On Fri, Jun 08, 2018 at 02:29:39PM +0300, Heikki Krogerus wrote:
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> new file mode 100644
> index 000000000000..a5054d86a4d9
> --- /dev/null
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -0,0 +1,543 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/**
> + * USB Typec-C DisplayPort Alternate Mode driver
> + *
> + * Copyright (C) 2018 Intel Corporation
> + * Author: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> + *
> + * 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(cmd) (VDO(USB_TYPEC_DP_SID, 1, cmd) | \
> + VDO_OPOS(USB_TYPEC_DP_MODE))
> +
> +/* DisplayPort alt mode specific commands */
> +#define DP_CMD_STATUS_UPDATE VDO_CMD_VENDOR(0)
> +#define DP_CMD_CONFIGURE VDO_CMD_VENDOR(1)
> +
> +enum {
> + DP_CONF_USB,
> + DP_CONF_DFP_D,
> + DP_CONF_UFP_D,
> + DP_CONF_DUAL_D,
> +};
> +
> +/* DisplayPort Capabilities VDO bits */
> +#define DP_CAP_CAPABILITY(_cap_) ((_cap_) & 3)
> +#define DP_CAP_UFP_D 1
> +#define DP_CAP_DFP_D 2
> +#define DP_CAP_DFP_D_AND_UFP_D 3
> +#define DP_CAP_DP_SIGNALING BIT(2) /* Always set */
> +#define DP_CAP_GEN2 BIT(3) /* Reserved after v1.0b */
> +#define DP_CAP_RECEPTACLE BIT(6)
> +#define DP_CAP_USB BIT(7)
> +#define DP_CAP_DFP_D_PIN_ASSIGN(_cap_) (((_cap_) & GENMASK(15, 8)) >> 8)
> +#define DP_CAP_UFP_D_PIN_ASSIGN(_cap_) (((_cap_) & GENMASK(23, 16)) >> 16)
> +
> +enum {
> + DP_PIN_ASSIGN_A, /* Not supported after v1.0b */
> + DP_PIN_ASSIGN_B, /* Not supported after v1.0b */
> + DP_PIN_ASSIGN_C,
> + DP_PIN_ASSIGN_D,
> + DP_PIN_ASSIGN_E,
> + DP_PIN_ASSIGN_F, /* Not supported after v1.0b */
> +};
> +
> +/* Helper for setting/getting the pin assignement value to the configuration */
> +#define DP_CONF_SET_PIN_ASSIGN(_a_) ((_a_) << 8)
> +#define DP_CONF_GET_PIN_ASSIGN(_conf_) (((_conf_) & GENMASK(15, 8)) >> 8)
> +
> +/* 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_NONE,
> + 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;
> + struct work_struct work;
> + struct typec_altmode *alt;
> + const struct typec_altmode *port;
> +};
> +
> +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:
> + dp->data.conf = 0;
> + 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
> + 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)
> +{
> + u8 state;
> + 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);
> +
> + state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
> + ret = typec_altmode_notify(dp->alt, TYPEC_MODAL_STATE(state),
> + &dp->data);
> + if (ret)
> + return ret;
> +
> + sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
> +
> + return 0;
> +}
> +
> +static void dp_altmode_work(struct work_struct *work)
> +{
> + struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
> + u32 header = 0;
> + 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_CMD_STATUS_UPDATE);
> + vdo = 1;
> + break;
> + case DP_STATE_CONFIGURE:
> + 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");
> + break;
> + }
> + header = DP_HEADER(DP_CMD_CONFIGURE);
> + vdo = dp->data.conf;
> + break;
> + case DP_STATE_EXIT:
> + if (typec_altmode_exit(dp->alt))
> + dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
> + break;
> + default:
> + break;
> + }
> +
> + if (header) {
> + if (typec_altmode_vdm(dp->alt, header, &vdo, 2))
> + dev_err(&dp->alt->dev, "unable to send VDM\n");
> + }
> +
> + mutex_unlock(&dp->lock);
> +}
FYI. Currently this little state machine is horribly racy. It needs to
be fixed.
> +static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
> +{
> + struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
> + u8 state;
> +
> + mutex_lock(&dp->lock);
> +
> + dp->state = DP_STATE_NONE;
> + dp->data.status = vdo;
> + dp_altmode_status_update(dp);
> +
> + if (dp->state == DP_STATE_NONE) {
> + state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
> + if (typec_altmode_notify(dp->alt, TYPEC_MODAL_STATE(state),
> + &dp->data))
> + dev_err(&alt->dev, "%s: notification failed\n",
> + __func__);
> + } else {
> + 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);
> +
> + dp->state = DP_STATE_NONE;
> +
> + 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_NONE)
> + schedule_work(&dp->work);
> +
> + 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);
> + int conf;
> + int ret;
> +
> + conf = sysfs_match_string(configurations, buf);
> + if (conf < 0)
> + return conf;
> +
> + mutex_lock(&dp->lock);
> +
> + ret = dp_altmode_configure(dp, conf);
> + if (!ret && dp->alt->active) {
> + dp->state = DP_STATE_CONFIGURE;
> + schedule_work(&dp->work);
> + }
> +
> + 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_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;
> + }
> +
> + /* Only send Configure command if a configuration has been set */
> + if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
> + dp->state = DP_STATE_CONFIGURE;
> + schedule_work(&dp->work);
> + }
> +
> + dp->data.conf &= ~DP_CONF_PIN_ASSIGNEMENT_MASK;
> + 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,
> +};
> +
> +static 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;
> +}
> +
> +static void dp_altmode_remove(struct typec_altmode *alt)
> +{
> + sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
> +}
> +
> +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@xxxxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("DisplayPort Alternate Mode");
Br,
--
heikki
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