On 07/25/2012 05:34 PM, Stephen Warren wrote:
> From: Stephen Warren <[email protected]>
>
> It's quite legitimate for a DT node to specify #size-cells=0. One example
> is a node that's used to collect a number of non-memory-mapped devices.
> In that scenario, there may be multiple child nodes with the same name
> (type) thus necessitating the use of unit addresses in node names, and
> reg properties:
Does anyone have any comment on this patch?
> / {
> regulators {
> compatible = "simple-bus";
> #address-cells = <1>;
> #size-cells = <0>;
>
> regulator@0 {
> compatible = "regulator-fixed";
> reg = <0>;
> ...
> };
>
> regulator@1 {
> compatible = "regulator-fixed";
> reg = <1>;
> ...
> };
>
> ...
> };
> };
>
> However, #size-cells=0 prevents translation of reg property values into
> the parent node's address space. In turn, this triggers the kernel to
> emit error messages during boot, such as:
>
> prom_parse: Bad cell count for /regulators/regulator@0
>
> To prevent printing these error messages for legitimate DT content, a
> number of changes are made:
>
> 1) of_get_address()/of_get_pci_address() are modified only to validate
> the value of #address-cells, and not #size-cells.
>
> 2) of_can_translate_address() is added to indicate whether address
> translation is possible.
>
> 3) of_device_make_bus_id() is modified to name devices based on the
> translated address only where possible, and otherwise fall back to
> using the (first cell of the) raw untranslated address.
>
> 4) of_device_alloc() is modified to create memory resources for a device
> only if the address can be translated into the CPU's address space.
>
> Signed-off-by: Stephen Warren <[email protected]>
> ---
> drivers/of/address.c | 27 +++++++++++++++++++++++----
> drivers/of/platform.c | 16 +++++++++++++---
> include/linux/of_address.h | 1 +
> 3 files changed, 37 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/of/address.c b/drivers/of/address.c
> index 7e262a6..7a07751 100644
> --- a/drivers/of/address.c
> +++ b/drivers/of/address.c
> @@ -9,8 +9,8 @@
>
> /* Max address size we deal with */
> #define OF_MAX_ADDR_CELLS 4
> -#define OF_CHECK_COUNTS(na, ns) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS
> && \
> - (ns) > 0)
> +#define OF_CHECK_ADDR_COUNT(na) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
> +#define OF_CHECK_COUNTS(na, ns) (OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
>
> static struct of_bus *of_match_bus(struct device_node *np);
> static int __of_address_to_resource(struct device_node *dev,
> @@ -182,7 +182,7 @@ const __be32 *of_get_pci_address(struct device_node *dev,
> int bar_no, u64 *size,
> }
> bus->count_cells(dev, &na, &ns);
> of_node_put(parent);
> - if (!OF_CHECK_COUNTS(na, ns))
> + if (!OF_CHECK_ADDR_COUNT(na))
> return NULL;
>
> /* Get "reg" or "assigned-addresses" property */
> @@ -490,6 +490,25 @@ u64 of_translate_dma_address(struct device_node *dev,
> const __be32 *in_addr)
> }
> EXPORT_SYMBOL(of_translate_dma_address);
>
> +bool of_can_translate_address(struct device_node *dev)
> +{
> + struct device_node *parent;
> + struct of_bus *bus;
> + int na, ns;
> +
> + parent = of_get_parent(dev);
> + if (parent == NULL)
> + return false;
> +
> + bus = of_match_bus(parent);
> + bus->count_cells(dev, &na, &ns);
> +
> + of_node_put(parent);
> +
> + return OF_CHECK_COUNTS(na, ns);
> +}
> +EXPORT_SYMBOL(of_can_translate_address);
> +
> const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
> unsigned int *flags)
> {
> @@ -506,7 +525,7 @@ const __be32 *of_get_address(struct device_node *dev, int
> index, u64 *size,
> bus = of_match_bus(parent);
> bus->count_cells(dev, &na, &ns);
> of_node_put(parent);
> - if (!OF_CHECK_COUNTS(na, ns))
> + if (!OF_CHECK_ADDR_COUNT(na))
> return NULL;
>
> /* Get "reg" or "assigned-addresses" property */
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index e44f8c2..9bdeaf3 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -78,6 +78,7 @@ void of_device_make_bus_id(struct device *dev)
> struct device_node *node = dev->of_node;
> const u32 *reg;
> u64 addr;
> + const __be32 *addrp;
> int magic;
>
> #ifdef CONFIG_PPC_DCR
> @@ -105,7 +106,15 @@ void of_device_make_bus_id(struct device *dev)
> */
> reg = of_get_property(node, "reg", NULL);
> if (reg) {
> - addr = of_translate_address(node, reg);
> + if (of_can_translate_address(node)) {
> + addr = of_translate_address(node, reg);
> + } else {
> + addrp = of_get_address(node, 0, NULL, NULL);
> + if (addrp)
> + addr = of_read_number(addrp, 1);
> + else
> + addr = OF_BAD_ADDR;
> + }
> if (addr != OF_BAD_ADDR) {
> dev_set_name(dev, "%llx.%s",
> (unsigned long long)addr, node->name);
> @@ -140,8 +149,9 @@ struct platform_device *of_device_alloc(struct
> device_node *np,
> return NULL;
>
> /* count the io and irq resources */
> - while (of_address_to_resource(np, num_reg, &temp_res) == 0)
> - num_reg++;
> + if (of_can_translate_address(np))
> + while (of_address_to_resource(np, num_reg, &temp_res) == 0)
> + num_reg++;
> num_irq = of_irq_count(np);
>
> /* Populate the resource table */
> diff --git a/include/linux/of_address.h b/include/linux/of_address.h
> index 01b925a..c3cdc10 100644
> --- a/include/linux/of_address.h
> +++ b/include/linux/of_address.h
> @@ -6,6 +6,7 @@
>
> #ifdef CONFIG_OF_ADDRESS
> extern u64 of_translate_address(struct device_node *np, const __be32 *addr);
> +extern bool of_can_translate_address(struct device_node *dev);
> extern int of_address_to_resource(struct device_node *dev, int index,
> struct resource *r);
> extern struct device_node *of_find_matching_node_by_address(
>
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