Hi Philipp,
Thank you for the review.
On Tue, Jul 27, 2021 at 8:13 AM Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote:
>
> Hi Prabhakar,
>
> On Mon, 2021-07-26 at 19:28 +0100, Lad Prabhakar wrote:
> > Add ADC driver support for Renesas RZ/G2L A/D converter in SW
> > trigger mode.
> >
> > A/D Converter block is a successive approximation analog-to-digital
> > converter with a 12-bit accuracy and supports a maximum of 8 input
> > channels.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > ---
> > MAINTAINERS | 8 +
> > drivers/iio/adc/Kconfig | 10 +
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/rzg2l_adc.c | 595 ++++++++++++++++++++++++++++++++++++
> > 4 files changed, 614 insertions(+)
> > create mode 100644 drivers/iio/adc/rzg2l_adc.c
> >
> [...]
> > diff --git a/drivers/iio/adc/rzg2l_adc.c b/drivers/iio/adc/rzg2l_adc.c
> > new file mode 100644
> > index 000000000000..d05a3208ff9d
> > --- /dev/null
> > +++ b/drivers/iio/adc/rzg2l_adc.c
> > @@ -0,0 +1,595 @@
> [...]
> > +static void rzg2l_adc_pm_runtime_disable(void *data)
> > +{
> > + struct iio_dev *indio_dev = data;
> > +
> > + pm_runtime_disable(indio_dev->dev.parent);
> > +}
> > +
> > +static void rzg2l_adc_reset_assert(void *data)
> > +{
> > + struct reset_control *reset = data;
> > +
> > + reset_control_assert(reset);
> > +}
> > +
> > +static int rzg2l_adc_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct iio_dev *indio_dev;
> > + struct rzg2l_adc *adc;
> > + int ret;
> > + int irq;
> > +
> > + indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
> > + if (!indio_dev)
> > + return -ENOMEM;
> > +
> > + adc = iio_priv(indio_dev);
> > +
> > + ret = rzg2l_adc_parse_properties(pdev, adc);
> > + if (ret)
> > + return ret;
> > +
> > + adc->base = devm_platform_ioremap_resource(pdev, 0);
> > + if (IS_ERR(adc->base))
> > + return PTR_ERR(adc->base);
> > +
> > + irq = platform_get_irq(pdev, 0);
> > + if (irq < 0) {
> > + dev_err(dev, "no irq resource\n");
> > + return irq;
> > + }
> > +
> > + adc->pclk = devm_clk_get(dev, "pclk");
> > + if (IS_ERR(adc->pclk)) {
> > + dev_err(dev, "Failed to get pclk");
> > + return PTR_ERR(adc->pclk);
> > + }
> > +
> > + adc->adclk = devm_clk_get(dev, "adclk");
> > + if (IS_ERR(adc->adclk)) {
> > + dev_err(dev, "Failed to get adclk");
> > + return PTR_ERR(adc->adclk);
> > + }
> > +
> > + adc->adrstn = devm_reset_control_get_exclusive(dev, "adrst-n");
> > + if (IS_ERR(adc->adrstn)) {
> > + dev_err(dev, "failed to get adrstn\n");
> > + return PTR_ERR(adc->adrstn);
> > + }
>
> I'd request the "presetn" control up here, so if that fails we don't
> touch the "adrst-n" reset line.
>
Ok will move the devm_reset_control_get_exclusive() call for presetn here.
> > + ret = devm_add_action_or_reset(&pdev->dev,
> > + rzg2l_adc_reset_assert, adc->adrstn);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to register adrstn assert devm action, %d\n",
> > + ret);
> > + return ret;
> > + }
>
> This is the wrong way around. Installing devres actions should be done
> after the thing they are supposed to revert in case of error. You should
> move this down below the reset_control_deassert(adc->adrstn).
>
Ouch my understanding was, there won't be any harm in asserting the
reset line. Agree with will move this below
reset_control_deassert(adc->adrstn).
> > +
> > + adc->presetn = devm_reset_control_get_exclusive(dev, "presetn");
> > + if (IS_ERR(adc->presetn)) {
> > + dev_err(dev, "failed to get presetn\n");
> > + return PTR_ERR(adc->presetn);
> > + }
> > +
> > + ret = devm_add_action_or_reset(&pdev->dev,
> > + rzg2l_adc_reset_assert, adc->presetn);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to register presetn assert devm action, %d\n",
> > + ret);
> > + return ret;
> > + }
>
> Same as above, this belongs after the presetn deassert below.
>
Agreed.
> > +
> > + ret = reset_control_deassert(adc->adrstn);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to deassert adrstn pin, %d\n", ret);
> > + return ret;
> > + }
>
> Here is the place to install the adrstn assert action.
>
Agreed will move the devres action here.
> > + ret = reset_control_deassert(adc->presetn);
> > + if (ret) {
> > + dev_err(&pdev->dev, "failed to deassert presetn pin, %d\n", ret);
> > + return ret;
> > + }
>
> And here is the place to install the presetn assert action.
>
Agreed will move the devres action here.
Cheers,
Prabhakar
> regards
> Philipp
