usb: chipidea: support runtime power management for otg fsm mode

This patch adds runtime power management support for otg fsm mode, since
A-device in a_idle state cannot detect data pulse irq after suspended, here
enable wakeup by connection before suspend to make it can be resumed by DP;
and handle wakeup from that state like SRP.

Signed-off-by: Li Jun <jun.li@freescale.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 39 insertions, 4 deletions

diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 4b22d7c..74fea4f 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -798,11 +798,11 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 			: CI_ROLE_GADGET;
 	}
 
-	/* only update vbus status for peripheral */
-	if (ci->role == CI_ROLE_GADGET)
-		ci_handle_vbus_change(ci);
-
 	if (!ci_otg_is_fsm_mode(ci)) {
+		/* only update vbus status for peripheral */
+		if (ci->role == CI_ROLE_GADGET)
+			ci_handle_vbus_change(ci);
+
 		ret = ci_role_start(ci, ci->role);
 		if (ret) {
 			dev_err(dev, "can't start %s role\n",
@@ -861,6 +861,33 @@ static int ci_hdrc_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM
+/* Prepare wakeup by SRP before suspend */
+static void ci_otg_fsm_suspend_for_srp(struct ci_hdrc *ci)
+{
+	if ((ci->fsm.otg->state == OTG_STATE_A_IDLE) &&
+				!hw_read_otgsc(ci, OTGSC_ID)) {
+		hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_PP,
+								PORTSC_PP);
+		hw_write(ci, OP_PORTSC, PORTSC_W1C_BITS | PORTSC_WKCN,
+								PORTSC_WKCN);
+	}
+}
+
+/* Handle SRP when wakeup by data pulse */
+static void ci_otg_fsm_wakeup_by_srp(struct ci_hdrc *ci)
+{
+	if ((ci->fsm.otg->state == OTG_STATE_A_IDLE) &&
+		(ci->fsm.a_bus_drop == 1) && (ci->fsm.a_bus_req == 0)) {
+		if (!hw_read_otgsc(ci, OTGSC_ID)) {
+			ci->fsm.a_srp_det = 1;
+			ci->fsm.a_bus_drop = 0;
+		} else {
+			ci->fsm.id = 1;
+		}
+		ci_otg_queue_work(ci);
+	}
+}
+
 static void ci_controller_suspend(struct ci_hdrc *ci)
 {
 	disable_irq(ci->irq);
@@ -894,6 +921,8 @@ static int ci_controller_resume(struct device *dev)
 		pm_runtime_mark_last_busy(ci->dev);
 		pm_runtime_put_autosuspend(ci->dev);
 		enable_irq(ci->irq);
+		if (ci_otg_is_fsm_mode(ci))
+			ci_otg_fsm_wakeup_by_srp(ci);
 	}
 
 	return 0;
@@ -921,6 +950,9 @@ static int ci_suspend(struct device *dev)
 	}
 
 	if (device_may_wakeup(dev)) {
+		if (ci_otg_is_fsm_mode(ci))
+			ci_otg_fsm_suspend_for_srp(ci);
+
 		usb_phy_set_wakeup(ci->usb_phy, true);
 		enable_irq_wake(ci->irq);
 	}
@@ -963,6 +995,9 @@ static int ci_runtime_suspend(struct device *dev)
 		return 0;
 	}
 
+	if (ci_otg_is_fsm_mode(ci))
+		ci_otg_fsm_suspend_for_srp(ci);
+
 	usb_phy_set_wakeup(ci->usb_phy, true);
 	ci_controller_suspend(ci);