On 08/01/2012 03:40 PM, Stephen Warren wrote:
> 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?
No. Looks fine. I'll apply for 3.7 or do you have something that depends
on it?
Rob
>
>> / {
>> 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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