drm: bridge: cdns-mhdp8546: Enable HDCP

This patch enable HDCP in MHDP driver.
Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1618078542-30679-1-git-send-email-pthombar@cadence.com

drivers/gpu/drm/bridge/cadence/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_DRM_CDNS_MHDP8546) += cdns-mhdp8546.o
-cdns-mhdp8546-y := cdns-mhdp8546-core.o
+cdns-mhdp8546-y := cdns-mhdp8546-core.o cdns-mhdp8546-hdcp.o
 cdns-mhdp8546-$(CONFIG_DRM_CDNS_MHDP8546_J721E) += cdns-mhdp8546-j721e.o

drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c

@@ -42,6 +42,7 @@
 #include <drm/drm_connector.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_dp_helper.h>
+#include <drm/drm_hdcp.h>
 #include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
@@ -49,7 +50,7 @@
 #include <asm/unaligned.h>
 
 #include "cdns-mhdp8546-core.h"
-
+#include "cdns-mhdp8546-hdcp.h"
 #include "cdns-mhdp8546-j721e.h"
 
 static int cdns_mhdp_mailbox_read(struct cdns_mhdp_device *mhdp)
@@ -1614,10 +1615,51 @@ enum drm_mode_status cdns_mhdp_mode_valid(struct drm_connector *conn,
 	return MODE_OK;
 }
 
+static int cdns_mhdp_connector_atomic_check(struct drm_connector *conn,
+					    struct drm_atomic_state *state)
+{
+	struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
+	struct drm_connector_state *old_state, *new_state;
+	struct drm_crtc_state *crtc_state;
+	u64 old_cp, new_cp;
+
+	if (!mhdp->hdcp_supported)
+		return 0;
+
+	old_state = drm_atomic_get_old_connector_state(state, conn);
+	new_state = drm_atomic_get_new_connector_state(state, conn);
+	old_cp = old_state->content_protection;
+	new_cp = new_state->content_protection;
+
+	if (old_state->hdcp_content_type != new_state->hdcp_content_type &&
+	    new_cp != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
+		new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+		goto mode_changed;
+	}
+
+	if (!new_state->crtc) {
+		if (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
+			new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+		return 0;
+	}
+
+	if (old_cp == new_cp ||
+	    (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
+	     new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED))
+		return 0;
+
+mode_changed:
+	crtc_state = drm_atomic_get_new_crtc_state(state, new_state->crtc);
+	crtc_state->mode_changed = true;
+
+	return 0;
+}
+
 static const struct drm_connector_helper_funcs cdns_mhdp_conn_helper_funcs = {
 	.detect_ctx = cdns_mhdp_connector_detect,
 	.get_modes = cdns_mhdp_get_modes,
 	.mode_valid = cdns_mhdp_mode_valid,
+	.atomic_check = cdns_mhdp_connector_atomic_check,
 };
 
 static const struct drm_connector_funcs cdns_mhdp_conn_funcs = {
@@ -1662,7 +1704,10 @@ static int cdns_mhdp_connector_init(struct cdns_mhdp_device *mhdp)
 		return ret;
 	}
 
-	return 0;
+	if (mhdp->hdcp_supported)
+		ret = drm_connector_attach_content_protection_property(conn, true);
+
+	return ret;
 }
 
 static int cdns_mhdp_attach(struct drm_bridge *bridge,
@@ -1957,6 +2002,15 @@ static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge,
 	if (WARN_ON(!conn_state))
 		goto out;
 
+	if (mhdp->hdcp_supported &&
+	    mhdp->hw_state == MHDP_HW_READY &&
+	    conn_state->content_protection ==
+	    DRM_MODE_CONTENT_PROTECTION_DESIRED) {
+		mutex_unlock(&mhdp->link_mutex);
+		cdns_mhdp_hdcp_enable(mhdp, conn_state->hdcp_content_type);
+		mutex_lock(&mhdp->link_mutex);
+	}
+
 	crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
 	if (WARN_ON(!crtc_state))
 		goto out;
@@ -2000,6 +2054,9 @@ static void cdns_mhdp_atomic_disable(struct drm_bridge *bridge,
 
 	mutex_lock(&mhdp->link_mutex);
 
+	if (mhdp->hdcp_supported)
+		cdns_mhdp_hdcp_disable(mhdp);
+
 	mhdp->bridge_enabled = false;
 	cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
 	resp &= ~CDNS_DP_FRAMER_EN;
@@ -2288,7 +2345,6 @@ static irqreturn_t cdns_mhdp_irq_handler(int irq, void *data)
 	struct cdns_mhdp_device *mhdp = data;
 	u32 apb_stat, sw_ev0;
 	bool bridge_attached;
-	int ret;
 
 	apb_stat = readl(mhdp->regs + CDNS_APB_INT_STATUS);
 	if (!(apb_stat & CDNS_APB_INT_MASK_SW_EVENT_INT))
@@ -2307,6 +2363,43 @@ static irqreturn_t cdns_mhdp_irq_handler(int irq, void *data)
 	spin_unlock(&mhdp->start_lock);
 
 	if (bridge_attached && (sw_ev0 & CDNS_DPTX_HPD)) {
+		schedule_work(&mhdp->hpd_work);
+	}
+
+	if (sw_ev0 & ~CDNS_DPTX_HPD) {
+		mhdp->sw_events |= (sw_ev0 & ~CDNS_DPTX_HPD);
+		wake_up(&mhdp->sw_events_wq);
+	}
+
+	return IRQ_HANDLED;
+}
+
+u32 cdns_mhdp_wait_for_sw_event(struct cdns_mhdp_device *mhdp, u32 event)
+{
+	u32 ret;
+
+	ret = wait_event_timeout(mhdp->sw_events_wq,
+				 mhdp->sw_events & event,
+				 msecs_to_jiffies(500));
+	if (!ret) {
+		dev_dbg(mhdp->dev, "SW event 0x%x timeout\n", event);
+		goto sw_event_out;
+	}
+
+	ret = mhdp->sw_events;
+	mhdp->sw_events &= ~event;
+
+sw_event_out:
+	return ret;
+}
+
+static void cdns_mhdp_hpd_work(struct work_struct *work)
+{
+	struct cdns_mhdp_device *mhdp = container_of(work,
+						     struct cdns_mhdp_device,
+						     hpd_work);
+	int ret;
+
 	ret = cdns_mhdp_update_link_status(mhdp);
 	if (mhdp->connector.dev) {
 		if (ret < 0)
@@ -2316,9 +2409,6 @@ static irqreturn_t cdns_mhdp_irq_handler(int irq, void *data)
 	} else {
 		drm_bridge_hpd_notify(&mhdp->bridge, cdns_mhdp_detect(mhdp));
 	}
-	}
-
-	return IRQ_HANDLED;
 }
 
 static int cdns_mhdp_probe(struct platform_device *pdev)
@@ -2356,6 +2446,15 @@ static int cdns_mhdp_probe(struct platform_device *pdev)
 		return PTR_ERR(mhdp->regs);
 	}
 
+	mhdp->sapb_regs = devm_platform_ioremap_resource_byname(pdev, "mhdptx-sapb");
+	if (IS_ERR(mhdp->sapb_regs)) {
+		mhdp->hdcp_supported = false;
+		dev_warn(dev,
+			 "Failed to get SAPB memory resource, HDCP not supported\n");
+	} else {
+		mhdp->hdcp_supported = true;
+	}
+
 	mhdp->phy = devm_of_phy_get_by_index(dev, pdev->dev.of_node, 0);
 	if (IS_ERR(mhdp->phy)) {
 		dev_err(dev, "no PHY configured\n");
@@ -2430,13 +2529,18 @@ static int cdns_mhdp_probe(struct platform_device *pdev)
 
 	/* Initialize the work for modeset in case of link train failure */
 	INIT_WORK(&mhdp->modeset_retry_work, cdns_mhdp_modeset_retry_fn);
+	INIT_WORK(&mhdp->hpd_work, cdns_mhdp_hpd_work);
 
 	init_waitqueue_head(&mhdp->fw_load_wq);
+	init_waitqueue_head(&mhdp->sw_events_wq);
 
 	ret = cdns_mhdp_load_firmware(mhdp);
 	if (ret)
 		goto phy_exit;
 
+	if (mhdp->hdcp_supported)
+		cdns_mhdp_hdcp_init(mhdp);
+
 	drm_bridge_add(&mhdp->bridge);
 
 	return 0;

drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.h

@@ -47,6 +47,10 @@ struct phy;
 
 #define CDNS_SW_EVENT0				0x00044
 #define CDNS_DPTX_HPD				BIT(0)
+#define CDNS_HDCP_TX_STATUS			BIT(4)
+#define CDNS_HDCP2_TX_IS_KM_STORED		BIT(5)
+#define CDNS_HDCP2_TX_STORE_KM			BIT(6)
+#define CDNS_HDCP_TX_IS_RCVR_ID_VALID		BIT(7)
 
 #define CDNS_SW_EVENT1				0x00048
 #define CDNS_SW_EVENT2				0x0004c
@@ -339,8 +343,17 @@ struct cdns_mhdp_platform_info {
 #define to_cdns_mhdp_bridge_state(s) \
 		container_of(s, struct cdns_mhdp_bridge_state, base)
 
+struct cdns_mhdp_hdcp {
+	struct delayed_work check_work;
+	struct work_struct prop_work;
+	struct mutex mutex; /* mutex to protect hdcp.value */
+	u32 value;
+	u8 hdcp_content_type;
+};
+
 struct cdns_mhdp_device {
 	void __iomem *regs;
+	void __iomem *sapb_regs;
 	void __iomem *j721e_regs;
 
 	struct device *dev;
@@ -392,9 +405,18 @@ struct cdns_mhdp_device {
 
 	/* Work struct to schedule a uevent on link train failure */
 	struct work_struct modeset_retry_work;
+	struct work_struct hpd_work;
+
+	wait_queue_head_t sw_events_wq;
+	u32 sw_events;
+
+	struct cdns_mhdp_hdcp hdcp;
+	bool hdcp_supported;
 };
 
 #define connector_to_mhdp(x) container_of(x, struct cdns_mhdp_device, connector)
 #define bridge_to_mhdp(x) container_of(x, struct cdns_mhdp_device, bridge)
 
+u32 cdns_mhdp_wait_for_sw_event(struct cdns_mhdp_device *mhdp, uint32_t event);
+
 #endif

drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-hdcp.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Cadence MHDP8546 DP bridge driver.
+ *
+ * Copyright (C) 2020 Cadence Design Systems, Inc.
+ *
+ */
+
+#ifndef CDNS_MHDP8546_HDCP_H
+#define CDNS_MHDP8546_HDCP_H
+
+#include "cdns-mhdp8546-core.h"
+
+#define HDCP_MAX_RECEIVERS 32
+#define HDCP_RECEIVER_ID_SIZE_BYTES 5
+#define HDCP_STATUS_SIZE         0x5
+#define HDCP_PORT_STS_AUTH       0x1
+#define HDCP_PORT_STS_LAST_ERR_SHIFT 0x5
+#define HDCP_PORT_STS_LAST_ERR_MASK  (0x0F << 5)
+#define GET_HDCP_PORT_STS_LAST_ERR(__sts__) \
+	(((__sts__) & HDCP_PORT_STS_LAST_ERR_MASK) >> \
+	HDCP_PORT_STS_LAST_ERR_SHIFT)
+
+#define HDCP_CONFIG_1_4     BIT(0) /* use HDCP 1.4 only */
+#define HDCP_CONFIG_2_2     BIT(1) /* use HDCP 2.2 only */
+/* use All HDCP versions */
+#define HDCP_CONFIG_ALL     (BIT(0) | BIT(1))
+#define HDCP_CONFIG_NONE    0
+
+enum {
+	HDCP_GENERAL_SET_LC_128,
+	HDCP_SET_SEED,
+};
+
+enum {
+	HDCP_TRAN_CONFIGURATION,
+	HDCP2X_TX_SET_PUBLIC_KEY_PARAMS,
+	HDCP2X_TX_SET_DEBUG_RANDOM_NUMBERS,
+	HDCP2X_TX_RESPOND_KM,
+	HDCP1_TX_SEND_KEYS,
+	HDCP1_TX_SEND_RANDOM_AN,
+	HDCP_TRAN_STATUS_CHANGE,
+	HDCP2X_TX_IS_KM_STORED,
+	HDCP2X_TX_STORE_KM,
+	HDCP_TRAN_IS_REC_ID_VALID,
+	HDCP_TRAN_RESPOND_RECEIVER_ID_VALID,
+	HDCP_TRAN_TEST_KEYS,
+	HDCP2X_TX_SET_KM_KEY_PARAMS,
+	HDCP_NUM_OF_SUPPORTED_MESSAGES
+};
+
+enum {
+	HDCP_CONTENT_TYPE_0,
+	HDCP_CONTENT_TYPE_1,
+};
+
+#define DRM_HDCP_CHECK_PERIOD_MS (128 * 16)
+
+#define HDCP_PAIRING_R_ID 5
+#define HDCP_PAIRING_M_LEN 16
+#define HDCP_KM_LEN 16
+#define HDCP_PAIRING_M_EKH 16
+
+struct cdns_hdcp_pairing_data {
+	u8 receiver_id[HDCP_PAIRING_R_ID];
+	u8 m[HDCP_PAIRING_M_LEN];
+	u8 km[HDCP_KM_LEN];
+	u8 ekh[HDCP_PAIRING_M_EKH];
+};
+
+enum {
+	HDCP_TX_2,
+	HDCP_TX_1,
+	HDCP_TX_BOTH,
+};
+
+#define DLP_MODULUS_N 384
+#define DLP_E 3
+
+struct cdns_hdcp_tx_public_key_param {
+	u8 N[DLP_MODULUS_N];
+	u8 E[DLP_E];
+};
+
+int cdns_mhdp_hdcp_set_public_key_param(struct cdns_mhdp_device *mhdp,
+					struct cdns_hdcp_tx_public_key_param *val);
+int cdns_mhdp_hdcp_set_lc(struct cdns_mhdp_device *mhdp, u8 *val);
+int cdns_mhdp_hdcp_enable(struct cdns_mhdp_device *mhdp, u8 content_type);
+int cdns_mhdp_hdcp_disable(struct cdns_mhdp_device *mhdp);
+void cdns_mhdp_hdcp_init(struct cdns_mhdp_device *mhdp);
+
+#endif