On Thu, Feb 20, 2020 at 10:29:35PM +0100, Linus Walleij wrote:
> When we spawn a SCSI device from an ATA device in libata-scsi
> the SCSI device had no relation to the device tree.
>
> The DT binding allows us to define port nodes under a
> PATA (IDE) or SATA host controller, so we can have proper device
> nodes for these devices.
>
> If OF is enabled, walk the children of the host controller node
> to see if there is a valid device tree node to assign. The reg
> is used to match to ID 0 for the master device and ID 1 for the
> slave device.
>
> The corresponding device tree bindings have been accepted by
> the device tree maintainers.
>
> Cc: Chris Healy <cphealy@xxxxxxxxx>
> Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Cc: Bart Van Assche <bvanassche@xxxxxxx>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> drivers/ata/libata-scsi.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index eb2eb599e602..0610a3a86de3 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -36,6 +36,7 @@
> #include <linux/suspend.h>
> #include <asm/unaligned.h>
> #include <linux/ioprio.h>
> +#include <linux/of.h>
>
> #include "libata.h"
> #include "libata-transport.h"
> @@ -4582,6 +4583,33 @@ int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
> return rc;
> }
>
> +#ifdef CONFIG_OF
> +static void ata_scsi_assign_ofnode(struct ata_device *dev, struct ata_port *ap)
> +{
> + struct scsi_device *sdev = dev->sdev;
> + struct device *d = ap->host->dev;
> + struct device_node *np = d->of_node;
> + struct device_node *child;
> +
> + for_each_available_child_of_node(np, child) {
> + int ret;
> + u32 val;
> +
> + ret = of_property_read_u32(child, "reg", &val);
> + if (ret)
> + continue;
> + if (val == dev->devno) {
> + dev_info(d, "found matching device node\n");
Does that add any value or should it be dev_dbg (if anything) ?
> + sdev->sdev_gendev.of_node = child;
of_node_put(child);
break/return;
or is it on purpose to assign the last child if there are multiple matches ?
> + }
> + }
> +}
> +#else
> +static void ata_scsi_assign_ofnode(struct ata_device *dev, struct ata_port *ap)
> +{
> +}
> +#endif
> +
> void ata_scsi_scan_host(struct ata_port *ap, int sync)
> {
> int tries = 5;
> @@ -4607,6 +4635,7 @@ void ata_scsi_scan_host(struct ata_port *ap, int sync)
> NULL);
> if (!IS_ERR(sdev)) {
> dev->sdev = sdev;
> + ata_scsi_assign_ofnode(dev, ap);
> scsi_device_put(sdev);
> } else {
> dev->sdev = NULL;
> --
> 2.21.1
>
