From 0bb9c2b27f5e503e683ad27a0f0a6286f5b5da34 Mon Sep 17 00:00:00 2001 From: Dhinakaran Pandiyan Date: Wed, 6 Sep 2017 17:14:58 -0700 Subject: [PATCH] drm/dp/mst: Sideband message transaction to power up/down nodes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The POWER_DOWN_PHY and POWER_UP_PHY sideband message transactions allow the source to reqest any node in a mst path or a whole path to be powered down or up. This allows drivers to target a specific sink in the MST topology, an improvement over just power managing the imediate downstream device. Secondly, since the request-reply protocol waits for an ACK, we can be sure that a downstream sink has enough time to respond to a power up/down request. v2: Fix memory leak (Lyude) Cc: Lyude Cc: Ville Syrjälä Cc: Harry Wentland Signed-off-by: Dhinakaran Pandiyan Link: https://patchwork.freedesktop.org/patch/msgid/20170907001458.9399-1-dhinakaran.pandiyan@intel.com Reviewed-by: Lyude Paul Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/drm_dp_mst_topology.c | 74 +++++++++++++++++++++++++++++++++++ include/drm/drm_dp_mst_helper.h | 2 + 2 files changed, 76 insertions(+) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 41b492f..70dcfa5 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -294,6 +294,12 @@ static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req, memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes); idx += req->u.i2c_write.num_bytes; break; + + case DP_POWER_DOWN_PHY: + case DP_POWER_UP_PHY: + buf[idx] = (req->u.port_num.port_number & 0xf) << 4; + idx++; + break; } raw->cur_len = idx; } @@ -538,6 +544,21 @@ fail_len: return false; } +static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw, + struct drm_dp_sideband_msg_reply_body *repmsg) +{ + int idx = 1; + + repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf; + idx++; + if (idx > raw->curlen) { + DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n", + idx, raw->curlen); + return false; + } + return true; +} + static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw, struct drm_dp_sideband_msg_reply_body *msg) { @@ -567,6 +588,9 @@ static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw, return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg); case DP_ALLOCATE_PAYLOAD: return drm_dp_sideband_parse_allocate_payload_ack(raw, msg); + case DP_POWER_DOWN_PHY: + case DP_POWER_UP_PHY: + return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg); default: DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type); return false; @@ -693,6 +717,22 @@ static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_n return 0; } +static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg, + int port_num, bool power_up) +{ + struct drm_dp_sideband_msg_req_body req; + + if (power_up) + req.req_type = DP_POWER_UP_PHY; + else + req.req_type = DP_POWER_DOWN_PHY; + + req.u.port_num.port_number = port_num; + drm_dp_encode_sideband_req(&req, msg); + msg->path_msg = true; + return 0; +} + static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_vcpi *vcpi) { @@ -1724,6 +1764,40 @@ fail_put: return ret; } +int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port, bool power_up) +{ + struct drm_dp_sideband_msg_tx *txmsg; + int len, ret; + + port = drm_dp_get_validated_port_ref(mgr, port); + if (!port) + return -EINVAL; + + txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); + if (!txmsg) { + drm_dp_put_port(port); + return -ENOMEM; + } + + txmsg->dst = port->parent; + len = build_power_updown_phy(txmsg, port->port_num, power_up); + drm_dp_queue_down_tx(mgr, txmsg); + + ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg); + if (ret > 0) { + if (txmsg->reply.reply_type == 1) + ret = -EINVAL; + else + ret = 0; + } + kfree(txmsg); + drm_dp_put_port(port); + + return ret; +} +EXPORT_SYMBOL(drm_dp_send_power_updown_phy); + static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr, int id, struct drm_dp_payload *payload) diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h index d55abb7..7f78d26 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -631,5 +631,7 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr, int slots); +int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port, bool power_up); #endif -- 2.7.4