[PATCH v1 0/2] usb: typec: mux: tusb1046: add HPD_IN override support

[PATCH v1 0/2] usb: typec: mux: tusb1046: add HPD_IN override support

[Ajit Singh]

For boards where HPD_IN is not asserted by hardware, the TUSB1046
allows software to force it high over I2C using the HPDIN_OVERRIDE
bit in the General register (0x0A).

Add the optional ti,hpd-in-override property and driver support
to force HPD_IN high when DisplayPort mode is selected, and clear
the override when switching to USB or Safe mode.

Ajit Singh (2):
  dt-bindings: usb: ti,tusb1046: document HPD_IN override
  usb: typec: mux: tusb1046: support HPD_IN override

 .../devicetree/bindings/usb/ti,tusb1046.yaml       |  9 +++++++++
 drivers/usb/typec/mux/tusb1046.c                   | 14 ++++++++++++++
 2 files changed, 23 insertions(+)

-- 
2.50.1 (Apple Git-155)

[PATCH v1 1/2] dt-bindings: usb: ti,tusb1046: document HPD_IN override

[Ajit Singh]

For boards where HPD_IN is not asserted by hardware, the TUSB1046
can force it high over I2C using the HPDIN_OVERRIDE bit in the
General register (0x0A).

Document the optional ti,hpd-in-override property to force HPD_IN
high when DisplayPort mode is selected.

Signed-off-by: Ajit Singh <blfizzyy@gmail.com>
---
 Documentation/devicetree/bindings/usb/ti,tusb1046.yaml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/ti,tusb1046.yaml b/Documentation/devicetree/bindings/usb/ti,tusb1046.yaml
index e1501ea6b50b..58e9fde3ca71 100644
--- a/Documentation/devicetree/bindings/usb/ti,tusb1046.yaml
+++ b/Documentation/devicetree/bindings/usb/ti,tusb1046.yaml
@@ -20,6 +20,14 @@ properties:
   reg:
     maxItems: 1
 
+  ti,hpd-in-override:
+    type: boolean
+    description: |
+      Force the HPD_IN signal high through the HPDIN_OVERRIDE bit in the
+      General register while DisplayPort Alt Mode is active. This is useful
+      on boards where HPD_IN is not driven by the downstream DisplayPort
+      sink.
+
 required:
   - compatible
   - reg
@@ -39,6 +47,7 @@ examples:
 
             mode-switch;
             orientation-switch;
+            ti,hpd-in-override;
 
             port {
                 endpoint {
-- 
2.50.1 (Apple Git-155)

[PATCH v1 2/2] usb: typec: mux: tusb1046: support HPD_IN override

[Ajit Singh]

For boards where HPD_IN is not asserted by hardware, software can
force it high over I2C using the HPDIN_OVERRIDE bit in the General
register (0x0A).

Add support for the optional ti,hpd-in-override property to force
HPD_IN high when DisplayPort mode is selected. Clear the override
when switching to USB or Safe mode, and preserve the existing
bit value when the property is absent.

Signed-off-by: Ajit Singh <blfizzyy@gmail.com>
---
 drivers/usb/typec/mux/tusb1046.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/usb/typec/mux/tusb1046.c b/drivers/usb/typec/mux/tusb1046.c
index 34ef81f75693..c21b1f8b9786 100644
--- a/drivers/usb/typec/mux/tusb1046.c
+++ b/drivers/usb/typec/mux/tusb1046.c
@@ -21,6 +21,7 @@
 /* General register bits */
 #define TUSB1046_GENERAL_FLIPSEL BIT(2)
 #define TUSB1046_GENERAL_CTLSEL  GENMASK(1, 0)
+#define TUSB1046_GENERAL_HPDIN_OVERRIDE BIT(3)
 
 /* Mux modes */
 #define TUSB1046_CTLSEL_DISABLED          0x0
@@ -32,6 +33,7 @@ struct tusb1046_priv {
 	struct i2c_client *client;
 	struct typec_switch_dev *sw;
 	struct typec_mux_dev *mux;
+	bool hpdin_override;
 
 	/* Lock General register during accesses */
 	struct mutex general_reg_lock;
@@ -44,6 +46,7 @@ static int tusb1046_mux_set(struct typec_mux_dev *mux,
 	struct i2c_client *client = priv->client;
 	struct device *dev = &client->dev;
 	int mode, val, ret = 0;
+	bool dp_active = false;
 
 	if (state->mode >= TYPEC_STATE_MODAL &&
 	    state->alt->svid != USB_TYPEC_DP_SID)
@@ -67,9 +70,11 @@ static int tusb1046_mux_set(struct typec_mux_dev *mux,
 	case TYPEC_DP_STATE_C:
 	case TYPEC_DP_STATE_E:
 		mode = TUSB1046_CTLSEL_4LANE_DP;
+		dp_active = true;
 		break;
 	case TYPEC_DP_STATE_D:
 		mode = TUSB1046_CTLSEL_USB3_AND_2LANE_DP;
+		dp_active = true;
 		break;
 	case TYPEC_STATE_SAFE:
 	default:
@@ -80,6 +85,13 @@ static int tusb1046_mux_set(struct typec_mux_dev *mux,
 	val &= ~TUSB1046_GENERAL_CTLSEL;
 	val |= mode;
 
+	if (priv->hpdin_override) {
+		if (dp_active)
+			val |= TUSB1046_GENERAL_HPDIN_OVERRIDE;
+		else
+			val &= ~TUSB1046_GENERAL_HPDIN_OVERRIDE;
+	}
+
 	ret = i2c_smbus_write_byte_data(client, TUSB1046_REG_GENERAL, val);
 
 out_unlock:
@@ -131,6 +143,8 @@ static int tusb1046_i2c_probe(struct i2c_client *client)
 		return -ENOMEM;
 
 	priv->client = client;
+	priv->hpdin_override =
+		device_property_read_bool(dev, "ti,hpd-in-override");
 
 	mutex_init(&priv->general_reg_lock);
 
-- 
2.50.1 (Apple Git-155)

Re: [PATCH v1 2/2] usb: typec: mux: tusb1046: support HPD_IN override

[Heikki Krogerus]

On Wed, Nov 04, 2026 at 01:12:02PM +0530, Ajit Singh wrote:
> For boards where HPD_IN is not asserted by hardware, software can
> force it high over I2C using the HPDIN_OVERRIDE bit in the General
> register (0x0A).
> 
> Add support for the optional ti,hpd-in-override property to force
> HPD_IN high when DisplayPort mode is selected. Clear the override
> when switching to USB or Safe mode, and preserve the existing
> bit value when the property is absent.
> 
> Signed-off-by: Ajit Singh <blfizzyy@gmail.com>

Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/usb/typec/mux/tusb1046.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/usb/typec/mux/tusb1046.c b/drivers/usb/typec/mux/tusb1046.c
> index 34ef81f75693..c21b1f8b9786 100644
> --- a/drivers/usb/typec/mux/tusb1046.c
> +++ b/drivers/usb/typec/mux/tusb1046.c
> @@ -21,6 +21,7 @@
>  /* General register bits */
>  #define TUSB1046_GENERAL_FLIPSEL BIT(2)
>  #define TUSB1046_GENERAL_CTLSEL  GENMASK(1, 0)
> +#define TUSB1046_GENERAL_HPDIN_OVERRIDE BIT(3)
>  
>  /* Mux modes */
>  #define TUSB1046_CTLSEL_DISABLED          0x0
> @@ -32,6 +33,7 @@ struct tusb1046_priv {
>  	struct i2c_client *client;
>  	struct typec_switch_dev *sw;
>  	struct typec_mux_dev *mux;
> +	bool hpdin_override;
>  
>  	/* Lock General register during accesses */
>  	struct mutex general_reg_lock;
> @@ -44,6 +46,7 @@ static int tusb1046_mux_set(struct typec_mux_dev *mux,
>  	struct i2c_client *client = priv->client;
>  	struct device *dev = &client->dev;
>  	int mode, val, ret = 0;
> +	bool dp_active = false;
>  
>  	if (state->mode >= TYPEC_STATE_MODAL &&
>  	    state->alt->svid != USB_TYPEC_DP_SID)
> @@ -67,9 +70,11 @@ static int tusb1046_mux_set(struct typec_mux_dev *mux,
>  	case TYPEC_DP_STATE_C:
>  	case TYPEC_DP_STATE_E:
>  		mode = TUSB1046_CTLSEL_4LANE_DP;
> +		dp_active = true;
>  		break;
>  	case TYPEC_DP_STATE_D:
>  		mode = TUSB1046_CTLSEL_USB3_AND_2LANE_DP;
> +		dp_active = true;
>  		break;
>  	case TYPEC_STATE_SAFE:
>  	default:
> @@ -80,6 +85,13 @@ static int tusb1046_mux_set(struct typec_mux_dev *mux,
>  	val &= ~TUSB1046_GENERAL_CTLSEL;
>  	val |= mode;
>  
> +	if (priv->hpdin_override) {
> +		if (dp_active)
> +			val |= TUSB1046_GENERAL_HPDIN_OVERRIDE;
> +		else
> +			val &= ~TUSB1046_GENERAL_HPDIN_OVERRIDE;
> +	}
> +
>  	ret = i2c_smbus_write_byte_data(client, TUSB1046_REG_GENERAL, val);
>  
>  out_unlock:
> @@ -131,6 +143,8 @@ static int tusb1046_i2c_probe(struct i2c_client *client)
>  		return -ENOMEM;
>  
>  	priv->client = client;
> +	priv->hpdin_override =
> +		device_property_read_bool(dev, "ti,hpd-in-override");
>  
>  	mutex_init(&priv->general_reg_lock);
>  
> -- 
> 2.50.1 (Apple Git-155)
> 

-- 
heikki