diff options
Diffstat (limited to 'drivers/gpu/drm/drm_dp_mst_topology.c')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 142 |
1 files changed, 132 insertions, 10 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 0984b9a34d55..82add736e17d 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -36,6 +36,8 @@ #include <drm/drm_print.h> #include <drm/drm_probe_helper.h> +#include "drm_crtc_helper_internal.h" + /** * DOC: dp mst helper * @@ -53,6 +55,9 @@ static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, int id, struct drm_dp_payload *payload); +static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port, + int offset, int size, u8 *bytes); static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int offset, int size, u8 *bytes); @@ -1483,6 +1488,52 @@ static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port) return send_link; } +/** + * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband + * @aux: Fake sideband AUX CH + * @offset: address of the (first) register to read + * @buffer: buffer to store the register values + * @size: number of bytes in @buffer + * + * Performs the same functionality for remote devices via + * sideband messaging as drm_dp_dpcd_read() does for local + * devices via actual AUX CH. + * + * Return: Number of bytes read, or negative error code on failure. + */ +ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux, + unsigned int offset, void *buffer, size_t size) +{ + struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, + aux); + + return drm_dp_send_dpcd_read(port->mgr, port, + offset, size, buffer); +} + +/** + * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband + * @aux: Fake sideband AUX CH + * @offset: address of the (first) register to write + * @buffer: buffer containing the values to write + * @size: number of bytes in @buffer + * + * Performs the same functionality for remote devices via + * sideband messaging as drm_dp_dpcd_write() does for local + * devices via actual AUX CH. + * + * Return: 0 on success, negative error code on failure. + */ +ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux, + unsigned int offset, void *buffer, size_t size) +{ + struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, + aux); + + return drm_dp_send_dpcd_write(port->mgr, port, + offset, size, buffer); +} + static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid) { int ret; @@ -1526,6 +1577,46 @@ static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, strlcat(proppath, temp, proppath_size); } +/** + * drm_dp_mst_connector_late_register() - Late MST connector registration + * @connector: The MST connector + * @port: The MST port for this connector + * + * Helper to register the remote aux device for this MST port. Drivers should + * call this from their mst connector's late_register hook to enable MST aux + * devices. + * + * Return: 0 on success, negative error code on failure. + */ +int drm_dp_mst_connector_late_register(struct drm_connector *connector, + struct drm_dp_mst_port *port) +{ + DRM_DEBUG_KMS("registering %s remote bus for %s\n", + port->aux.name, connector->kdev->kobj.name); + + port->aux.dev = connector->kdev; + return drm_dp_aux_register_devnode(&port->aux); +} +EXPORT_SYMBOL(drm_dp_mst_connector_late_register); + +/** + * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration + * @connector: The MST connector + * @port: The MST port for this connector + * + * Helper to unregister the remote aux device for this MST port, registered by + * drm_dp_mst_connector_late_register(). Drivers should call this from their mst + * connector's early_unregister hook. + */ +void drm_dp_mst_connector_early_unregister(struct drm_connector *connector, + struct drm_dp_mst_port *port) +{ + DRM_DEBUG_KMS("unregistering %s remote bus for %s\n", + port->aux.name, connector->kdev->kobj.name); + drm_dp_aux_unregister_devnode(&port->aux); +} +EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister); + static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, struct drm_device *dev, struct drm_dp_link_addr_reply_port *port_msg) @@ -1548,6 +1639,7 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, port->mgr = mstb->mgr; port->aux.name = "DPMST"; port->aux.dev = dev->dev; + port->aux.is_remote = true; /* * Make sure the memory allocation for our parent branch stays @@ -1816,7 +1908,6 @@ static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, return false; } -#if 0 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes) { struct drm_dp_sideband_msg_req_body req; @@ -1829,7 +1920,6 @@ static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 return 0; } -#endif static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr, bool up, u8 *msg, int len) @@ -2441,26 +2531,58 @@ int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr) } EXPORT_SYMBOL(drm_dp_update_payload_part2); -#if 0 /* unused as of yet */ static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, - int offset, int size) + int offset, int size, u8 *bytes) { int len; + int ret = 0; struct drm_dp_sideband_msg_tx *txmsg; + struct drm_dp_mst_branch *mstb; + + mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); + if (!mstb) + return -EINVAL; txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); - if (!txmsg) - return -ENOMEM; + if (!txmsg) { + ret = -ENOMEM; + goto fail_put; + } - len = build_dpcd_read(txmsg, port->port_num, 0, 8); + len = build_dpcd_read(txmsg, port->port_num, offset, size); txmsg->dst = port->parent; drm_dp_queue_down_tx(mgr, txmsg); - return 0; + ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); + if (ret < 0) + goto fail_free; + + /* DPCD read should never be NACKed */ + if (txmsg->reply.reply_type == 1) { + DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n", + mstb, port->port_num, offset, size); + ret = -EIO; + goto fail_free; + } + + if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) { + ret = -EPROTO; + goto fail_free; + } + + ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes, + size); + memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret); + +fail_free: + kfree(txmsg); +fail_put: + drm_dp_mst_topology_put_mstb(mstb); + + return ret; } -#endif static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, @@ -2489,7 +2611,7 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); if (ret > 0) { if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) - ret = -EINVAL; + ret = -EIO; else ret = 0; } |