diff options
Diffstat (limited to 'drivers/usb/typec/altmodes/displayport.c')
| -rw-r--r-- | drivers/usb/typec/altmodes/displayport.c | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c new file mode 100644 index 000000000000..3f06e94771a7 --- /dev/null +++ b/drivers/usb/typec/altmodes/displayport.c @@ -0,0 +1,580 @@ +// 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(cmd) (VDO(USB_TYPEC_DP_SID, 1, cmd) | \ + VDO_OPOS(USB_TYPEC_DP_MODE)) + +enum { + DP_CONF_USB, + DP_CONF_DFP_D, + DP_CONF_UFP_D, + DP_CONF_DUAL_D, +}; + +/* 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_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 + 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_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_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, +}; + +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) +{ + struct dp_altmode *dp = typec_altmode_get_drvdata(alt); + + sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group); + cancel_work_sync(&dp->work); +} + +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"); |