Commit b965b631 authored by Badhri Jagan Sridharan's avatar Badhri Jagan Sridharan Committed by Greg Kroah-Hartman
Browse files

staging: typec: tcpm: typec: tcpm: Wait for CC debounce before PD excg 



Once, Rp or Rd is switched, wait for PD_T_CC_DEBOUNCE. If not the
PS_RDY message transmitted might result in failure.
Also, Only wait for PD_T_SRCSWAPSTDBY while in
PR_SWAP_SRC_SNK_TRANSITION_OFF. PD_T_PS_SOURCE_OFF is the overall
time after which the initial sink would issue hard reset.

Signed-off-by: default avatarBadhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f3b73364

drivers/staging/typec/pd.h

+2 −0
Original line number Diff line number Diff line
@@ -278,6 +278,8 @@ static inline unsigned int rdo_max_power(u32 rdo) 
#define PD_T_VCONN_SOURCE_ON	100

#define PD_T_SINK_REQUEST	100	/* 100 ms minimum */

#define PD_T_ERROR_RECOVERY	100	/* minimum 25 is insufficient */

#define PD_T_SRCSWAPSTDBY      625     /* Maximum of 650ms */

#define PD_T_NEWSRC            250     /* Maximum of 275ms */



#define PD_T_DRP_TRY		100	/* 75 - 150 ms */

#define PD_T_DRP_TRYWAIT	600	/* 400 - 800 ms */

drivers/staging/typec/tcpm.c

+22 −3
Original line number Diff line number Diff line
@@ -90,9 +90,11 @@ 
	S(PR_SWAP_START),			\

	S(PR_SWAP_SRC_SNK_TRANSITION_OFF),	\

	S(PR_SWAP_SRC_SNK_SOURCE_OFF),		\

	S(PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED), \

	S(PR_SWAP_SRC_SNK_SINK_ON),		\

	S(PR_SWAP_SNK_SRC_SINK_OFF),		\

	S(PR_SWAP_SNK_SRC_SOURCE_ON),		\

	S(PR_SWAP_SNK_SRC_SOURCE_ON_VBUS_RAMPED_UP),    \

						\

	S(VCONN_SWAP_ACCEPT),			\

	S(VCONN_SWAP_SEND),			\
@@ -1400,7 +1402,7 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port, 
					       SNK_TRANSITION_SINK_VBUS, 0);

			}

			break;

		case PR_SWAP_SRC_SNK_SOURCE_OFF:

		case PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED:

			tcpm_set_state(port, PR_SWAP_SRC_SNK_SINK_ON, 0);

			break;

		case PR_SWAP_SNK_SRC_SINK_OFF:
@@ -2684,11 +2686,17 @@ static void run_state_machine(struct tcpm_port *port) 
	case PR_SWAP_SRC_SNK_TRANSITION_OFF:

		tcpm_set_vbus(port, false);

		port->explicit_contract = false;

		/* allow time for Vbus discharge, must be < tSrcSwapStdby */

		tcpm_set_state(port, PR_SWAP_SRC_SNK_SOURCE_OFF,

			       PD_T_PS_SOURCE_OFF);

			       PD_T_SRCSWAPSTDBY);

		break;

	case PR_SWAP_SRC_SNK_SOURCE_OFF:

		tcpm_set_cc(port, TYPEC_CC_RD);

		/* allow CC debounce */

		tcpm_set_state(port, PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED,

			       PD_T_CC_DEBOUNCE);

		break;

	case PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED:

		/*

		 * USB-PD standard, 6.2.1.4, Port Power Role:

		 * "During the Power Role Swap Sequence, for the initial Source
@@ -2714,6 +2722,15 @@ static void run_state_machine(struct tcpm_port *port) 
	case PR_SWAP_SNK_SRC_SOURCE_ON:

		tcpm_set_cc(port, tcpm_rp_cc(port));

		tcpm_set_vbus(port, true);

		/*

		 * allow time VBUS ramp-up, must be < tNewSrc

		 * Also, this window overlaps with CC debounce as well.

		 * So, Wait for the max of two which is PD_T_NEWSRC

		 */

		tcpm_set_state(port, PR_SWAP_SNK_SRC_SOURCE_ON_VBUS_RAMPED_UP,

			       PD_T_NEWSRC);

		break;

	case PR_SWAP_SNK_SRC_SOURCE_ON_VBUS_RAMPED_UP:

		/*

		 * USB PD standard, 6.2.1.4:

		 * "Subsequent Messages initiated by the Policy Engine,
@@ -2984,8 +3001,10 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1, 
	case PR_SWAP_SNK_SRC_SINK_OFF:

	case PR_SWAP_SRC_SNK_TRANSITION_OFF:

	case PR_SWAP_SRC_SNK_SOURCE_OFF:

	case PR_SWAP_SRC_SNK_SOURCE_OFF_CC_DEBOUNCED:

	case PR_SWAP_SNK_SRC_SOURCE_ON:

		/*

		 * CC state change is expected here; we just turned off power.

		 * CC state change is expected in PR_SWAP

		 * Ignore it.

		 */

		break;

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