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 ? */
> + 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);
> --
Hi Yoshihiro, the shared_hcd is used for USB3 only [1], this patch may
not be suitable for supporting companion controller at OTG framework.
For companion or other USB2 controllers, both primary hcd and shard hcd
are NULL for HCD core.
[1] http://www.spinics.net/lists/linux-usb/msg139630.html
--
Best Regards,
Peter Chen
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