From a52d69153e59302c6e58c099fd96601a8c493272 Mon Sep 17 00:00:00 2001
From: Elaine Zhang <zhangqing@rock-chips.com>
Date: Wed, 5 Jun 2024 11:02:44 +0800
Subject: [PATCH 1/7] arm64: dts: rockchip: rk3576: set aclk_php to 250M by
 default

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Change-Id: I5c0277bbc2f7583df5a93ec72d87b7c103ade20e
---
 arch/arm64/boot/dts/rockchip/rk3576.dtsi | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3576.dtsi b/arch/arm64/boot/dts/rockchip/rk3576.dtsi
index 4ed99a665cf0..cf5ba9547c2f 100644
--- a/arch/arm64/boot/dts/rockchip/rk3576.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3576.dtsi
@@ -1781,7 +1781,8 @@
 			<&cru CLK_UART_FRAC_1>, <&cru CLK_UART_FRAC_2>,
 			<&cru CLK_AUDIO_FRAC_0>, <&cru CLK_AUDIO_FRAC_1>,
 			<&cru CLK_CPLL_DIV2>, <&cru CLK_CPLL_DIV4>,
-			<&cru CLK_CPLL_DIV10>, <&cru FCLK_DDR_CM0_CORE>;
+			<&cru CLK_CPLL_DIV10>, <&cru FCLK_DDR_CM0_CORE>,
+			<&cru ACLK_PHP_ROOT>;
 		assigned-clock-parents = <&cru PLL_AUPLL>;
 		assigned-clock-rates =
 			<0>,
@@ -1790,7 +1791,8 @@
 			<96000000>, <128000000>,
 			<45158400>, <49152000>,
 			<500000000>, <250000000>,
-			<100000000>, <500000000>;
+			<100000000>, <500000000>,
+			<250000000>;
 	};
 
 	i2c0: i2c@27300000 {

From dcaa39ee96cb26b4a72327b0595eb0db8d0b169e Mon Sep 17 00:00:00 2001
From: Chandler Chen <chandler.chen@rock-chips.com>
Date: Thu, 30 May 2024 17:13:27 +0800
Subject: [PATCH 2/7] video: rockchip: mpp: fix unused buffer move fail issue

When dmabuf cache disable:
1.move most recently used link node to link tail,
instead of calculate oldest ktime when buffer full.
2.For those buffer import by ioctl MPP_CMD_TRANS_FD_TO_IOVA,
move to static_list instead of used_list,
and don't increase extra kref,
so that it will release when user space call
ioctl MPP_CMD_RELEASE_FD.

Change-Id: I38f209c24f6cc7e831338e2417050e3ef39226f9
Signed-off-by: Chandler Chen <chandler.chen@rock-chips.com>
---
 drivers/video/rockchip/mpp/mpp_common.c |  4 +-
 drivers/video/rockchip/mpp/mpp_iommu.c  | 52 ++++++++++++++++++-------
 drivers/video/rockchip/mpp/mpp_iommu.h  |  8 +++-
 3 files changed, 46 insertions(+), 18 deletions(-)

diff --git a/drivers/video/rockchip/mpp/mpp_common.c b/drivers/video/rockchip/mpp/mpp_common.c
index bfe7d9715088..0e7261c8dd50 100644
--- a/drivers/video/rockchip/mpp/mpp_common.c
+++ b/drivers/video/rockchip/mpp/mpp_common.c
@@ -1363,7 +1363,7 @@ static int mpp_process_request(struct mpp_session *session,
 
 			mpp_iommu_down_read(mpp->iommu_info);
 			buffer = mpp_dma_import_fd(mpp->iommu_info,
-						   session->dma, fd);
+						   session->dma, fd, 1);
 			mpp_iommu_up_read(mpp->iommu_info);
 			if (IS_ERR_OR_NULL(buffer)) {
 				mpp_err("can not import fd %d\n", fd);
@@ -1770,7 +1770,7 @@ mpp_task_attach_fd(struct mpp_task *task, int fd)
 		mem_region->is_dup = true;
 	} else {
 		mpp_iommu_down_read(mpp->iommu_info);
-		buffer = mpp_dma_import_fd(mpp->iommu_info, dma, fd);
+		buffer = mpp_dma_import_fd(mpp->iommu_info, dma, fd, 0);
 		mpp_iommu_up_read(mpp->iommu_info);
 		if (IS_ERR(buffer)) {
 			mpp_err("can't import dma-buf %d\n", fd);
diff --git a/drivers/video/rockchip/mpp/mpp_iommu.c b/drivers/video/rockchip/mpp/mpp_iommu.c
index ee1bea35248c..9a3589314e0e 100644
--- a/drivers/video/rockchip/mpp/mpp_iommu.c
+++ b/drivers/video/rockchip/mpp/mpp_iommu.c
@@ -33,6 +33,7 @@ mpp_dma_find_buffer_fd(struct mpp_dma_session *dma, int fd)
 	struct dma_buf *dmabuf;
 	struct mpp_dma_buffer *out = NULL;
 	struct mpp_dma_buffer *buffer = NULL, *n;
+	int find = 0;
 
 	dmabuf = dma_buf_get(fd);
 	if (IS_ERR(dmabuf))
@@ -47,9 +48,26 @@ mpp_dma_find_buffer_fd(struct mpp_dma_session *dma, int fd)
 		 */
 		if (buffer->dmabuf == dmabuf) {
 			out = buffer;
+			find = 1;
+			list_move_tail(&buffer->link, &buffer->dma->used_list);
 			break;
 		}
 	}
+	if (!find) {
+		list_for_each_entry_safe(buffer, n,
+					&dma->static_list, link) {
+			/*
+			 * fd may dup several and point the same dambuf.
+			 * thus, here should be distinguish with the dmabuf.
+			 */
+			if (buffer->dmabuf == dmabuf) {
+				out = buffer;
+				list_move_tail(&buffer->link, &buffer->dma->static_list);
+				break;
+			}
+		}
+	}
+
 	mutex_unlock(&dma->list_mutex);
 	dma_buf_put(dmabuf);
 
@@ -84,22 +102,20 @@ static int
 mpp_dma_remove_extra_buffer(struct mpp_dma_session *dma)
 {
 	struct mpp_dma_buffer *n;
-	struct mpp_dma_buffer *oldest = NULL, *buffer = NULL;
-	ktime_t oldest_time = ktime_set(0, 0);
+	struct mpp_dma_buffer *removable = NULL, *buffer = NULL;
 
 	if (dma->buffer_count > dma->max_buffers) {
 		mutex_lock(&dma->list_mutex);
 		list_for_each_entry_safe(buffer, n,
 					 &dma->used_list,
 					 link) {
-			if (ktime_to_ns(oldest_time) == 0 ||
-			    ktime_after(oldest_time, buffer->last_used)) {
-				oldest_time = buffer->last_used;
-				oldest = buffer;
+			if (kref_read(&buffer->ref) == 1) {
+				removable = buffer;
+				break;
 			}
 		}
-		if (oldest && kref_read(&oldest->ref) == 1)
-			kref_put(&oldest->ref, mpp_dma_release_buffer);
+		if (removable)
+			kref_put(&removable->ref, mpp_dma_release_buffer);
 		mutex_unlock(&dma->list_mutex);
 	}
 
@@ -176,7 +192,7 @@ int mpp_dma_free(struct mpp_dma_buffer *buffer)
 
 struct mpp_dma_buffer *mpp_dma_import_fd(struct mpp_iommu_info *iommu_info,
 					 struct mpp_dma_session *dma,
-					 int fd)
+					 int fd, int static_use)
 {
 	int ret = 0;
 	struct sg_table *sgt;
@@ -196,10 +212,8 @@ struct mpp_dma_buffer *mpp_dma_import_fd(struct mpp_iommu_info *iommu_info,
 	/* Check whether in dma session */
 	buffer = mpp_dma_find_buffer_fd(dma, fd);
 	if (!IS_ERR_OR_NULL(buffer)) {
-		if (kref_get_unless_zero(&buffer->ref)) {
-			buffer->last_used = ktime_get();
+		if (kref_get_unless_zero(&buffer->ref))
 			return buffer;
-		}
 		dev_dbg(dma->dev, "missing the fd %d\n", fd);
 	}
 
@@ -224,7 +238,6 @@ struct mpp_dma_buffer *mpp_dma_import_fd(struct mpp_iommu_info *iommu_info,
 
 	buffer->dmabuf = dmabuf;
 	buffer->dir = DMA_BIDIRECTIONAL;
-	buffer->last_used = ktime_get();
 
 	attach = dma_buf_attach(buffer->dmabuf, dma->dev);
 	if (IS_ERR(attach)) {
@@ -247,13 +260,16 @@ struct mpp_dma_buffer *mpp_dma_import_fd(struct mpp_iommu_info *iommu_info,
 
 	kref_init(&buffer->ref);
 
-	if (!IS_ENABLED(CONFIG_DMABUF_CACHE))
+	if (!static_use && !IS_ENABLED(CONFIG_DMABUF_CACHE))
 		/* Increase the reference for used outside the buffer pool */
 		kref_get(&buffer->ref);
 
 	mutex_lock(&dma->list_mutex);
 	dma->buffer_count++;
-	list_add_tail(&buffer->link, &dma->used_list);
+	if (static_use)
+		list_add_tail(&buffer->link, &dma->static_list);
+	else
+		list_add_tail(&buffer->link, &dma->used_list);
 	mutex_unlock(&dma->list_mutex);
 
 	return buffer;
@@ -333,6 +349,11 @@ int mpp_dma_session_destroy(struct mpp_dma_session *dma)
 				 link) {
 		kref_put(&buffer->ref, mpp_dma_release_buffer);
 	}
+	list_for_each_entry_safe(buffer, n,
+				 &dma->static_list,
+				 link) {
+		kref_put(&buffer->ref, mpp_dma_release_buffer);
+	}
 	mutex_unlock(&dma->list_mutex);
 
 	kfree(dma);
@@ -354,6 +375,7 @@ mpp_dma_session_create(struct device *dev, u32 max_buffers)
 	mutex_init(&dma->list_mutex);
 	INIT_LIST_HEAD(&dma->unused_list);
 	INIT_LIST_HEAD(&dma->used_list);
+	INIT_LIST_HEAD(&dma->static_list);
 
 	if (max_buffers > MPP_SESSION_MAX_BUFFERS) {
 		mpp_debug(DEBUG_IOCTL, "session_max_buffer %d must less than %d\n",
diff --git a/drivers/video/rockchip/mpp/mpp_iommu.h b/drivers/video/rockchip/mpp/mpp_iommu.h
index fc5d4bd63210..265f276de281 100644
--- a/drivers/video/rockchip/mpp/mpp_iommu.h
+++ b/drivers/video/rockchip/mpp/mpp_iommu.h
@@ -57,6 +57,12 @@ struct mpp_dma_session {
 	/* the buffer used in session */
 	struct list_head unused_list;
 	struct list_head used_list;
+	/*
+	 * For those buffer import by ioctl MPP_CMD_TRANS_FD_TO_IOVA,
+	 * move to static_list instead of used_list and don't increase extra kref,
+	 * so that it will release when user space call ioctl MPP_CMD_RELEASE_FD.
+	 */
+	struct list_head static_list;
 	struct mpp_dma_buffer dma_bufs[MPP_SESSION_MAX_BUFFERS];
 	/* the mutex for the above buffer list */
 	struct mutex list_mutex;
@@ -108,7 +114,7 @@ int mpp_dma_free(struct mpp_dma_buffer *buffer);
 
 struct mpp_dma_buffer *
 mpp_dma_import_fd(struct mpp_iommu_info *iommu_info,
-		  struct mpp_dma_session *dma, int fd);
+		  struct mpp_dma_session *dma, int fd, int static_use);
 int mpp_dma_release(struct mpp_dma_session *dma,
 		    struct mpp_dma_buffer *buffer);
 int mpp_dma_release_fd(struct mpp_dma_session *dma, int fd);

From 9aba6831dd39e5f25c0e9b84c30ff9cad32e1f61 Mon Sep 17 00:00:00 2001
From: Zheng zhiqi <looper.zheng@rock-chips.com>
Date: Thu, 25 Apr 2024 17:45:58 +0800
Subject: [PATCH 3/7] arm64: dts: rockchip: rk3576-vehiclke-evb: use vehicle
 sound

1. open spi1 dev
2. change spi codec to dummy codec
3. remove es8388 sound

This patch keeps the vehicle sound to be "car-rk3308-sound" since the
audio HAL use it fixed.

Change-Id: I6a968e09f548cffa64088bfba0c7c266f3727146
Signed-off-by: Zheng zhiqi <looper.zheng@rock-chips.com>
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
---
 .../boot/dts/rockchip/rk3576-vehicle-evb.dtsi | 115 ++++--------------
 1 file changed, 23 insertions(+), 92 deletions(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3576-vehicle-evb.dtsi b/arch/arm64/boot/dts/rockchip/rk3576-vehicle-evb.dtsi
index 1f396ccb7d00..8b1d556eb4a0 100644
--- a/arch/arm64/boot/dts/rockchip/rk3576-vehicle-evb.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3576-vehicle-evb.dtsi
@@ -8,61 +8,6 @@
 #include "rk3576-rk806.dtsi"
 
 / {
-	es8388_sound: es8388-sound {
-		status = "disabled";
-		compatible = "rockchip,multicodecs-card";
-		rockchip,card-name = "rockchip-es8388";
-		hp-det-gpio = <&gpio0 RK_PD3 GPIO_ACTIVE_LOW>;
-		io-channels = <&saradc 3>;
-		io-channel-names = "adc-detect";
-		keyup-threshold-microvolt = <1800000>;
-		poll-interval = <100>;
-		spk-con-gpio = <&gpio2 RK_PB1 GPIO_ACTIVE_HIGH>;
-		hp-con-gpio = <&gpio3 RK_PD6 GPIO_ACTIVE_HIGH>;
-		rockchip,format = "i2s";
-		rockchip,mclk-fs = <256>;
-		rockchip,cpu = <&sai1>;
-		rockchip,codec = <&es8388>;
-		rockchip,audio-routing =
-			"Headphone", "LOUT1",
-			"Headphone", "ROUT1",
-			"Speaker", "LOUT2",
-			"Speaker", "ROUT2",
-			"Headphone", "Headphone Power",
-			"Headphone", "Headphone Power",
-			"Speaker", "Speaker Power",
-			"Speaker", "Speaker Power",
-			"LINPUT1", "Main Mic",
-			"LINPUT2", "Main Mic",
-			"RINPUT1", "Headset Mic",
-			"RINPUT2", "Headset Mic";
-		pinctrl-names = "default";
-		pinctrl-0 = <&hp_det>;
-		play-pause-key {
-			label = "playpause";
-			linux,code = <KEY_PLAYPAUSE>;
-			press-threshold-microvolt = <2000>;
-		};
-	};
-
-	pdmics: dummy-codec {
-		status = "disabled";
-		compatible = "rockchip,dummy-codec";
-		#sound-dai-cells = <0>;
-	};
-
-	pdm_mic_array: pdm-mic-array {
-		status = "disabled";
-		compatible = "simple-audio-card";
-		simple-audio-card,name = "rockchip,pdm-mic-array";
-		simple-audio-card,cpu {
-			sound-dai = <&pdm1>;
-		};
-		simple-audio-card,codec {
-			sound-dai = <&pdmics>;
-		};
-	};
-
 	vcc5v0_buck: vcc5v0-buck {
 		compatible = "regulator-fixed";
 		regulator-name = "vcc5v0_buck";
@@ -142,8 +87,6 @@
 		vin-supply = <&vcc_3v3_s0>;
 	};
 
-
-
 	vcc5v0_host_usb30: vcc5v0-host-usb30 {
 		compatible = "regulator-fixed";
 		regulator-name = "vcc5v0_host_usb30";
@@ -176,7 +119,13 @@
 		vin-supply = <&vcc5v0_buck>;
 	};
 
-	car_rk3308_sound: car-rk3308-sound {
+	dummy_codec: dummy-codec {
+		status = "okay";
+		compatible = "rockchip,dummy-codec";
+		#sound-dai-cells = <0>;
+	};
+
+	vehicle_adsp_sound: vehicle-adsp-sound {
 		status = "okay";
 		compatible = "simple-audio-card";
 		simple-audio-card,name = "rockchip,car-rk3308-sound";
@@ -190,7 +139,7 @@
 			dai-tdm-slot-width = <32>;
 		};
 		codec_master: simple-audio-card,codec {
-			sound-dai = <&spi_codec>;
+			sound-dai = <&dummy_codec>;
 		};
 	};
 };
@@ -223,7 +172,6 @@
 	status = "okay";
 };
 
-
 &gmac0 {
 	/* Use rgmii-rxid mode to disable rx delay inside Soc */
 	phy-mode = "rgmii-rxid";
@@ -325,7 +273,6 @@
 	pinctrl-names = "default";
 	pinctrl-0 = <&i2c7m1_xfer>;
 
-
 	icm42607_acc: icm_acc@68 {
 		status = "okay";
 		compatible = "icm42607_acc";
@@ -393,12 +340,6 @@
 		};
 	};
 
-	headphone {
-		hp_det: hp-det {
-			rockchip,pins = <0 RK_PD3 RK_FUNC_GPIO &pcfg_pull_up>;
-		};
-	};
-
 	s35390a {
 		s35390a_int: s35390a-int {
 			rockchip,pins = <0 RK_PA0 RK_FUNC_GPIO &pcfg_pull_up>;
@@ -435,12 +376,6 @@
 			rockchip,pins = <1 RK_PC6 RK_FUNC_GPIO &pcfg_pull_up>;
 		};
 	};
-
-	rk3308 {
-		rk3308_reset: rk3308-reset {
-			rockchip,pins = <2 RK_PC1 RK_FUNC_GPIO &pcfg_pull_none>;
-		};
-	};
 };
 
 &route_hdmi {
@@ -452,15 +387,15 @@
 	status = "okay";
 	pinctrl-names = "default";
 	pinctrl-0 = <&sai1m0_lrck
-			&sai1m0_sclk
-			&sai1m0_sdi0
-			&sai1m0_sdi1
-			&sai1m0_sdi2
-			&sai1m0_sdi3
-			&sai1m0_sdo0
-			&sai1m0_sdo1
-			&sai1m0_sdo2
-			&sai1m0_sdo3>;
+		     &sai1m0_sclk
+		     &sai1m0_sdi0
+		     &sai1m0_sdi1
+		     &sai1m0_sdi2
+		     &sai1m0_sdi3
+		     &sai1m0_sdo0
+		     &sai1m0_sdo1
+		     &sai1m0_sdo2
+		     &sai1m0_sdo3>;
 };
 
 &sdmmc {
@@ -469,18 +404,14 @@
 
 &spi1 {
 	status = "okay";
-	pinctrl-names = "default";
+	max-freq = <50000000>; /* spi internal clk, don't modify */
+	pinctrl-names = "default", "high_speed";
 	pinctrl-0 = <&spi1m1_csn0 &spi1m1_pins>;
-
-	spi_codec: spi-codec@1 {
-		compatible ="rockchip,spi-codec";
-		reg = <1>;
+	spi_dev@0 {
+		compatible = "rockchip,spidev";
+		reg = <0>;
+		spi-max-frequency = <50000000>;
 		spi-lsb-first;
-		spi-max-frequency = <5000000>;
-		#sound-dai-cells = <0>;
-		pinctrl-names = "default";
-		pinctrl-0 = <&rk3308_reset>;
-		status = "okay";
 	};
 };
 

From f48e683a54336609cc6bb2ac864991a249a04f14 Mon Sep 17 00:00:00 2001
From: Sugar Zhang <sugar.zhang@rock-chips.com>
Date: Tue, 4 Jun 2024 20:26:00 +0800
Subject: [PATCH 4/7] dmaengine: pl330: Workaround for interleaved for GKI

Once upstream is merged, this patch can be dropped.
also for line CONFIG_NO_GKI

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Change-Id: I2b0fc69aa6673e46dcd65e0369ab4353e7c4f9fc
---
 drivers/dma/pl330.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 178f90623fbe..25db2656ebdd 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2943,6 +2943,8 @@ static struct dma_async_tx_descriptor *pl330_prep_interleaved_dma(
 
 #ifdef CONFIG_NO_GKI
 	nump = xt->nump;
+#else
+	nump = xt->sgl[1].size;
 #endif
 	numf = xt->numf;
 	size = xt->sgl[0].size;

From 56d2082cec84e411066f283c26e9516fd222b4cf Mon Sep 17 00:00:00 2001
From: Sugar Zhang <sugar.zhang@rock-chips.com>
Date: Tue, 4 Jun 2024 20:38:25 +0800
Subject: [PATCH 5/7] ASoC: rockchip: multi-dais: Workaround for interleaved
 for GKI

Once upstream is merged, this patch can be dropped.
also for line CONFIG_NO_GKI

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Change-Id: I83f5a08e93010741c26ec044f70b388a50e6c7a9
---
 sound/soc/rockchip/rockchip_multi_dais_pcm.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sound/soc/rockchip/rockchip_multi_dais_pcm.c b/sound/soc/rockchip/rockchip_multi_dais_pcm.c
index d0173bfd54aa..0feab27b477d 100644
--- a/sound/soc/rockchip/rockchip_multi_dais_pcm.c
+++ b/sound/soc/rockchip/rockchip_multi_dais_pcm.c
@@ -196,6 +196,8 @@ static int dmaengine_config_interleaved(struct snd_pcm_substream *substream,
 
 #ifdef CONFIG_NO_GKI
 	xt->nump = nump;
+#else
+	xt->sgl[1].size = nump;
 #endif
 	xt->numf = numf;
 
@@ -692,8 +694,14 @@ static int dmaengine_mpcm_open(struct snd_soc_component *component,
 	if (!prtd)
 		return -ENOMEM;
 
+#ifdef CONFIG_NO_GKI
 	prtd->xt = kzalloc(sizeof(struct dma_interleaved_template) +
 			   sizeof(struct data_chunk), GFP_KERNEL);
+#else
+	prtd->xt = kzalloc(sizeof(struct dma_interleaved_template) +
+			   sizeof(struct data_chunk) * 2, GFP_KERNEL);
+
+#endif
 	if (!prtd->xt) {
 		kfree(prtd);
 		return -ENOMEM;

From 675c5920332125afb122feb436ba0934a8ee69e7 Mon Sep 17 00:00:00 2001
From: Zhang Yubing <yubing.zhang@rock-chips.com>
Date: Tue, 30 Apr 2024 09:48:50 +0800
Subject: [PATCH 6/7] arm64: configs: rockchip_linux_defconfig: enable
 CONFIG_ROCKCHIP_DP_MST_AUX_CLIENT

Change-Id: If1070103e6b0468456d8c480a73c0315095a3b59
Signed-off-by: Zhang Yubing <yubing.zhang@rock-chips.com>
---
 arch/arm64/configs/rockchip_linux_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/rockchip_linux_defconfig b/arch/arm64/configs/rockchip_linux_defconfig
index 67f36e8b9884..b5c3d2e42d86 100644
--- a/arch/arm64/configs/rockchip_linux_defconfig
+++ b/arch/arm64/configs/rockchip_linux_defconfig
@@ -355,6 +355,7 @@ CONFIG_ROCKCHIP_INNO_HDMI=y
 CONFIG_ROCKCHIP_LVDS=y
 CONFIG_ROCKCHIP_RGB=y
 CONFIG_ROCKCHIP_DW_HDCP2=y
+CONFIG_ROCKCHIP_DP_MST_AUX_CLIENT=y
 CONFIG_DRM_PANEL_SIMPLE=y
 CONFIG_DRM_DISPLAY_CONNECTOR=y
 CONFIG_DRM_SII902X=y

From 33c51f42c402b76fd06e46d1ae73f8b7080b6f43 Mon Sep 17 00:00:00 2001
From: Zhang Yubing <yubing.zhang@rock-chips.com>
Date: Tue, 30 Apr 2024 09:08:42 +0800
Subject: [PATCH 7/7] drm/rockchip: dp-mst-sim: support mst device without aux
 client

some MST-capable device may not support Messaging AUX Client.
In this case, sideband MSG can't be transferred between DPTX
and the MST device. A solution is to simulate a Messaging AUX
client in MST device side to deal with sideband MSG.

Change-Id: I7c68f6d0bd88501c4e19097e3a1f9a9fabcf2698
Signed-off-by: Zhang Yubing <yubing.zhang@rock-chips.com>
---
 drivers/gpu/drm/rockchip/Kconfig              |   6 +
 drivers/gpu/drm/rockchip/Makefile             |   3 +
 .../drm/rockchip/rockchip_dp_mst_aux_client.c | 326 ++++++
 .../drm/rockchip/rockchip_dp_mst_aux_client.h |  41 +
 .../rockchip_dp_mst_aux_client_helper.c       | 938 ++++++++++++++++++
 .../rockchip_dp_mst_aux_client_helper.h       | 117 +++
 6 files changed, 1431 insertions(+)
 create mode 100644 drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client.c
 create mode 100644 drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client.h
 create mode 100644 drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client_helper.c
 create mode 100644 drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client_helper.h

diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig
index 686d52e368a0..3c39856f234a 100644
--- a/drivers/gpu/drm/rockchip/Kconfig
+++ b/drivers/gpu/drm/rockchip/Kconfig
@@ -173,6 +173,12 @@ config ROCKCHIP_DW_HDCP2
 	  Choose this option to enable support for the Synopsys
 	  Designware HDCP2 Controller.
 
+config ROCKCHIP_DP_MST_AUX_CLIENT
+	tristate "dp mst aux client"
+	select DRM_DISPLAY_DP_HELPER
+	help
+	  This selects support dp mst device that not support aux client.
+
 source "drivers/gpu/drm/rockchip/rk618/Kconfig"
 
 endif
diff --git a/drivers/gpu/drm/rockchip/Makefile b/drivers/gpu/drm/rockchip/Makefile
index 3809b69975bc..2bf6b589b957 100644
--- a/drivers/gpu/drm/rockchip/Makefile
+++ b/drivers/gpu/drm/rockchip/Makefile
@@ -32,3 +32,6 @@ obj-$(CONFIG_ROCKCHIP_PANEL_NOTIFIER) += rockchip_panel_notifier.o
 obj-$(CONFIG_ROCKCHIP_DW_HDCP2) += dw_hdcp2.o
 obj-$(CONFIG_DRM_ROCKCHIP) += rockchipdrm.o
 obj-$(CONFIG_DRM_ROCKCHIP_RK618) += rk618/
+
+rockchip_aux_client-y := rockchip_dp_mst_aux_client.o rockchip_dp_mst_aux_client_helper.o
+obj-$(CONFIG_ROCKCHIP_DP_MST_AUX_CLIENT) += rockchip_aux_client.o
diff --git a/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client.c b/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client.c
new file mode 100644
index 000000000000..a763cfa8c1d8
--- /dev/null
+++ b/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Rockchip DP MST simulation axu client
+ *
+ * Copyright (c) 2024 Rockchip Electronics Co. Ltd.
+ *
+ * Author: Zhang Yubing <yubing.zhang@rock-chips.com>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_modes.h>
+#include <drm/display/drm_dp_helper.h>
+#include <video/display_timing.h>
+#include <video/of_display_timing.h>
+#include <video/videomode.h>
+
+#include "rockchip_dp_mst_aux_client_helper.h"
+#include "rockchip_dp_mst_aux_client.h"
+
+static DEFINE_MUTEX(aux_client_lock);
+static LIST_HEAD(aux_client_list);
+
+#define to_rockchip_dp_aux_client(x) container_of((x), struct rockchip_dp_aux_client, bridge)
+
+static const struct rockchip_dp_mst_sim_port output_port = {
+	false, false, true, 3, false, 0x12,
+	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+	0, 0, 2520, 2520, NULL, 0
+};
+
+struct rockchip_dp_aux_client *rockchip_dp_get_aux_client(struct device_node *node,
+							  char *handle_name)
+{
+	struct rockchip_dp_aux_client *aux_client;
+	struct device_node *dev_node;
+
+	dev_node = of_parse_phandle(node, handle_name, 0);
+	if (!dev_node)
+		return NULL;
+
+	mutex_lock(&aux_client_lock);
+	list_for_each_entry(aux_client, &aux_client_list, head)
+		if (aux_client->dev->of_node == dev_node)
+			goto out;
+	aux_client = ERR_PTR(-EPROBE_DEFER);
+
+out:
+	mutex_unlock(&aux_client_lock);
+	of_node_put(dev_node);
+
+	return aux_client;
+}
+EXPORT_SYMBOL(rockchip_dp_get_aux_client);
+
+static void rockchip_register_dp_aux_client(struct rockchip_dp_aux_client *aux_client)
+{
+
+	mutex_lock(&aux_client_lock);
+	list_add(&aux_client->head, &aux_client_list);
+	mutex_unlock(&aux_client_lock);
+}
+
+static void rockchip_unregister_dp_aux_client(struct rockchip_dp_aux_client *aux_client)
+{
+
+	mutex_lock(&aux_client_lock);
+	list_del(&aux_client->head);
+	mutex_unlock(&aux_client_lock);
+}
+
+static int rockchip_dp_aux_client_register_hpd_irq(struct rockchip_dp_aux_client *aux_client,
+	void (*hpd_irq_cb)(void *), void *dev)
+{
+	aux_client->host_dev = dev;
+	aux_client->hpd_irq_cb = hpd_irq_cb;
+
+	return 0;
+}
+
+static int rockchip_dp_aux_client_register_transfer(struct rockchip_dp_aux_client *aux_client,
+	ssize_t (*transfer_cb)(struct drm_dp_aux *, struct drm_dp_aux_msg *))
+{
+	aux_client->transfer_cb = transfer_cb;
+
+	return 0;
+}
+
+static ssize_t rockchip_dp_sim_transfer(struct rockchip_dp_aux_client *aux_client,
+	struct drm_dp_aux *drm_aux,
+	struct drm_dp_aux_msg *msg)
+{
+	int ret;
+
+	ret = rockchip_dp_mst_sim_transfer(aux_client->mst_ctx, msg);
+	if (ret < 0) {
+		if (aux_client->transfer_cb)
+			ret = aux_client->transfer_cb(drm_aux, msg);
+		else
+			ret = -EIO;
+	} else {
+		ret = msg->size;
+	}
+
+	return ret;
+}
+
+static void rockchip_dp_sim_host_hpd_irq(void *host_dev)
+{
+	struct rockchip_dp_aux_client *aux_client = host_dev;
+
+	if (aux_client->hpd_irq_cb)
+		aux_client->hpd_irq_cb(aux_client->host_dev);
+}
+
+static void rockchip_dp_sim_update_dtd(struct edid *edid,
+				       struct drm_display_mode *mode)
+{
+	struct detailed_timing *dtd = &edid->detailed_timings[0];
+	struct detailed_pixel_timing *pd = &dtd->data.pixel_data;
+	u32 h_blank = mode->htotal - mode->hdisplay;
+	u32 v_blank = mode->vtotal - mode->vdisplay;
+	u32 h_img = 0, v_img = 0;
+
+	dtd->pixel_clock = cpu_to_le16(mode->clock / 10);
+
+	pd->hactive_lo = mode->hdisplay & 0xFF;
+	pd->hblank_lo = h_blank & 0xFF;
+	pd->hactive_hblank_hi = ((h_blank >> 8) & 0xF) |
+			((mode->hdisplay >> 8) & 0xF) << 4;
+
+	pd->vactive_lo = mode->vdisplay & 0xFF;
+	pd->vblank_lo = v_blank & 0xFF;
+	pd->vactive_vblank_hi = ((v_blank >> 8) & 0xF) |
+			((mode->vdisplay >> 8) & 0xF) << 4;
+
+	pd->hsync_offset_lo =
+		(mode->hsync_start - mode->hdisplay) & 0xFF;
+	pd->hsync_pulse_width_lo =
+		(mode->hsync_end - mode->hsync_start) & 0xFF;
+	pd->vsync_offset_pulse_width_lo =
+		(((mode->vsync_start - mode->vdisplay) & 0xF) << 4) |
+		((mode->vsync_end - mode->vsync_start) & 0xF);
+
+	pd->hsync_vsync_offset_pulse_width_hi =
+		((((mode->hsync_start - mode->hdisplay) >> 8) & 0x3) << 6) |
+		((((mode->hsync_end - mode->hsync_start) >> 8) & 0x3) << 4) |
+		((((mode->vsync_start - mode->vdisplay) >> 4) & 0x3) << 2) |
+		((((mode->vsync_end - mode->vsync_start) >> 4) & 0x3) << 0);
+
+	pd->width_mm_lo = h_img & 0xFF;
+	pd->height_mm_lo = v_img & 0xFF;
+	pd->width_height_mm_hi = (((h_img >> 8) & 0xF) << 4) |
+		((v_img >> 8) & 0xF);
+
+	pd->hborder = 0;
+	pd->vborder = 0;
+	pd->misc = 0;
+}
+
+static void rockchip_dp_sim_update_checksum(struct edid *edid)
+{
+	u8 *data = (u8 *)edid;
+	u32 i, sum = 0;
+
+	for (i = 0; i < EDID_LENGTH - 1; i++)
+		sum += data[i];
+
+	edid->checksum = 0x100 - (sum & 0xFF);
+}
+
+static int rockchip_dp_aux_client_parse(struct rockchip_dp_aux_client *aux_client)
+{
+	struct device_node *of_node = aux_client->dev->of_node;
+	struct device_node *node;
+	struct rockchip_dp_mst_sim_port *ports;
+	struct drm_display_mode mode_buf, *mode = &mode_buf;
+	int rc, port_num, i;
+	struct edid *edid;
+
+	const u8 edid_buf[EDID_LENGTH] = {
+		0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x44, 0x6D,
+		0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x1B, 0x10, 0x01, 0x03,
+		0x80, 0x50, 0x2D, 0x78, 0x0A, 0x0D, 0xC9, 0xA0, 0x57, 0x47,
+		0x98, 0x27, 0x12, 0x48, 0x4C, 0x00, 0x00, 0x00, 0x01, 0x01,
+		0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+		0x01, 0x01, 0x01, 0x01,
+	};
+
+	port_num = of_get_child_count(of_node);
+
+	if (!port_num)
+		return 0;
+
+	if (port_num >= 15)
+		return -EINVAL;
+
+	ports = kcalloc(port_num, sizeof(*ports), GFP_KERNEL);
+	if (!ports)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_child_of_node(of_node, node) {
+		struct display_timing dt;
+		struct videomode vm;
+
+		edid = kzalloc(sizeof(*edid), GFP_KERNEL);
+		if (!edid) {
+			rc = -ENOMEM;
+			goto fail;
+		}
+		memcpy(edid, edid_buf, sizeof(edid_buf));
+
+		if (!of_get_display_timing(node, "display-timings", &dt)) {
+			videomode_from_timing(&dt, &vm);
+			drm_display_mode_from_videomode(&vm, mode);
+			rockchip_dp_sim_update_dtd(edid, mode);
+		}
+
+		rockchip_dp_sim_update_checksum(edid);
+		memcpy(&ports[i], &output_port, sizeof(*ports));
+		ports[i].peer_guid[0] = i;
+		ports[i].edid = (u8 *)edid;
+		ports[i].edid_size = sizeof(*edid);
+		i++;
+	}
+
+	rc = rockchip_dp_mst_sim_update(aux_client->mst_ctx, port_num, ports);
+
+fail:
+	for (i = 0; i < port_num; i++)
+		kfree(ports[i].edid);
+	kfree(ports);
+
+	return rc;
+}
+
+static int rockchip_dp_aux_client_probe(struct platform_device *pdev)
+{
+	struct rockchip_dp_aux_client *aux_client;
+	struct rockchip_dp_mst_sim_cfg cfg;
+	int ret;
+
+	aux_client = devm_kzalloc(&pdev->dev, sizeof(*aux_client), GFP_KERNEL);
+	if (!aux_client)
+		return -ENOMEM;
+
+	aux_client->dev = &pdev->dev;
+	aux_client->register_hpd_irq = rockchip_dp_aux_client_register_hpd_irq;
+	aux_client->register_transfer = rockchip_dp_aux_client_register_transfer;
+	aux_client->transfer = rockchip_dp_sim_transfer;
+
+	memset(&cfg, 0, sizeof(cfg));
+	cfg.host_dev = aux_client;
+	cfg.host_hpd_irq = rockchip_dp_sim_host_hpd_irq;
+	cfg.guid[0] = 0xff;
+
+	ret = rockchip_dp_mst_sim_create(&cfg, &aux_client->mst_ctx);
+	if (ret)
+		return ret;
+
+	ret = rockchip_dp_aux_client_parse(aux_client);
+	if (ret)
+		goto fail;
+
+	platform_set_drvdata(pdev, aux_client);
+
+	rockchip_register_dp_aux_client(aux_client);
+
+	return 0;
+
+fail:
+	rockchip_dp_mst_sim_destroy(aux_client->mst_ctx);
+	return ret;
+}
+
+static int rockchip_dp_aux_client_remove(struct platform_device *pdev)
+{
+	struct rockchip_dp_aux_client *aux_client;
+
+	aux_client = platform_get_drvdata(pdev);
+	if (!aux_client)
+		return 0;
+
+	rockchip_unregister_dp_aux_client(aux_client);
+	rockchip_dp_mst_sim_destroy(aux_client->mst_ctx);
+
+	return 0;
+}
+
+static const struct of_device_id dt_match[] = {
+	{ .compatible = "rockchip,dp-mst-sim" },
+	{},
+};
+
+static struct platform_driver rockchip_dp_aux_client_driver = {
+	.probe = rockchip_dp_aux_client_probe,
+	.remove = rockchip_dp_aux_client_remove,
+	.driver = {
+		.name = "rockchip_dp_aux_client",
+		.of_match_table = dt_match,
+	},
+};
+
+static int __init rockchip_dp_aux_client_register(void)
+{
+	return platform_driver_register(&rockchip_dp_aux_client_driver);
+}
+
+static void __exit rockchip_dp_aux_client_unregister(void)
+{
+	platform_driver_unregister(&rockchip_dp_aux_client_driver);
+}
+
+module_init(rockchip_dp_aux_client_register);
+module_exit(rockchip_dp_aux_client_unregister);
+
+MODULE_AUTHOR("Zhang Yubing <yubing.zhang@rock-chips.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Rockchip DP Simulate Aux Client Driver");
diff --git a/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client.h b/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client.h
new file mode 100644
index 000000000000..857768ada93a
--- /dev/null
+++ b/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2024 Rockchip Electronics Co. Ltd.
+ * Author: Zhang Yubing <yubing.zhang@rock-chips.com>
+ */
+
+#ifndef _ROCKCHIP_DP_MST_AUX_CLIENT_H_
+#define _ROCKCHIP_DP_MST_AUX_CLIENT_H_
+
+#include <linux/types.h>
+#include <drm/display/drm_dp_helper.h>
+
+struct rockchip_dp_aux_client {
+	struct device *dev;
+	struct list_head head;
+	void *mst_ctx;
+	void *host_dev;
+	void (*hpd_irq_cb)(void *host_dev);
+	ssize_t (*transfer_cb)(struct drm_dp_aux *drm_aux,
+			       struct drm_dp_aux_msg *msg);
+	int (*register_hpd_irq)(struct rockchip_dp_aux_client *aux_client,
+				void (*hpd_irq_cb)(void *), void *dev);
+	int (*register_transfer)(struct rockchip_dp_aux_client *aux_client,
+				 ssize_t (*transfer)(struct drm_dp_aux *, struct drm_dp_aux_msg *));
+	ssize_t (*transfer)(struct rockchip_dp_aux_client *aux_client,
+			struct drm_dp_aux *drm_aux,
+			struct drm_dp_aux_msg *msg);
+};
+
+#if IS_REACHABLE(CONFIG_ROCKCHIP_DP_MST_AUX_CLIENT)
+struct rockchip_dp_aux_client *rockchip_dp_get_aux_client(struct device_node *node,
+							  char *handle_name);
+#else
+static inline struct rockchip_dp_aux_client *rockchip_dp_get_aux_client(struct device_node *node,
+									char *handle_name)
+{
+	return NULL;
+}
+#endif
+
+#endif
diff --git a/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client_helper.c b/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client_helper.c
new file mode 100644
index 000000000000..18d8fa850774
--- /dev/null
+++ b/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client_helper.c
@@ -0,0 +1,938 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Rockchip DP MST simulation axu client
+ *
+ * Copyright (c) 2024 Rockchip Electronics Co. Ltd.
+ *
+ * Author: Zhang Yubing <yubing.zhang@rock-chips.com>
+ */
+
+#include <linux/types.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <drm/drm_fixed.h>
+#include <drm/drm_edid.h>
+#include <drm/drm_print.h>
+#include <drm/display/drm_dp_mst_helper.h>
+
+#include "rockchip_dp_mst_aux_client_helper.h"
+
+#define DDC_SEGMENT_ADDR 0x30
+
+struct rockchip_dp_mst_sim_context {
+	void *host_dev;
+	void (*host_hpd_irq)(void *host_dev);
+	void (*host_req)(void *host_dev, const u8 *in, int in_size,
+			u8 *out, int *out_size);
+
+	struct rockchip_dp_mst_sim_port *ports;
+	u32 port_num;
+
+	struct drm_dp_sideband_msg_rx down_req;
+	struct drm_dp_sideband_msg_rx down_rep;
+
+	struct mutex session_lock;
+	struct completion session_comp;
+	struct workqueue_struct *wq;
+
+	u8 esi[16];
+	u8 guid[16];
+	u8 dpcd[1024];
+};
+
+struct rockchip_dp_mst_sim_work {
+	struct work_struct base;
+	struct rockchip_dp_mst_sim_context *ctx;
+	unsigned int address;
+	u8 buffer[256];
+	size_t size;
+};
+
+static void rockchip_dp_sideband_hex_dump(const char *name,
+					  u32 address, u8 *buffer, size_t size)
+{
+	char prefix[64];
+	int i, linelen, remaining = size;
+	const int rowsize = 16;
+	u8 linebuf[64];
+
+	snprintf(prefix, sizeof(prefix), "%s(%d) %4xh(%2zu): ",
+		name, current->pid, address, size);
+
+	for (i = 0; i < size; i += rowsize) {
+		linelen = min(remaining, rowsize);
+		remaining -= rowsize;
+
+		hex_dump_to_buffer(buffer + i, linelen, rowsize, 1,
+			linebuf, sizeof(linebuf), false);
+
+		pr_debug("%s%s\n", prefix, linebuf);
+	}
+}
+
+static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
+{
+	u8 bitmask = 0x80;
+	u8 bitshift = 7;
+	u8 array_index = 0;
+	int number_of_bits = num_nibbles * 4;
+	u8 remainder = 0;
+
+	while (number_of_bits != 0) {
+		number_of_bits--;
+		remainder <<= 1;
+		remainder |= (data[array_index] & bitmask) >> bitshift;
+		bitmask >>= 1;
+		bitshift--;
+		if (bitmask == 0) {
+			bitmask = 0x80;
+			bitshift = 7;
+			array_index++;
+		}
+		if ((remainder & 0x10) == 0x10)
+			remainder ^= 0x13;
+	}
+
+	number_of_bits = 4;
+	while (number_of_bits != 0) {
+		number_of_bits--;
+		remainder <<= 1;
+		if ((remainder & 0x10) != 0)
+			remainder ^= 0x13;
+	}
+
+	return remainder;
+}
+
+static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
+{
+	u8 bitmask = 0x80;
+	u8 bitshift = 7;
+	u8 array_index = 0;
+	int number_of_bits = number_of_bytes * 8;
+	u16 remainder = 0;
+
+	while (number_of_bits != 0) {
+		number_of_bits--;
+		remainder <<= 1;
+		remainder |= (data[array_index] & bitmask) >> bitshift;
+		bitmask >>= 1;
+		bitshift--;
+		if (bitmask == 0) {
+			bitmask = 0x80;
+			bitshift = 7;
+			array_index++;
+		}
+		if ((remainder & 0x100) == 0x100)
+			remainder ^= 0xd5;
+	}
+
+	number_of_bits = 8;
+	while (number_of_bits != 0) {
+		number_of_bits--;
+		remainder <<= 1;
+		if ((remainder & 0x100) != 0)
+			remainder ^= 0xd5;
+	}
+
+	return remainder & 0xff;
+}
+
+static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
+					   u8 *buf, int buflen, u8 *hdrlen)
+{
+	u8 crc4;
+	u8 len;
+	int i;
+	u8 idx;
+
+	if (buf[0] == 0)
+		return false;
+	len = 3;
+	len += ((buf[0] & 0xf0) >> 4) / 2;
+	if (len > buflen)
+		return false;
+	crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
+
+	if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
+		DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
+		return false;
+	}
+
+	hdr->lct = (buf[0] & 0xf0) >> 4;
+	hdr->lcr = (buf[0] & 0xf);
+	idx = 1;
+	for (i = 0; i < (hdr->lct / 2); i++)
+		hdr->rad[i] = buf[idx++];
+	hdr->broadcast = (buf[idx] >> 7) & 0x1;
+	hdr->path_msg = (buf[idx] >> 6) & 0x1;
+	hdr->msg_len = buf[idx] & 0x3f;
+	idx++;
+	hdr->somt = (buf[idx] >> 7) & 0x1;
+	hdr->eomt = (buf[idx] >> 6) & 0x1;
+	hdr->seqno = (buf[idx] >> 4) & 0x1;
+	idx++;
+	*hdrlen = idx;
+	return true;
+}
+
+static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
+				      u8 *replybuf, u8 replybuflen, bool hdr)
+{
+	int ret;
+	u8 crc4;
+
+	if (hdr) {
+		u8 hdrlen;
+		struct drm_dp_sideband_msg_hdr recv_hdr;
+
+		ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr,
+			replybuf, replybuflen, &hdrlen);
+		if (ret == false)
+			return false;
+
+		/*
+		 * ignore out-of-order messages or messages that are part of a
+		 * failed transaction
+		 */
+		if (!recv_hdr.somt && !msg->have_somt)
+			return false;
+
+		/* get length contained in this portion */
+		msg->curchunk_len = recv_hdr.msg_len;
+		msg->curchunk_hdrlen = hdrlen;
+
+		/* we have already gotten an somt - don't bother parsing */
+		if (recv_hdr.somt && msg->have_somt)
+			return false;
+
+		if (recv_hdr.somt) {
+			memcpy(&msg->initial_hdr, &recv_hdr,
+				sizeof(struct drm_dp_sideband_msg_hdr));
+			msg->have_somt = true;
+		}
+		if (recv_hdr.eomt)
+			msg->have_eomt = true;
+
+		/* copy the bytes for the remainder of this header chunk */
+		msg->curchunk_idx = min(msg->curchunk_len,
+			(u8)(replybuflen - hdrlen));
+		memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
+	} else {
+		memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
+		msg->curchunk_idx += replybuflen;
+	}
+
+	if (msg->curchunk_idx >= msg->curchunk_len) {
+		/* do CRC */
+		crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
+		if (crc4 != msg->chunk[msg->curchunk_len - 1])
+			pr_warn("msg crc4 check fail\n");
+		/* copy chunk into bigger msg */
+		memcpy(&msg->msg[msg->curlen], msg->chunk,
+			msg->curchunk_len - 1);
+		msg->curlen += msg->curchunk_len - 1;
+	}
+	return true;
+}
+
+static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
+					   u8 *buf, int *len)
+{
+	int idx = 0;
+	int i;
+	u8 crc4;
+
+	buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
+	for (i = 0; i < (hdr->lct / 2); i++)
+		buf[idx++] = hdr->rad[i];
+	buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
+		(hdr->msg_len & 0x3f);
+	buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
+
+	crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
+	buf[idx - 1] |= (crc4 & 0xf);
+
+	*len = idx;
+}
+
+static bool rockchip_dp_get_one_sb_msg(struct drm_dp_sideband_msg_rx *msg,
+				       struct drm_dp_aux_msg *aux_msg)
+{
+	int ret;
+
+	if (!msg->have_somt) {
+		ret = drm_dp_sideband_msg_build(msg,
+			aux_msg->buffer, aux_msg->size, true);
+		if (!ret) {
+			pr_err("sideband hdr build failed\n");
+			return false;
+		}
+	} else {
+		ret = drm_dp_sideband_msg_build(msg,
+			aux_msg->buffer, aux_msg->size, false);
+		if (!ret) {
+			pr_err("sideband msg build failed\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int
+rockchip_dp_sideband_build_nak_rep(struct rockchip_dp_mst_sim_context *ctx)
+{
+	struct drm_dp_sideband_msg_rx *msg = &ctx->down_req;
+	u8 *buf = ctx->down_rep.msg;
+	int idx = 0;
+
+	buf[idx] = msg->msg[0] | 0x80;
+	idx++;
+
+	memcpy(&buf[idx], ctx->guid, 16);
+	idx += 16;
+
+	buf[idx] = 0x4;
+	idx++;
+
+	buf[idx] = 0;
+	idx++;
+
+	return idx;
+}
+
+
+static int
+rockchip_dp_sideband_build_link_address_rep(struct rockchip_dp_mst_sim_context *ctx)
+{
+	struct rockchip_dp_mst_sim_port *port;
+	u8 *buf = ctx->down_rep.msg;
+	int idx = 0;
+	u32 i, tmp;
+
+	buf[idx] = DP_LINK_ADDRESS;
+	idx++;
+
+	memcpy(&buf[idx], ctx->guid, 16);
+	idx += 16;
+
+	buf[idx] = ctx->port_num;
+	idx++;
+
+	for (i = 0; i < ctx->port_num; i++) {
+		port = &ctx->ports[i];
+
+		tmp = 0;
+		if (port->input)
+			tmp |= 0x80;
+		tmp |= port->pdt << 4;
+		tmp |= i & 0xF;
+		buf[idx] = tmp;
+		idx++;
+
+		tmp = 0;
+		if (port->mcs)
+			tmp |= 0x80;
+		if (port->ddps)
+			tmp |= 0x40;
+
+		if (port->input) {
+			buf[idx] = tmp;
+			idx++;
+			continue;
+		}
+
+		if (port->ldps)
+			tmp |= 0x20;
+		buf[idx] = tmp;
+		idx++;
+
+		buf[idx] = port->dpcd_rev;
+		idx++;
+
+		memcpy(&buf[idx], port->peer_guid, 16);
+		idx += 16;
+
+		buf[idx] = (port->num_sdp_streams << 4) |
+			(port->num_sdp_stream_sinks);
+		idx++;
+	}
+
+	return idx;
+}
+
+static int rockchip_dp_sideband_build_remote_i2c_read_rep(struct rockchip_dp_mst_sim_context *ctx)
+{
+	struct rockchip_dp_mst_sim_port *port;
+	struct drm_dp_remote_i2c_read i2c_read;
+	u8 *buf;
+	int idx;
+	u32 i, start, len;
+
+	buf = ctx->down_req.msg;
+	idx = 1;
+
+	i2c_read.num_transactions = buf[idx] & 0x3;
+	i2c_read.port_number = buf[idx] >> 4;
+	idx++;
+
+	if (i2c_read.port_number >= ctx->port_num)
+		goto err;
+
+	for (i = 0; i < i2c_read.num_transactions; i++) {
+		i2c_read.transactions[i].i2c_dev_id = buf[idx] & 0x7f;
+		idx++;
+
+		i2c_read.transactions[i].num_bytes = buf[idx];
+		idx++;
+
+		i2c_read.transactions[i].bytes = &buf[idx];
+		idx += i2c_read.transactions[i].num_bytes;
+
+		i2c_read.transactions[i].no_stop_bit = (buf[idx] >> 4) & 0x1;
+		i2c_read.transactions[i].i2c_transaction_delay = buf[idx] & 0xf;
+		idx++;
+	}
+
+	i2c_read.read_i2c_device_id = buf[idx];
+	idx++;
+
+	i2c_read.num_bytes_read = buf[idx];
+	idx++;
+
+	port = &ctx->ports[i2c_read.port_number];
+
+	if (i2c_read.num_transactions == 1) {
+		if (i2c_read.transactions[0].i2c_dev_id != DDC_ADDR ||
+		    i2c_read.transactions[0].num_bytes != 1) {
+			pr_err("unsupported i2c address\n");
+			goto err;
+		}
+
+		start = i2c_read.transactions[0].bytes[0];
+	} else if (i2c_read.num_transactions == 2) {
+		if (i2c_read.transactions[0].i2c_dev_id != DDC_SEGMENT_ADDR ||
+		    i2c_read.transactions[0].num_bytes != 1 ||
+		    i2c_read.transactions[1].i2c_dev_id != DDC_ADDR ||
+		    i2c_read.transactions[1].num_bytes != 1) {
+			pr_err("unsupported i2c address\n");
+			goto err;
+		}
+
+		start = i2c_read.transactions[0].bytes[0] * EDID_LENGTH * 2 +
+			i2c_read.transactions[1].bytes[0];
+	} else {
+		pr_err("unsupported i2c transaction\n");
+		goto err;
+	}
+
+	len = i2c_read.num_bytes_read;
+
+	if (start + len > port->edid_size) {
+		pr_err("edid data exceeds maximum\n");
+		goto err;
+	}
+
+	buf = ctx->down_rep.msg;
+	idx = 0;
+
+	buf[idx] = DP_REMOTE_I2C_READ;
+	idx++;
+
+	buf[idx] = i2c_read.port_number;
+	idx++;
+
+	buf[idx] = len;
+	idx++;
+
+	memcpy(&buf[idx], &port->edid[start], len);
+	idx += len;
+
+	return idx;
+err:
+	return rockchip_dp_sideband_build_nak_rep(ctx);
+}
+
+static int
+rockchip_dp_sideband_build_enum_path_resources_rep(struct rockchip_dp_mst_sim_context *ctx)
+{
+	struct rockchip_dp_mst_sim_port *port;
+	u8 port_num;
+	u8 *buf;
+	int idx;
+
+	buf = ctx->down_req.msg;
+	port_num = buf[1] >> 4;
+
+	if (port_num >= ctx->port_num) {
+		pr_err("invalid port num\n");
+		goto err;
+	}
+
+	port = &ctx->ports[port_num];
+
+	buf = ctx->down_rep.msg;
+	idx = 0;
+
+	buf[idx] = DP_ENUM_PATH_RESOURCES;
+	idx++;
+
+	buf[idx] = port_num << 4;
+	idx++;
+
+	buf[idx] = port->full_pbn >> 8;
+	idx++;
+
+	buf[idx] = port->full_pbn & 0xFF;
+	idx++;
+
+	buf[idx] = port->avail_pbn >> 8;
+	idx++;
+
+	buf[idx] = port->avail_pbn & 0xFF;
+	idx++;
+
+	return idx;
+err:
+	return rockchip_dp_sideband_build_nak_rep(ctx);
+}
+
+static int
+rockchip_dp_sideband_build_allocate_payload_rep(struct rockchip_dp_mst_sim_context *ctx)
+{
+	struct drm_dp_allocate_payload allocate_payload;
+	u8 *buf;
+	int idx;
+	u32 i;
+
+	buf = ctx->down_req.msg;
+	idx = 1;
+
+	allocate_payload.port_number = buf[idx] >> 4;
+	allocate_payload.number_sdp_streams = buf[idx] & 0xF;
+	idx++;
+
+	allocate_payload.vcpi = buf[idx];
+	idx++;
+
+	allocate_payload.pbn = (buf[idx] << 8) | buf[idx+1];
+	idx += 2;
+
+	for (i = 0; i <  allocate_payload.number_sdp_streams / 2; i++) {
+		allocate_payload.sdp_stream_sink[i * 2] = buf[idx] >> 4;
+		allocate_payload.sdp_stream_sink[i * 2 + 1] = buf[idx] & 0xf;
+		idx++;
+	}
+	if (allocate_payload.number_sdp_streams & 1) {
+		i =  allocate_payload.number_sdp_streams - 1;
+		allocate_payload.sdp_stream_sink[i] = buf[idx] >> 4;
+		idx++;
+	}
+
+	if (allocate_payload.port_number >= ctx->port_num) {
+		pr_err("invalid port num\n");
+		goto err;
+	}
+
+	buf = ctx->down_rep.msg;
+	idx = 0;
+
+	buf[idx] = DP_ALLOCATE_PAYLOAD;
+	idx++;
+
+	buf[idx] = allocate_payload.port_number;
+	idx++;
+
+	buf[idx] = allocate_payload.vcpi;
+	idx++;
+
+	buf[idx] = allocate_payload.pbn >> 8;
+	idx++;
+
+	buf[idx] = allocate_payload.pbn & 0xFF;
+	idx++;
+
+	return idx;
+err:
+	return rockchip_dp_sideband_build_nak_rep(ctx);
+}
+
+static int
+rockchip_dp_sideband_build_power_updown_phy_rep(struct rockchip_dp_mst_sim_context *ctx)
+{
+	u8 port_num;
+	u8 *buf;
+	int idx;
+
+	buf = ctx->down_req.msg;
+	port_num = buf[1] >> 4;
+
+	if (port_num >= ctx->port_num) {
+		pr_err("invalid port num\n");
+		goto err;
+	}
+
+	buf = ctx->down_rep.msg;
+	idx = 0;
+
+	buf[idx] = ctx->down_req.msg[0];
+	idx++;
+
+	buf[idx] = port_num;
+	idx++;
+
+	return idx;
+err:
+	return rockchip_dp_sideband_build_nak_rep(ctx);
+}
+
+static int
+rockchip_dp_sideband_build_clear_payload_id_table_rep(struct rockchip_dp_mst_sim_context *ctx)
+{
+	u8 *buf = ctx->down_rep.msg;
+	int idx = 0;
+
+	buf[idx] = DP_CLEAR_PAYLOAD_ID_TABLE;
+	idx++;
+
+	return idx;
+}
+
+static inline int
+rockchip_dp_sideband_update_esi(struct rockchip_dp_mst_sim_context *ctx)
+{
+	ctx->esi[0] = ctx->port_num;
+	ctx->esi[1] = DP_DOWN_REP_MSG_RDY;
+	ctx->esi[2] = 0;
+
+	return 0;
+}
+
+static inline bool
+rockchip_dp_sideband_pending_esi(struct rockchip_dp_mst_sim_context *ctx)
+{
+	return !!(ctx->esi[1] & DP_DOWN_REP_MSG_RDY);
+}
+
+static int rockchip_dp_mst_sim_clear_esi(struct rockchip_dp_mst_sim_context *ctx,
+					 struct drm_dp_aux_msg *msg)
+{
+	size_t i;
+	u8 old_esi = ctx->esi[1];
+	u32 addr = msg->address - DP_SINK_COUNT_ESI;
+
+	if (msg->size - addr >= 16) {
+		msg->reply = DP_AUX_NATIVE_REPLY_NACK;
+		return 0;
+	}
+
+	mutex_lock(&ctx->session_lock);
+
+	for (i = 0; i < msg->size; i++)
+		ctx->esi[addr + i] &= ~((u8 *)msg->buffer)[i];
+
+	if ((old_esi & DP_DOWN_REP_MSG_RDY) &&
+			!(ctx->esi[1] & DP_DOWN_REP_MSG_RDY)) {
+		complete(&ctx->session_comp);
+	}
+
+	mutex_unlock(&ctx->session_lock);
+
+	msg->reply = DP_AUX_NATIVE_REPLY_ACK;
+	return 0;
+}
+
+static int rockchip_dp_mst_sim_read_esi(struct rockchip_dp_mst_sim_context *ctx,
+					struct drm_dp_aux_msg *msg)
+{
+	u32 addr = msg->address - DP_SINK_COUNT_ESI;
+
+	if (msg->size - addr >= 16) {
+		msg->reply = DP_AUX_NATIVE_REPLY_NACK;
+		return 0;
+	}
+
+	memcpy(msg->buffer, &ctx->esi[addr], msg->size);
+	msg->reply = DP_AUX_NATIVE_REPLY_ACK;
+
+	return 0;
+}
+
+static int rockchip_dp_mst_sim_down_req_internal(struct rockchip_dp_mst_sim_context *ctx,
+						 struct drm_dp_aux_msg *aux_msg)
+{
+	struct drm_dp_sideband_msg_rx *msg = &ctx->down_req;
+	struct drm_dp_sideband_msg_hdr hdr;
+	bool seqno;
+	int ret, size, len, hdr_len;
+
+	ret = rockchip_dp_get_one_sb_msg(msg, aux_msg);
+	if (!ret)
+		return -EINVAL;
+
+	if (!msg->have_eomt)
+		return 0;
+
+	seqno = msg->initial_hdr.seqno;
+
+	switch (msg->msg[0]) {
+	case DP_LINK_ADDRESS:
+		size = rockchip_dp_sideband_build_link_address_rep(ctx);
+		break;
+	case DP_REMOTE_I2C_READ:
+		size = rockchip_dp_sideband_build_remote_i2c_read_rep(ctx);
+		break;
+	case DP_ENUM_PATH_RESOURCES:
+		size = rockchip_dp_sideband_build_enum_path_resources_rep(ctx);
+		break;
+	case DP_ALLOCATE_PAYLOAD:
+		size = rockchip_dp_sideband_build_allocate_payload_rep(ctx);
+		break;
+	case DP_POWER_DOWN_PHY:
+	case DP_POWER_UP_PHY:
+		size = rockchip_dp_sideband_build_power_updown_phy_rep(ctx);
+		break;
+	case DP_CLEAR_PAYLOAD_ID_TABLE:
+		size = rockchip_dp_sideband_build_clear_payload_id_table_rep(ctx);
+		break;
+	default:
+		size = rockchip_dp_sideband_build_nak_rep(ctx);
+		break;
+	}
+
+	if (ctx->host_req)
+		ctx->host_req(ctx->host_dev,
+			ctx->down_req.msg, ctx->down_req.curlen,
+			ctx->down_rep.msg, &size);
+
+	memset(msg, 0, sizeof(*msg));
+	msg = &ctx->down_rep;
+	msg->curlen = 0;
+
+	while (msg->curlen < size) {
+		/* copy data */
+		len = min(size - msg->curlen, 44);
+		memcpy(&ctx->dpcd[3], &msg->msg[msg->curlen], len);
+		msg->curlen += len;
+
+		/* build header */
+		memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
+		hdr.broadcast = 0;
+		hdr.path_msg = 0;
+		hdr.lct = 1;
+		hdr.lcr = 0;
+		hdr.seqno = seqno;
+		hdr.msg_len = len + 1;
+		hdr.eomt = (msg->curlen == size);
+		hdr.somt = (msg->curlen == len);
+		drm_dp_encode_sideband_msg_hdr(&hdr, ctx->dpcd, &hdr_len);
+
+		/* build crc */
+		ctx->dpcd[len + 3] = drm_dp_msg_data_crc4(&ctx->dpcd[3], len);
+
+		/* update esi */
+		mutex_lock(&ctx->session_lock);
+		rockchip_dp_sideband_update_esi(ctx);
+		mutex_unlock(&ctx->session_lock);
+
+		/* notify host */
+		ctx->host_hpd_irq(ctx->host_dev);
+
+		/* wait until esi is cleared */
+		mutex_lock(&ctx->session_lock);
+		while (rockchip_dp_sideband_pending_esi(ctx)) {
+			mutex_unlock(&ctx->session_lock);
+			wait_for_completion(&ctx->session_comp);
+			mutex_lock(&ctx->session_lock);
+		}
+		mutex_unlock(&ctx->session_lock);
+	}
+
+	return 0;
+}
+
+static void rockchip_dp_mst_sim_down_req_work(struct work_struct *work)
+{
+	struct rockchip_dp_mst_sim_work *sim_work =
+		container_of(work, struct rockchip_dp_mst_sim_work, base);
+	struct drm_dp_aux_msg msg;
+
+	msg.address = sim_work->address;
+	msg.buffer = sim_work->buffer;
+	msg.size = sim_work->size;
+
+	rockchip_dp_mst_sim_down_req_internal(sim_work->ctx, &msg);
+
+	kfree(sim_work);
+}
+
+static int rockchip_dp_mst_sim_down_req(struct rockchip_dp_mst_sim_context *ctx,
+					struct drm_dp_aux_msg *aux_msg)
+{
+	struct rockchip_dp_mst_sim_work *work;
+
+	if (aux_msg->size >= 256) {
+		aux_msg->reply = DP_AUX_NATIVE_REPLY_NACK;
+		return 0;
+	}
+
+	rockchip_dp_sideband_hex_dump("request",
+		aux_msg->address, aux_msg->buffer, aux_msg->size);
+
+	work = kzalloc(sizeof(*work), GFP_KERNEL);
+	if (!work) {
+		aux_msg->reply = DP_AUX_NATIVE_REPLY_NACK;
+		return 0;
+	}
+
+	work->ctx = ctx;
+	work->address = aux_msg->address;
+	work->size = aux_msg->size;
+	memcpy(work->buffer, aux_msg->buffer, aux_msg->size);
+
+	INIT_WORK(&work->base, rockchip_dp_mst_sim_down_req_work);
+	queue_work(ctx->wq, &work->base);
+
+	aux_msg->reply = DP_AUX_NATIVE_REPLY_ACK;
+	return 0;
+}
+
+static int rockchip_dp_mst_sim_down_rep(struct rockchip_dp_mst_sim_context *ctx,
+		struct drm_dp_aux_msg *msg)
+{
+	u32 addr = msg->address - DP_SIDEBAND_MSG_DOWN_REP_BASE;
+
+	memcpy(msg->buffer, &ctx->dpcd[addr], msg->size);
+	msg->reply = DP_AUX_NATIVE_REPLY_ACK;
+
+	rockchip_dp_sideband_hex_dump("reply",
+		addr, msg->buffer, msg->size);
+
+	return 0;
+}
+
+int rockchip_dp_mst_sim_transfer(void *mst_sim_context, struct drm_dp_aux_msg *msg)
+{
+	if (msg->request == DP_AUX_NATIVE_WRITE) {
+		if (msg->address >= DP_SIDEBAND_MSG_DOWN_REQ_BASE &&
+		    msg->address < DP_SIDEBAND_MSG_DOWN_REQ_BASE + 256)
+			return rockchip_dp_mst_sim_down_req(mst_sim_context, msg);
+
+		if (msg->address >= DP_SINK_COUNT_ESI &&
+		    msg->address < DP_SINK_COUNT_ESI + 14)
+			return rockchip_dp_mst_sim_clear_esi(mst_sim_context, msg);
+	} else if (msg->request == DP_AUX_NATIVE_READ) {
+		if (msg->address >= DP_SIDEBAND_MSG_DOWN_REP_BASE &&
+		    msg->address < DP_SIDEBAND_MSG_DOWN_REP_BASE + 256)
+			return rockchip_dp_mst_sim_down_rep(mst_sim_context, msg);
+
+		if (msg->address >= DP_SINK_COUNT_ESI &&
+		    msg->address < DP_SINK_COUNT_ESI + 14)
+			return rockchip_dp_mst_sim_read_esi(mst_sim_context, msg);
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(rockchip_dp_mst_sim_transfer);
+
+int rockchip_dp_mst_sim_update(void *mst_sim_context, u32 port_num,
+			      struct rockchip_dp_mst_sim_port *ports)
+{
+	struct rockchip_dp_mst_sim_context *ctx = mst_sim_context;
+	u8 *edid;
+	int rc = 0;
+	u32 i;
+
+	if (port_num >= 15)
+		return -EINVAL;
+
+	mutex_lock(&ctx->session_lock);
+
+	for (i = 0; i < ctx->port_num; i++)
+		kfree(ctx->ports[i].edid);
+	kfree(ctx->ports);
+	ctx->port_num = 0;
+
+	ctx->ports = kcalloc(port_num, sizeof(*ports), GFP_KERNEL);
+	if (!ctx->ports) {
+		rc = -ENOMEM;
+		goto fail;
+	}
+
+	ctx->port_num = port_num;
+	for (i = 0; i < port_num; i++) {
+		ctx->ports[i] = ports[i];
+		if (ports[i].edid_size) {
+			if (!ports[i].edid) {
+				rc = -EINVAL;
+				goto fail;
+			}
+
+			edid = kzalloc(ports[i].edid_size,
+					GFP_KERNEL);
+			if (!edid) {
+				rc = -ENOMEM;
+				goto fail;
+			}
+
+			memcpy(edid, ports[i].edid, ports[i].edid_size);
+			ctx->ports[i].edid = edid;
+		}
+	}
+
+fail:
+	if (rc) {
+		for (i = 0; i < ctx->port_num; i++)
+			kfree(ctx->ports[i].edid);
+		kfree(ctx->ports);
+	}
+
+	mutex_unlock(&ctx->session_lock);
+	return rc;
+}
+EXPORT_SYMBOL(rockchip_dp_mst_sim_update);
+
+int rockchip_dp_mst_sim_create(const struct rockchip_dp_mst_sim_cfg *cfg,
+			       void **mst_sim_context)
+{
+	struct rockchip_dp_mst_sim_context *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->host_dev = cfg->host_dev;
+	ctx->host_hpd_irq = cfg->host_hpd_irq;
+	ctx->host_req = cfg->host_req;
+	memcpy(ctx->guid, cfg->guid, 16);
+
+	mutex_init(&ctx->session_lock);
+	init_completion(&ctx->session_comp);
+
+	ctx->wq = create_singlethread_workqueue("dp_mst_sim");
+	if (IS_ERR_OR_NULL(ctx->wq)) {
+		pr_err("Error creating wq\n");
+		kfree(ctx);
+		return -EPERM;
+	}
+
+	*mst_sim_context = ctx;
+	return 0;
+}
+EXPORT_SYMBOL(rockchip_dp_mst_sim_create);
+
+int rockchip_dp_mst_sim_destroy(void *mst_sim_context)
+{
+	struct rockchip_dp_mst_sim_context *ctx = mst_sim_context;
+	u32 i;
+
+	for (i = 0; i < ctx->port_num; i++)
+		kfree(ctx->ports[i].edid);
+	kfree(ctx->ports);
+
+	destroy_workqueue(ctx->wq);
+
+	return 0;
+}
+EXPORT_SYMBOL(rockchip_dp_mst_sim_destroy);
diff --git a/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client_helper.h b/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client_helper.h
new file mode 100644
index 000000000000..3e3453094537
--- /dev/null
+++ b/drivers/gpu/drm/rockchip/rockchip_dp_mst_aux_client_helper.h
@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2024 Rockchip Electronics Co. Ltd.
+ *
+ * Author: Zhang Yubing <yubing.zhang@rock-chips.com>
+ */
+
+#ifndef _ROCKCHIP_DP_MST_AUX_CLIENT_HELPER_H_
+#define _ROCKCHIP_DP_MST_AUX_CLIENT_HELPER_H_
+
+#include <linux/types.h>
+#include <drm/display/drm_dp_helper.h>
+
+/**
+ * struct rockchip_dp_mst_sim_port - MST port configuration
+ * @input: if this port is an input port.
+ * @mcs: message capability status - DP 1.2 spec.
+ * @ddps: DisplayPort Device Plug Status - DP 1.2
+ * @pdt: Peer Device Type
+ * @ldps: Legacy Device Plug Status
+ * @dpcd_rev: DPCD revision of device on this port
+ * @peer_guid: Peer GUID on this port
+ * @num_sdp_streams: Number of simultaneous streams
+ * @num_sdp_stream_sinks: Number of stream sinks
+ * @full_pbn: Full bandwidth for this port.
+ * @avail_pbn: Available bandwidth for this port.
+ * @edid: EDID data on this port.
+ * @edid_size: size of EDID data on this port.
+ */
+struct rockchip_dp_mst_sim_port {
+	bool input;
+	bool mcs;
+	bool ddps;
+	u8 pdt;
+	bool ldps;
+	u8 dpcd_rev;
+	u8 peer_guid[16];
+	u8 num_sdp_streams;
+	u8 num_sdp_stream_sinks;
+	u16 full_pbn;
+	u16 avail_pbn;
+	const u8 *edid;
+	u32 edid_size;
+};
+
+/**
+ * struct rockchip_dp_mst_sim_cfg - MST simulator configuration
+ * @host_dev: host device pointer used in callback functions
+ * @guid: GUID of the top MST branch.
+ */
+struct rockchip_dp_mst_sim_cfg {
+	void *host_dev;
+	u8 guid[16];
+
+	/**
+	 * @host_hpd_irq:
+	 *
+	 * This callback is invoked whenever simulator need to
+	 * notify host that there is a HPD_IRQ.
+	 * @host_dev: host_dev pointer
+	 */
+	void (*host_hpd_irq)(void *host_dev);
+
+	/**
+	 * @host_req:
+	 *
+	 * This callback is invoked whenever simulator's reply is ready
+	 * to response downstream request. Host can use this function
+	 * to replace the reply generated by simulator.
+	 * @host_dev: host_dev pointer
+	 * @in: pointer of downstream request buffer to simulator
+	 * @in_size: size of downstream request buffer to simulator
+	 * @out: pointer of downstream reply from simulator
+	 * @out_size: pointer of size of downstream reply from simulator
+	 *
+	 * This callback is optional.
+	 */
+	void (*host_req)(void *host_dev, const u8 *in, int in_size,
+			 u8 *out, int *out_size);
+};
+
+/**
+ * rockchip_dp_mst_sim_create - Create simulator context
+ * @cfg: see dp_mst_sim_cfg
+ * @mst_sim_context: simulator context returned
+ * return: 0 if successful
+ */
+int rockchip_dp_mst_sim_create(const struct rockchip_dp_mst_sim_cfg *cfg,
+			       void **mst_sim_context);
+
+/**
+ * rockchip_dp_mst_sim_destroy - Destroy simulator context
+ * @mst_sim_context: simulator context
+ * return: 0 if successful
+ */
+int rockchip_dp_mst_sim_destroy(void *mst_sim_context);
+
+/**
+ * dp_mst_sim_transfer - Send aux message to simulator context
+ * @mst_sim_context: simulator context
+ * @msg: aux message
+ * return: 0 if successful
+ */
+int rockchip_dp_mst_sim_transfer(void *mst_sim_context, struct drm_dp_aux_msg *msg);
+
+/**
+ * dp_mst_sim_update - Update port configuration
+ * @mst_sim_context: simulator context
+ * @port_num: number of ports
+ * @ports: ports configuration
+ * return: 0 if successful
+ */
+int rockchip_dp_mst_sim_update(void *mst_sim_context, u32 port_num,
+			       struct rockchip_dp_mst_sim_port *ports);
+
+#endif /* _ROCKCHIP_DP_MST_AUX_CLIENT_HELPER_H_ */
+