[U-Boot] [PATCH v2 3/3] dm: gpio: Implement open drain for MPC85XX GPIO

[Mario Six]

On Thu, May 19, 2016 at 5:59 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Mario,
>
> On 10 May 2016 at 01:51, Mario Six <mario.six at gdsys.cc> wrote:
>> This patch implements the open-drain setting feature for the MPC85XX
>> GPIO controller.
>>
>> Signed-off-by: Mario Six <mario.six at gdsys.cc>
>> ---
>>
>> v3:
>> - Added missing commit message
>> - Fixed white space issues in function headers
>>
>> ---
>>  drivers/gpio/Kconfig        |  6 +++---
>>  drivers/gpio/mpc85xx_gpio.c | 19 +++++++++++++++++++
>>  2 files changed, 22 insertions(+), 3 deletions(-)
>
> Reviewed-by: Simon Glass <sjg at chromium.org>
>
> But please see below.
>
>>
>> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
>> index 068ee63..b250622 100644
>> --- a/drivers/gpio/Kconfig
>> +++ b/drivers/gpio/Kconfig
>> @@ -162,9 +162,9 @@ config MPC85XX_GPIO
>>           configurable to match the actual GPIO count of the SoC (e.g. the
>>           32/32/23 banks of the P1022 SoC).
>>
>> -         The standard functions of input/output mode, and output value setting
>> -         are supported; the open-drain capability of the controller is not
>> -         supported yet.
>> +         Aside from the standard functions of input/output mode, and output
>> +         value setting, the open-drain feature, which can configure individual
>> +         GPIOs to work as open-drain outputs, is supported.
>>
>>           The driver has been tested on MPC85XX, but it is likely that other
>>           PowerQUICC III devices will work as well.
>> diff --git a/drivers/gpio/mpc85xx_gpio.c b/drivers/gpio/mpc85xx_gpio.c
>> index acf0414..dc6193c 100644
>> --- a/drivers/gpio/mpc85xx_gpio.c
>> +++ b/drivers/gpio/mpc85xx_gpio.c
>> @@ -73,6 +73,25 @@ static inline void mpc85xx_gpio_set_high(struct ccsr_gpio *base,
>>         setbits_be32(&base->gpdir, gpios);
>>  }
>>
>> +static inline int mpc85xx_gpio_open_drain_val(struct ccsr_gpio *base,
>> +                                             unsigned int mask)
>> +{
>> +       /* Read the requested values */
>> +       return in_be32(&base->gpodr) & mask;
>> +}
>> +
>> +static inline void mpc85xx_gpio_open_drain_on(struct ccsr_gpio *base,
>> +                                             unsigned int gpios)
>> +{
>> +       setbits_be32(&base->gpodr, gpios);
>
> Why gpios? This would normally be 'offset', indicating that it is the
> GPIO offset within the bank.
>
> Also the code seems odd - don't you need to convert the value into a mask?
>

Ah, yes. Sorry, just noticed that I missed the actual
mpc85xx_gpio_{set,get}_open_drain functions when merging the patches. You might
notice that nothing is actually added to the dm_gpio_ops structure as well
(that's what I get for trying to follow the original code style too closely).
Will add those in v4, and the test/dm/gpio.c / sandbox additions as well.

>> +}
>> +
>> +static inline void mpc85xx_gpio_open_drain_off(struct ccsr_gpio *base,
>> +                                              unsigned int gpios)
>> +{
>> +       clrbits_be32(&base->gpodr, gpios);
>> +}
>> +
>>  static int mpc85xx_gpio_direction_input(struct udevice *dev, unsigned int gpio)
>>  {
>>         struct mpc85xx_gpio_data *data = dev_get_priv(dev);
>> --
>> 2.7.0.GIT
>>
>
> Regards,
> Simon

Thanks for reviewing!

Best regards,
Mario