Re: [PATCH v3 3/3] usb: typec: hd3ss3220: support configuring role preference based on fwnode property and typec_operation

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

On Wed, Dec 11, 2024 at 05:32:47PM +0100, Oliver Facklam wrote:
> The TI HD3SS3220 Type-C controller supports configuring
> its role preference when operating as a dual-role port
> through the SOURCE_PREF field of the General Control Register.
> 
> The previous driver behavior was to set the role preference
> based on the dr_set typec_operation.
> However, the controller does not support swapping the data role
> on an active connection due to its lack of Power Delivery support.
> 
> Remove previous dr_set typec_operation, and support setting
> the role preference based on the corresponding fwnode property,
> as well as the try_role typec_operation.
> 
> Signed-off-by: Oliver Facklam <oliver.facklam@zuehlke.com>

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

> ---
>  drivers/usb/typec/hd3ss3220.c | 72 ++++++++++++++++++++++++++++---------------
>  1 file changed, 47 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/usb/typec/hd3ss3220.c b/drivers/usb/typec/hd3ss3220.c
> index e2059b925ab15733ff097e940751759ed51e0ab3..3ecc688dda82a371929e204a490a68c8e9d81fe9 100644
> --- a/drivers/usb/typec/hd3ss3220.c
> +++ b/drivers/usb/typec/hd3ss3220.c
> @@ -127,8 +127,25 @@ static int hd3ss3220_set_port_type(struct hd3ss3220 *hd3ss3220, int type)
>  	return err;
>  }
>  
> -static int hd3ss3220_set_source_pref(struct hd3ss3220 *hd3ss3220, int src_pref)
> +static int hd3ss3220_set_source_pref(struct hd3ss3220 *hd3ss3220, int prefer_role)
>  {
> +	int src_pref;
> +
> +	switch (prefer_role) {
> +	case TYPEC_NO_PREFERRED_ROLE:
> +		src_pref = HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_DEFAULT;
> +		break;
> +	case TYPEC_SINK:
> +		src_pref = HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_TRY_SNK;
> +		break;
> +	case TYPEC_SOURCE:
> +		src_pref = HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_TRY_SRC;
> +		break;
> +	default:
> +		dev_err(hd3ss3220->dev, "bad role preference: %d\n", prefer_role);
> +		return -EINVAL;
> +	}
> +
>  	return regmap_update_bits(hd3ss3220->regmap, HD3SS3220_REG_GEN_CTRL,
>  				  HD3SS3220_REG_GEN_CTRL_SRC_PREF_MASK,
>  				  src_pref);
> @@ -160,27 +177,11 @@ static enum usb_role hd3ss3220_get_attached_state(struct hd3ss3220 *hd3ss3220)
>  	return attached_state;
>  }
>  
> -static int hd3ss3220_dr_set(struct typec_port *port, enum typec_data_role role)
> +static int hd3ss3220_try_role(struct typec_port *port, int role)
>  {
>  	struct hd3ss3220 *hd3ss3220 = typec_get_drvdata(port);
> -	enum usb_role role_val;
> -	int pref, ret = 0;
>  
> -	if (role == TYPEC_HOST) {
> -		role_val = USB_ROLE_HOST;
> -		pref = HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_TRY_SRC;
> -	} else {
> -		role_val = USB_ROLE_DEVICE;
> -		pref = HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_TRY_SNK;
> -	}
> -
> -	ret = hd3ss3220_set_source_pref(hd3ss3220, pref);
> -	usleep_range(10, 100);
> -
> -	usb_role_switch_set_role(hd3ss3220->role_sw, role_val);
> -	typec_set_data_role(hd3ss3220->port, role);
> -
> -	return ret;
> +	return hd3ss3220_set_source_pref(hd3ss3220, role);
>  }
>  
>  static int hd3ss3220_port_type_set(struct typec_port *port, enum typec_port_type type)
> @@ -191,7 +192,7 @@ static int hd3ss3220_port_type_set(struct typec_port *port, enum typec_port_type
>  }
>  
>  static const struct typec_operations hd3ss3220_ops = {
> -	.dr_set = hd3ss3220_dr_set,
> +	.try_role = hd3ss3220_try_role,
>  	.port_type_set = hd3ss3220_port_type_set,
>  };
>  
> @@ -200,9 +201,6 @@ static void hd3ss3220_set_role(struct hd3ss3220 *hd3ss3220)
>  	enum usb_role role_state = hd3ss3220_get_attached_state(hd3ss3220);
>  
>  	usb_role_switch_set_role(hd3ss3220->role_sw, role_state);
> -	if (role_state == USB_ROLE_NONE)
> -		hd3ss3220_set_source_pref(hd3ss3220,
> -				HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_DEFAULT);
>  
>  	switch (role_state) {
>  	case USB_ROLE_HOST:
> @@ -293,6 +291,28 @@ static int hd3ss3220_configure_port_type(struct hd3ss3220 *hd3ss3220,
>  	return hd3ss3220_set_port_type(hd3ss3220, cap->type);
>  }
>  
> +static int hd3ss3220_configure_source_pref(struct hd3ss3220 *hd3ss3220,
> +					   struct fwnode_handle *connector,
> +					   struct typec_capability *cap)
> +{
> +	/*
> +	 * Preferred role can be configured through device tree
> +	 */
> +	const char *cap_str;
> +	int ret;
> +
> +	ret = fwnode_property_read_string(connector, "try-power-role", &cap_str);
> +	if (ret)
> +		return 0;
> +
> +	ret = typec_find_power_role(cap_str);
> +	if (ret < 0)
> +		return ret;
> +
> +	cap->prefer_role = ret;
> +	return hd3ss3220_set_source_pref(hd3ss3220, cap->prefer_role);
> +}
> +
>  static const struct regmap_config config = {
>  	.reg_bits = 8,
>  	.val_bits = 8,
> @@ -319,8 +339,6 @@ static int hd3ss3220_probe(struct i2c_client *client)
>  	if (IS_ERR(hd3ss3220->regmap))
>  		return PTR_ERR(hd3ss3220->regmap);
>  
> -	hd3ss3220_set_source_pref(hd3ss3220,
> -				  HD3SS3220_REG_GEN_CTRL_SRC_PREF_DRP_DEFAULT);
>  	/* For backward compatibility check the connector child node first */
>  	connector = device_get_named_child_node(hd3ss3220->dev, "connector");
>  	if (connector) {
> @@ -348,6 +366,10 @@ static int hd3ss3220_probe(struct i2c_client *client)
>  	typec_cap.ops = &hd3ss3220_ops;
>  	typec_cap.fwnode = connector;
>  
> +	ret = hd3ss3220_configure_source_pref(hd3ss3220, connector, &typec_cap);
> +	if (ret < 0)
> +		goto err_put_role;
> +
>  	ret = hd3ss3220_configure_port_type(hd3ss3220, connector, &typec_cap);
>  	if (ret < 0)
>  		goto err_put_role;
> 
> -- 
> 2.34.1

-- 
heikki