From 285046aa11ad85a4de24891f5458d45f50d1bcc5 Mon Sep 17 00:00:00 2001
From: Gregory Herrero <gregory.herrero@intel.com>
Date: Wed, 29 Apr 2015 22:09:19 +0200
Subject: [PATCH] usb: dwc2: add hibernation core parameter

dwc2 may not be able to exit from hibernation if the hardware
does not provide a way to detect resume signalling in this state.
Thus, add the possibility to disable hibernation feature.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
 drivers/usb/dwc2/core.c      | 24 ++++++++++++++++++++++++
 drivers/usb/dwc2/core.h      |  7 +++++++
 drivers/usb/dwc2/core_intr.c |  7 ++++---
 drivers/usb/dwc2/platform.c  |  2 ++
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index 7f461e3bc7a1..e5b546f1152e 100644
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -342,6 +342,9 @@ int dwc2_exit_hibernation(struct dwc2_hsotg *hsotg, bool restore)
 	u32 pcgcctl;
 	int ret = 0;
 
+	if (!hsotg->core_params->hibernation)
+		return -ENOTSUPP;
+
 	pcgcctl = readl(hsotg->regs + PCGCTL);
 	pcgcctl &= ~PCGCTL_STOPPCLK;
 	writel(pcgcctl, hsotg->regs + PCGCTL);
@@ -392,6 +395,9 @@ int dwc2_enter_hibernation(struct dwc2_hsotg *hsotg)
 	u32 pcgcctl;
 	int ret = 0;
 
+	if (!hsotg->core_params->hibernation)
+		return -ENOTSUPP;
+
 	/* Backup all registers */
 	ret = dwc2_backup_global_registers(hsotg);
 	if (ret) {
@@ -2998,6 +3004,23 @@ static void dwc2_set_param_external_id_pin_ctl(struct dwc2_hsotg *hsotg,
 	hsotg->core_params->external_id_pin_ctl = val;
 }
 
+static void dwc2_set_param_hibernation(struct dwc2_hsotg *hsotg,
+		int val)
+{
+	if (DWC2_OUT_OF_BOUNDS(val, 0, 1)) {
+		if (val >= 0) {
+			dev_err(hsotg->dev,
+				"'%d' invalid for parameter hibernation\n",
+				val);
+			dev_err(hsotg->dev, "hibernation must be 0 or 1\n");
+		}
+		val = 0;
+		dev_dbg(hsotg->dev, "Setting hibernation to %d\n", val);
+	}
+
+	hsotg->core_params->hibernation = val;
+}
+
 /*
  * This function is called during module intialization to pass module parameters
  * for the DWC_otg core.
@@ -3043,6 +3066,7 @@ void dwc2_set_parameters(struct dwc2_hsotg *hsotg,
 	dwc2_set_param_otg_ver(hsotg, params->otg_ver);
 	dwc2_set_param_uframe_sched(hsotg, params->uframe_sched);
 	dwc2_set_param_external_id_pin_ctl(hsotg, params->external_id_pin_ctl);
+	dwc2_set_param_hibernation(hsotg, params->hibernation);
 }
 
 /**
diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index d7fb1f793207..53b8de03f102 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -336,6 +336,12 @@ enum dwc2_ep0_state {
  *                      case.
  *                      0 - No (default)
  *                      1 - Yes
+ * @hibernation:	Specifies whether the controller support hibernation.
+ *			If hibernation is enabled, the controller will enter
+ *			hibernation in both peripheral and host mode when
+ *			needed.
+ *			0 - No (default)
+ *			1 - Yes
  *
  * The following parameters may be specified when starting the module. These
  * parameters define how the DWC_otg controller should be configured. A
@@ -374,6 +380,7 @@ struct dwc2_core_params {
 	int ahbcfg;
 	int uframe_sched;
 	int external_id_pin_ctl;
+	int hibernation;
 };
 
 /**
diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index 9e510bb612bd..927be1e8b3dc 100644
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -347,7 +347,7 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
 			dctl &= ~DCTL_RMTWKUPSIG;
 			writel(dctl, hsotg->regs + DCTL);
 			ret = dwc2_exit_hibernation(hsotg, true);
-			if (ret)
+			if (ret && (ret != -ENOTSUPP))
 				dev_err(hsotg->dev, "exit hibernation failed\n");
 
 			call_gadget(hsotg, resume);
@@ -428,8 +428,9 @@ static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
 
 			ret = dwc2_enter_hibernation(hsotg);
 			if (ret) {
-				dev_err(hsotg->dev,
-					"enter hibernation failed\n");
+				if (ret != -ENOTSUPP)
+					dev_err(hsotg->dev,
+							"enter hibernation failed\n");
 				goto skip_power_saving;
 			}
 
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 2562c9019955..90935304185a 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -78,6 +78,7 @@ static const struct dwc2_core_params params_bcm2835 = {
 	.ahbcfg				= 0x10,
 	.uframe_sched			= 0,
 	.external_id_pin_ctl		= -1,
+	.hibernation			= -1,
 };
 
 static const struct dwc2_core_params params_rk3066 = {
@@ -107,6 +108,7 @@ static const struct dwc2_core_params params_rk3066 = {
 	.ahbcfg				= 0x7, /* INCR16 */
 	.uframe_sched			= -1,
 	.external_id_pin_ctl		= -1,
+	.hibernation			= -1,
 };
 
 /**