drm/i915: add DP 1.2 MST support (v0.7)

This adds DP 1.2 MST support on Haswell systems.

Notes:
a) this reworks irq handling for DP MST ports, so that we can
avoid the mode config locking in the current hpd handlers, as
we need to process up/down msgs at a better time.

Changes since v0.1:
use PORT_PCH_HOTPLUG to detect short vs long pulses
add a workqueue to deal with digital events as they can get blocked on the
main workqueue beyong mode_config mutex
fix a bunch of modeset checker warnings
acks irqs in the driver
cleanup the MST encoders

Changes since v0.2:
check irq status again in work handler
move around bring up and tear down to fix DPMS on/off
use path properties.

Changes since v0.3:
updates for mst apis
more state checker fixes
irq handling improvements
fbcon handling support
improved reference counting of link - fixes redocking.

Changes since v0.4:
handle gpu reset hpd reinit without oopsing
check link status on HPD irqs
fix suspend/resume

Changes since v0.5:
use proper functions to get max link/lane counts
fix another checker backtrace - due to connectors disappearing.
set output type in more places fro, unknown->displayport
don't talk to devices if no HPD asserted
check mst on short irqs only
check link status properly
rebase onto prepping irq changes.
drop unsued force_act

Changes since v0.6:
cleanup unused struct entry.

[airlied: fix some sparse warnings].

Reviewed-by: Todd Previte <tprevite@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
new file mode 100644
index 0000000..ec48d56
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -0,0 +1,534 @@
+/*
+ * Copyright © 2008 Intel Corporation
+ *             2014 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <drm/drmP.h>
+#include "i915_drv.h"
+#include "intel_drv.h"
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_edid.h>
+
+static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
+					struct intel_crtc_config *pipe_config)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = encoder->base.dev;
+	int bpp;
+	int lane_count, slots;
+	struct drm_display_mode *adjusted_mode = &pipe_config->adjusted_mode;
+	struct intel_connector *found = NULL, *intel_connector;
+	int mst_pbn;
+
+	pipe_config->dp_encoder_is_mst = true;
+	pipe_config->has_pch_encoder = false;
+	pipe_config->has_dp_encoder = true;
+	bpp = 24;
+	/*
+	 * for MST we always configure max link bw - the spec doesn't
+	 * seem to suggest we should do otherwise.
+	 */
+	lane_count = drm_dp_max_lane_count(intel_dp->dpcd);
+	intel_dp->link_bw = intel_dp_max_link_bw(intel_dp);
+	intel_dp->lane_count = lane_count;
+
+	pipe_config->pipe_bpp = 24;
+	pipe_config->port_clock = drm_dp_bw_code_to_link_rate(intel_dp->link_bw);
+
+	list_for_each_entry(intel_connector, &dev->mode_config.connector_list, base.head) {
+		if (intel_connector->new_encoder == encoder) {
+			found = intel_connector;
+			break;
+		}
+	}
+
+	if (!found) {
+		DRM_ERROR("can't find connector\n");
+		return false;
+	}
+
+	mst_pbn = drm_dp_calc_pbn_mode(adjusted_mode->clock, bpp);
+
+	pipe_config->pbn = mst_pbn;
+	slots = drm_dp_find_vcpi_slots(&intel_dp->mst_mgr, mst_pbn);
+
+	intel_link_compute_m_n(bpp, lane_count,
+			       adjusted_mode->crtc_clock,
+			       pipe_config->port_clock,
+			       &pipe_config->dp_m_n);
+
+	pipe_config->dp_m_n.tu = slots;
+	return true;
+
+}
+
+static void intel_mst_disable_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	int ret;
+
+	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
+
+	drm_dp_mst_reset_vcpi_slots(&intel_dp->mst_mgr, intel_mst->port);
+
+	ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
+	if (ret) {
+		DRM_ERROR("failed to update payload %d\n", ret);
+	}
+}
+
+static void intel_mst_post_disable_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+
+	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
+
+	/* this can fail */
+	drm_dp_check_act_status(&intel_dp->mst_mgr);
+	/* and this can also fail */
+	drm_dp_update_payload_part2(&intel_dp->mst_mgr);
+
+	drm_dp_mst_deallocate_vcpi(&intel_dp->mst_mgr, intel_mst->port);
+
+	intel_dp->active_mst_links--;
+	intel_mst->port = NULL;
+	if (intel_dp->active_mst_links == 0) {
+		intel_dig_port->base.post_disable(&intel_dig_port->base);
+		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_OFF);
+	}
+}
+
+static void intel_mst_pre_enable_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = encoder->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum port port = intel_dig_port->port;
+	int ret;
+	uint32_t temp;
+	struct intel_connector *found = NULL, *intel_connector;
+	int slots;
+	struct drm_crtc *crtc = encoder->base.crtc;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+
+	list_for_each_entry(intel_connector, &dev->mode_config.connector_list, base.head) {
+		if (intel_connector->new_encoder == encoder) {
+			found = intel_connector;
+			break;
+		}
+	}
+
+	if (!found) {
+		DRM_ERROR("can't find connector\n");
+		return;
+	}
+
+	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
+	intel_mst->port = found->port;
+
+	if (intel_dp->active_mst_links == 0) {
+		enum port port = intel_ddi_get_encoder_port(encoder);
+
+		I915_WRITE(PORT_CLK_SEL(port), intel_crtc->config.ddi_pll_sel);
+
+		intel_ddi_init_dp_buf_reg(&intel_dig_port->base);
+
+		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
+
+
+		intel_dp_start_link_train(intel_dp);
+		intel_dp_complete_link_train(intel_dp);
+		intel_dp_stop_link_train(intel_dp);
+	}
+
+	ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,
+				       intel_mst->port, intel_crtc->config.pbn, &slots);
+	if (ret == false) {
+		DRM_ERROR("failed to allocate vcpi\n");
+		return;
+	}
+
+
+	intel_dp->active_mst_links++;
+	temp = I915_READ(DP_TP_STATUS(port));
+	I915_WRITE(DP_TP_STATUS(port), temp);
+
+	ret = drm_dp_update_payload_part1(&intel_dp->mst_mgr);
+}
+
+static void intel_mst_enable_dp(struct intel_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum port port = intel_dig_port->port;
+	int ret;
+
+	DRM_DEBUG_KMS("%d\n", intel_dp->active_mst_links);
+
+	if (wait_for((I915_READ(DP_TP_STATUS(port)) & DP_TP_STATUS_ACT_SENT),
+		     1))
+		DRM_ERROR("Timed out waiting for ACT sent\n");
+
+	ret = drm_dp_check_act_status(&intel_dp->mst_mgr);
+
+	ret = drm_dp_update_payload_part2(&intel_dp->mst_mgr);
+}
+
+static bool intel_dp_mst_enc_get_hw_state(struct intel_encoder *encoder,
+				      enum pipe *pipe)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	*pipe = intel_mst->pipe;
+	if (intel_mst->port)
+		return true;
+	return false;
+}
+
+static void intel_dp_mst_enc_get_config(struct intel_encoder *encoder,
+					struct intel_crtc_config *pipe_config)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
+	struct intel_digital_port *intel_dig_port = intel_mst->primary;
+	struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
+	struct drm_device *dev = encoder->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum transcoder cpu_transcoder = crtc->config.cpu_transcoder;
+	u32 temp, flags = 0;
+
+	pipe_config->has_dp_encoder = true;
+
+	temp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
+	if (temp & TRANS_DDI_PHSYNC)
+		flags |= DRM_MODE_FLAG_PHSYNC;
+	else
+		flags |= DRM_MODE_FLAG_NHSYNC;
+	if (temp & TRANS_DDI_PVSYNC)
+		flags |= DRM_MODE_FLAG_PVSYNC;
+	else
+		flags |= DRM_MODE_FLAG_NVSYNC;
+
+	switch (temp & TRANS_DDI_BPC_MASK) {
+	case TRANS_DDI_BPC_6:
+		pipe_config->pipe_bpp = 18;
+		break;
+	case TRANS_DDI_BPC_8:
+		pipe_config->pipe_bpp = 24;
+		break;
+	case TRANS_DDI_BPC_10:
+		pipe_config->pipe_bpp = 30;
+		break;
+	case TRANS_DDI_BPC_12:
+		pipe_config->pipe_bpp = 36;
+		break;
+	default:
+		break;
+	}
+	pipe_config->adjusted_mode.flags |= flags;
+	intel_dp_get_m_n(crtc, pipe_config);
+
+	intel_ddi_clock_get(&intel_dig_port->base, pipe_config);
+}
+
+static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_dp *intel_dp = intel_connector->mst_port;
+	struct edid *edid;
+	int ret;
+
+	edid = drm_dp_mst_get_edid(connector, &intel_dp->mst_mgr, intel_connector->port);
+	if (!edid)
+		return 0;
+
+	ret = intel_connector_update_modes(connector, edid);
+	kfree(edid);
+
+	return ret;
+}
+
+static enum drm_connector_status
+intel_mst_port_dp_detect(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_dp *intel_dp = intel_connector->mst_port;
+
+	return drm_dp_mst_detect_port(&intel_dp->mst_mgr, intel_connector->port);
+}
+
+static enum drm_connector_status
+intel_dp_mst_detect(struct drm_connector *connector, bool force)
+{
+	enum drm_connector_status status;
+	status = intel_mst_port_dp_detect(connector);
+	return status;
+}
+
+static int
+intel_dp_mst_set_property(struct drm_connector *connector,
+			  struct drm_property *property,
+			  uint64_t val)
+{
+	return 0;
+}
+
+static void
+intel_dp_mst_connector_destroy(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+
+	if (!IS_ERR_OR_NULL(intel_connector->edid))
+		kfree(intel_connector->edid);
+
+	drm_connector_cleanup(connector);
+	kfree(connector);
+}
+
+static const struct drm_connector_funcs intel_dp_mst_connector_funcs = {
+	.dpms = intel_connector_dpms,
+	.detect = intel_dp_mst_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.set_property = intel_dp_mst_set_property,
+	.destroy = intel_dp_mst_connector_destroy,
+};
+
+static int intel_dp_mst_get_modes(struct drm_connector *connector)
+{
+	return intel_dp_mst_get_ddc_modes(connector);
+}
+
+static enum drm_mode_status
+intel_dp_mst_mode_valid(struct drm_connector *connector,
+			struct drm_display_mode *mode)
+{
+	/* TODO - validate mode against available PBN for link */
+	if (mode->clock < 10000)
+		return MODE_CLOCK_LOW;
+
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
+		return MODE_H_ILLEGAL;
+
+	return MODE_OK;
+}
+
+static struct drm_encoder *intel_mst_best_encoder(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_dp *intel_dp = intel_connector->mst_port;
+	return &intel_dp->mst_encoders[0]->base.base;
+}
+
+static const struct drm_connector_helper_funcs intel_dp_mst_connector_helper_funcs = {
+	.get_modes = intel_dp_mst_get_modes,
+	.mode_valid = intel_dp_mst_mode_valid,
+	.best_encoder = intel_mst_best_encoder,
+};
+
+static void intel_dp_mst_encoder_destroy(struct drm_encoder *encoder)
+{
+	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(encoder);
+
+	drm_encoder_cleanup(encoder);
+	kfree(intel_mst);
+}
+
+static const struct drm_encoder_funcs intel_dp_mst_enc_funcs = {
+	.destroy = intel_dp_mst_encoder_destroy,
+};
+
+static bool intel_dp_mst_get_hw_state(struct intel_connector *connector)
+{
+	if (connector->encoder) {
+		enum pipe pipe;
+		if (!connector->encoder->get_hw_state(connector->encoder, &pipe))
+			return false;
+		return true;
+	}
+	return false;
+}
+
+static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, char *pathprop)
+{
+	struct intel_dp *intel_dp = container_of(mgr, struct intel_dp, mst_mgr);
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_connector *intel_connector;
+	struct drm_connector *connector;
+	int i;
+
+	intel_connector = kzalloc(sizeof(*intel_connector), GFP_KERNEL);
+	if (!intel_connector)
+		return NULL;
+
+	connector = &intel_connector->base;
+	drm_connector_init(dev, connector, &intel_dp_mst_connector_funcs, DRM_MODE_CONNECTOR_DisplayPort);
+	drm_connector_helper_add(connector, &intel_dp_mst_connector_helper_funcs);
+
+	intel_connector->unregister = intel_connector_unregister;
+	intel_connector->get_hw_state = intel_dp_mst_get_hw_state;
+	intel_connector->mst_port = intel_dp;
+	intel_connector->port = port;
+
+	for (i = PIPE_A; i <= PIPE_C; i++) {
+		drm_mode_connector_attach_encoder(&intel_connector->base,
+						  &intel_dp->mst_encoders[i]->base.base);
+	}
+	intel_dp_add_properties(intel_dp, connector);
+
+	drm_object_attach_property(&connector->base, dev->mode_config.path_property, 0);
+	drm_mode_connector_set_path_property(connector, pathprop);
+	drm_reinit_primary_mode_group(dev);
+	mutex_lock(&dev->mode_config.mutex);
+	drm_fb_helper_add_one_connector(&dev_priv->fbdev->helper, connector);
+	mutex_unlock(&dev->mode_config.mutex);
+	drm_connector_register(&intel_connector->base);
+	return connector;
+}
+
+static void intel_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
+					   struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct drm_device *dev = connector->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	/* need to nuke the connector */
+	mutex_lock(&dev->mode_config.mutex);
+	intel_connector_dpms(connector, DRM_MODE_DPMS_OFF);
+	mutex_unlock(&dev->mode_config.mutex);
+
+	intel_connector->unregister(intel_connector);
+
+	mutex_lock(&dev->mode_config.mutex);
+	drm_fb_helper_remove_one_connector(&dev_priv->fbdev->helper, connector);
+	drm_connector_cleanup(connector);
+	mutex_unlock(&dev->mode_config.mutex);
+
+	drm_reinit_primary_mode_group(dev);
+
+	kfree(intel_connector);
+	DRM_DEBUG_KMS("\n");
+}
+
+static void intel_dp_mst_hotplug(struct drm_dp_mst_topology_mgr *mgr)
+{
+	struct intel_dp *intel_dp = container_of(mgr, struct intel_dp, mst_mgr);
+	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+
+	drm_kms_helper_hotplug_event(dev);
+}
+
+static struct drm_dp_mst_topology_cbs mst_cbs = {
+	.add_connector = intel_dp_add_mst_connector,
+	.destroy_connector = intel_dp_destroy_mst_connector,
+	.hotplug = intel_dp_mst_hotplug,
+};
+
+static struct intel_dp_mst_encoder *
+intel_dp_create_fake_mst_encoder(struct intel_digital_port *intel_dig_port, enum pipe pipe)
+{
+	struct intel_dp_mst_encoder *intel_mst;
+	struct intel_encoder *intel_encoder;
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+
+	intel_mst = kzalloc(sizeof(*intel_mst), GFP_KERNEL);
+
+	if (!intel_mst)
+		return NULL;
+
+	intel_mst->pipe = pipe;
+	intel_encoder = &intel_mst->base;
+	intel_mst->primary = intel_dig_port;
+
+	drm_encoder_init(dev, &intel_encoder->base, &intel_dp_mst_enc_funcs,
+			 DRM_MODE_ENCODER_DPMST);
+
+	intel_encoder->type = INTEL_OUTPUT_DP_MST;
+	intel_encoder->crtc_mask = 0x7;
+	intel_encoder->cloneable = 0;
+
+	intel_encoder->compute_config = intel_dp_mst_compute_config;
+	intel_encoder->disable = intel_mst_disable_dp;
+	intel_encoder->post_disable = intel_mst_post_disable_dp;
+	intel_encoder->pre_enable = intel_mst_pre_enable_dp;
+	intel_encoder->enable = intel_mst_enable_dp;
+	intel_encoder->get_hw_state = intel_dp_mst_enc_get_hw_state;
+	intel_encoder->get_config = intel_dp_mst_enc_get_config;
+
+	return intel_mst;
+
+}
+
+static bool
+intel_dp_create_fake_mst_encoders(struct intel_digital_port *intel_dig_port)
+{
+	int i;
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+
+	for (i = PIPE_A; i <= PIPE_C; i++)
+		intel_dp->mst_encoders[i] = intel_dp_create_fake_mst_encoder(intel_dig_port, i);
+	return true;
+}
+
+int
+intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_base_id)
+{
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	int ret;
+
+	intel_dp->can_mst = true;
+	intel_dp->mst_mgr.cbs = &mst_cbs;
+
+	/* create encoders */
+	intel_dp_create_fake_mst_encoders(intel_dig_port);
+	ret = drm_dp_mst_topology_mgr_init(&intel_dp->mst_mgr, dev->dev, &intel_dp->aux, 16, 3, conn_base_id);
+	if (ret) {
+		intel_dp->can_mst = false;
+		return ret;
+	}
+	return 0;
+}
+
+void
+intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port)
+{
+	struct intel_dp *intel_dp = &intel_dig_port->dp;
+
+	if (!intel_dp->can_mst)
+		return;
+
+	drm_dp_mst_topology_mgr_destroy(&intel_dp->mst_mgr);
+	/* encoders will get killed by normal cleanup */
+}