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

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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: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Badhri Jagan Sridharan 2017-08-28 10:23:20 -07:00 committed by Greg Kroah-Hartman
parent f3b73364a1
commit b965b6317f
2 changed files with 24 additions and 3 deletions
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2
drivers/staging/typec/pd.h
View file

@ -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 */

25
drivers/staging/typec/tcpm.c
View file

@ -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;