From 5d61b165c892853f2daf6220d2ec6577487e273a Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Wed, 25 Jul 2012 17:34:37 -0600 Subject: [PATCH] of: Allow busses with #size-cells=0 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: / { 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 Signed-off-by: Rob Herring --- 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 7e262a6124c5..7a07751428de 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 e44f8c2d239d..9bdeaf30b17d 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 01b925ad8d78..c3cdc1025c30 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( -- 2.30.2