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

Laurent Pinchart
2023-01-06T11:47:41Z

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