26
0e3bb7d6 HK	27	/* Pin assignments that use USB3.1 Gen2 signaling to carry DP protocol */
	28	#define DP_PIN_ASSIGN_GEN2_BR_MASK (BIT(DP_PIN_ASSIGN_A) \| \
	29	BIT(DP_PIN_ASSIGN_B))
	30
	31	/* Pin assignments that use DP v1.3 signaling to carry DP protocol */
	32	#define DP_PIN_ASSIGN_DP_BR_MASK (BIT(DP_PIN_ASSIGN_C) \| \
	33	BIT(DP_PIN_ASSIGN_D) \| \
	34	BIT(DP_PIN_ASSIGN_E) \| \
	35	BIT(DP_PIN_ASSIGN_F))
	36
	37	/* DP only pin assignments */
	38	#define DP_PIN_ASSIGN_DP_ONLY_MASK (BIT(DP_PIN_ASSIGN_A) \| \
	39	BIT(DP_PIN_ASSIGN_C) \| \
	40	BIT(DP_PIN_ASSIGN_E))
	41
	42	/* Pin assignments where one channel is for USB */
	43	#define DP_PIN_ASSIGN_MULTI_FUNC_MASK (BIT(DP_PIN_ASSIGN_B) \| \
	44	BIT(DP_PIN_ASSIGN_D) \| \
	45	BIT(DP_PIN_ASSIGN_F))
	46
	47	enum dp_state {
	48	DP_STATE_IDLE,
	49	DP_STATE_ENTER,
	50	DP_STATE_UPDATE,
	51	DP_STATE_CONFIGURE,
	52	DP_STATE_EXIT,
	53	};
	54
	55	struct dp_altmode {
	56	struct typec_displayport_data data;
	57
	58	enum dp_state state;
	59
	60	struct mutex lock; /* device lock */
	61	struct work_struct work;
	62	struct typec_altmode *alt;
	63	const struct typec_altmode *port;
	64	};
	65
	66	static int dp_altmode_notify(struct dp_altmode *dp)
	67	{
	68	u8 state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
	69
	70	return typec_altmode_notify(dp->alt, TYPEC_MODAL_STATE(state),
	71	&dp->data);
	72	}
	73
	74	static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
	75	{
	76	u32 conf = DP_CONF_SIGNALING_DP; /* Only DP signaling supported */
	77	u8 pin_assign = 0;
	78
	79	switch (con) {
	80	case DP_STATUS_CON_DISABLED:
	81	return 0;
	82	case DP_STATUS_CON_DFP_D:
	83	conf \|= DP_CONF_UFP_U_AS_DFP_D;
	84	pin_assign = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo) &
	85	DP_CAP_DFP_D_PIN_ASSIGN(dp->port->vdo);
	86	break;
	87	case DP_STATUS_CON_UFP_D:
	88	case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
	89	conf \|= DP_CONF_UFP_U_AS_UFP_D;
	90	pin_assign = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo) &
91	DP_CAP_UFP_D_PIN_ASSIGN(dp->port->vdo);
92	break;
93	default:
94	break;
95	}
96
97	/* Determining the initial pin assignment. */
98	if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
99	/* Is USB together with DP preferred */
100	if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
101	pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
102	pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
09fed4d6	103	else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK)
0e3bb7d6 HK	104	pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
	105
	106	if (!pin_assign)
	107	return -EINVAL;
	108
	109	conf \|= DP_CONF_SET_PIN_ASSIGN(pin_assign);
	110	}
	111
	112	dp->data.conf = conf;
	113
	114	return 0;
	115	}
	116
	117	static int dp_altmode_status_update(struct dp_altmode *dp)
	118	{
	119	bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
	120	u8 con = DP_STATUS_CONNECTION(dp->data.status);
	121	int ret = 0;
	122
	123	if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
	124	dp->data.conf = 0;
	125	dp->state = DP_STATE_CONFIGURE;
	126	} else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
	127	dp->state = DP_STATE_EXIT;
	128	} else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
	129	ret = dp_altmode_configure(dp, con);
	130	if (!ret)
	131	dp->state = DP_STATE_CONFIGURE;
	132	}
	133
	134	return ret;
	135	}
	136
	137	static int dp_altmode_configured(struct dp_altmode *dp)
	138	{
	139	int ret;
	140
	141	sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");
	142
	143	if (!dp->data.conf)
	144	return typec_altmode_notify(dp->alt, TYPEC_STATE_USB,
	145	&dp->data);
	146
	147	ret = dp_altmode_notify(dp);
	148	if (ret)
	149	return ret;
	150
	151	sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
	152
	153	return 0;
	154	}
	155
	156	static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
	157	{
d266e968	158	u32 header = DP_HEADER(dp, DP_CMD_CONFIGURE);
0e3bb7d6 HK	159	int ret;
	160
	161	ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE, &dp->data);
	162	if (ret) {
	163	dev_err(&dp->alt->dev,
	164	"unable to put to connector to safe mode\n");
	165	return ret;
	166	}
	167
	168	ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
	169	if (ret) {
	170	if (DP_CONF_GET_PIN_ASSIGN(dp->data.conf))
	171	dp_altmode_notify(dp);
	172	else
	173	typec_altmode_notify(dp->alt, TYPEC_STATE_USB,
	174	&dp->data);
	175	}
	176
	177	return ret;
	178	}
	179
	180	static void dp_altmode_work(struct work_struct *work)
	181	{
	182	struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
	183	u32 header;
	184	u32 vdo;
	185	int ret;
	186
	187	mutex_lock(&dp->lock);
	188
	189	switch (dp->state) {
	190	case DP_STATE_ENTER:
	191	ret = typec_altmode_enter(dp->alt);
	192	if (ret)
	193	dev_err(&dp->alt->dev, "failed to enter mode\n");
	194	break;
	195	case DP_STATE_UPDATE:
d266e968	196	header = DP_HEADER(dp, DP_CMD_STATUS_UPDATE);
0e3bb7d6 HK	197	vdo = 1;
	198	ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
	199	if (ret)
	200	dev_err(&dp->alt->dev,
	201	"unable to send Status Update command (%d)\n",
	202	ret);
	203	break;
	204	case DP_STATE_CONFIGURE:
	205	ret = dp_altmode_configure_vdm(dp, dp->data.conf);
	206	if (ret)
	207	dev_err(&dp->alt->dev,
	208	"unable to send Configure command (%d)\n", ret);
	209	break;
	210	case DP_STATE_EXIT:
	211	if (typec_altmode_exit(dp->alt))
	212	dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
	213	break;
	214	default:
	215	break;
	216	}
	217
	218	dp->state = DP_STATE_IDLE;
	219
	220	mutex_unlock(&dp->lock);
	221	}
	222
	223	static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
	224	{
	225	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
	226	u8 old_state;
	227
	228	mutex_lock(&dp->lock);
	229
	230	old_state = dp->state;
	231	dp->data.status = vdo;
	232
	233	if (old_state != DP_STATE_IDLE)
	234	dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
	235	old_state);
	236
	237	if (dp_altmode_status_update(dp))
	238	dev_warn(&alt->dev, "%s: status update failed\n", __func__);
	239
	240	if (dp_altmode_notify(dp))
	241	dev_err(&alt->dev, "%s: notification failed\n", __func__);
	242
	243	if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
	244	schedule_work(&dp->work);
	245
	246	mutex_unlock(&dp->lock);
	247	}
	248
	249	static int dp_altmode_vdm(struct typec_altmode *alt,
	250	const u32 hdr, const u32 *vdo, int count)
	251	{
	252	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
	253	int cmd_type = PD_VDO_CMDT(hdr);
	254	int cmd = PD_VDO_CMD(hdr);
	255	int ret = 0;
	256
	257	mutex_lock(&dp->lock);
	258
	259	if (dp->state != DP_STATE_IDLE) {
	260	ret = -EBUSY;
261	goto err_unlock;
262	}
263
264	switch (cmd_type) {
265	case CMDT_RSP_ACK:
266	switch (cmd) {
267	case CMD_ENTER_MODE:
268	dp->state = DP_STATE_UPDATE;
269	break;
270	case CMD_EXIT_MODE:
271	dp->data.status = 0;
272	dp->data.conf = 0;
273	break;
274	case DP_CMD_STATUS_UPDATE:
275	dp->data.status = *vdo;
276	ret = dp_altmode_status_update(dp);
277	break;
278	case DP_CMD_CONFIGURE:
279	ret = dp_altmode_configured(dp);
280	break;
281	default:
282	break;
283	}
284	break;
285	case CMDT_RSP_NAK:
286	switch (cmd) {
287	case DP_CMD_CONFIGURE:
288	dp->data.conf = 0;
289	ret = dp_altmode_configured(dp);
290	break;
291	default:
292	break;
293	}
294	break;
295	default:
296	break;
297	}
298
299	if (dp->state != DP_STATE_IDLE)
300	schedule_work(&dp->work);
301
302	err_unlock:
303	mutex_unlock(&dp->lock);
304	return ret;
305	}
306
307	static int dp_altmode_activate(struct typec_altmode *alt, int activate)
308	{
309	return activate ? typec_altmode_enter(alt) : typec_altmode_exit(alt);
310	}
311
312	static const struct typec_altmode_ops dp_altmode_ops = {
313	.attention = dp_altmode_attention,
314	.vdm = dp_altmode_vdm,
315	.activate = dp_altmode_activate,
316	};
317
318	static const char * const configurations[] = {
319	[DP_CONF_USB] = "USB",
320	[DP_CONF_DFP_D] = "source",
321	[DP_CONF_UFP_D] = "sink",
322	};
323
324	static ssize_t
325	configuration_store(struct device dev, struct device_attribute attr,
326	const char *buf, size_t size)
327	{
328	struct dp_altmode *dp = dev_get_drvdata(dev);
329	u32 conf;
330	u32 cap;
331	int con;
98a1a0c7	332	int ret = 0;
0e3bb7d6 HK	333
	334	con = sysfs_match_string(configurations, buf);
	335	if (con < 0)
	336	return con;
	337
	338	mutex_lock(&dp->lock);
	339
	340	if (dp->state != DP_STATE_IDLE) {
	341	ret = -EBUSY;
	342	goto err_unlock;
	343	}
	344
	345	cap = DP_CAP_CAPABILITY(dp->alt->vdo);
	346
	347	if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) \|\|
98a1a0c7 CIK	348	(con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D))) {
	349	ret = -EINVAL;
	350	goto err_unlock;
	351	}
0e3bb7d6 HK	352
	353	conf = dp->data.conf & ~DP_CONF_DUAL_D;
	354	conf \|= con;
	355
	356	if (dp->alt->active) {
	357	ret = dp_altmode_configure_vdm(dp, conf);
	358	if (ret)
	359	goto err_unlock;
	360	}
	361
	362	dp->data.conf = conf;
	363
	364	err_unlock:
	365	mutex_unlock(&dp->lock);
	366
	367	return ret ? ret : size;
	368	}
	369
	370	static ssize_t configuration_show(struct device *dev,
	371	struct device_attribute attr, char buf)
	372	{
	373	struct dp_altmode *dp = dev_get_drvdata(dev);
	374	int len;
	375	u8 cap;
	376	u8 cur;
	377	int i;
	378
	379	mutex_lock(&dp->lock);
	380
	381	cap = DP_CAP_CAPABILITY(dp->alt->vdo);
	382	cur = DP_CONF_CURRENTLY(dp->data.conf);
	383
	384	len = sprintf(buf, "%s ", cur ? "USB" : "[USB]");
	385
	386	for (i = 1; i < ARRAY_SIZE(configurations); i++) {
	387	if (i == cur)
	388	len += sprintf(buf + len, "[%s] ", configurations[i]);
	389	else if ((i == DP_CONF_DFP_D && cap & DP_CAP_DFP_D) \|\|
	390	(i == DP_CONF_UFP_D && cap & DP_CAP_UFP_D))
	391	len += sprintf(buf + len, "%s ", configurations[i]);
	392	}
	393
	394	mutex_unlock(&dp->lock);
	395
	396	buf[len - 1] = '\n';
	397	return len;
	398	}
	399	static DEVICE_ATTR_RW(configuration);
	400
	401	static const char * const pin_assignments[] = {
	402	[DP_PIN_ASSIGN_A] = "A",
	403	[DP_PIN_ASSIGN_B] = "B",
	404	[DP_PIN_ASSIGN_C] = "C",
	405	[DP_PIN_ASSIGN_D] = "D",
	406	[DP_PIN_ASSIGN_E] = "E",
	407	[DP_PIN_ASSIGN_F] = "F",
	408	};
	409
	410	static ssize_t
	411	pin_assignment_store(struct device dev, struct device_attribute attr,
	412	const char *buf, size_t size)
	413	{
	414	struct dp_altmode *dp = dev_get_drvdata(dev);
	415	u8 assignments;
416	u32 conf;
417	int ret;
418
419	ret = sysfs_match_string(pin_assignments, buf);
420	if (ret < 0)
421	return ret;
422
423	conf = DP_CONF_SET_PIN_ASSIGN(BIT(ret));
424	ret = 0;
425
426	mutex_lock(&dp->lock);
427
428	if (conf & dp->data.conf)
429	goto out_unlock;
430
431	if (dp->state != DP_STATE_IDLE) {
432	ret = -EBUSY;
433	goto out_unlock;
434	}
435
436	if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
437	assignments = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
438	else
439	assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);
440
441	if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
442	ret = -EINVAL;
443	goto out_unlock;
444	}
445
446	conf \|= dp->data.conf & ~DP_CONF_PIN_ASSIGNEMENT_MASK;
447
448	/* Only send Configure command if a configuration has been set */
449	if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
450	ret = dp_altmode_configure_vdm(dp, conf);
451	if (ret)
452	goto out_unlock;
453	}
454
455	dp->data.conf = conf;
456
457	out_unlock:
458	mutex_unlock(&dp->lock);
459
460	return ret ? ret : size;
461	}
462
463	static ssize_t pin_assignment_show(struct device *dev,
464	struct device_attribute attr, char buf)
465	{
466	struct dp_altmode *dp = dev_get_drvdata(dev);
467	u8 assignments;
468	int len = 0;
469	u8 cur;
470	int i;
471
472	mutex_lock(&dp->lock);
473
474	cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
475
476	if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
477	assignments = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
478	else
479	assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);
480
481	for (i = 0; assignments; assignments >>= 1, i++) {
482	if (assignments & 1) {
483	if (i == cur)
484	len += sprintf(buf + len, "[%s] ",
485	pin_assignments[i]);
486	else
487	len += sprintf(buf + len, "%s ",
488	pin_assignments[i]);
489	}
490	}
491
492	mutex_unlock(&dp->lock);
493
494	buf[len - 1] = '\n';
495	return len;
496	}
497	static DEVICE_ATTR_RW(pin_assignment);
498
499	static struct attribute *dp_altmode_attrs[] = {
500	&dev_attr_configuration.attr,
501	&dev_attr_pin_assignment.attr,
502	NULL
503	};
504
505	static const struct attribute_group dp_altmode_group = {
506	.name = "displayport",
507	.attrs = dp_altmode_attrs,
508	};
509
d266e968	510	int dp_altmode_probe(struct typec_altmode *alt)
0e3bb7d6 HK	511	{
	512	const struct typec_altmode *port = typec_altmode_get_partner(alt);
	513	struct dp_altmode *dp;
	514	int ret;
	515
	516	/* FIXME: Port can only be DFP_U. */
	517
	518	/* Make sure we have compatiple pin configurations */
	519	if (!(DP_CAP_DFP_D_PIN_ASSIGN(port->vdo) &
	520	DP_CAP_UFP_D_PIN_ASSIGN(alt->vdo)) &&
	521	!(DP_CAP_UFP_D_PIN_ASSIGN(port->vdo) &
	522	DP_CAP_DFP_D_PIN_ASSIGN(alt->vdo)))
	523	return -ENODEV;
	524
	525	ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group);
	526	if (ret)
	527	return ret;
	528
	529	dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
	530	if (!dp)
	531	return -ENOMEM;
	532
	533	INIT_WORK(&dp->work, dp_altmode_work);
	534	mutex_init(&dp->lock);
	535	dp->port = port;
	536	dp->alt = alt;
	537
	538	alt->desc = "DisplayPort";
	539	alt->ops = &dp_altmode_ops;
	540
	541	typec_altmode_set_drvdata(alt, dp);
	542
	543	dp->state = DP_STATE_ENTER;
	544	schedule_work(&dp->work);
	545
	546	return 0;
	547	}
d266e968	548	EXPORT_SYMBOL_GPL(dp_altmode_probe);
0e3bb7d6	549
d266e968	550	void dp_altmode_remove(struct typec_altmode *alt)
0e3bb7d6 HK	551	{
	552	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
	553
	554	sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
	555	cancel_work_sync(&dp->work);
	556	}
d266e968	557	EXPORT_SYMBOL_GPL(dp_altmode_remove);
0e3bb7d6 HK	558
	559	static const struct typec_device_id dp_typec_id[] = {
	560	{ USB_TYPEC_DP_SID, USB_TYPEC_DP_MODE },
	561	{ },
	562	};
	563	MODULE_DEVICE_TABLE(typec, dp_typec_id);
	564
	565	static struct typec_altmode_driver dp_altmode_driver = {
	566	.id_table = dp_typec_id,
	567	.probe = dp_altmode_probe,
	568	.remove = dp_altmode_remove,
	569	.driver = {
	570	.name = "typec_displayport",
	571	.owner = THIS_MODULE,
	572	},
	573	};
	574	module_typec_altmode_driver(dp_altmode_driver);
	575
	576	MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
	577	MODULE_LICENSE("GPL v2");
	578	MODULE_DESCRIPTION("DisplayPort Alternate Mode");