drm/bridge: anx7625: add HDCP support

This patch provides HDCP setting interface for userspace to dynamic
enable/disable HDCP function.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Xin Ji <xji@analogixsemi.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220106100127.1862702-2-xji@analogixsemi.com

drivers/gpu/drm/bridge/analogix/anx7625.c

@@ -26,6 +26,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_dp_helper.h>
 #include <drm/drm_edid.h>
+#include <drm/drm_hdcp.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_of.h>
 #include <drm/drm_panel.h>
@@ -213,6 +214,65 @@ static int wait_aux_op_finish(struct anx7625_data *ctx)
 	return 0;
 }
 
+static int anx7625_aux_dpcd_read(struct anx7625_data *ctx,
+				 u32 address, u8 len, u8 *buf)
+{
+	struct device *dev = &ctx->client->dev;
+	int ret;
+	u8 addrh, addrm, addrl;
+	u8 cmd;
+
+	if (len > MAX_DPCD_BUFFER_SIZE) {
+		dev_err(dev, "exceed aux buffer len.\n");
+		return -EINVAL;
+	}
+
+	addrl = address & 0xFF;
+	addrm = (address >> 8) & 0xFF;
+	addrh = (address >> 16) & 0xFF;
+
+	cmd = DPCD_CMD(len, DPCD_READ);
+	cmd = ((len - 1) << 4) | 0x09;
+
+	/* Set command and length */
+	ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				AP_AUX_COMMAND, cmd);
+
+	/* Set aux access address */
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 AP_AUX_ADDR_7_0, addrl);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 AP_AUX_ADDR_15_8, addrm);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 AP_AUX_ADDR_19_16, addrh);
+
+	/* Enable aux access */
+	ret |= anx7625_write_or(ctx, ctx->i2c.rx_p0_client,
+				AP_AUX_CTRL_STATUS, AP_AUX_CTRL_OP_EN);
+
+	if (ret < 0) {
+		dev_err(dev, "cannot access aux related register.\n");
+		return -EIO;
+	}
+
+	usleep_range(2000, 2100);
+
+	ret = wait_aux_op_finish(ctx);
+	if (ret) {
+		dev_err(dev, "aux IO error: wait aux op finish.\n");
+		return ret;
+	}
+
+	ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
+				     AP_AUX_BUFF_START, len, buf);
+	if (ret < 0) {
+		dev_err(dev, "read dpcd register failed\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
 static int anx7625_video_mute_control(struct anx7625_data *ctx,
 				      u8 status)
 {
@@ -669,6 +729,165 @@ static int anx7625_dpi_config(struct anx7625_data *ctx)
 	return ret;
 }
 
+static int anx7625_read_flash_status(struct anx7625_data *ctx)
+{
+	return anx7625_reg_read(ctx, ctx->i2c.rx_p0_client, R_RAM_CTRL);
+}
+
+static int anx7625_hdcp_key_probe(struct anx7625_data *ctx)
+{
+	int ret, val;
+	struct device *dev = &ctx->client->dev;
+	u8 ident[FLASH_BUF_LEN];
+
+	ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				FLASH_ADDR_HIGH, 0x91);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 FLASH_ADDR_LOW, 0xA0);
+	if (ret < 0) {
+		dev_err(dev, "IO error : set key flash address.\n");
+		return ret;
+	}
+
+	ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				FLASH_LEN_HIGH, (FLASH_BUF_LEN - 1) >> 8);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 FLASH_LEN_LOW, (FLASH_BUF_LEN - 1) & 0xFF);
+	if (ret < 0) {
+		dev_err(dev, "IO error : set key flash len.\n");
+		return ret;
+	}
+
+	ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				R_FLASH_RW_CTRL, FLASH_READ);
+	ret |= readx_poll_timeout(anx7625_read_flash_status,
+				  ctx, val,
+				  ((val & FLASH_DONE) || (val < 0)),
+				  2000,
+				  2000 * 150);
+	if (ret) {
+		dev_err(dev, "flash read access fail!\n");
+		return -EIO;
+	}
+
+	ret = anx7625_reg_block_read(ctx, ctx->i2c.rx_p0_client,
+				     FLASH_BUF_BASE_ADDR,
+				     FLASH_BUF_LEN, ident);
+	if (ret < 0) {
+		dev_err(dev, "read flash data fail!\n");
+		return -EIO;
+	}
+
+	if (ident[29] == 0xFF && ident[30] == 0xFF && ident[31] == 0xFF)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int anx7625_hdcp_key_load(struct anx7625_data *ctx)
+{
+	int ret;
+	struct device *dev = &ctx->client->dev;
+
+	/* Select HDCP 1.4 KEY */
+	ret = anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				R_BOOT_RETRY, 0x12);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 FLASH_ADDR_HIGH, HDCP14KEY_START_ADDR >> 8);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 FLASH_ADDR_LOW, HDCP14KEY_START_ADDR & 0xFF);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 R_RAM_LEN_H, HDCP14KEY_SIZE >> 12);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 R_RAM_LEN_L, HDCP14KEY_SIZE >> 4);
+
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 R_RAM_ADDR_H, 0);
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 R_RAM_ADDR_L, 0);
+	/* Enable HDCP 1.4 KEY load */
+	ret |= anx7625_reg_write(ctx, ctx->i2c.rx_p0_client,
+				 R_RAM_CTRL, DECRYPT_EN | LOAD_START);
+	dev_dbg(dev, "load HDCP 1.4 key done\n");
+	return ret;
+}
+
+static int anx7625_hdcp_disable(struct anx7625_data *ctx)
+{
+	int ret;
+	struct device *dev = &ctx->client->dev;
+
+	dev_dbg(dev, "disable HDCP 1.4\n");
+
+	/* Disable HDCP */
+	ret = anx7625_write_and(ctx, ctx->i2c.rx_p1_client, 0xee, 0x9f);
+	/* Try auth flag */
+	ret |= anx7625_write_or(ctx, ctx->i2c.rx_p1_client, 0xec, 0x10);
+	/* Interrupt for DRM */
+	ret |= anx7625_write_or(ctx, ctx->i2c.rx_p1_client, 0xff, 0x01);
+	if (ret < 0)
+		dev_err(dev, "fail to disable HDCP\n");
+
+	return anx7625_write_and(ctx, ctx->i2c.tx_p0_client,
+				 TX_HDCP_CTRL0, ~HARD_AUTH_EN & 0xFF);
+}
+
+static int anx7625_hdcp_enable(struct anx7625_data *ctx)
+{
+	u8 bcap;
+	int ret;
+	struct device *dev = &ctx->client->dev;
+
+	ret = anx7625_hdcp_key_probe(ctx);
+	if (ret) {
+		dev_dbg(dev, "no key found, not to do hdcp\n");
+		return ret;
+	}
+
+	/* Read downstream capability */
+	anx7625_aux_dpcd_read(ctx, 0x68028, 1, &bcap);
+	if (!(bcap & 0x01)) {
+		pr_warn("downstream not support HDCP 1.4, cap(%x).\n", bcap);
+		return 0;
+	}
+
+	dev_dbg(dev, "enable HDCP 1.4\n");
+
+	/* First clear HDCP state */
+	ret = anx7625_reg_write(ctx, ctx->i2c.tx_p0_client,
+				TX_HDCP_CTRL0,
+				KSVLIST_VLD | BKSV_SRM_PASS | RE_AUTHEN);
+	usleep_range(1000, 1100);
+	/* Second clear HDCP state */
+	ret |= anx7625_reg_write(ctx, ctx->i2c.tx_p0_client,
+				 TX_HDCP_CTRL0,
+				 KSVLIST_VLD | BKSV_SRM_PASS | RE_AUTHEN);
+
+	/* Set time for waiting KSVR */
+	ret |= anx7625_reg_write(ctx, ctx->i2c.tx_p0_client,
+				 SP_TX_WAIT_KSVR_TIME, 0xc8);
+	/* Set time for waiting R0 */
+	ret |= anx7625_reg_write(ctx, ctx->i2c.tx_p0_client,
+				 SP_TX_WAIT_R0_TIME, 0xb0);
+	ret |= anx7625_hdcp_key_load(ctx);
+	if (ret) {
+		pr_warn("prepare HDCP key failed.\n");
+		return ret;
+	}
+
+	ret = anx7625_write_or(ctx, ctx->i2c.rx_p1_client, 0xee, 0x20);
+
+	/* Try auth flag */
+	ret |= anx7625_write_or(ctx, ctx->i2c.rx_p1_client, 0xec, 0x10);
+	/* Interrupt for DRM */
+	ret |= anx7625_write_or(ctx, ctx->i2c.rx_p1_client, 0xff, 0x01);
+	if (ret < 0)
+		dev_err(dev, "fail to enable HDCP\n");
+
+	return anx7625_write_or(ctx, ctx->i2c.tx_p0_client,
+				TX_HDCP_CTRL0, HARD_AUTH_EN);
+}
+
 static void anx7625_dp_start(struct anx7625_data *ctx)
 {
 	int ret;
@@ -679,6 +898,9 @@ static void anx7625_dp_start(struct anx7625_data *ctx)
 		return;
 	}
 
+	/* Disable HDCP */
+	anx7625_write_and(ctx, ctx->i2c.rx_p1_client, 0xee, 0x9f);
+
 	if (ctx->pdata.is_dpi)
 		ret = anx7625_dpi_config(ctx);
 	else
@@ -686,6 +908,10 @@ static void anx7625_dp_start(struct anx7625_data *ctx)
 
 	if (ret < 0)
 		DRM_DEV_ERROR(dev, "MIPI phy setup error.\n");
+
+	ctx->hdcp_cp = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
+
+	ctx->dp_en = 1;
 }
 
 static void anx7625_dp_stop(struct anx7625_data *ctx)
@@ -705,6 +931,10 @@ static void anx7625_dp_stop(struct anx7625_data *ctx)
 	ret |= anx7625_video_mute_control(ctx, 1);
 	if (ret < 0)
 		DRM_DEV_ERROR(dev, "IO error : mute video fail\n");
+
+	ctx->hdcp_cp = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
+
+	ctx->dp_en = 0;
 }
 
 static int sp_tx_rst_aux(struct anx7625_data *ctx)
@@ -1697,6 +1927,83 @@ static int anx7625_attach_dsi(struct anx7625_data *ctx)
 	return 0;
 }
 
+static void hdcp_check_work_func(struct work_struct *work)
+{
+	u8 status;
+	struct delayed_work *dwork;
+	struct anx7625_data *ctx;
+	struct device *dev;
+	struct drm_device *drm_dev;
+
+	dwork = to_delayed_work(work);
+	ctx = container_of(dwork, struct anx7625_data, hdcp_work);
+	dev = &ctx->client->dev;
+
+	if (!ctx->connector) {
+		dev_err(dev, "HDCP connector is null!");
+		return;
+	}
+
+	drm_dev = ctx->connector->dev;
+	drm_modeset_lock(&drm_dev->mode_config.connection_mutex, NULL);
+	mutex_lock(&ctx->hdcp_wq_lock);
+
+	status = anx7625_reg_read(ctx, ctx->i2c.tx_p0_client, 0);
+	dev_dbg(dev, "sink HDCP status check: %.02x\n", status);
+	if (status & BIT(1)) {
+		ctx->hdcp_cp = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+		drm_hdcp_update_content_protection(ctx->connector,
+						   ctx->hdcp_cp);
+		dev_dbg(dev, "update CP to ENABLE\n");
+	}
+
+	mutex_unlock(&ctx->hdcp_wq_lock);
+	drm_modeset_unlock(&drm_dev->mode_config.connection_mutex);
+}
+
+static int anx7625_connector_atomic_check(struct anx7625_data *ctx,
+					  struct drm_connector_state *state)
+{
+	struct device *dev = &ctx->client->dev;
+	int cp;
+
+	dev_dbg(dev, "hdcp state check\n");
+	cp = state->content_protection;
+
+	if (cp == ctx->hdcp_cp)
+		return 0;
+
+	if (cp == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
+		if (ctx->dp_en) {
+			dev_dbg(dev, "enable HDCP\n");
+			anx7625_hdcp_enable(ctx);
+
+			queue_delayed_work(ctx->hdcp_workqueue,
+					   &ctx->hdcp_work,
+					   msecs_to_jiffies(2000));
+		}
+	}
+
+	if (cp == DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
+		if (ctx->hdcp_cp != DRM_MODE_CONTENT_PROTECTION_ENABLED) {
+			dev_err(dev, "current CP is not ENABLED\n");
+			return -EINVAL;
+		}
+		anx7625_hdcp_disable(ctx);
+		ctx->hdcp_cp = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
+		drm_hdcp_update_content_protection(ctx->connector,
+						   ctx->hdcp_cp);
+		dev_dbg(dev, "update CP to UNDESIRE\n");
+	}
+
+	if (cp == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
+		dev_err(dev, "Userspace illegal set to PROTECTION ENABLE\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int anx7625_bridge_attach(struct drm_bridge *bridge,
 				 enum drm_bridge_attach_flags flags)
 {
@@ -1920,8 +2227,11 @@ static int anx7625_bridge_atomic_check(struct drm_bridge *bridge,
 	struct device *dev = &ctx->client->dev;
 
 	dev_dbg(dev, "drm bridge atomic check\n");
-	return anx7625_bridge_mode_fixup(bridge, &crtc_state->mode,
-					 &crtc_state->adjusted_mode);
+
+	anx7625_bridge_mode_fixup(bridge, &crtc_state->mode,
+				  &crtc_state->adjusted_mode);
+
+	return anx7625_connector_atomic_check(ctx, conn_state);
 }
 
 static void anx7625_bridge_atomic_enable(struct drm_bridge *bridge,
@@ -2189,6 +2499,15 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	anx7625_init_gpio(platform);
 
 	mutex_init(&platform->lock);
+	mutex_init(&platform->hdcp_wq_lock);
+
+	INIT_DELAYED_WORK(&platform->hdcp_work, hdcp_check_work_func);
+	platform->hdcp_workqueue = create_workqueue("hdcp workqueue");
+	if (!platform->hdcp_workqueue) {
+		dev_err(dev, "fail to create work queue\n");
+		ret = -ENOMEM;
+		goto free_platform;
+	}
 
 	platform->pdata.intp_irq = client->irq;
 	if (platform->pdata.intp_irq) {
@@ -2198,7 +2517,7 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 		if (!platform->workqueue) {
 			DRM_DEV_ERROR(dev, "fail to create work queue\n");
 			ret = -ENOMEM;
-			goto free_platform;
+			goto free_hdcp_wq;
 		}
 
 		ret = devm_request_threaded_irq(dev, platform->pdata.intp_irq,
@@ -2268,6 +2587,10 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	if (platform->workqueue)
 		destroy_workqueue(platform->workqueue);
 
+free_hdcp_wq:
+	if (platform->hdcp_workqueue)
+		destroy_workqueue(platform->hdcp_workqueue);
+
 free_platform:
 	kfree(platform);
 
@@ -2283,6 +2606,12 @@ static int anx7625_i2c_remove(struct i2c_client *client)
 	if (platform->pdata.intp_irq)
 		destroy_workqueue(platform->workqueue);
 
+	if (platform->hdcp_workqueue) {
+		cancel_delayed_work(&platform->hdcp_work);
+		flush_workqueue(platform->workqueue);
+		destroy_workqueue(platform->workqueue);
+	}
+
 	if (!platform->pdata.low_power_mode)
 		pm_runtime_put_sync_suspend(&client->dev);
 

drivers/gpu/drm/bridge/analogix/anx7625.h

@@ -59,10 +59,23 @@
 
 /***************************************************************/
 /* Register definition of device address 0x70 */
-#define  I2C_ADDR_70_DPTX              0x70
-
-#define SP_TX_LINK_BW_SET_REG 0xA0
-#define SP_TX_LANE_COUNT_SET_REG 0xA1
+#define TX_HDCP_CTRL0			0x01
+#define STORE_AN			BIT(7)
+#define RX_REPEATER			BIT(6)
+#define RE_AUTHEN			BIT(5)
+#define SW_AUTH_OK			BIT(4)
+#define HARD_AUTH_EN			BIT(3)
+#define ENC_EN				BIT(2)
+#define BKSV_SRM_PASS			BIT(1)
+#define KSVLIST_VLD			BIT(0)
+
+#define SP_TX_WAIT_R0_TIME		0x40
+#define SP_TX_WAIT_KSVR_TIME		0x42
+#define SP_TX_SYS_CTRL1_REG		0x80
+#define HDCP2TX_FW_EN			BIT(4)
+
+#define SP_TX_LINK_BW_SET_REG		0xA0
+#define SP_TX_LANE_COUNT_SET_REG	0xA1
 
 #define M_VID_0 0xC0
 #define M_VID_1 0xC1
@@ -71,6 +84,12 @@
 #define N_VID_1 0xC4
 #define N_VID_2 0xC5
 
+#define KEY_START_ADDR			0x9000
+#define KEY_RESERVED			416
+
+#define HDCP14KEY_START_ADDR		(KEY_START_ADDR + KEY_RESERVED)
+#define HDCP14KEY_SIZE			624
+
 /***************************************************************/
 /* Register definition of device address 0x72 */
 #define AUX_RST	0x04
@@ -155,9 +174,43 @@
 
 #define  I2C_ADDR_7E_FLASH_CONTROLLER  0x7E
 
+#define R_BOOT_RETRY		0x00
+#define R_RAM_ADDR_H		0x01
+#define R_RAM_ADDR_L		0x02
+#define R_RAM_LEN_H		0x03
+#define R_RAM_LEN_L		0x04
 #define FLASH_LOAD_STA          0x05
 #define FLASH_LOAD_STA_CHK	BIT(7)
 
+#define R_RAM_CTRL              0x05
+/* bit positions */
+#define FLASH_DONE              BIT(7)
+#define BOOT_LOAD_DONE          BIT(6)
+#define CRC_OK                  BIT(5)
+#define LOAD_DONE               BIT(4)
+#define O_RW_DONE               BIT(3)
+#define FUSE_BUSY               BIT(2)
+#define DECRYPT_EN              BIT(1)
+#define LOAD_START              BIT(0)
+
+#define FLASH_ADDR_HIGH         0x0F
+#define FLASH_ADDR_LOW          0x10
+#define FLASH_LEN_HIGH          0x31
+#define FLASH_LEN_LOW           0x32
+#define R_FLASH_RW_CTRL         0x33
+/* bit positions */
+#define READ_DELAY_SELECT       BIT(7)
+#define GENERAL_INSTRUCTION_EN  BIT(6)
+#define FLASH_ERASE_EN          BIT(5)
+#define RDID_READ_EN            BIT(4)
+#define REMS_READ_EN            BIT(3)
+#define WRITE_STATUS_EN         BIT(2)
+#define FLASH_READ              BIT(1)
+#define FLASH_WRITE             BIT(0)
+
+#define FLASH_BUF_BASE_ADDR     0x60
+#define FLASH_BUF_LEN           0x20
+
 #define  XTAL_FRQ_SEL    0x3F
 /* bit field positions */
 #define  XTAL_FRQ_SEL_POS    5
@@ -184,10 +237,15 @@
 #define AP_AUX_CTRL_ADDRONLY 0x20
 
 #define AP_AUX_BUFF_START 0x15
-#define PIXEL_CLOCK_L 0x25
-#define PIXEL_CLOCK_H 0x26
+#define PIXEL_CLOCK_L	0x25
+#define PIXEL_CLOCK_H	0x26
+
+#define AP_AUX_COMMAND	0x27  /* com+len */
+#define LENGTH_SHIFT	4
+#define DPCD_READ	0x09
+#define DPCD_WRITE	0x08
+#define DPCD_CMD(len, cmd)	((((len) - 1) << LENGTH_SHIFT) | (cmd))
 
-#define AP_AUX_COMMAND 0x27  /* com+len */
 /* Bit 0&1: 3D video structure */
 /* 0x01: frame packing,  0x02:Line alternative, 0x03:Side-by-side(full) */
 #define AP_AV_STATUS 0x28
@@ -392,16 +450,23 @@ struct anx7625_data {
 	struct platform_device *audio_pdev;
 	int hpd_status;
 	int hpd_high_cnt;
+	int dp_en;
+	int hdcp_cp;
 	/* Lock for work queue */
 	struct mutex lock;
 	struct i2c_client *client;
 	struct anx7625_i2c_client i2c;
 	struct i2c_client *last_client;
+	struct timer_list hdcp_timer;
 	struct s_edid_data slimport_edid_p;
 	struct device *codec_dev;
 	hdmi_codec_plugged_cb plugged_cb;
 	struct work_struct work;
 	struct workqueue_struct *workqueue;
+	struct delayed_work hdcp_work;
+	struct workqueue_struct *hdcp_workqueue;
+	/* Lock for hdcp work queue */
+	struct mutex hdcp_wq_lock;
 	char edid_block;
 	struct display_timing dt;
 	u8 display_timing_valid;