Re: [PATCH] gpio-exar: Use correct property prefix and document bindings

[Jan Kiszka]

On 2017-07-17 19:48, Rob Herring wrote:
> On Thu, Jul 13, 2017 at 08:44:26AM +0200, Jan Kiszka wrote:
>> The device-specific property should be prefixed with the vendor name
>> Change this and document the bindings of this platform device.
> 
> You are breaking backwards compatibility. You minimally need to state 
> that and why that is okay in this case.

There is no previous version yet: The patch that introduced this just
entered for 4.13. Linus remarked that "linux," is the wrong prefix and
wanted this to be changed before this version becomes final.

> 
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>> ---
>>  Documentation/devicetree/bindings/gpio/gpio-exar.txt | 5 +++++
>>  drivers/gpio/gpio-exar.c                             | 2 +-
>>  drivers/tty/serial/8250/8250_exar.c                  | 4 ++--
>>  3 files changed, 8 insertions(+), 3 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-exar.txt
>>
>> diff --git a/Documentation/devicetree/bindings/gpio/gpio-exar.txt b/Documentation/devicetree/bindings/gpio/gpio-exar.txt
>> new file mode 100644
>> index 000000000000..452180229b36
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/gpio/gpio-exar.txt
>> @@ -0,0 +1,5 @@
>> +Exportable MPIO interface of Exar UART chips
>> +
>> +Required properties of platform device:
> 
> platform device is a Linuxism.

Will drop the term.

> 
>> + - exar,first-pin: first exportable pins (0..15)
>> + - ngpios: number of exportable pins (1..16)
> 
> Required, but you don't use it?

We do, see the code (parts visible below).

> 
>> diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
>> index fb8d304cfa17..0ecd2369c2ca 100644
>> --- a/drivers/gpio/gpio-exar.c
>> +++ b/drivers/gpio/gpio-exar.c
>> @@ -132,7 +132,7 @@ static int gpio_exar_probe(struct platform_device *pdev)
>>  	if (!p)
>>  		return -ENOMEM;
>>  
>> -	ret = device_property_read_u32(&pdev->dev, "linux,first-pin",
>> +	ret = device_property_read_u32(&pdev->dev, "exar,first-pin",
>>  				       &first_pin);
>>  	if (ret)
>>  		return ret;
>> diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
>> index b5c98e5bf524..c6360fbdf808 100644
>> --- a/drivers/tty/serial/8250/8250_exar.c
>> +++ b/drivers/tty/serial/8250/8250_exar.c
>> @@ -261,7 +261,7 @@ __xr17v35x_register_gpio(struct pci_dev *pcidev,
>>  }
>>  
>>  static const struct property_entry exar_gpio_properties[] = {
>> -	PROPERTY_ENTRY_U32("linux,first-pin", 0),
>> +	PROPERTY_ENTRY_U32("exar,first-pin", 0),
>>  	PROPERTY_ENTRY_U32("ngpios", 16),
>>  	{ }
>>  };
>> @@ -326,7 +326,7 @@ static int iot2040_rs485_config(struct uart_port *port,
>>  }
>>  
>>  static const struct property_entry iot2040_gpio_properties[] = {
>> -	PROPERTY_ENTRY_U32("linux,first-pin", 10),
>> +	PROPERTY_ENTRY_U32("exar,first-pin", 10),
>>  	PROPERTY_ENTRY_U32("ngpios", 1),
>>  	{ }
>>  };
>> -- 
>> 2.12.3
>> --
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Thanks,
Jan

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