[U-Boot] [PATCH v2 04/16] dm: core: Add a new api to get indexed device address

[Simon Glass]

+Stephen

Hi,

On 4 November 2015 at 01:16, Mugunthan V N <mugunthanvnm at ti.com> wrote:
> Add new api to get device address based on index.
>
> Signed-off-by: Mugunthan V N <mugunthanvnm at ti.com>
> ---
>  drivers/core/device.c | 16 ++++++++++++----
>  include/dm/device.h   | 10 ++++++++++
>  2 files changed, 22 insertions(+), 4 deletions(-)

You are touching critical core code so I think we need to be careful here.

>
> diff --git a/drivers/core/device.c b/drivers/core/device.c
> index 758f390..3cdcab5 100644
> --- a/drivers/core/device.c
> +++ b/drivers/core/device.c
> @@ -581,18 +581,21 @@ const char *dev_get_uclass_name(struct udevice *dev)
>         return dev->uclass->uc_drv->name;
>  }
>
> -fdt_addr_t dev_get_addr(struct udevice *dev)
> +fdt_addr_t dev_get_addr_index(struct udevice *dev, int index)
>  {
>  #if CONFIG_IS_ENABLED(OF_CONTROL)
>         fdt_addr_t addr;
>
>         if (CONFIG_IS_ENABLED(OF_TRANSLATE)) {
>                 const fdt32_t *reg;
> +               int len = 0;
>
> -               reg = fdt_getprop(gd->fdt_blob, dev->of_offset, "reg", NULL);
> -               if (!reg)
> +               reg = fdt_getprop(gd->fdt_blob, dev->of_offset, "reg", &len);
> +               if (!reg || (len <= (index * sizeof(fdt32_t) * 2)))
>                         return FDT_ADDR_T_NONE;
>
> +               reg += index * 2;
> +

This seems to be assuming that the address and size each occupy a
single cell, but that is not the case in general (e.g. with 64-bit
machines).

I think you need to call fdt_addr_cells() and fdt_size_cells(). See
fdtdec_get_addr_size_auto_parent() as an example.

>                 /*
>                  * Use the full-fledged translate function for complex
>                  * bus setups.
> @@ -608,7 +611,7 @@ fdt_addr_t dev_get_addr(struct udevice *dev)
>         addr = fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
>                                                 dev->parent->of_offset,
>                                                 dev->of_offset, "reg",
> -                                               0, NULL);
> +                                               index, NULL);
>         if (CONFIG_IS_ENABLED(SIMPLE_BUS) && addr != FDT_ADDR_T_NONE) {
>                 if (device_get_uclass_id(dev->parent) == UCLASS_SIMPLE_BUS)
>                         addr = simple_bus_translate(dev->parent, addr);
> @@ -620,6 +623,11 @@ fdt_addr_t dev_get_addr(struct udevice *dev)
>  #endif
>  }
>
> +fdt_addr_t dev_get_addr(struct udevice *dev)
> +{
> +       return dev_get_addr_index(dev, 0);
> +}
> +
>  bool device_has_children(struct udevice *dev)
>  {
>         return !list_empty(&dev->child_head);
> diff --git a/include/dm/device.h b/include/dm/device.h
> index 28ba4ca..4de66d7 100644
> --- a/include/dm/device.h
> +++ b/include/dm/device.h
> @@ -454,6 +454,16 @@ int device_find_next_child(struct udevice **devp);
>  fdt_addr_t dev_get_addr(struct udevice *dev);
>
>  /**
> + * dev_get_addr() - Get the reg property of a device

dev_get_addr_index

> + *
> + * @dev: Pointer to a device
> + * @index: reg address array index

I don't think this is sufficiently clear. Can you add a comment saying
that the 'reg' property can hold a list of <addr, size> pairs and
@index is used to select which one is used?

> + *
> + * @return addr
> + */
> +fdt_addr_t dev_get_addr_index(struct udevice *dev, int index);
> +
> +/**
>   * device_has_children() - check if a device has any children
>   *
>   * @dev:       Device to check
> --
> 2.6.2.280.g74301d6
>

Regards,
Simon