Re: [PATCH v6 6/6] typec: tcpm: Add support for sink PPS related messages

[Guenter Roeck]

On Thu, Mar 22, 2018 at 03:52:07PM +0000, Adam Thomson wrote:
> This commit adds sink side support for Get_Status, Status,
> Get_PPS_Status and PPS_Status handling. As there's the
> potential for a partner to respond with Not_Supported,
> handling of this message is also added. Sending of
> Not_Supported is added to handle messagescreceived but not
> yet handled.
> 
> Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>
> Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
>  drivers/usb/typec/tcpm.c | 143 ++++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 134 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c
> index c859cba..fffe97d 100644
> --- a/drivers/usb/typec/tcpm.c
> +++ b/drivers/usb/typec/tcpm.c
> @@ -19,7 +19,9 @@
>  #include <linux/slab.h>
>  #include <linux/spinlock.h>
>  #include <linux/usb/pd.h>
> +#include <linux/usb/pd_ado.h>
>  #include <linux/usb/pd_bdo.h>
> +#include <linux/usb/pd_ext_sdb.h>
>  #include <linux/usb/pd_vdo.h>
>  #include <linux/usb/tcpm.h>
>  #include <linux/usb/typec.h>
> @@ -113,6 +115,11 @@
>  	S(SNK_TRYWAIT_VBUS),			\
>  	S(BIST_RX),				\
>  						\
> +	S(GET_STATUS_SEND),			\
> +	S(GET_STATUS_SEND_TIMEOUT),		\
> +	S(GET_PPS_STATUS_SEND),			\
> +	S(GET_PPS_STATUS_SEND_TIMEOUT),		\
> +						\
>  	S(ERROR_RECOVERY),			\
>  	S(PORT_RESET),				\
>  	S(PORT_RESET_WAIT_OFF)
> @@ -143,6 +150,7 @@ enum pd_msg_request {
>  	PD_MSG_NONE = 0,
>  	PD_MSG_CTRL_REJECT,
>  	PD_MSG_CTRL_WAIT,
> +	PD_MSG_CTRL_NOT_SUPP,
>  	PD_MSG_DATA_SINK_CAP,
>  	PD_MSG_DATA_SOURCE_CAP,
>  };
> @@ -1398,10 +1406,42 @@ static int tcpm_validate_caps(struct tcpm_port *port, const u32 *pdo,
>  /*
>   * PD (data, control) command handling functions
>   */
> +static inline enum tcpm_state ready_state(struct tcpm_port *port)
> +{
> +	if (port->pwr_role == TYPEC_SOURCE)
> +		return SRC_READY;
> +	else
> +		return SNK_READY;
> +}
>  
>  static int tcpm_pd_send_control(struct tcpm_port *port,
>  				enum pd_ctrl_msg_type type);
>  
> +static void tcpm_handle_alert(struct tcpm_port *port, const __le32 *payload,
> +			      int cnt)
> +{
> +	u32 p0 = le32_to_cpu(payload[0]);
> +	unsigned int type = usb_pd_ado_type(p0);
> +
> +	if (!type) {
> +		tcpm_log(port, "Alert message received with no type");
> +		return;
> +	}
> +
> +	/* Just handling non-battery alerts for now */
> +	if (!(type & USB_PD_ADO_TYPE_BATT_STATUS_CHANGE)) {
> +		switch (port->state) {
> +		case SRC_READY:
> +		case SNK_READY:
> +			tcpm_set_state(port, GET_STATUS_SEND, 0);
> +			break;
> +		default:
> +			tcpm_queue_message(port, PD_MSG_CTRL_WAIT);
> +			break;
> +		}
> +	}
> +}
> +
>  static void tcpm_pd_data_request(struct tcpm_port *port,
>  				 const struct pd_message *msg)
>  {
> @@ -1487,6 +1527,14 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
>  			tcpm_set_state(port, BIST_RX, 0);
>  		}
>  		break;
> +	case PD_DATA_ALERT:
> +		tcpm_handle_alert(port, msg->payload, cnt);
> +		break;
> +	case PD_DATA_BATT_STATUS:
> +	case PD_DATA_GET_COUNTRY_INFO:
> +		/* Currently unsupported */
> +		tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
> +		break;
>  	default:
>  		tcpm_log(port, "Unhandled data message type %#x", type);
>  		break;
> @@ -1569,6 +1617,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
>  		break;
>  	case PD_CTRL_REJECT:
>  	case PD_CTRL_WAIT:
> +	case PD_CTRL_NOT_SUPP:
>  		switch (port->state) {
>  		case SNK_NEGOTIATE_CAPABILITIES:
>  			/* USB PD specification, Figure 8-43 */
> @@ -1688,12 +1737,75 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
>  			break;
>  		}
>  		break;
> +	case PD_CTRL_GET_SOURCE_CAP_EXT:
> +	case PD_CTRL_GET_STATUS:
> +	case PD_CTRL_FR_SWAP:
> +	case PD_CTRL_GET_PPS_STATUS:
> +	case PD_CTRL_GET_COUNTRY_CODES:
> +		/* Currently not supported */
> +		tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
> +		break;
>  	default:
>  		tcpm_log(port, "Unhandled ctrl message type %#x", type);
>  		break;
>  	}
>  }
>  
> +static void tcpm_pd_ext_msg_request(struct tcpm_port *port,
> +				    const struct pd_message *msg)
> +{
> +	enum pd_ext_msg_type type = pd_header_type_le(msg->header);
> +	unsigned int data_size = pd_ext_header_data_size_le(msg->ext_msg.header);
> +
> +	if (!(msg->ext_msg.header && PD_EXT_HDR_CHUNKED)) {
> +		tcpm_log(port, "Unchunked extended messages unsupported");
> +		return;
> +	}
> +
> +	if (data_size > (PD_EXT_MAX_CHUNK_DATA)) {

I really think you can trust that the compiler understands that it is supposed
to compare against PD_EXT_MAX_CHUNK_DATA.

> +		tcpm_log(port, "Chunk handling not yet supported");
> +		return;
> +	}
> +
> +	switch (type) {
> +	case PD_EXT_STATUS:
> +		/*
> +		 * If PPS related events raised then get PPS status to clear
> +		 * (see USB PD 3.0 Spec, 6.5.2.4)
> +		 */
> +		if (msg->ext_msg.data[USB_PD_EXT_SDB_EVENT_FLAGS] &
> +		    USB_PD_EXT_SDB_PPS_EVENTS)
> +			tcpm_set_state(port, GET_PPS_STATUS_SEND, 0);
> +		else
> +			tcpm_set_state(port, ready_state(port), 0);
> +		break;
> +	case PD_EXT_PPS_STATUS:
> +		/*
> +		 * For now the PPS status message is used to clear events
> +		 * and nothing more.
> +		 */
> +		tcpm_set_state(port, ready_state(port), 0);
> +		break;
> +	case PD_EXT_SOURCE_CAP_EXT:
> +	case PD_EXT_GET_BATT_CAP:
> +	case PD_EXT_GET_BATT_STATUS:
> +	case PD_EXT_BATT_CAP:
> +	case PD_EXT_GET_MANUFACTURER_INFO:
> +	case PD_EXT_MANUFACTURER_INFO:
> +	case PD_EXT_SECURITY_REQUEST:
> +	case PD_EXT_SECURITY_RESPONSE:
> +	case PD_EXT_FW_UPDATE_REQUEST:
> +	case PD_EXT_FW_UPDATE_RESPONSE:
> +	case PD_EXT_COUNTRY_INFO:
> +	case PD_EXT_COUNTRY_CODES:
> +		tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
> +		break;
> +	default:
> +		tcpm_log(port, "Unhandle extended message type %#x", type);

s/Unhandle/Unhandled/

> +		break;
> +	}
> +}
> +
>  static void tcpm_pd_rx_handler(struct work_struct *work)
>  {
>  	struct pd_rx_event *event = container_of(work,
> @@ -1734,7 +1846,9 @@ static void tcpm_pd_rx_handler(struct work_struct *work)
>  				 "Data role mismatch, initiating error recovery");
>  			tcpm_set_state(port, ERROR_RECOVERY, 0);
>  		} else {
> -			if (cnt)
> +			if (msg->header & PD_HEADER_EXT_HDR)
> +				tcpm_pd_ext_msg_request(port, msg);
> +			else if (cnt)
>  				tcpm_pd_data_request(port, msg);
>  			else
>  				tcpm_pd_ctrl_request(port, msg);
> @@ -1795,6 +1909,9 @@ static bool tcpm_send_queued_message(struct tcpm_port *port)
>  		case PD_MSG_CTRL_REJECT:
>  			tcpm_pd_send_control(port, PD_CTRL_REJECT);
>  			break;
> +		case PD_MSG_CTRL_NOT_SUPP:
> +			tcpm_pd_send_control(port, PD_CTRL_NOT_SUPP);
> +			break;
>  		case PD_MSG_DATA_SINK_CAP:
>  			tcpm_pd_send_sink_caps(port);
>  			break;
> @@ -2481,14 +2598,6 @@ static inline enum tcpm_state hard_reset_state(struct tcpm_port *port)
>  	return SNK_UNATTACHED;
>  }
>  
> -static inline enum tcpm_state ready_state(struct tcpm_port *port)
> -{
> -	if (port->pwr_role == TYPEC_SOURCE)
> -		return SRC_READY;
> -	else
> -		return SNK_READY;
> -}
> -
>  static inline enum tcpm_state unattached_state(struct tcpm_port *port)
>  {
>  	if (port->port_type == TYPEC_PORT_DRP) {
> @@ -3191,6 +3300,22 @@ static void run_state_machine(struct tcpm_port *port)
>  		/* Always switch to unattached state */
>  		tcpm_set_state(port, unattached_state(port), 0);
>  		break;
> +	case GET_STATUS_SEND:
> +		tcpm_pd_send_control(port, PD_CTRL_GET_STATUS);
> +		tcpm_set_state(port, GET_STATUS_SEND_TIMEOUT,
> +			       PD_T_SENDER_RESPONSE);
> +		break;
> +	case GET_STATUS_SEND_TIMEOUT:
> +		tcpm_set_state(port, ready_state(port), 0);
> +		break;
> +	case GET_PPS_STATUS_SEND:
> +		tcpm_pd_send_control(port, PD_CTRL_GET_PPS_STATUS);
> +		tcpm_set_state(port, GET_PPS_STATUS_SEND_TIMEOUT,
> +			       PD_T_SENDER_RESPONSE);
> +		break;
> +	case GET_PPS_STATUS_SEND_TIMEOUT:
> +		tcpm_set_state(port, ready_state(port), 0);
> +		break;
>  	case ERROR_RECOVERY:
>  		tcpm_swap_complete(port, -EPROTO);
>  		tcpm_pps_complete(port, -EPROTO);
> -- 
> 1.9.1
>