[U-Boot] [RFC PATCH] gpio: zynq: Setup bank_name to dev->name

[Michal Simek <michal.simek@xilinx.com>]

On 24.7.2018 21:39, Stefan Herbrechtsmeier wrote:
> Am 24.07.2018 um 10:37 schrieb Michal Simek:
>> On 23.7.2018 20:29, Stefan Herbrechtsmeier wrote:
>>> Am 23.07.2018 um 11:08 schrieb Michal Simek:
>>>> On 20.7.2018 21:31, Stefan Herbrechtsmeier wrote:
>>>>> Am 12.07.2018 um 16:04 schrieb Michal Simek:
>>>>>> There should be proper bank name setup to distiguish between
>>>>>> different
>>>>>> gpio drivers. Use dev->name for it.
>>>>>>
>>>>>> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
>>>>>> ---
>>>>>>
>>>>>>     drivers/gpio/zynq_gpio.c | 2 ++
>>>>>>     1 file changed, 2 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/gpio/zynq_gpio.c b/drivers/gpio/zynq_gpio.c
>>>>>> index 26f69b1a713f..f793ee5754a8 100644
>>>>>> --- a/drivers/gpio/zynq_gpio.c
>>>>>> +++ b/drivers/gpio/zynq_gpio.c
>>>>>> @@ -337,6 +337,8 @@ static int zynq_gpio_probe(struct udevice *dev)
>>>>>>         struct zynq_gpio_privdata *priv = dev_get_priv(dev);
>>>>>>         struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
>>>>>>     +    uc_priv->bank_name = dev->name;
>>>>>> +
>>>>>>         if (priv->p_data)
>>>>>>             uc_priv->gpio_count = priv->p_data->ngpio;
>>>>>>     
>>>>> Does this not lead to ugly names because the gpio number is append to
>>>>> the bank_name? Have you check the "gpio status -a" output?
>>>> Yes I was checking it. Names are composed together but also just
>>>> numbers
>>>> works as before.
>>>>
>>>> gpio at ff0a00000: input: 0 [ ]
>>>> gpio at ff0a00001: input: 0 [ ]
>>>> gpio at ff0a00002: input: 0 [ ]
>>>> gpio at ff0a00003: input: 0 [ ]
>>>> gpio at ff0a00004: input: 0 [ ]
>>>> gpio at ff0a00005: input: 0 [ ]
>>>> gpio at ff0a00006: input: 0 [ ]
>>>> gpio at ff0a00007: input: 0 [ ]
>>>> gpio at ff0a00008: input: 0 [ ]
>>>> gpio at ff0a00009: input: 0 [ ]
>>> Do you think that this are meaningful names? It isn't possible to
>>> separate the device and pin number as well as it mix hex and decimal
>>> numbers.
>>>
>>>> If you know better way how to setup a bank name please let me know
>>>> but I
>>>> need to distinguish ps gpio from pl one and for pl we need to know the
>>>> address.
>>> I know the use case.
>>>
>>> A lot of drivers use the bank_name from the device tree, some drivers
>>> append an underscore to the bank name and others add the req_seq of the
>>> device to an alphabetic character.
>>>
>>>>> Other drivers use the gpio-bank-name from the device tree.
>>>> I can't see this property inside Linux kernel. If this has been
>>>> reviewed
>>>> by dt guys please let me know.
>>> This property is only used by u-boot. I think it isn't needed by the
>>> Linux kernel.
>> I am happy to use consistent solution but what's that?
> 
> Consistent solution between what?

all drivers. Name should be composed consistently among all drivers.
It means drivers shouldn't add additional "_" in driver code for example.

> 
>> Mixing name with hex and int is not nice but adding "_" or something
>> else is just a pain in driver code. If this is done in core I am fine
>> with that but adding this code to all drivers don't look like generic
>> solution at all.
> 
> Normally the bank name is an alphabetic character or string. Maybe we
> could add the device name to the gpio_lookup_name function and add an
> additional optional device name parameter to the gpio command.
> 
>> Using additional u-boot property is not good too.
>>
>> I have mentioned in "gpio: xilinx: Convert driver to DM"
>> (sha1:10441ec9224d0d269dc512819a32c0785a6338d3)
>> that uc-priv->name is completely unused. Maybe this should be dev->name
>> and bank_name should be really used for banks.
> 
> Isn't the uc-priv->name used for the label of the request?

Last time when I looked at it and I didn't see this name listed anywhere
in output.


>> Then in gpio status -a can be
>>
>> Device gpio at a0001000:
>> Bank:
>> ...
>>
>> but not sure how gpio commands will work to address exact pin from
>> prompt. Because this is normally working
>> gpio toggle gpio at a00010001
> 
> With an optional device name this would be:
> gpio toggle gpio at a0001000 1
> 
> Alternative the gpio command could support the requested labels:
> gpio toggle second-gpio

I am open to see this solution. Feel free to invest your time support
this but I have no time for that.

Thanks,
Michal