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

From: Roger Quadros
Date: Wed Apr 20 2016 - 03:04:00 EST


On 20/04/16 08:08, Yoshihiro Shimoda wrote:
> Hi,
>
>> From: Peter Chen
>> Sent: Tuesday, April 19, 2016 6:18 PM
>>
>> On Fri, Apr 15, 2016 at 10:03:16AM +0000, Yoshihiro Shimoda wrote:
>>> 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 ? */
>>
>> %s/comanion/companion
>
> Thank you for pointing it out!
>
> Roger, would you fix this in your v7 patch set?

Yes, I'll fix it locally. You don't need to post it again.

--
cheers,
-roger

>
>> I have a little puzzled with companion controller and shared hcd, let me
>> post a topic for it.
>
> I looked at the email thread.
> It is very useful information to me! :)
>
> Best regards,
> Yoshihiro Shimoda
>
>> Peter
>>
>>> + 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
>>>
>>> --
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>>
>> --
>>
>> Best Regards,
>> Peter Chen