[U-Boot] [PATCH v2] gpio: dwapb_gpio: Add reset ctrl to driver

Marek Vasut marex at denx.de
Thu Aug 16 09:45:28 UTC 2018


On 08/16/2018 11:39 AM, Ley Foon Tan wrote:
> On Thu, Aug 16, 2018 at 4:46 PM, Marek Vasut <marex at denx.de> wrote:
>> On 08/16/2018 10:39 AM, Ley Foon Tan wrote:
>>> On Thu, Aug 16, 2018 at 4:28 PM, Marek Vasut <marex at denx.de> wrote:
>>>> On 08/16/2018 07:46 AM, Ley Foon Tan wrote:
>>>>> Add code to reset all reset signals as in gpio 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:
>>>>> - Move reset to probe() function.
>>>>> ---
>>>>>  drivers/gpio/dwapb_gpio.c | 20 +++++++++++++++++++-
>>>>>  1 file changed, 19 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/gpio/dwapb_gpio.c b/drivers/gpio/dwapb_gpio.c
>>>>> index 7cf2d47..dfe1e6d 100644
>>>>> --- a/drivers/gpio/dwapb_gpio.c
>>>>> +++ b/drivers/gpio/dwapb_gpio.c
>>>>> @@ -15,6 +15,7 @@
>>>>>  #include <dm/lists.h>
>>>>>  #include <dm/root.h>
>>>>>  #include <errno.h>
>>>>> +#include <reset.h>
>>>>>
>>>>>  DECLARE_GLOBAL_DATA_PTR;
>>>>>
>>>>> @@ -99,13 +100,30 @@ static const struct dm_gpio_ops gpio_dwapb_ops = {
>>>>>       .get_function           = dwapb_gpio_get_function,
>>>>>  };
>>>>>
>>>>> +static void gpio_dwapb_reset(struct udevice *dev)
>>>>> +{
>>>>> +     struct reset_ctl_bulk reset_bulk;
>>>>> +     int ret;
>>>>> +
>>>>> +     ret = reset_get_bulk(dev, &reset_bulk);
>>>>> +     if (ret) {
>>>>> +             dev_warn(dev, "Can't get reset: %d\n", ret);
>>>>> +             return;
>>>>> +     }
>>>>> +
>>>>> +     reset_deassert_bulk(&reset_bulk);
>>>>> +}
>>>>> +
>>>>>  static int gpio_dwapb_probe(struct udevice *dev)
>>>>>  {
>>>>>       struct gpio_dev_priv *priv = dev_get_uclass_priv(dev);
>>>>>       struct gpio_dwapb_platdata *plat = dev->platdata;
>>>>>
>>>>> -     if (!plat)
>>>>> +     if (!plat) {
>>>>> +             /* Reset on parent device only */
>>>>> +             gpio_dwapb_reset(dev);
>>>>>               return 0;
>>>>> +     }
>>>>>
>>>>>       priv->gpio_count = plat->pins;
>>>>>       priv->bank_name = plat->name;
>>>>>
>>>>
>>>> What about .remove() and reset_release ?
>>> This driver doesn't implement .remove, should we add this to assert reset?
>>
>> Yes
> Okay, will try to add it.
> 
> BTW, when .remove will be call in Uboot?

When removing the driver and possibly before booting Linux.

-- 
Best regards,
Marek Vasut


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