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

[Ley Foon Tan]

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.

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.

>
>> +             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