usb: chipidea: otg: add A idle to B disconnect timer

B-device detects that bus is idle for more than TB_AIDL_BDIS min and
begins HNP by turning off pullup on DP, this allows the bus to discharge
to the SE0 state. This timer was missed and failed with PET test:
6.8.5 B-UUT HNP of USB OTG and EH automated compliance plan v1.2,
this patch is to fix this timing issue.

Acked-by: Peter Chen <[e-mail]>
Signed-off-by: Li Jun <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/chipidea/otg_fsm.c

···
 	TA_AIDL_BDIS,
 	TB_ASE0_BRST,
 	TA_BIDL_ADIS,
+	TB_AIDL_BDIS,
 	TB_SE0_SRP,
 	TB_SRP_FAIL,
 	0,
···
 	return 0;
 }
 
+static int b_aidl_bdis_tmout(struct ci_hdrc *ci)
+{
+	ci->fsm.a_bus_suspend = 1;
+	return 0;
+}
+
 static int b_se0_srp_tmout(struct ci_hdrc *ci)
 {
 	ci->fsm.b_se0_srp = 1;
···
 	a_aidl_bdis_tmout,	/* A_AIDL_BDIS */
 	b_ase0_brst_tmout,	/* B_ASE0_BRST */
 	a_bidl_adis_tmout,	/* A_BIDL_ADIS */
+	b_aidl_bdis_tmout,	/* B_AIDL_BDIS */
 	b_se0_srp_tmout,	/* B_SE0_SRP */
 	b_srp_fail_tmout,	/* B_SRP_FAIL */
 	NULL,			/* A_WAIT_ENUM */
···
 		break;
 	case OTG_STATE_B_PERIPHERAL:
 		if ((intr_sts & USBi_SLI) && port_conn && otg_bsess_vld) {
-			fsm->a_bus_suspend = 1;
-			ci_otg_queue_work(ci);
+			ci_otg_add_timer(ci, B_AIDL_BDIS);
 		} else if (intr_sts & USBi_PCI) {
+			ci_otg_del_timer(ci, B_AIDL_BDIS);
 			if (fsm->a_bus_suspend == 1)
 				fsm->a_bus_suspend = 0;
 		}

drivers/usb/chipidea/otg_fsm.h

···
 /* SSEND time before SRP */
 #define TB_SSEND_SRP         (1500)	/* minimum 1.5 sec, section:5.1.2 */
 
+#define TB_AIDL_BDIS         (20)	/* 4ms ~ 150ms, section 5.2.1 */
+
 #if IS_ENABLED(CONFIG_USB_OTG_FSM)
 
 int ci_hdrc_otg_fsm_init(struct ci_hdrc *ci);