lkml.org 
[lkml]   [2021]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH v3 2/3] iio: adc: Add driver for Renesas RZ/G2L A/D converter
    Hi Philipp,

    Thank you for the review.

    On Tue, Jul 27, 2021 at 8:13 AM Philipp Zabel <p.zabel@pengutronix.de> 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@bp.renesas.com>
    > > Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
    > > ---
    > > 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

    \
     
     \ /
      Last update: 2021-07-27 10:03    [W:6.949 / U:0.236 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site