1 files changed, 254 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
new file mode 100644
index 000000000..3e085c5f2
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_lspcon.c
@@ -0,0 +1,254 @@
+/*
+ * Copyright © 2016 Intel Corporation
+ *
+ * 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/drm_edid.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_dp_dual_mode_helper.h>
+#include "intel_drv.h"
+
+static struct intel_dp *lspcon_to_intel_dp(struct intel_lspcon *lspcon)
+{
+	struct intel_digital_port *dig_port =
+		container_of(lspcon, struct intel_digital_port, lspcon);
+
+	return &dig_port->dp;
+}
+
+static const char *lspcon_mode_name(enum drm_lspcon_mode mode)
+{
+	switch (mode) {
+	case DRM_LSPCON_MODE_PCON:
+		return "PCON";
+	case DRM_LSPCON_MODE_LS:
+		return "LS";
+	case DRM_LSPCON_MODE_INVALID:
+		return "INVALID";
+	default:
+		MISSING_CASE(mode);
+		return "INVALID";
+	}
+}
+
+static enum drm_lspcon_mode lspcon_get_current_mode(struct intel_lspcon *lspcon)
+{
+	enum drm_lspcon_mode current_mode;
+	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
+
+	if (drm_lspcon_get_mode(adapter, &current_mode)) {
+		DRM_DEBUG_KMS("Error reading LSPCON mode\n");
+		return DRM_LSPCON_MODE_INVALID;
+	}
+	return current_mode;
+}
+
+static enum drm_lspcon_mode lspcon_wait_mode(struct intel_lspcon *lspcon,
+					     enum drm_lspcon_mode mode)
+{
+	enum drm_lspcon_mode current_mode;
+
+	current_mode = lspcon_get_current_mode(lspcon);
+	if (current_mode == mode)
+		goto out;
+
+	DRM_DEBUG_KMS("Waiting for LSPCON mode %s to settle\n",
+		      lspcon_mode_name(mode));
+
+	wait_for((current_mode = lspcon_get_current_mode(lspcon)) == mode, 400);
+	if (current_mode != mode)
+		DRM_ERROR("LSPCON mode hasn't settled\n");
+
+out:
+	DRM_DEBUG_KMS("Current LSPCON mode %s\n",
+		      lspcon_mode_name(current_mode));
+
+	return current_mode;
+}
+
+static int lspcon_change_mode(struct intel_lspcon *lspcon,
+			      enum drm_lspcon_mode mode)
+{
+	int err;
+	enum drm_lspcon_mode current_mode;
+	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
+
+	err = drm_lspcon_get_mode(adapter, &current_mode);
+	if (err) {
+		DRM_ERROR("Error reading LSPCON mode\n");
+		return err;
+	}
+
+	if (current_mode == mode) {
+		DRM_DEBUG_KMS("Current mode = desired LSPCON mode\n");
+		return 0;
+	}
+
+	err = drm_lspcon_set_mode(adapter, mode);
+	if (err < 0) {
+		DRM_ERROR("LSPCON mode change failed\n");
+		return err;
+	}
+
+	lspcon->mode = mode;
+	DRM_DEBUG_KMS("LSPCON mode changed done\n");
+	return 0;
+}
+
+static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
+{
+	u8 rev;
+
+	if (drm_dp_dpcd_readb(&lspcon_to_intel_dp(lspcon)->aux, DP_DPCD_REV,
+			      &rev) != 1) {
+		DRM_DEBUG_KMS("Native AUX CH down\n");
+		return false;
+	}
+
+	DRM_DEBUG_KMS("Native AUX CH up, DPCD version: %d.%d\n",
+		      rev >> 4, rev & 0xf);
+
+	return true;
+}
+
+static bool lspcon_probe(struct intel_lspcon *lspcon)
+{
+	int retry;
+	enum drm_dp_dual_mode_type adaptor_type;
+	struct i2c_adapter *adapter = &lspcon_to_intel_dp(lspcon)->aux.ddc;
+	enum drm_lspcon_mode expected_mode;
+
+	expected_mode = lspcon_wake_native_aux_ch(lspcon) ?
+			DRM_LSPCON_MODE_PCON : DRM_LSPCON_MODE_LS;
+
+	/* Lets probe the adaptor and check its type */
+	for (retry = 0; retry < 6; retry++) {
+		if (retry)
+			usleep_range(500, 1000);
+
+		adaptor_type = drm_dp_dual_mode_detect(adapter);
+		if (adaptor_type == DRM_DP_DUAL_MODE_LSPCON)
+			break;
+	}
+
+	if (adaptor_type != DRM_DP_DUAL_MODE_LSPCON) {
+		DRM_DEBUG_KMS("No LSPCON detected, found %s\n",
+			       drm_dp_get_dual_mode_type_name(adaptor_type));
+		return false;
+	}
+
+	/* Yay ... got a LSPCON device */
+	DRM_DEBUG_KMS("LSPCON detected\n");
+	lspcon->mode = lspcon_wait_mode(lspcon, expected_mode);
+	lspcon->active = true;
+	return true;
+}
+
+static void lspcon_resume_in_pcon_wa(struct intel_lspcon *lspcon)
+{
+	struct intel_dp *intel_dp = lspcon_to_intel_dp(lspcon);
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	unsigned long start = jiffies;
+
+	while (1) {
+		if (intel_digital_port_connected(&dig_port->base)) {
+			DRM_DEBUG_KMS("LSPCON recovering in PCON mode after %u ms\n",
+				      jiffies_to_msecs(jiffies - start));
+			return;
+		}
+
+		if (time_after(jiffies, start + msecs_to_jiffies(1000)))
+			break;
+
+		usleep_range(10000, 15000);
+	}
+
+	DRM_DEBUG_KMS("LSPCON DP descriptor mismatch after resume\n");
+}
+
+void lspcon_resume(struct intel_lspcon *lspcon)
+{
+	enum drm_lspcon_mode expected_mode;
+
+	if (lspcon_wake_native_aux_ch(lspcon)) {
+		expected_mode = DRM_LSPCON_MODE_PCON;
+		lspcon_resume_in_pcon_wa(lspcon);
+	} else {
+		expected_mode = DRM_LSPCON_MODE_LS;
+	}
+
+	if (lspcon_wait_mode(lspcon, expected_mode) == DRM_LSPCON_MODE_PCON)
+		return;
+
+	if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON))
+		DRM_ERROR("LSPCON resume failed\n");
+	else
+		DRM_DEBUG_KMS("LSPCON resume success\n");
+}
+
+void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon)
+{
+	lspcon_wait_mode(lspcon, DRM_LSPCON_MODE_PCON);
+}
+
+bool lspcon_init(struct intel_digital_port *intel_dig_port)
+{
+	struct intel_dp *dp = &intel_dig_port->dp;
+	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
+	struct drm_device *dev = intel_dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+
+	if (!HAS_LSPCON(dev_priv)) {
+		DRM_ERROR("LSPCON is not supported on this platform\n");
+		return false;
+	}
+
+	lspcon->active = false;
+	lspcon->mode = DRM_LSPCON_MODE_INVALID;
+
+	if (!lspcon_probe(lspcon)) {
+		DRM_ERROR("Failed to probe lspcon\n");
+		return false;
+	}
+
+	/*
+	* In the SW state machine, lets Put LSPCON in PCON mode only.
+	* In this way, it will work with both HDMI 1.4 sinks as well as HDMI
+	* 2.0 sinks.
+	*/
+	if (lspcon->active && lspcon->mode != DRM_LSPCON_MODE_PCON) {
+		if (lspcon_change_mode(lspcon, DRM_LSPCON_MODE_PCON) < 0) {
+			DRM_ERROR("LSPCON mode change to PCON failed\n");
+			return false;
+		}
+	}
+
+	if (!intel_dp_read_dpcd(dp)) {
+		DRM_ERROR("LSPCON DPCD read failed\n");
+		return false;
+	}
+
+	drm_dp_read_desc(&dp->aux, &dp->desc, drm_dp_is_branch(dp->dpcd));
+
+	DRM_DEBUG_KMS("Success: LSPCON init\n");
+	return true;
+}