RE: [PATCH v6 07/12] usb: otg: add OTG/dual-role core

[Yoshihiro Shimoda]

Hi,

> From: Yoshihiro Shimoda
> Sent: Friday, April 15, 2016 6:59 PM
> 
> Hi,
> 
> > From: Roger Quadros
> > Sent: Thursday, April 14, 2016 8:32 PM
> >
> > On 14/04/16 14:15, Yoshihiro Shimoda wrote:
> > > Hi,
> > >
> < snip >
> > >>> @@ -865,7 +867,8 @@ int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
> > >>>  	 * we're ready only if we have shared HCD
> > >>>  	 * or we don't need shared HCD.
> > >>>  	 */
> > >>> -	if (otg->shared_hcd.hcd || !otg->primary_hcd.hcd->shared_hcd) {
> > >>> +	if (otg->shared_hcd.hcd || (!otg->caps->needs_companion &&
> > >>> +				    !otg->primary_hcd.hcd->shared_hcd)) {
> > >>>  		otg->host = hcd_to_bus(hcd);
> > >>>  		/* FIXME: set bus->otg_port if this is true OTG port with HNP */
> > >>>
> > >>
> > >> These changes look good to me. Thanks.
> > >
> > > Thank you for the comment.
> > > If we change the "needs_companion" place to the otg_config,
> > > do we need to add a flag into the otg, instead of otg->caps?
> >
> > Yes we can add a flag in struct usb_otg.
> 
> Thank you for the comment.
> 
> I made a fixed patch.
> So, should I send this patch to ML after you sent v7 patches?
> Or, would you apply this patch before you send v7 patches?

Oops, I sent this email without my patch...

---
Subject: [PATCH] usb: otg: add hcd companion support

Since some host controller (e.g. EHCI) needs a companion host controller
(e.g. OHCI), this patch adds such a configuration to use it in the OTG
core.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
 Documentation/devicetree/bindings/usb/generic.txt |  3 +++
 drivers/usb/common/usb-otg.c                      | 17 +++++++++++++----
 include/linux/usb/otg.h                           |  7 ++++++-
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt
index f6866c1..1db1c33 100644
--- a/Documentation/devicetree/bindings/usb/generic.txt
+++ b/Documentation/devicetree/bindings/usb/generic.txt
@@ -27,6 +27,9 @@ Optional properties:
  - otg-controller: phandle to otg controller. Host or gadget controllers can
 			contain this property to link it to a particular OTG
 			controller.
+ - hcd-needs-companion: must be present if otg controller is dealing with
+			EHCI host controller that needs a companion OHCI host
+			controller.
 
 This is an attribute to a USB controller such as:
 
diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
index 41e762a..83c8c96 100644
--- a/drivers/usb/common/usb-otg.c
+++ b/drivers/usb/common/usb-otg.c
@@ -20,6 +20,7 @@
 #include <linux/list.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
+#include <linux/usb/of.h>
 #include <linux/usb/otg.h>
 #include <linux/usb/gadget.h>
 #include <linux/workqueue.h>
@@ -600,6 +601,10 @@ struct usb_otg *usb_otg_register(struct device *dev,
 	else
 		INIT_WORK(&otg->work, usb_otg_work);
 
+	if (of_find_property(dev->of_node, "hcd-needs-companion", NULL) ||
+	    config->hcd_needs_companion)	/* needs comanion ? */
+		otg->flags |= OTG_FLAG_HCD_NEEDS_COMPANION;
+
 	otg->wq = create_singlethread_workqueue("usb_otg");
 	if (!otg->wq) {
 		dev_err(dev, "otg: %s: can't create workqueue\n",
@@ -823,13 +828,15 @@ int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
 	/* HCD will be started by OTG fsm when needed */
 	mutex_lock(&otg->fsm.lock);
 	if (otg->primary_hcd.hcd) {
-		/* probably a shared HCD ? */
-		if (usb_otg_hcd_is_primary_hcd(hcd)) {
+		/* probably a shared HCD or a companion OHCI HCD ? */
+		if (!(otg->flags & OTG_FLAG_HCD_NEEDS_COMPANION) &&
+		    usb_otg_hcd_is_primary_hcd(hcd)) {
 			dev_err(otg_dev, "otg: primary host already registered\n");
 			goto err;
 		}
 
-		if (hcd->shared_hcd == otg->primary_hcd.hcd) {
+		if (otg->flags & OTG_FLAG_HCD_NEEDS_COMPANION ||
+		    (hcd->shared_hcd == otg->primary_hcd.hcd)) {
 			if (otg->shared_hcd.hcd) {
 				dev_err(otg_dev, "otg: shared host already registered\n");
 				goto err;
@@ -865,7 +872,9 @@ int usb_otg_register_hcd(struct usb_hcd *hcd, unsigned int irqnum,
 	 * we're ready only if we have shared HCD
 	 * or we don't need shared HCD.
 	 */
-	if (otg->shared_hcd.hcd || !otg->primary_hcd.hcd->shared_hcd) {
+	if (otg->shared_hcd.hcd ||
+	    (!(otg->flags & OTG_FLAG_HCD_NEEDS_COMPANION) &&
+	     !otg->primary_hcd.hcd->shared_hcd)) {
 		otg->host = hcd_to_bus(hcd);
 		/* FIXME: set bus->otg_port if this is true OTG port with HNP */
 
diff --git a/include/linux/usb/otg.h b/include/linux/usb/otg.h
index b094352..6f4ca77 100644
--- a/include/linux/usb/otg.h
+++ b/include/linux/usb/otg.h
@@ -57,7 +57,8 @@ struct otg_hcd {
  * @list: list of otg controllers
  * @work: otg state machine work
  * @wq: otg state machine work queue
- * @flags: to track if host/gadget is running
+ * @flags: to track if host/gadget is running, or to indicate if hcd needs
+ *	   companion
  */
 struct usb_otg {
 	u8			default_a;
@@ -84,6 +85,7 @@ struct usb_otg {
 	u32 flags;
 #define OTG_FLAG_GADGET_RUNNING (1 << 0)
 #define OTG_FLAG_HOST_RUNNING (1 << 1)
+#define OTG_FLAG_HCD_NEEDS_COMPANION (1 << 2)
 	/* use otg->fsm.lock for serializing access */
 
 /*------------- deprecated interface -----------------------------*/
@@ -125,11 +127,14 @@ struct usb_otg_caps {
  * @caps: otg capabilities of the controller
  * @ops: otg fsm operations
  * @otg_work: optional custom otg state machine work function
+ * @hcd_needs_companion: Indicates if host controller needs a companion
+ *			 controller
  */
 struct usb_otg_config {
 	struct usb_otg_caps *otg_caps;
 	struct otg_fsm_ops *fsm_ops;
 	void (*otg_work)(struct work_struct *work);
+	bool hcd_needs_companion;
 };
 
 extern const char *usb_otg_state_string(enum usb_otg_state state);
-- 
1.9.1