Re: [PATCH v8 08/14] usb: otg: add OTG/dual-role core

From: Roger Quadros
Date: Fri May 20 2016 - 05:19:35 EST

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In reply to: Roger Quadros: "Re: [PATCH v8 08/14] usb: otg: add OTG/dual-role core"
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On 20/05/16 11:31, Roger Quadros wrote:
> On 18/05/16 15:59, Roger Quadros wrote:
>> Hi Peter,
>>
>> On 18/05/16 10:45, Peter Chen wrote:
>>>
>>>
>>> On Mon, May 16, 2016 at 5:00 PM, Roger Quadros <rogerq@xxxxxx <mailto:rogerq@xxxxxx>> wrote:
>>>
>>> On 13/05/16 13:03, Roger Quadros wrote:
>>> > It provides APIs for the following tasks
>>> >
>>> > - Registering an OTG/dual-role capable controller
>>> > - Registering Host and Gadget controllers to OTG core
>>> > - Providing inputs to and kicking the OTG state machine
>>> >
>>> > Provide a dual-role device (DRD) state machine.
>>> > DRD mode is a reduced functionality OTG mode. In this mode
>>> > we don't support SRP, HNP and dynamic role-swap.
>>> >
>>> > In DRD operation, the controller mode (Host or Peripheral)
>>> > is decided based on the ID pin status. Once a cable plug (Type-A
>>> > or Type-B) is attached the controller selects the state
>>> > and doesn't change till the cable in unplugged and a different
>>> > cable type is inserted.
>>> >
>>> > As we don't need most of the complex OTG states and OTG timers
>>> > we implement a lean DRD state machine in usb-otg.c.
>>> > The DRD state machine is only interested in 2 hardware inputs
>>> > 'id' and 'b_sess_vld'.
>>> >
>>> > Signed-off-by: Roger Quadros <rogerq@xxxxxx <mailto:rogerq@xxxxxx>>
>>> > ---
>>> > drivers/usb/common/Makefile | 2 +-
>>> > drivers/usb/common/usb-otg.c | 1042 ++++++++++++++++++++++++++++++++++++++++++
>>> > drivers/usb/core/Kconfig | 4 +-
>>> > include/linux/usb/gadget.h | 2 +
>>> > include/linux/usb/hcd.h | 1 +
>>> > include/linux/usb/otg-fsm.h | 7 +
>>> > include/linux/usb/otg.h | 154 ++++++-
>>> > 7 files changed, 1206 insertions(+), 6 deletions(-)
>>> > create mode 100644 drivers/usb/common/usb-otg.c
>>>
>>>
>>> This patch causes the following build issues when CONFIG_USB_GADGET=m, CONFIG_USB=m,
>>> CONFIG_USB_COMMON=m and CONFIG_USB_OTG=y
>>>
>>> ERROR: "usb_otg_register_gadget" [drivers/usb/gadget/udc/udc-core.ko] undefined!
>>> ERROR: "usb_otg_unregister_gadget" [drivers/usb/gadget/udc/udc-core.ko] undefined!
>>> ERROR: "usb_otg_register_hcd" [drivers/usb/core/usbcore.ko] undefined!
>>> ERROR: "usb_otg_unregister_hcd" [drivers/usb/core/usbcore.ko] undefined!
>>> ERROR: "otg_statemachine" [drivers/usb/chipidea/ci_hdrc.ko] undefined!
>>> scripts/Makefile.modpost:91: recipe for target '__modpost' failed
>>> make[1]: *** [__modpost] Error 1
>>> Makefile:1141: recipe for target 'modules' failed
>>> make: *** [modules] Error 2
>>> make: *** Waiting for unfinished jobs....
>>>
>>> drivers/built-in.o: In function `drd_set_state':
>>> usb-otg.c:(.text+0x2b4242): undefined reference to `usb_otg_state_string'
>>> drivers/built-in.o: In function `drd_statemachine':
>>> (.text+0x2b4b4c): undefined reference to `usb_otg_state_string'
>>> Makefile:937: recipe for target 'vmlinux' failed
>>>
>>> I'll fix it up with the following diff.
>>>
>>> diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
>>> index dca7856..16a5b55 100644
>>> --- a/drivers/usb/Makefile
>>> +++ b/drivers/usb/Makefile
>>> @@ -59,5 +59,6 @@ obj-$(CONFIG_USB_RENESAS_USBHS) += renesas_usbhs/
>>> obj-$(CONFIG_USB_GADGET) += gadget/
>>>
>>> obj-$(CONFIG_USB_COMMON) += common/
>>> +obj-$(CONFIG_USB_OTG) += common/
>>>
>>> obj-$(CONFIG_USBIP_CORE) += usbip/
>>> diff --git a/drivers/usb/common/usb-otg.c b/drivers/usb/common/usb-otg.c
>>> index 77048aa..17e449e 100644
>>> --- a/drivers/usb/common/usb-otg.c
>>> +++ b/drivers/usb/common/usb-otg.c
>>> @@ -56,6 +56,30 @@ static int usb_otg_hcd_is_primary_hcd(struct usb_hcd *hcd)
>>> return hcd == hcd->primary_hcd;
>>> }
>>>
>>> +static const char *otg_state_string(enum usb_otg_state state)
>>> +{
>>> + static const char *const names[] = {
>>> + [OTG_STATE_A_IDLE] = "a_idle",
>>> + [OTG_STATE_A_WAIT_VRISE] = "a_wait_vrise",
>>> + [OTG_STATE_A_WAIT_BCON] = "a_wait_bcon",
>>> + [OTG_STATE_A_HOST] = "a_host",
>>> + [OTG_STATE_A_SUSPEND] = "a_suspend",
>>> + [OTG_STATE_A_PERIPHERAL] = "a_peripheral",
>>> + [OTG_STATE_A_WAIT_VFALL] = "a_wait_vfall",
>>> + [OTG_STATE_A_VBUS_ERR] = "a_vbus_err",
>>> + [OTG_STATE_B_IDLE] = "b_idle",
>>> + [OTG_STATE_B_SRP_INIT] = "b_srp_init",
>>> + [OTG_STATE_B_PERIPHERAL] = "b_peripheral",
>>> + [OTG_STATE_B_WAIT_ACON] = "b_wait_acon",
>>> + [OTG_STATE_B_HOST] = "b_host",
>>> + };
>>> +
>>> + if (state < 0 || state >= ARRAY_SIZE(names))
>>> + return "UNDEFINED";
>>> +
>>> + return names[state];
>>> +}
>>> +
>>>
>>>
>>>
>>> From my point, make another copy for otg stuff is not a good way,
>>> could we make folder under usb/ named otg for dedicated otg stuffs,
>>> in that case, build otg stuffs can not depend on USB_COMMON.
>>
>> OK. I can try that. I'll delete otg_state_string from usb-common.c and
>> move it into usb/otg/usb-otg.c
>>
>> I'll also move usb-otg-fsm.c to usb/otg/.
>
> But we can't delete usb_otg_state_string() from usb-common.c. That is used at a
> number of places whether OTG is enabled or not.
>
> One option is to make usb-common built in when otg is enabled. What do you say?
>

This should also get solved if we make USB_OTG tristate so that it is same as
USB_COMMON.

However I haven't had success in making Kconfig behave like this.

USB_OTG = y if USB == y && GADGET = m
USB_OTG = y if USB == m && GADGET = y

Is there any Kconfig trickery to get this behaviour?

cheers,
-roger

> cheers,
> -roger
>
>>> /**
>>> * Check if the OTG device is in our wait list and return
>>> * otg_wait_data, else NULL.
>>> @@ -433,7 +457,7 @@ static void drd_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
>>>
>>> fsm->state_changed = 1;
>>> dev_dbg(otg->dev, "otg: set state: %s\n",
>>> - usb_otg_state_string(new_state));
>>> + otg_state_string(new_state));
>>> switch (new_state) {
>>> case OTG_STATE_B_IDLE:
>>> drd_set_protocol(fsm, PROTO_UNDEF);
>>> @@ -449,7 +473,7 @@ static void drd_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
>>> break;
>>> default:
>>> dev_warn(otg->dev, "%s: otg: invalid state: %s\n",
>>> - __func__, usb_otg_state_string(new_state));
>>> + __func__, otg_state_string(new_state));
>>> break;
>>> }
>>>
>>> @@ -507,7 +531,7 @@ int drd_statemachine(struct usb_otg *otg)
>>>
>>> default:
>>> dev_err(otg->dev, "%s: otg: invalid usb-drd state: %s\n",
>>> - __func__, usb_otg_state_string(state));
>>> + __func__, otg_state_string(state));
>>> break;
>>> }
>>>
>>> --
>>> cheers,
>>> -roger
>>> --
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>>>
>>>
>>>
>>> --
>>> BR,
>>> Peter Chen
>> --
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Next message: Eric Auger: "Re: [PATCH] vfio: platform: use vfio_iommu_group_get/put"
Previous message: Guenter Roeck: "Re: Crash in -next due to 'drivers/of: Fix depth when unflattening devicetree'"
In reply to: Roger Quadros: "Re: [PATCH v8 08/14] usb: otg: add OTG/dual-role core"
Next in thread: Peter Chen: "Re: [PATCH v8 08/14] usb: otg: add OTG/dual-role core"
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