Re: [PATCH v2 2/3] iio: adc: sun20i-gpadc: add A523 gpadc support

[Andre Przywara <andre.przywara@arm.com>]

On Wed, 13 May 2026 17:16:38 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

Hi,

> On Wed, 13 May 2026 13:53:49 +0200
> Andre Przywara <andre.przywara@arm.com> wrote:
> 
> > Hi Sanjay,
> > 
> > thanks for having a look!
> > 
> > On 5/13/26 13:44, Sanjay Chitroda wrote:  
> > > 
> > > 
> > > On 13 May 2026 10:29:43 am IST, Michal Piekos <michal.piekos@mmpsystems.pl> wrote:    
> > >> A523 differs from existing sun20i-gpadc-iio by having two clocks; bus
> > >> clock and module clock.
> > >>
> > >> Change driver to enable all clocks.
> > >>
> > >> Signed-off-by: Michal Piekos <michal.piekos@mmpsystems.pl>
> > >> ---
> > >> drivers/iio/adc/sun20i-gpadc-iio.c | 11 +++++++----
> > >> 1 file changed, 7 insertions(+), 4 deletions(-)
> > >>
> > >> diff --git a/drivers/iio/adc/sun20i-gpadc-iio.c b/drivers/iio/adc/sun20i-gpadc-iio.c
> > >> index 861c14da75ad..3f1f07b3a385 100644
> > >> --- a/drivers/iio/adc/sun20i-gpadc-iio.c
> > >> +++ b/drivers/iio/adc/sun20i-gpadc-iio.c
> > >> @@ -180,7 +180,7 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
> > >> 	struct iio_dev *indio_dev;
> > >> 	struct sun20i_gpadc_iio *info;
> > >> 	struct reset_control *rst;
> > >> -	struct clk *clk;
> > >> +	struct clk_bulk_data *clks;
> > >> 	int irq;
> > >> 	int ret;
> > >>
> > >> @@ -205,9 +205,11 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
> > >> 	if (IS_ERR(info->regs))
> > >> 		return PTR_ERR(info->regs);
> > >>
> > >> -	clk = devm_clk_get_enabled(dev, NULL);
> > >> -	if (IS_ERR(clk))
> > >> -		return dev_err_probe(dev, PTR_ERR(clk), "failed to enable bus clock\n");
> > >> +	ret = devm_clk_bulk_get_all_enabled(dev, &clks);
> > >> +	if (ret <= 0)    
> > > 
> > > Thank you Michal for the change.
> > > 
> > > Have you validated the changes ?
> > > It looks while success ret would be 0 and it would give return error.    
> > 
> > But devm_clk_bulk_get_all_enabled() returns the number of clocks found 
> > and enabled. And since we need at least one, I think this is correct, 
> > and the error message below reflects that.  
> 
> True but passing 0 to dev_err_probe() isn't going to do the right thing.
> 
> Though from this function, 0 is an error you need to return an error code
> not 0 which to the caller looks like a success.

Ah, that's true - should have read your email first before answering to
Andy ;-)

So yeah, that needs a split handling, for == 0, and for < 0.

Cheers,
Andre

> 
> 
> 
> > 
> > To me that change looks good:
> > 
> > Reviewed-by: Andre Przywara <andre.przywara@arm.com>
> > 
> > Cheers,
> > Andre
> > 
> >   
> > > 
> > > Thanks, Sanjay
> > > 
> > >     
> > >> +		return dev_err_probe(
> > >> +			dev, ret,
> > >> +			"failed to enable clocks or no clocks defined\n");
> > >>
> > >> 	rst = devm_reset_control_get_exclusive(dev, NULL);
> > >> 	if (IS_ERR(rst))
> > >> @@ -243,6 +245,7 @@ static int sun20i_gpadc_probe(struct platform_device *pdev)
> > >>
> > >> static const struct of_device_id sun20i_gpadc_of_id[] = {
> > >> 	{ .compatible = "allwinner,sun20i-d1-gpadc" },
> > >> +	{ .compatible = "allwinner,sun55i-a523-gpadc" },
> > >> 	{ }
> > >> };
> > >> MODULE_DEVICE_TABLE(of, sun20i_gpadc_of_id);
> > >>    
> > >     
> >   
> 
>