Hi,
>
>On 11/08/2019 14:59, Pawel Laszczak wrote:
>> Hi,
>>
>>>
>>> On 21/07/2019 21:32, Pawel Laszczak wrote:
>>>> This patch introduce new Cadence USBSS DRD driver to Linux kernel.
>>>>
>>>> The Cadence USBSS DRD Controller is a highly configurable IP Core which
>>>> can be instantiated as Dual-Role Device (DRD), Peripheral Only and
>>>> Host Only (XHCI)configurations.
>>>>
>>>> The current driver has been validated with FPGA platform. We have
>>>> support for PCIe bus, which is used on FPGA prototyping.
>>>>
>>>> The host side of USBSS-DRD controller is compliant with XHCI
>>>> specification, so it works with standard XHCI Linux driver.
>>>>
>>>> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
>>>> ---
>>>> drivers/usb/Kconfig | 2 +
>>>> drivers/usb/Makefile | 2 +
>>>> drivers/usb/cdns3/Kconfig | 46 +
>>>> drivers/usb/cdns3/Makefile | 17 +
>>>> drivers/usb/cdns3/cdns3-pci-wrap.c | 203 +++
>>>> drivers/usb/cdns3/core.c | 554 +++++++
>>>> drivers/usb/cdns3/core.h | 109 ++
>>>> drivers/usb/cdns3/debug.h | 171 ++
>>>> drivers/usb/cdns3/debugfs.c | 87 ++
>>>> drivers/usb/cdns3/drd.c | 390 +++++
>>>> drivers/usb/cdns3/drd.h | 166 ++
>>>> drivers/usb/cdns3/ep0.c | 914 +++++++++++
>>>> drivers/usb/cdns3/gadget-export.h | 28 +
>>>> drivers/usb/cdns3/gadget.c | 2338 ++++++++++++++++++++++++++++
>>>> drivers/usb/cdns3/gadget.h | 1321 ++++++++++++++++
>>>> drivers/usb/cdns3/host-export.h | 28 +
>>>> drivers/usb/cdns3/host.c | 71 +
>>>> drivers/usb/cdns3/trace.c | 11 +
>>>> drivers/usb/cdns3/trace.h | 493 ++++++
>>>> 19 files changed, 6951 insertions(+)
>>>> create mode 100644 drivers/usb/cdns3/Kconfig
>>>> create mode 100644 drivers/usb/cdns3/Makefile
>>>> create mode 100644 drivers/usb/cdns3/cdns3-pci-wrap.c
>>>> create mode 100644 drivers/usb/cdns3/core.c
>>>> create mode 100644 drivers/usb/cdns3/core.h
>>>> create mode 100644 drivers/usb/cdns3/debug.h
>>>> create mode 100644 drivers/usb/cdns3/debugfs.c
>>>> create mode 100644 drivers/usb/cdns3/drd.c
>>>> create mode 100644 drivers/usb/cdns3/drd.h
>>>> create mode 100644 drivers/usb/cdns3/ep0.c
>>>> create mode 100644 drivers/usb/cdns3/gadget-export.h
>>>> create mode 100644 drivers/usb/cdns3/gadget.c
>>>> create mode 100644 drivers/usb/cdns3/gadget.h
>>>> create mode 100644 drivers/usb/cdns3/host-export.h
>>>> create mode 100644 drivers/usb/cdns3/host.c
>>>> create mode 100644 drivers/usb/cdns3/trace.c
>>>> create mode 100644 drivers/usb/cdns3/trace.h
>>>>
>>>> diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig
>>>> index e4b27413f528..c2e78882f8c2 100644
>>>> --- a/drivers/usb/Kconfig
>>>> +++ b/drivers/usb/Kconfig
>>>> @@ -113,6 +113,8 @@ source "drivers/usb/usbip/Kconfig"
>>>>
>>>> endif
>>>>
<snip>
>>>> + real_role = cdsn3_real_role_switch_get(cdns->dev);
>>>> +
>>>> + current_role = role;
>>>> + dev_dbg(cdns->dev, "Switching role");
>>>> +
>>>> + ret = cdns3_role_start(cdns, real_role);
>>>> + if (ret) {
>>>> + /* Back to current role */
>>>> + dev_err(cdns->dev, "set %d has failed, back to %d\n",
>>>> + role, current_role);
>>>> + ret = cdns3_role_start(cdns, current_role);
>>>> + if (ret)
>>>> + dev_err(cdns->dev, "back to %d failed too\n",
>>>> + current_role);
>>>> + }
>>>> +exit:
>>>> + pm_runtime_put_sync(cdns->dev);
>>>> + return ret;
>>>> +}
>>>> +
>>>> +static const struct usb_role_switch_desc cdns3_switch_desc = {
>>>> + .set = cdns3_role_switch_set,
>>>> + .get = cdsn3_real_role_switch_get,
>>>> + .allow_userspace_control = true,
>>>
>>> how does user initiated cdns3_role_switch_set() via sysfs co-exist with role
>>> changes done by hardware events. e.g. ID/VBUS?
>>>
>>
>> Do you expect any issues whit this, have you seen any problem with this
>> on your platform ?
>>
>> I assume that it should work in this way:
>> 1. user change role by sysfs
>> 2. Driver change the role according with user request.
>> 3. If we receive correct ID/VBUS then role should not be changed
>> because new role is the same as current set in point 2.
>>
>
>I have not tested this series yet.
>My understanding is that if user sets role to "host" or "device" then it should
>remain in that role irrespective of ID/VBUS. Once user sets it to "none" then
>port should set role based on ID/VBUS.
According with your understanding it works the same way as by debugfs.
Now I have no doubts to remove debugfs.c file :)
>
>>
>>>> +};
>>>> +
>>>> +/**
>>>> + * cdns3_probe - probe for cdns3 core device
>>>> + * @pdev: Pointer to cdns3 core platform device
>>>> + *
>>>> + * Returns 0 on success otherwise negative errno
>>>> + */
>>>> +static int cdns3_probe(struct platform_device *pdev)
<snip>
>>>> + * Returns 0 on success otherwise negative errno
>>>> + */
>>>> +int cdns3_drd_update_mode(struct cdns3 *cdns)
>>>> +{
>>>> + int ret = 0;
>>>> +
>>>> + if (cdns->desired_dr_mode == cdns->current_dr_mode)
>>>> + return ret;
>>>> +
>>>> + switch (cdns->desired_dr_mode) {
>>>> + case USB_DR_MODE_PERIPHERAL:
>>>> + ret = cdns3_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
>>>> + break;
>>>> + case USB_DR_MODE_HOST:
>>>> + ret = cdns3_set_mode(cdns, USB_DR_MODE_HOST);
>>>> + break;
>>>> + case USB_DR_MODE_OTG:
>>>> + ret = cdns3_init_otg_mode(cdns);
>>>> + break;
>>>> + default:
>>>> + dev_err(cdns->dev, "Unsupported mode of operation %d\n",
>>>> + cdns->dr_mode);
>>>> + return -EINVAL;
>>>> + }
>>>> +
>>>> + return ret;
>>>> +}
>>>> +
>>>> +static irqreturn_t cdns3_drd_thread_irq(int irq, void *data)
>>>> +{
>>>> + struct cdns3 *cdns = data;
>>>> +
>>>> + usb_role_switch_set_role(cdns->role_sw, cdns->role);
>>>
>>> How to ensure that HW events don't step over user chosen role?
>>
>> I need to think about this and find out how to test it and eventually force
>> such cases.
>>
>> But I assume that after attaching/detaching plug the user chosen role can
>> be forgotten.
>>
>
>No. Only when user sets role to none then role should be based on HW.
Ok, I will try to test it in next week.
>>>
>
><snip>
Cheers,
Pawell
