Hi Martin,
One more thing that I forgot to mention:
On 19/09/2023 18:59, tumic@xxxxxxxxxx wrote:
> From: Martin Tůma <martin.tuma@xxxxxxxxxxxxxxxxxxxxx>
>
> Digiteq Automotive MGB4 is a modular frame grabber PCIe card for automotive
> video interfaces. As for now, two modules - FPD-Link and GMSL - are
> available and supported by the driver. The card has two inputs and two
> outputs (FPD-Link only).
>
> In addition to the video interfaces it also provides a trigger signal
> interface and a MTD interface for FPGA firmware upload.
>
> Signed-off-by: Martin Tůma <martin.tuma@xxxxxxxxxxxxxxxxxxxxx>
> ---
<snip>
> +static ssize_t video_source_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct video_device *vdev = to_video_device(dev);
> + struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
> + struct mgb4_dev *mgbdev = voutdev->mgbdev;
> + struct mgb4_vin_dev *loopin_new = NULL, *loopin_old = NULL;
> + unsigned long val;
> + ssize_t ret;
> + u32 config;
> + int i;
> +
> + ret = kstrtoul(buf, 10, &val);
> + if (ret)
> + return ret;
> + if (val > 3)
> + return -EINVAL;
> +
> + if (test_and_set_bit(0, &mgbdev->io_reconfig))
> + return -EBUSY;
You need some documentation here on how and why io_reconfig is used, with a reference
to the queue_setup functions, and there you need a reference back to this function.
It is something unusual, and unusual code needs documentation.
> +
> + ret = -EBUSY;
> + for (i = 0; i < MGB4_VIN_DEVICES; i++)
> + if (mgbdev->vin[i] && is_busy(&mgbdev->vin[i]->vdev))
> + goto end;
> + for (i = 0; i < MGB4_VOUT_DEVICES; i++)
> + if (mgbdev->vout[i] && is_busy(&mgbdev->vout[i]->vdev))
> + goto end;
> +
> + config = mgb4_read_reg(&mgbdev->video, voutdev->config->regs.config);
> +
> + if (((config & 0xc) >> 2) < MGB4_VIN_DEVICES)
> + loopin_old = mgbdev->vin[(config & 0xc) >> 2];
> + if (val < MGB4_VIN_DEVICES)
> + loopin_new = mgbdev->vin[val];
> + if (loopin_old && loopin_cnt(loopin_old) == 1)
> + mgb4_mask_reg(&mgbdev->video, loopin_old->config->regs.config,
> + 0x2, 0x0);
> + if (loopin_new)
> + mgb4_mask_reg(&mgbdev->video, loopin_new->config->regs.config,
> + 0x2, 0x2);
> +
> + if (val == voutdev->config->id + MGB4_VIN_DEVICES)
> + mgb4_write_reg(&mgbdev->video, voutdev->config->regs.config,
> + config & ~(1 << 1));
> + else
> + mgb4_write_reg(&mgbdev->video, voutdev->config->regs.config,
> + config | (1U << 1));
> +
> + mgb4_mask_reg(&mgbdev->video, voutdev->config->regs.config, 0xc,
> + val << 2);
> +
> + ret = count;
> +end:
> + clear_bit(0, &mgbdev->io_reconfig);
> +
> + return ret;
> +}
Regards,
Hans
