[PATCH v5 0/7] drm/bridge: imx: Add HDMI PAI driver on i.MX8MP

[PATCH v5 0/7] drm/bridge: imx: Add HDMI PAI driver on i.MX8MP

[Shengjiu Wang]

The HDMI TX Parallel Audio Interface (HTX_PAI) is a digital module that
acts as the bridge between the Audio Subsystem to the HDMI TX Controller.

Add HDMI PAI driver on i.MX8MP to make HDMI audio function fully work.

changes in v5:
- add empty line commit message for patch 7
- remove blank line in dts node
- add component_unbind_all when dw_hdmi_probe return error

changes in v4:
- separate dts for soc and board
- bind hdmi_pai with hdmi_tx by moving some code to .bind() and .unbind()
- add "select DRM_DW_HDMI" to fix build error reported by test robot
- remove unnecessary code/definition in pai driver

changes in v3:
- add space and 'U' in asoundef.h
- add more commit message for binding doc commit
- add bitfield.h header for fixing build error

changes in v2:
- address some comments on commit messages
- add two more commits:
  add definitions for the bits in IEC958 subframe
  add API dw_hdmi_set_sample_iec958() for iec958 format
- use component helper in hdmi_pai and hdmi_tx driver
- use regmap in hdmi_pai driver.
- add clocks in binding doc

Shengjiu Wang (7):
  dt-bindings: display: imx: add HDMI PAI for i.MX8MP
  ALSA: Add definitions for the bits in IEC958 subframe
  drm/bridge: dw-hdmi: Add API dw_hdmi_to_plat_data() to get plat_data
  drm/bridge: dw-hdmi: Add API dw_hdmi_set_sample_iec958() for iec958
    format
  drm/bridge: imx: add driver for HDMI TX Parallel Audio Interface
  arm64: dts: imx8mp: Add hdmi parallel audio interface node
  arm64: dts: imx8mp-evk: enable hdmi_pai device

 .../display/bridge/fsl,imx8mp-hdmi-tx.yaml    |  12 ++
 .../display/imx/fsl,imx8mp-hdmi-pai.yaml      |  69 ++++++++
 arch/arm64/boot/dts/freescale/imx8mp-evk.dts  |   4 +
 arch/arm64/boot/dts/freescale/imx8mp.dtsi     |  27 ++-
 drivers/gpu/drm/bridge/imx/Kconfig            |  11 ++
 drivers/gpu/drm/bridge/imx/Makefile           |   1 +
 drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pai.c  | 158 ++++++++++++++++++
 drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c   |  65 ++++++-
 .../drm/bridge/synopsys/dw-hdmi-gp-audio.c    |   5 +
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c     |  18 +-
 include/drm/bridge/dw_hdmi.h                  |  11 +-
 include/sound/asoundef.h                      |   9 +
 12 files changed, 382 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml
 create mode 100644 drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pai.c

-- 
2.34.1

[PATCH v5 1/7] dt-bindings: display: imx: add HDMI PAI for i.MX8MP

[Shengjiu Wang]

Add binding for the i.MX8MP HDMI parallel Audio interface block.

The HDMI TX Parallel Audio Interface (HTX_PAI) is a digital module that
acts as the bridge between the Audio Subsystem to the HDMI TX Controller.
This IP block is found in the HDMI subsystem of the i.MX8MP SoC.

Aud2htx module in Audio Subsystem, HDMI PAI module and HDMI TX
Controller compose the HDMI audio pipeline.

In fsl,imx8mp-hdmi-tx.yaml, add port@2 that is linked to pai_to_hdmi_tx.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../display/bridge/fsl,imx8mp-hdmi-tx.yaml    | 12 ++++
 .../display/imx/fsl,imx8mp-hdmi-pai.yaml      | 69 +++++++++++++++++++
 2 files changed, 81 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml

diff --git a/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml b/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml
index 05442d437755..6211ab8bbb0e 100644
--- a/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml
@@ -49,6 +49,10 @@ properties:
         $ref: /schemas/graph.yaml#/properties/port
         description: HDMI output port
 
+      port@2:
+        $ref: /schemas/graph.yaml#/properties/port
+        description: Parallel audio input port
+
     required:
       - port@0
       - port@1
@@ -98,5 +102,13 @@ examples:
                     remote-endpoint = <&hdmi0_con>;
                 };
             };
+
+            port@2 {
+                reg = <2>;
+
+                endpoint {
+                    remote-endpoint = <&pai_to_hdmi_tx>;
+                };
+            };
         };
     };
diff --git a/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml b/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml
new file mode 100644
index 000000000000..4f99682a308d
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/imx/fsl,imx8mp-hdmi-pai.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale i.MX8MP HDMI Parallel Audio Interface
+
+maintainers:
+  - Shengjiu Wang <shengjiu.wang@nxp.com>
+
+description:
+  The HDMI TX Parallel Audio Interface (HTX_PAI) is a bridge between the
+  Audio Subsystem to the HDMI TX Controller.
+
+properties:
+  compatible:
+    const: fsl,imx8mp-hdmi-pai
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: apb
+
+  power-domains:
+    maxItems: 1
+
+  port:
+    $ref: /schemas/graph.yaml#/properties/port
+    description: Output to the HDMI TX controller.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+  - power-domains
+  - port
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/imx8mp-clock.h>
+    #include <dt-bindings/power/imx8mp-power.h>
+
+    audio-bridge@32fc4800 {
+        compatible = "fsl,imx8mp-hdmi-pai";
+        reg = <0x32fc4800 0x800>;
+        interrupt-parent = <&irqsteer_hdmi>;
+        interrupts = <14>;
+        clocks = <&clk IMX8MP_CLK_HDMI_APB>;
+        clock-names = "apb";
+        power-domains = <&hdmi_blk_ctrl IMX8MP_HDMIBLK_PD_PAI>;
+
+        port {
+            pai_to_hdmi_tx: endpoint {
+                remote-endpoint = <&hdmi_tx_from_pai>;
+            };
+        };
+    };
-- 
2.34.1

[PATCH v5 2/7] ALSA: Add definitions for the bits in IEC958 subframe

[Shengjiu Wang]

The IEC958 subframe format SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE are used
in HDMI and DisplayPort to describe the audio stream, but hardware device
may need to reorder the IEC958 bits for internal transmission, so need
these standard bits definitions for IEC958 subframe format.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
---
 include/sound/asoundef.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/sound/asoundef.h b/include/sound/asoundef.h
index 09b2c3dffb30..c4a929d4fd51 100644
--- a/include/sound/asoundef.h
+++ b/include/sound/asoundef.h
@@ -12,6 +12,15 @@
  *        Digital audio interface					    *
  *                                                                          *
  ****************************************************************************/
+/* IEC958 subframe format */
+#define IEC958_SUBFRAME_PREAMBLE_MASK	(0xfU)
+#define IEC958_SUBFRAME_AUXILIARY_MASK	(0xfU << 4)
+#define IEC958_SUBFRAME_SAMPLE_24_MASK	(0xffffffU << 4)
+#define IEC958_SUBFRAME_SAMPLE_20_MASK	(0xfffffU << 8)
+#define IEC958_SUBFRAME_VALIDITY	(0x1U << 28)
+#define IEC958_SUBFRAME_USER_DATA	(0x1U << 29)
+#define IEC958_SUBFRAME_CHANNEL_STATUS	(0x1U << 30)
+#define IEC958_SUBFRAME_PARITY		(0x1U << 31)
 
 /* AES/IEC958 channel status bits */
 #define IEC958_AES0_PROFESSIONAL	(1<<0)	/* 0 = consumer, 1 = professional */
-- 
2.34.1

[PATCH v5 3/7] drm/bridge: dw-hdmi: Add API dw_hdmi_to_plat_data() to get plat_data

[Shengjiu Wang]

Add API dw_hdmi_to_plat_data() to fetch plat_data because audio device
driver needs it to enable(disable)_audio().

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Acked-by: Liu Ying <victor.liu@nxp.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 6 ++++++
 include/drm/bridge/dw_hdmi.h              | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 206b099a35e9..8d096b569cf1 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -198,6 +198,12 @@ struct dw_hdmi {
 	enum drm_connector_status last_connector_result;
 };
 
+const struct dw_hdmi_plat_data *dw_hdmi_to_plat_data(struct dw_hdmi *hdmi)
+{
+	return hdmi->plat_data;
+}
+EXPORT_SYMBOL_GPL(dw_hdmi_to_plat_data);
+
 #define HDMI_IH_PHY_STAT0_RX_SENSE \
 	(HDMI_IH_PHY_STAT0_RX_SENSE0 | HDMI_IH_PHY_STAT0_RX_SENSE1 | \
 	 HDMI_IH_PHY_STAT0_RX_SENSE2 | HDMI_IH_PHY_STAT0_RX_SENSE3)
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index 6a46baa0737c..b8fc4fdf5a21 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -208,4 +208,6 @@ void dw_hdmi_phy_setup_hpd(struct dw_hdmi *hdmi, void *data);
 
 bool dw_hdmi_bus_fmt_is_420(struct dw_hdmi *hdmi);
 
+const struct dw_hdmi_plat_data *dw_hdmi_to_plat_data(struct dw_hdmi *hdmi);
+
 #endif /* __IMX_HDMI_H__ */
-- 
2.34.1

[PATCH v5 4/7] drm/bridge: dw-hdmi: Add API dw_hdmi_set_sample_iec958() for iec958 format

[Shengjiu Wang]

Add API dw_hdmi_set_sample_iec958() for IEC958 format because audio device
driver needs IEC958 information to configure this specific setting.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Acked-by: Liu Ying <victor.liu@nxp.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-gp-audio.c |  5 +++++
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c          | 12 +++++++++++-
 include/drm/bridge/dw_hdmi.h                       |  3 ++-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-gp-audio.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-gp-audio.c
index ab18f9a3bf23..df7a37eb47f4 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-gp-audio.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-gp-audio.c
@@ -90,6 +90,11 @@ static int audio_hw_params(struct device *dev,  void *data,
 				   params->iec.status[0] & IEC958_AES0_NONAUDIO);
 	dw_hdmi_set_sample_width(dw->data.hdmi, params->sample_width);
 
+	if (daifmt->bit_fmt == SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE)
+		dw_hdmi_set_sample_iec958(dw->data.hdmi, 1);
+	else
+		dw_hdmi_set_sample_iec958(dw->data.hdmi, 0);
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 8d096b569cf1..3b77e73ac0ea 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -177,6 +177,7 @@ struct dw_hdmi {
 
 	spinlock_t audio_lock;
 	struct mutex audio_mutex;
+	unsigned int sample_iec958;
 	unsigned int sample_non_pcm;
 	unsigned int sample_width;
 	unsigned int sample_rate;
@@ -718,6 +719,14 @@ void dw_hdmi_set_sample_non_pcm(struct dw_hdmi *hdmi, unsigned int non_pcm)
 }
 EXPORT_SYMBOL_GPL(dw_hdmi_set_sample_non_pcm);
 
+void dw_hdmi_set_sample_iec958(struct dw_hdmi *hdmi, unsigned int iec958)
+{
+	mutex_lock(&hdmi->audio_mutex);
+	hdmi->sample_iec958 = iec958;
+	mutex_unlock(&hdmi->audio_mutex);
+}
+EXPORT_SYMBOL_GPL(dw_hdmi_set_sample_iec958);
+
 void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate)
 {
 	mutex_lock(&hdmi->audio_mutex);
@@ -849,7 +858,8 @@ static void dw_hdmi_gp_audio_enable(struct dw_hdmi *hdmi)
 				    hdmi->channels,
 				    hdmi->sample_width,
 				    hdmi->sample_rate,
-				    hdmi->sample_non_pcm);
+				    hdmi->sample_non_pcm,
+				    hdmi->sample_iec958);
 }
 
 static void dw_hdmi_gp_audio_disable(struct dw_hdmi *hdmi)
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index b8fc4fdf5a21..095cdd9b7424 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -145,7 +145,7 @@ struct dw_hdmi_plat_data {
 
 	/* Platform-specific audio enable/disable (optional) */
 	void (*enable_audio)(struct dw_hdmi *hdmi, int channel,
-			     int width, int rate, int non_pcm);
+			     int width, int rate, int non_pcm, int iec958);
 	void (*disable_audio)(struct dw_hdmi *hdmi);
 
 	/* Vendor PHY support */
@@ -179,6 +179,7 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense);
 int dw_hdmi_set_plugged_cb(struct dw_hdmi *hdmi, hdmi_codec_plugged_cb fn,
 			   struct device *codec_dev);
 void dw_hdmi_set_sample_non_pcm(struct dw_hdmi *hdmi, unsigned int non_pcm);
+void dw_hdmi_set_sample_iec958(struct dw_hdmi *hdmi, unsigned int iec958);
 void dw_hdmi_set_sample_width(struct dw_hdmi *hdmi, unsigned int width);
 void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate);
 void dw_hdmi_set_channel_count(struct dw_hdmi *hdmi, unsigned int cnt);
-- 
2.34.1

[PATCH v5 5/7] drm/bridge: imx: add driver for HDMI TX Parallel Audio Interface

[Shengjiu Wang]

The HDMI TX Parallel Audio Interface (HTX_PAI) is a digital module that
acts as the bridge between the Audio Subsystem to the HDMI TX Controller.
This IP block is found in the HDMI subsystem of the i.MX8MP SoC.

Data received from the audio subsystem can have an arbitrary component
ordering. The HTX_PAI block has integrated muxing options to select which
sections of the 32-bit input data word will be mapped to each IEC60958
field. The HTX_PAI_FIELD_CTRL register contains mux selects to
individually select P,C,U,V,Data, and Preamble.

Use component helper so that imx8mp-hdmi-tx will be aggregate driver,
imx8mp-hdmi-pai will be component driver, then imx8mp-hdmi-pai can use
bind() ops to get the plat_data from imx8mp-hdmi-tx device.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Liu Ying <victor.liu@nxp.com>
---
 drivers/gpu/drm/bridge/imx/Kconfig           |  11 ++
 drivers/gpu/drm/bridge/imx/Makefile          |   1 +
 drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pai.c | 158 +++++++++++++++++++
 drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c  |  65 +++++++-
 include/drm/bridge/dw_hdmi.h                 |   6 +
 5 files changed, 236 insertions(+), 5 deletions(-)
 create mode 100644 drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pai.c

diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
index 9a480c6abb85..b9028a5e5a06 100644
--- a/drivers/gpu/drm/bridge/imx/Kconfig
+++ b/drivers/gpu/drm/bridge/imx/Kconfig
@@ -18,12 +18,23 @@ config DRM_IMX8MP_DW_HDMI_BRIDGE
 	depends on OF
 	depends on COMMON_CLK
 	select DRM_DW_HDMI
+	imply DRM_IMX8MP_HDMI_PAI
 	imply DRM_IMX8MP_HDMI_PVI
 	imply PHY_FSL_SAMSUNG_HDMI_PHY
 	help
 	  Choose this to enable support for the internal HDMI encoder found
 	  on the i.MX8MP SoC.
 
+config DRM_IMX8MP_HDMI_PAI
+	tristate "Freescale i.MX8MP HDMI PAI bridge support"
+	depends on OF
+	select DRM_DW_HDMI
+	select REGMAP
+	select REGMAP_MMIO
+	help
+	  Choose this to enable support for the internal HDMI TX Parallel
+	  Audio Interface found on the Freescale i.MX8MP SoC.
+
 config DRM_IMX8MP_HDMI_PVI
 	tristate "Freescale i.MX8MP HDMI PVI bridge support"
 	depends on OF
diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
index dd5d48584806..8d01fda25451 100644
--- a/drivers/gpu/drm/bridge/imx/Makefile
+++ b/drivers/gpu/drm/bridge/imx/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_DRM_IMX_LDB_HELPER) += imx-ldb-helper.o
 obj-$(CONFIG_DRM_IMX_LEGACY_BRIDGE) += imx-legacy-bridge.o
 obj-$(CONFIG_DRM_IMX8MP_DW_HDMI_BRIDGE) += imx8mp-hdmi-tx.o
+obj-$(CONFIG_DRM_IMX8MP_HDMI_PAI) += imx8mp-hdmi-pai.o
 obj-$(CONFIG_DRM_IMX8MP_HDMI_PVI) += imx8mp-hdmi-pvi.o
 obj-$(CONFIG_DRM_IMX8QM_LDB) += imx8qm-ldb.o
 obj-$(CONFIG_DRM_IMX8QXP_LDB) += imx8qxp-ldb.o
diff --git a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pai.c b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pai.c
new file mode 100644
index 000000000000..8d13a35b206a
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-pai.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2025 NXP
+ */
+
+#include <linux/bitfield.h>
+#include <linux/component.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <drm/bridge/dw_hdmi.h>
+#include <sound/asoundef.h>
+
+#define HTX_PAI_CTRL			0x00
+#define   ENABLE			BIT(0)
+
+#define HTX_PAI_CTRL_EXT		0x04
+#define   WTMK_HIGH_MASK		GENMASK(31, 24)
+#define   WTMK_LOW_MASK			GENMASK(23, 16)
+#define   NUM_CH_MASK			GENMASK(10, 8)
+#define   WTMK_HIGH(n)			FIELD_PREP(WTMK_HIGH_MASK, (n))
+#define   WTMK_LOW(n)			FIELD_PREP(WTMK_LOW_MASK, (n))
+#define   NUM_CH(n)			FIELD_PREP(NUM_CH_MASK, (n) - 1)
+
+#define HTX_PAI_FIELD_CTRL		0x08
+#define   PRE_SEL			GENMASK(28, 24)
+#define   D_SEL				GENMASK(23, 20)
+#define   V_SEL				GENMASK(19, 15)
+#define   U_SEL				GENMASK(14, 10)
+#define   C_SEL				GENMASK(9, 5)
+#define   P_SEL				GENMASK(4, 0)
+
+struct imx8mp_hdmi_pai {
+	struct regmap	*regmap;
+};
+
+static void imx8mp_hdmi_pai_enable(struct dw_hdmi *dw_hdmi, int channel,
+				   int width, int rate, int non_pcm,
+				   int iec958)
+{
+	const struct dw_hdmi_plat_data *pdata = dw_hdmi_to_plat_data(dw_hdmi);
+	struct imx8mp_hdmi_pai *hdmi_pai = pdata->priv_audio;
+	int val;
+
+	/* PAI set control extended */
+	val =  WTMK_HIGH(3) | WTMK_LOW(3);
+	val |= NUM_CH(channel);
+	regmap_write(hdmi_pai->regmap, HTX_PAI_CTRL_EXT, val);
+
+	/* IEC60958 format */
+	if (iec958) {
+		val = FIELD_PREP_CONST(P_SEL,
+				       __bf_shf(IEC958_SUBFRAME_PARITY));
+		val |= FIELD_PREP_CONST(C_SEL,
+					__bf_shf(IEC958_SUBFRAME_CHANNEL_STATUS));
+		val |= FIELD_PREP_CONST(U_SEL,
+					__bf_shf(IEC958_SUBFRAME_USER_DATA));
+		val |= FIELD_PREP_CONST(V_SEL,
+					__bf_shf(IEC958_SUBFRAME_VALIDITY));
+		val |= FIELD_PREP_CONST(D_SEL,
+					__bf_shf(IEC958_SUBFRAME_SAMPLE_24_MASK));
+		val |= FIELD_PREP_CONST(PRE_SEL,
+					__bf_shf(IEC958_SUBFRAME_PREAMBLE_MASK));
+	} else {
+		/*
+		 * The allowed PCM widths are 24bit and 32bit, as they are supported
+		 * by aud2htx module.
+		 * for 24bit, D_SEL = 0, select all the bits.
+		 * for 32bit, D_SEL = 8, select 24bit in MSB.
+		 */
+		val = FIELD_PREP(D_SEL, width - 24);
+	}
+
+	regmap_write(hdmi_pai->regmap, HTX_PAI_FIELD_CTRL, val);
+
+	/* PAI start running */
+	regmap_write(hdmi_pai->regmap, HTX_PAI_CTRL, ENABLE);
+}
+
+static void imx8mp_hdmi_pai_disable(struct dw_hdmi *dw_hdmi)
+{
+	const struct dw_hdmi_plat_data *pdata = dw_hdmi_to_plat_data(dw_hdmi);
+	struct imx8mp_hdmi_pai *hdmi_pai = pdata->priv_audio;
+
+	/* Stop PAI */
+	regmap_write(hdmi_pai->regmap, HTX_PAI_CTRL, 0);
+}
+
+static const struct regmap_config imx8mp_hdmi_pai_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = HTX_PAI_FIELD_CTRL,
+};
+
+static int imx8mp_hdmi_pai_bind(struct device *dev, struct device *master, void *data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct dw_hdmi_plat_data *plat_data = data;
+	struct imx8mp_hdmi_pai *hdmi_pai;
+	struct resource *res;
+	void __iomem *base;
+
+	hdmi_pai = devm_kzalloc(dev, sizeof(*hdmi_pai), GFP_KERNEL);
+	if (!hdmi_pai)
+		return -ENOMEM;
+
+	base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	hdmi_pai->regmap = devm_regmap_init_mmio_clk(dev, "apb", base,
+						     &imx8mp_hdmi_pai_regmap_config);
+	if (IS_ERR(hdmi_pai->regmap)) {
+		dev_err(dev, "regmap init failed\n");
+		return PTR_ERR(hdmi_pai->regmap);
+	}
+
+	plat_data->enable_audio = imx8mp_hdmi_pai_enable;
+	plat_data->disable_audio = imx8mp_hdmi_pai_disable;
+	plat_data->priv_audio = hdmi_pai;
+
+	return 0;
+}
+
+static const struct component_ops imx8mp_hdmi_pai_ops = {
+	.bind   = imx8mp_hdmi_pai_bind,
+};
+
+static int imx8mp_hdmi_pai_probe(struct platform_device *pdev)
+{
+	return component_add(&pdev->dev, &imx8mp_hdmi_pai_ops);
+}
+
+static void imx8mp_hdmi_pai_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &imx8mp_hdmi_pai_ops);
+}
+
+static const struct of_device_id imx8mp_hdmi_pai_of_table[] = {
+	{ .compatible = "fsl,imx8mp-hdmi-pai" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx8mp_hdmi_pai_of_table);
+
+static struct platform_driver imx8mp_hdmi_pai_platform_driver = {
+	.probe		= imx8mp_hdmi_pai_probe,
+	.remove		= imx8mp_hdmi_pai_remove,
+	.driver		= {
+		.name	= "imx8mp-hdmi-pai",
+		.of_match_table = imx8mp_hdmi_pai_of_table,
+	},
+};
+module_platform_driver(imx8mp_hdmi_pai_platform_driver);
+
+MODULE_DESCRIPTION("i.MX8MP HDMI PAI driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
index 1e7a789ec289..32fd3554e267 100644
--- a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
+++ b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c
@@ -5,11 +5,13 @@
  */
 
 #include <linux/clk.h>
+#include <linux/component.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <drm/bridge/dw_hdmi.h>
 #include <drm/drm_modes.h>
+#include <drm/drm_of.h>
 
 struct imx8mp_hdmi {
 	struct dw_hdmi_plat_data plat_data;
@@ -79,10 +81,45 @@ static const struct dw_hdmi_phy_ops imx8mp_hdmi_phy_ops = {
 	.update_hpd	= dw_hdmi_phy_update_hpd,
 };
 
+static int imx8mp_dw_hdmi_bind(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct imx8mp_hdmi *hdmi = dev_get_drvdata(dev);
+	int ret;
+
+	ret = component_bind_all(dev, &hdmi->plat_data);
+	if (ret)
+		return dev_err_probe(dev, ret, "component_bind_all failed!\n");
+
+	hdmi->dw_hdmi = dw_hdmi_probe(pdev, &hdmi->plat_data);
+	if (IS_ERR(hdmi->dw_hdmi)) {
+		component_unbind_all(dev, &hdmi->plat_data);
+		return PTR_ERR(hdmi->dw_hdmi);
+	}
+
+	return 0;
+}
+
+static void imx8mp_dw_hdmi_unbind(struct device *dev)
+{
+	struct imx8mp_hdmi *hdmi = dev_get_drvdata(dev);
+
+	dw_hdmi_remove(hdmi->dw_hdmi);
+
+	component_unbind_all(dev, &hdmi->plat_data);
+}
+
+static const struct component_master_ops imx8mp_dw_hdmi_ops = {
+	.bind   = imx8mp_dw_hdmi_bind,
+	.unbind = imx8mp_dw_hdmi_unbind,
+};
+
 static int imx8mp_dw_hdmi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct dw_hdmi_plat_data *plat_data;
+	struct component_match *match = NULL;
+	struct device_node *remote;
 	struct imx8mp_hdmi *hdmi;
 
 	hdmi = devm_kzalloc(dev, sizeof(*hdmi), GFP_KERNEL);
@@ -102,20 +139,38 @@ static int imx8mp_dw_hdmi_probe(struct platform_device *pdev)
 	plat_data->priv_data = hdmi;
 	plat_data->phy_force_vendor = true;
 
-	hdmi->dw_hdmi = dw_hdmi_probe(pdev, plat_data);
-	if (IS_ERR(hdmi->dw_hdmi))
-		return PTR_ERR(hdmi->dw_hdmi);
-
 	platform_set_drvdata(pdev, hdmi);
 
+	/* port@2 is for hdmi_pai device */
+	remote = of_graph_get_remote_node(pdev->dev.of_node, 2, 0);
+	if (!remote) {
+		hdmi->dw_hdmi = dw_hdmi_probe(pdev, plat_data);
+		if (IS_ERR(hdmi->dw_hdmi))
+			return PTR_ERR(hdmi->dw_hdmi);
+	} else {
+		drm_of_component_match_add(dev, &match, component_compare_of, remote);
+
+		of_node_put(remote);
+
+		return component_master_add_with_match(dev, &imx8mp_dw_hdmi_ops, match);
+	}
+
 	return 0;
 }
 
 static void imx8mp_dw_hdmi_remove(struct platform_device *pdev)
 {
 	struct imx8mp_hdmi *hdmi = platform_get_drvdata(pdev);
+	struct device_node *remote;
 
-	dw_hdmi_remove(hdmi->dw_hdmi);
+	remote = of_graph_get_remote_node(pdev->dev.of_node, 2, 0);
+	if (remote) {
+		of_node_put(remote);
+
+		component_master_del(&pdev->dev, &imx8mp_dw_hdmi_ops);
+	} else {
+		dw_hdmi_remove(hdmi->dw_hdmi);
+	}
 }
 
 static int imx8mp_dw_hdmi_pm_suspend(struct device *dev)
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index 095cdd9b7424..336f062e1f9d 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -143,6 +143,12 @@ struct dw_hdmi_plat_data {
 					   const struct drm_display_info *info,
 					   const struct drm_display_mode *mode);
 
+	/*
+	 * priv_audio is specially used for additional audio device to get
+	 * driver data through this dw_hdmi_plat_data.
+	 */
+	void *priv_audio;
+
 	/* Platform-specific audio enable/disable (optional) */
 	void (*enable_audio)(struct dw_hdmi *hdmi, int channel,
 			     int width, int rate, int non_pcm, int iec958);
-- 
2.34.1

[PATCH v5 6/7] arm64: dts: imx8mp: Add hdmi parallel audio interface node

[Shengjiu Wang]

The HDMI TX Parallel Audio Interface (HTX_PAI) is a bridge between the
Audio Subsystem to the HDMI TX Controller.

Shrink register map size of hdmi_pvi to avoid overlapped hdmi_pai device.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
 arch/arm64/boot/dts/freescale/imx8mp.dtsi | 27 ++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp.dtsi b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
index bb24dba7338e..b733ec7ff3a5 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mp.dtsi
@@ -2063,7 +2063,7 @@ irqsteer_hdmi: interrupt-controller@32fc2000 {
 
 			hdmi_pvi: display-bridge@32fc4000 {
 				compatible = "fsl,imx8mp-hdmi-pvi";
-				reg = <0x32fc4000 0x1000>;
+				reg = <0x32fc4000 0x800>;
 				interrupt-parent = <&irqsteer_hdmi>;
 				interrupts = <12>;
 				power-domains = <&hdmi_blk_ctrl IMX8MP_HDMIBLK_PD_PVI>;
@@ -2089,6 +2089,23 @@ pvi_to_hdmi_tx: endpoint {
 				};
 			};
 
+			hdmi_pai: audio-bridge@32fc4800 {
+				compatible = "fsl,imx8mp-hdmi-pai";
+				reg = <0x32fc4800 0x800>;
+				interrupt-parent = <&irqsteer_hdmi>;
+				interrupts = <14>;
+				clocks = <&clk IMX8MP_CLK_HDMI_APB>;
+				clock-names = "apb";
+				power-domains = <&hdmi_blk_ctrl IMX8MP_HDMIBLK_PD_PAI>;
+				status = "disabled";
+
+				port {
+					pai_to_hdmi_tx: endpoint {
+						remote-endpoint = <&hdmi_tx_from_pai>;
+					};
+				};
+			};
+
 			lcdif3: display-controller@32fc6000 {
 				compatible = "fsl,imx8mp-lcdif";
 				reg = <0x32fc6000 0x1000>;
@@ -2140,6 +2157,14 @@ port@1 {
 						reg = <1>;
 						/* Point endpoint to the HDMI connector */
 					};
+
+					port@2 {
+						reg = <2>;
+
+						hdmi_tx_from_pai: endpoint {
+							remote-endpoint = <&pai_to_hdmi_tx>;
+						};
+					};
 				};
 			};
 
-- 
2.34.1

[PATCH v5 7/7] arm64: dts: imx8mp-evk: enable hdmi_pai device

[Shengjiu Wang]

Enable hdmi_pai device.

Aud2htx module, hdmi_pai and hdmi controller compose the hdmi audio
pipeline.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
 arch/arm64/boot/dts/freescale/imx8mp-evk.dts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
index c0cc5611048e..cc9351a5bd65 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
@@ -442,6 +442,10 @@ &flexcan2 {
 	status = "disabled";/* can2 pin conflict with pdm */
 };
 
+&hdmi_pai {
+	status = "okay";
+};
+
 &hdmi_pvi {
 	status = "okay";
 };
-- 
2.34.1

Re: [PATCH v5 4/7] drm/bridge: dw-hdmi: Add API dw_hdmi_set_sample_iec958() for iec958 format

[Luca Ceresoli]

Hello Shengjiu,

On Thu, 21 Aug 2025 15:31:28 +0800
Shengjiu Wang <shengjiu.wang@nxp.com> wrote:

> Add API dw_hdmi_set_sample_iec958() for IEC958 format because audio device
> driver needs IEC958 information to configure this specific setting.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> Acked-by: Liu Ying <victor.liu@nxp.com>

[...]

> +void dw_hdmi_set_sample_iec958(struct dw_hdmi *hdmi, unsigned int iec958)
> +{
> +	mutex_lock(&hdmi->audio_mutex);
> +	hdmi->sample_iec958 = iec958;
> +	mutex_unlock(&hdmi->audio_mutex);
> +}

Apologies for jumping in the discussion as late as in v5, but I noticed
this patch and I was wondering whether this mutex_lock/unlock() is
really needed, as you're copying an int.

Luca

-- 
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v5 4/7] drm/bridge: dw-hdmi: Add API dw_hdmi_set_sample_iec958() for iec958 format

[Shengjiu Wang]

On Tue, Sep 2, 2025 at 12:52 AM Luca Ceresoli <luca.ceresoli@bootlin.com> wrote:
>
> Hello Shengjiu,
>
> On Thu, 21 Aug 2025 15:31:28 +0800
> Shengjiu Wang <shengjiu.wang@nxp.com> wrote:
>
> > Add API dw_hdmi_set_sample_iec958() for IEC958 format because audio device
> > driver needs IEC958 information to configure this specific setting.
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> > Acked-by: Liu Ying <victor.liu@nxp.com>
>
> [...]
>
> > +void dw_hdmi_set_sample_iec958(struct dw_hdmi *hdmi, unsigned int iec958)
> > +{
> > +     mutex_lock(&hdmi->audio_mutex);
> > +     hdmi->sample_iec958 = iec958;
> > +     mutex_unlock(&hdmi->audio_mutex);
> > +}
>
> Apologies for jumping in the discussion as late as in v5, but I noticed
> this patch and I was wondering whether this mutex_lock/unlock() is
> really needed, as you're copying an int.

Thanks for your comments.

Seems it is not necessary to add mutex here. I just follow the code as
other similar functions.  I will send a new version to update it.

Best regards
Shengjiu Wang

Shengjiu Wang
>
> Luca
>
> --
> Luca Ceresoli, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com