Re: [PATCH 3/3] usb: typec: ps883x: Add USB4 mode and TBT3 altmode support

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Tue, Oct 14, 2025 at 06:06:47PM +0200, Konrad Dybcio wrote:
> From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> 
> This chip can do some more than the driver currently describes. Add
> support for configuring it for various flavors of TBT3/USB4 operation.
> 
> Reviewed-by: Jack Pham <jack.pham@oss.qualcomm.com>
> Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

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

> ---
>  drivers/usb/typec/mux/ps883x.c | 29 +++++++++++++++++++++++++++++
>  include/linux/usb/typec_tbt.h  |  1 +
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/usb/typec/mux/ps883x.c b/drivers/usb/typec/mux/ps883x.c
> index 72f1e737ca4b..7c61629b36d6 100644
> --- a/drivers/usb/typec/mux/ps883x.c
> +++ b/drivers/usb/typec/mux/ps883x.c
> @@ -14,15 +14,18 @@
>  #include <linux/mutex.h>
>  #include <linux/regmap.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/usb/pd.h>
>  #include <linux/usb/typec_altmode.h>
>  #include <linux/usb/typec_dp.h>
>  #include <linux/usb/typec_mux.h>
>  #include <linux/usb/typec_retimer.h>
> +#include <linux/usb/typec_tbt.h>
>  
>  #define REG_USB_PORT_CONN_STATUS_0		0x00
>  
>  #define CONN_STATUS_0_CONNECTION_PRESENT	BIT(0)
>  #define CONN_STATUS_0_ORIENTATION_REVERSED	BIT(1)
> +#define CONN_STATUS_0_ACTIVE_CABLE		BIT(2)
>  #define CONN_STATUS_0_USB_3_1_CONNECTED		BIT(5)
>  
>  #define REG_USB_PORT_CONN_STATUS_1		0x01
> @@ -34,6 +37,10 @@
>  
>  #define REG_USB_PORT_CONN_STATUS_2		0x02
>  
> +#define CONN_STATUS_2_TBT_CONNECTED		BIT(0)
> +#define CONN_STATUS_2_TBT_UNIDIR_LSRX_ACT_LT	BIT(4)
> +#define CONN_STATUS_2_USB4_CONNECTED		BIT(7)
> +
>  struct ps883x_retimer {
>  	struct i2c_client *client;
>  	struct gpio_desc *reset_gpio;
> @@ -95,6 +102,8 @@ static int ps883x_configure(struct ps883x_retimer *retimer, int cfg0,
>  
>  static int ps883x_set(struct ps883x_retimer *retimer, struct typec_retimer_state *state)
>  {
> +	struct typec_thunderbolt_data *tb_data;
> +	const struct enter_usb_data *eudo_data;
>  	int cfg0 = CONN_STATUS_0_CONNECTION_PRESENT;
>  	int cfg1 = 0x00;
>  	int cfg2 = 0x00;
> @@ -120,6 +129,18 @@ static int ps883x_set(struct ps883x_retimer *retimer, struct typec_retimer_state
>  				break;
>  			}
>  			break;
> +		case USB_TYPEC_TBT_SID:
> +			tb_data = state->data;
> +
> +			/* Unconditional */
> +			cfg2 |= CONN_STATUS_2_TBT_CONNECTED;
> +
> +			if (tb_data->cable_mode & TBT_CABLE_ACTIVE_PASSIVE)
> +				cfg0 |= CONN_STATUS_0_ACTIVE_CABLE;
> +
> +			if (tb_data->enter_vdo & TBT_ENTER_MODE_UNI_DIR_LSRX)
> +				cfg2 |= CONN_STATUS_2_TBT_UNIDIR_LSRX_ACT_LT;
> +			break;
>  		default:
>  			dev_err(&retimer->client->dev, "Got unsupported SID: 0x%x\n",
>  				state->alt->svid);
> @@ -135,6 +156,14 @@ static int ps883x_set(struct ps883x_retimer *retimer, struct typec_retimer_state
>  		case TYPEC_MODE_USB3:
>  			cfg0 |= CONN_STATUS_0_USB_3_1_CONNECTED;
>  			break;
> +		case TYPEC_MODE_USB4:
> +			eudo_data = state->data;
> +
> +			cfg2 |= CONN_STATUS_2_USB4_CONNECTED;
> +
> +			if (FIELD_GET(EUDO_CABLE_TYPE_MASK, eudo_data->eudo) != EUDO_CABLE_TYPE_PASSIVE)
> +				cfg0 |= CONN_STATUS_0_ACTIVE_CABLE;
> +			break;
>  		default:
>  			dev_err(&retimer->client->dev, "Got unsupported mode: %lu\n",
>  				state->mode);
> diff --git a/include/linux/usb/typec_tbt.h b/include/linux/usb/typec_tbt.h
> index 55dcea12082c..0b570f1b8bc8 100644
> --- a/include/linux/usb/typec_tbt.h
> +++ b/include/linux/usb/typec_tbt.h
> @@ -55,6 +55,7 @@ struct typec_thunderbolt_data {
>  
>  /* TBT3 Device Enter Mode VDO bits */
>  #define TBT_ENTER_MODE_CABLE_SPEED(s)	TBT_SET_CABLE_SPEED(s)
> +#define TBT_ENTER_MODE_UNI_DIR_LSRX	BIT(23)
>  #define TBT_ENTER_MODE_ACTIVE_CABLE	BIT(24)
>  
>  #endif /* __USB_TYPEC_TBT_H */
> 
> -- 
> 2.51.0

-- 
heikki