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

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

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