Re: [PATCH 2/8] media: imx-pxp: detect PXP version

Laurent Pinchart
2023-01-06T12:28:58Z

On Fri, Jan 06, 2023 at 01:47:32PM +0200, Laurent Pinchart wrote:
> Hi Michael,
>
> Thank you for the patch.
>
> On Thu, Jan 05, 2023 at 02:47:23PM +0100, Michael Tretter wrote:
> > Different versions of the Pixel Pipeline have different blocks and their
> > routing may be different. Read the PXP_HW_VERSION register to determine
> > the version of the PXP and print it to the log for debugging purposes.
>
> Is there a specific reason you chose to read the version register
> instead of basing the decision on the compatible string ?

Reading the rest of the series, you use the compatible strings later,
and never use the hw_version field. I'm tempted to propose dropping this
patch.

> > Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
> > ---
> > drivers/media/platform/nxp/imx-pxp.c | 18 ++++++++++++++++++
> > 1 file changed, 18 insertions(+)
> >
> > diff --git a/drivers/media/platform/nxp/imx-pxp.c b/drivers/media/platform/nxp/imx-pxp.c
> > index 689ae5e6ac62..05abe40558b0 100644
> > --- a/drivers/media/platform/nxp/imx-pxp.c
> > +++ b/drivers/media/platform/nxp/imx-pxp.c
> > @@ -10,6 +10,7 @@
> > * Pawel Osciak, <pawel@osciak.com>
> > * Marek Szyprowski, <m.szyprowski@samsung.com>
> > */
> > +#include <linux/bitfield.h>
> > #include <linux/clk.h>
> > #include <linux/delay.h>
> > #include <linux/dma-mapping.h>
> > @@ -52,6 +53,11 @@ MODULE_PARM_DESC(debug, "activates debug info");
> > #define MEM2MEM_HFLIP (1 << 0)
> > #define MEM2MEM_VFLIP (1 << 1)
> >
> > +#define PXP_VERSION_MAJOR(version) \
> > + FIELD_GET(BM_PXP_VERSION_MAJOR, version)
> > +#define PXP_VERSION_MINOR(version) \
> > + FIELD_GET(BM_PXP_VERSION_MINOR, version)
> > +
> > #define dprintk(dev, fmt, arg...) \
> > v4l2_dbg(1, debug, &dev->v4l2_dev, "%s: " fmt, __func__, ## arg)
> >
> > @@ -192,6 +198,8 @@ struct pxp_dev {
> > struct clk *clk;
> > void __iomem *mmio;
> >
> > + u32 hw_version;
> > +
> > atomic_t num_inst;
> > struct mutex dev_mutex;
> > spinlock_t irqlock;
> > @@ -1660,6 +1668,11 @@ static int pxp_soft_reset(struct pxp_dev *dev)
> > return 0;
> > }
> >
> > +static u32 pxp_read_version(struct pxp_dev *dev)
> > +{
> > + return readl(dev->mmio + HW_PXP_VERSION);
> > +}
> > +
> > static int pxp_probe(struct platform_device *pdev)
> > {
> > struct pxp_dev *dev;
> > @@ -1705,6 +1718,11 @@ static int pxp_probe(struct platform_device *pdev)
> > goto err_clk;
> > }
> >
> > + dev->hw_version = pxp_read_version(dev);
> > + dev_info(&pdev->dev, "PXP Version %d.%d\n",
>
> As the version can't be negative, I'd use %u.%u.
>
> > + PXP_VERSION_MAJOR(dev->hw_version),
> > + PXP_VERSION_MINOR(dev->hw_version));
> > +
>
> The driver now prints two messages at probe time, it would be nice to
> combine them, or remove the other one. That's a candidate for a future
> patch though.
>
> > ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
> > if (ret)
> > goto err_clk;

--
Regards,

Laurent Pinchart