From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH] of: Allow busses with #size-cells=0 Date: Wed, 01 Aug 2012 16:04:33 -0500 Message-ID: <501999E1.5090404@gmail.com> References: <1343259277-19037-1-git-send-email-swarren@wwwdotorg.org> <50199445.6090101@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <50199445.6090101-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Stephen Warren Cc: Stephen Warren , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, Mark Brown , Rob Herring List-Id: devicetree@vger.kernel.org On 08/01/2012 03:40 PM, Stephen Warren wrote: > On 07/25/2012 05:34 PM, Stephen Warren wrote: >> From: Stephen Warren >> >> 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 >> --- >> 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( >> > > _______________________________________________ > devicetree-discuss mailing list > devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org > https://lists.ozlabs.org/listinfo/devicetree-discuss >