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

Ley Foon Tan lftan.linux at gmail.com
Thu Aug 16 09:48:58 UTC 2018


On Thu, Aug 16, 2018 at 5:21 PM, Marek Vasut <marex at denx.de> wrote:
> 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.
Platforms that doesn't support reset framework shouldn't treat it as error.
Other drivers don't have CONFIG_RESET too.


>
>> 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
Regards
Ley Foon


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