[U-Boot] [PATCH v2] usb: dwc2: Add reset ctrl to driver

[Marek Vasut]

On 08/16/2018 11:18 AM, Ley Foon Tan wrote:
> On Thu, Aug 16, 2018 at 4:26 PM, Marek Vasut <marex at denx.de> wrote:
>> On 08/16/2018 07:45 AM, Ley Foon Tan wrote:
>>> Add code to reset all reset signals as in usb DT node. A reset property
>>> is an optional feature, so only print out a warning and do not fail if a
>>> reset property is not present.
>>>
>>> If a reset property is discovered, then use it to deassert, thus
>>> bringing the IP out of reset.
>>>
>>> Signed-off-by: Ley Foon Tan <ley.foon.tan at intel.com>
>>>
>>> ---
>>> v2:
>>> - Assert reset when .remove.
>>> ---
>>>  drivers/usb/host/dwc2.c | 31 +++++++++++++++++++++++++++++++
>>>  1 file changed, 31 insertions(+)
>>>
>>> diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
>>> index cbe065b..bee3b33 100644
>>> --- a/drivers/usb/host/dwc2.c
>>> +++ b/drivers/usb/host/dwc2.c
>>> @@ -15,6 +15,7 @@
>>>  #include <wait_bit.h>
>>>  #include <asm/io.h>
>>>  #include <power/regulator.h>
>>> +#include <reset.h>
>>>
>>>  #include "dwc2.h"
>>>
>>> @@ -49,6 +50,8 @@ struct dwc2_priv {
>>>        */
>>>       bool hnp_srp_disable;
>>>       bool oc_disable;
>>> +
>>> +     struct reset_ctl_bulk   resets;
>>>  };
>>>
>>>  #ifndef CONFIG_DM_USB
>>> @@ -1124,11 +1127,37 @@ int _submit_int_msg(struct dwc2_priv *priv, struct usb_device *dev,
>>>       }
>>>  }
>>>
>>> +static int dwc2_reset(struct udevice *dev)
>>> +{
>>> +     int ret;
>>> +     struct dwc2_priv *priv = dev_get_priv(dev);
>>> +
>>> +     ret = reset_get_bulk(dev, &priv->resets);
>>> +     if (ret) {
>>> +             dev_warn(dev, "Can't get reset: %d\n", ret);
>>
>> So this now generates a ton of warnings on Gen5 , right ?
>> Did you test it on any Gen5 board recently ?
> 
> Will change to "return 0" if can't find reset in dts, so it will not
> fail the probe.

But that's a valid error. Maybe some ifdef CONFIG_RESET would be more
appropriate ? Look at what the other drivers do.

> It will not print warning by default. I don't have Gen5 board, but I
> tested with Stratix 10 by removing reset from USB DT node. We will not
> see the warning.

Paging Simon, he's been doing a lot of good work on Gen5 recently. You
should CC him on changes too :)

>>> +             return ret;
>>> +     }
>>> +
>>> +     ret = reset_deassert_bulk(&priv->resets);
>>> +     if (ret) {
>>> +             reset_release_bulk(&priv->resets);
>>> +             dev_err(dev, "Failed to reset: %d\n", ret);
>>> +             return ret;
>>> +     }
>>> +
>>> +     return 0;
>>> +}
>>> +
>>>  static int dwc2_init_common(struct udevice *dev, struct dwc2_priv *priv)
>>>  {
>>>       struct dwc2_core_regs *regs = priv->regs;
>>>       uint32_t snpsid;
>>>       int i, j;
>>> +     int ret;
>>> +
>>> +     ret = dwc2_reset(dev);
>>> +     if (ret)
>>> +             return ret;
>>>
>>>       snpsid = readl(&regs->gsnpsid);
>>>       dev_info(dev, "Core Release: %x.%03x\n",
>>> @@ -1303,6 +1332,8 @@ static int dwc2_usb_remove(struct udevice *dev)
>>>
>>>       dwc2_uninit_common(priv->regs);
>>>
>>> +     reset_release_bulk(&priv->resets);
>>
>> Dont you need to assert the resets too ?
> reset_release_bulk will assert the reset if it is requested before.
>>
>>>       return 0;
>>>  }
>>>
>>>
>>
> Regards
> Ley Foon
> 


-- 
Best regards,
Marek Vasut