[U-Boot] [PATCH v2 09/11] dm: imx: gpio: Support driver model in MXC gpio driver

[Igor Grinberg]

On 09/17/14 17:03, Simon Glass wrote:
> Hi Igor,
> 
> On 17 September 2014 07:00, Igor Grinberg <grinberg at compulab.co.il <mailto:grinberg at compulab.co.il>> wrote:
> 
>     On 09/17/14 06:51, Simon Glass wrote:
>     > Add driver model support with this driver. In this case the platform data
>     > is in the driver. It would be better to put this into an SOC-specific file,
>     > but this is best attempted when more boards are moved over to use driver
>     > model.
>     >
>     > Signed-off-by: Simon Glass <sjg at chromium.org <mailto:sjg at chromium.org>>
>     > ---
>     >
>     > Changes in v2:
>     > - Change 'reserved' to 'requested'
>     > - Add an internal function to check if a GPIO is requested
>     > - Tidy up confusing code that creates names for gpio_request()
>     >
>     >  drivers/gpio/mxc_gpio.c | 302 +++++++++++++++++++++++++++++++++++++++++++++++-
>     >  1 file changed, 301 insertions(+), 1 deletion(-)
>     >
>     > diff --git a/drivers/gpio/mxc_gpio.c b/drivers/gpio/mxc_gpio.c
>     > index 6a572d5..9435d2f 100644
>     > --- a/drivers/gpio/mxc_gpio.c
>     > +++ b/drivers/gpio/mxc_gpio.c
> 
>     [...]

[...]

>     > +static int mxc_gpio_free(struct udevice *dev, unsigned offset)
>     > +{
>     > +     struct mxc_bank_info *bank = dev_get_priv(dev);
>     > +     int ret;
>     > +
>     > +     ret = check_requested(dev, offset, __func__);
>     > +     if (ret)
>     > +             return ret;
> 
>     In case of not requested gpio,
>     should we really print the error message and return -EPERM?
>     Or may be adopt free() behavior and just return silently?
>     Linux gpiolib gpio_free() uses WARN_ON(extra_checks) for
>     "not requested" cases, so it shouts only in DEBUG cases.
> 
> 
> I'm not sure - I intend to push this up to the DM layer at some point.
> I feel that keeping track of GPIO requested/free should be a common
> feature of the uclass rather than implemented in each driver.

Agreed. I've got the same feeling while looking at this.

> But until we have enough drivers to make it clear that this is acceptable,
> I'm leaving it as it is.
> 
> So for at least now I think this is correct. We might consider bringing
> in some sort of WARN system to U-Boot. The caller can ignore the return
> value anyway.

Ok.


-- 
Regards,
Igor.