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: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/typec/pd.h b/drivers/staging/typec/pd.h
index 510ef72..30b32ad 100644 (file)
--- a/drivers/staging/typec/pd.h
+++ b/drivers/staging/typec/pd.h
@@ -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 */

diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index fa2e59b..36a7098 100644 (file)
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -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
@@ -2715,6 +2723,15 @@ static void run_state_machine(struct tcpm_port *port)
                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,
                 * such as the PS_RDY Message sent to indicate that Vbus
@@ -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;