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

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

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 ?

> 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