1 files changed, 346 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c
new file mode 100644
index 000000000..785d76639
--- /dev/null
+++ b/drivers/gpu/drm/msm/dp/dp_drm.c
@@ -0,0 +1,346 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
+#include <drm/drm_crtc.h>
+
+#include "msm_drv.h"
+#include "msm_kms.h"
+#include "dp_drm.h"
+
+/**
+ * dp_bridge_detect - callback to determine if connector is connected
+ * @bridge: Pointer to drm bridge structure
+ * Returns: Bridge's 'is connected' status
+ */
+static enum drm_connector_status dp_bridge_detect(struct drm_bridge *bridge)
+{
+	struct msm_dp *dp;
+
+	dp = to_dp_bridge(bridge)->dp_display;
+
+	drm_dbg_dp(dp->drm_dev, "is_connected = %s\n",
+		(dp->is_connected) ? "true" : "false");
+
+	return (dp->is_connected) ? connector_status_connected :
+					connector_status_disconnected;
+}
+
+static int dp_bridge_atomic_check(struct drm_bridge *bridge,
+			    struct drm_bridge_state *bridge_state,
+			    struct drm_crtc_state *crtc_state,
+			    struct drm_connector_state *conn_state)
+{
+	struct msm_dp *dp;
+
+	dp = to_dp_bridge(bridge)->dp_display;
+
+	drm_dbg_dp(dp->drm_dev, "is_connected = %s\n",
+		(dp->is_connected) ? "true" : "false");
+
+	/*
+	 * There is no protection in the DRM framework to check if the display
+	 * pipeline has been already disabled before trying to disable it again.
+	 * Hence if the sink is unplugged, the pipeline gets disabled, but the
+	 * crtc->active is still true. Any attempt to set the mode or manually
+	 * disable this encoder will result in the crash.
+	 *
+	 * TODO: add support for telling the DRM subsystem that the pipeline is
+	 * disabled by the hardware and thus all access to it should be forbidden.
+	 * After that this piece of code can be removed.
+	 */
+	if (bridge->ops & DRM_BRIDGE_OP_HPD)
+		return (dp->is_connected) ? 0 : -ENOTCONN;
+
+	return 0;
+}
+
+
+/**
+ * dp_bridge_get_modes - callback to add drm modes via drm_mode_probed_add()
+ * @bridge: Poiner to drm bridge
+ * @connector: Pointer to drm connector structure
+ * Returns: Number of modes added
+ */
+static int dp_bridge_get_modes(struct drm_bridge *bridge, struct drm_connector *connector)
+{
+	int rc = 0;
+	struct msm_dp *dp;
+
+	if (!connector)
+		return 0;
+
+	dp = to_dp_bridge(bridge)->dp_display;
+
+	/* pluggable case assumes EDID is read when HPD */
+	if (dp->is_connected) {
+		rc = dp_display_get_modes(dp);
+		if (rc <= 0) {
+			DRM_ERROR("failed to get DP sink modes, rc=%d\n", rc);
+			return rc;
+		}
+	} else {
+		drm_dbg_dp(connector->dev, "No sink connected\n");
+	}
+	return rc;
+}
+
+static const struct drm_bridge_funcs dp_bridge_ops = {
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state   = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset           = drm_atomic_helper_bridge_reset,
+	.atomic_enable          = dp_bridge_atomic_enable,
+	.atomic_disable         = dp_bridge_atomic_disable,
+	.atomic_post_disable    = dp_bridge_atomic_post_disable,
+	.mode_set     = dp_bridge_mode_set,
+	.mode_valid   = dp_bridge_mode_valid,
+	.get_modes    = dp_bridge_get_modes,
+	.detect       = dp_bridge_detect,
+	.atomic_check = dp_bridge_atomic_check,
+	.hpd_enable   = dp_bridge_hpd_enable,
+	.hpd_disable  = dp_bridge_hpd_disable,
+	.hpd_notify   = dp_bridge_hpd_notify,
+};
+
+static int edp_bridge_atomic_check(struct drm_bridge *drm_bridge,
+				   struct drm_bridge_state *bridge_state,
+				   struct drm_crtc_state *crtc_state,
+				   struct drm_connector_state *conn_state)
+{
+	struct msm_dp *dp = to_dp_bridge(drm_bridge)->dp_display;
+
+	if (WARN_ON(!conn_state))
+		return -ENODEV;
+
+	conn_state->self_refresh_aware = dp->psr_supported;
+
+	if (!conn_state->crtc || !crtc_state)
+		return 0;
+
+	if (crtc_state->self_refresh_active && !dp->psr_supported)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void edp_bridge_atomic_enable(struct drm_bridge *drm_bridge,
+				     struct drm_bridge_state *old_bridge_state)
+{
+	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
+	struct msm_dp *dp = dp_bridge->dp_display;
+
+	/*
+	 * Check the old state of the crtc to determine if the panel
+	 * was put into psr state previously by the edp_bridge_atomic_disable.
+	 * If the panel is in psr, just exit psr state and skip the full
+	 * bridge enable sequence.
+	 */
+	crtc = drm_atomic_get_new_crtc_for_encoder(atomic_state,
+						   drm_bridge->encoder);
+	if (!crtc)
+		return;
+
+	old_crtc_state = drm_atomic_get_old_crtc_state(atomic_state, crtc);
+
+	if (old_crtc_state && old_crtc_state->self_refresh_active) {
+		dp_display_set_psr(dp, false);
+		return;
+	}
+
+	dp_bridge_atomic_enable(drm_bridge, old_bridge_state);
+}
+
+static void edp_bridge_atomic_disable(struct drm_bridge *drm_bridge,
+				      struct drm_bridge_state *old_bridge_state)
+{
+	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state = NULL, *old_crtc_state = NULL;
+	struct msm_dp_bridge *dp_bridge = to_dp_bridge(drm_bridge);
+	struct msm_dp *dp = dp_bridge->dp_display;
+
+	crtc = drm_atomic_get_old_crtc_for_encoder(atomic_state,
+						   drm_bridge->encoder);
+	if (!crtc)
+		goto out;
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(atomic_state, crtc);
+	if (!new_crtc_state)
+		goto out;
+
+	old_crtc_state = drm_atomic_get_old_crtc_state(atomic_state, crtc);
+	if (!old_crtc_state)
+		goto out;
+
+	/*
+	 * Set self refresh mode if current crtc state is active.
+	 *
+	 * If old crtc state is active, then this is a display disable
+	 * call while the sink is in psr state. So, exit psr here.
+	 * The eDP controller will be disabled in the
+	 * edp_bridge_atomic_post_disable function.
+	 *
+	 * We observed sink is stuck in self refresh if psr exit is skipped
+	 * when display disable occurs while the sink is in psr state.
+	 */
+	if (new_crtc_state->self_refresh_active) {
+		dp_display_set_psr(dp, true);
+		return;
+	} else if (old_crtc_state->self_refresh_active) {
+		dp_display_set_psr(dp, false);
+		return;
+	}
+
+out:
+	dp_bridge_atomic_disable(drm_bridge, old_bridge_state);
+}
+
+static void edp_bridge_atomic_post_disable(struct drm_bridge *drm_bridge,
+				struct drm_bridge_state *old_bridge_state)
+{
+	struct drm_atomic_state *atomic_state = old_bridge_state->base.state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state = NULL;
+
+	crtc = drm_atomic_get_old_crtc_for_encoder(atomic_state,
+						   drm_bridge->encoder);
+	if (!crtc)
+		return;
+
+	new_crtc_state = drm_atomic_get_new_crtc_state(atomic_state, crtc);
+	if (!new_crtc_state)
+		return;
+
+	/*
+	 * Self refresh mode is already set in edp_bridge_atomic_disable.
+	 */
+	if (new_crtc_state->self_refresh_active)
+		return;
+
+	dp_bridge_atomic_post_disable(drm_bridge, old_bridge_state);
+}
+
+/**
+ * edp_bridge_mode_valid - callback to determine if specified mode is valid
+ * @bridge: Pointer to drm bridge structure
+ * @info: display info
+ * @mode: Pointer to drm mode structure
+ * Returns: Validity status for specified mode
+ */
+static enum drm_mode_status edp_bridge_mode_valid(struct drm_bridge *bridge,
+					  const struct drm_display_info *info,
+					  const struct drm_display_mode *mode)
+{
+	struct msm_dp *dp;
+	int mode_pclk_khz = mode->clock;
+
+	dp = to_dp_bridge(bridge)->dp_display;
+
+	if (!dp || !mode_pclk_khz || !dp->connector) {
+		DRM_ERROR("invalid params\n");
+		return -EINVAL;
+	}
+
+	if (mode->clock > DP_MAX_PIXEL_CLK_KHZ)
+		return MODE_CLOCK_HIGH;
+
+	/*
+	 * The eDP controller currently does not have a reliable way of
+	 * enabling panel power to read sink capabilities. So, we rely
+	 * on the panel driver to populate only supported modes for now.
+	 */
+	return MODE_OK;
+}
+
+static const struct drm_bridge_funcs edp_bridge_ops = {
+	.atomic_enable = edp_bridge_atomic_enable,
+	.atomic_disable = edp_bridge_atomic_disable,
+	.atomic_post_disable = edp_bridge_atomic_post_disable,
+	.mode_set = dp_bridge_mode_set,
+	.mode_valid = edp_bridge_mode_valid,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_check = edp_bridge_atomic_check,
+};
+
+struct drm_bridge *dp_bridge_init(struct msm_dp *dp_display, struct drm_device *dev,
+			struct drm_encoder *encoder)
+{
+	int rc;
+	struct msm_dp_bridge *dp_bridge;
+	struct drm_bridge *bridge;
+
+	dp_bridge = devm_kzalloc(dev->dev, sizeof(*dp_bridge), GFP_KERNEL);
+	if (!dp_bridge)
+		return ERR_PTR(-ENOMEM);
+
+	dp_bridge->dp_display = dp_display;
+
+	bridge = &dp_bridge->bridge;
+	bridge->funcs = dp_display->is_edp ? &edp_bridge_ops : &dp_bridge_ops;
+	bridge->type = dp_display->connector_type;
+
+	/*
+	 * Many ops only make sense for DP. Why?
+	 * - Detect/HPD are used by DRM to know if a display is _physically_
+	 *   there, not whether the display is powered on / finished initting.
+	 *   On eDP we assume the display is always there because you can't
+	 *   know until power is applied. If we don't implement the ops DRM will
+	 *   assume our display is always there.
+	 * - Currently eDP mode reading is driven by the panel driver. This
+	 *   allows the panel driver to properly power itself on to read the
+	 *   modes.
+	 */
+	if (!dp_display->is_edp) {
+		bridge->ops =
+			DRM_BRIDGE_OP_DETECT |
+			DRM_BRIDGE_OP_HPD |
+			DRM_BRIDGE_OP_MODES;
+	}
+
+	drm_bridge_add(bridge);
+
+	rc = drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+	if (rc) {
+		DRM_ERROR("failed to attach bridge, rc=%d\n", rc);
+		drm_bridge_remove(bridge);
+
+		return ERR_PTR(rc);
+	}
+
+	if (dp_display->next_bridge) {
+		rc = drm_bridge_attach(encoder,
+					dp_display->next_bridge, bridge,
+					DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+		if (rc < 0) {
+			DRM_ERROR("failed to attach panel bridge: %d\n", rc);
+			drm_bridge_remove(bridge);
+			return ERR_PTR(rc);
+		}
+	}
+
+	return bridge;
+}
+
+/* connector initialization */
+struct drm_connector *dp_drm_connector_init(struct msm_dp *dp_display, struct drm_encoder *encoder)
+{
+	struct drm_connector *connector = NULL;
+
+	connector = drm_bridge_connector_init(dp_display->drm_dev, encoder);
+	if (IS_ERR(connector))
+		return connector;
+
+	drm_connector_attach_encoder(connector, encoder);
+
+	return connector;
+}