From 18308c94723e162ed121942335bc186e66820a7a Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Thu, 24 Apr 2014 11:30:02 -0400 Subject: of: introduce of_dma_get_range() helper The of_dma_get_range() allows to find "dma-range" property for the specified device and parse it. dma-ranges format: DMA addr (dma_addr) : naddr cells CPU addr (phys_addr_t) : pna cells size : nsize cells Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- drivers/of/address.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) (limited to 'drivers') diff --git a/drivers/of/address.c b/drivers/of/address.c index cb4242a69cd5..c54baee87d93 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -721,3 +721,90 @@ void __iomem *of_iomap(struct device_node *np, int index) return ioremap(res.start, resource_size(&res)); } EXPORT_SYMBOL(of_iomap); + +/** + * of_dma_get_range - Get DMA range info + * @np: device node to get DMA range info + * @dma_addr: pointer to store initial DMA address of DMA range + * @paddr: pointer to store initial CPU address of DMA range + * @size: pointer to store size of DMA range + * + * Look in bottom up direction for the first "dma-ranges" property + * and parse it. + * dma-ranges format: + * DMA addr (dma_addr) : naddr cells + * CPU addr (phys_addr_t) : pna cells + * size : nsize cells + * + * It returns -ENODEV if "dma-ranges" property was not found + * for this device in DT. + */ +int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size) +{ + struct device_node *node = of_node_get(np); + const __be32 *ranges = NULL; + int len, naddr, nsize, pna; + int ret = 0; + u64 dmaaddr; + + if (!node) + return -EINVAL; + + while (1) { + naddr = of_n_addr_cells(node); + nsize = of_n_size_cells(node); + node = of_get_next_parent(node); + if (!node) + break; + + ranges = of_get_property(node, "dma-ranges", &len); + + /* Ignore empty ranges, they imply no translation required */ + if (ranges && len > 0) + break; + + /* + * At least empty ranges has to be defined for parent node if + * DMA is supported + */ + if (!ranges) + break; + } + + if (!ranges) { + pr_debug("%s: no dma-ranges found for node(%s)\n", + __func__, np->full_name); + ret = -ENODEV; + goto out; + } + + len /= sizeof(u32); + + pna = of_n_addr_cells(node); + + /* dma-ranges format: + * DMA addr : naddr cells + * CPU addr : pna cells + * size : nsize cells + */ + dmaaddr = of_read_number(ranges, naddr); + *paddr = of_translate_dma_address(np, ranges); + if (*paddr == OF_BAD_ADDR) { + pr_err("%s: translation of DMA address(%pad) to CPU address failed node(%s)\n", + __func__, dma_addr, np->full_name); + ret = -EINVAL; + goto out; + } + *dma_addr = dmaaddr; + + *size = of_read_number(ranges + naddr + pna, nsize); + + pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n", + *dma_addr, *paddr, *size); + +out: + of_node_put(node); + + return ret; +} +EXPORT_SYMBOL_GPL(of_dma_get_range); -- cgit v1.2.3-58-ga151 From 92ea637edea36e58236e3124f199161da6f5c5de Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:03 -0400 Subject: of: introduce of_dma_is_coherent() helper The of_dma_is_coherent() helper parses the given DT device node to see if the "dma-coherent" property is supported and returns true or false accordingly. If the arch is always coherent or always noncoherent, then the default DMA ops has to be specified accordingly. Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Santosh Shilimkar Signed-off-by: Grygorii Strashko --- drivers/of/address.c | 23 +++++++++++++++++++++++ include/linux/of_address.h | 6 ++++++ 2 files changed, 29 insertions(+) (limited to 'drivers') diff --git a/drivers/of/address.c b/drivers/of/address.c index c54baee87d93..d244b2859aac 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -808,3 +808,26 @@ out: return ret; } EXPORT_SYMBOL_GPL(of_dma_get_range); + +/** + * of_dma_is_coherent - Check if device is coherent + * @np: device node + * + * It returns true if "dma-coherent" property was found + * for this device in DT. + */ +bool of_dma_is_coherent(struct device_node *np) +{ + struct device_node *node = of_node_get(np); + + while (node) { + if (of_property_read_bool(node, "dma-coherent")) { + of_node_put(node); + return true; + } + node = of_get_next_parent(node); + } + of_node_put(node); + return false; +} +EXPORT_SYMBOL_GPL(of_dma_is_coherent); \ No newline at end of file diff --git a/include/linux/of_address.h b/include/linux/of_address.h index 4d7b325af2ca..839a3521b28e 100644 --- a/include/linux/of_address.h +++ b/include/linux/of_address.h @@ -65,6 +65,7 @@ extern struct of_pci_range *of_pci_range_parser_one( struct of_pci_range *range); extern int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size); +extern bool of_dma_is_coherent(struct device_node *np); #else /* CONFIG_OF_ADDRESS */ static inline struct device_node *of_find_matching_node_by_address( struct device_node *from, @@ -98,6 +99,11 @@ static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr, { return -ENODEV; } + +static inline bool of_dma_is_coherent(struct device_node *np) +{ + return false; +} #endif /* CONFIG_OF_ADDRESS */ #ifdef CONFIG_OF -- cgit v1.2.3-58-ga151 From 591c1ee465ce5372385dbc41e7d3e36cbb477bd8 Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:04 -0400 Subject: of: configure the platform device dma parameters Retrieve DMA configuration from DT and setup platform device's DMA parameters. The DMA configuration in DT has to be specified using "dma-ranges" and "dma-coherent" properties if supported. We setup dma_pfn_offset using "dma-ranges" and dma_coherent_ops using "dma-coherent" device tree properties. The set_arch_dma_coherent_ops macro has to be defined by arch if it supports coherent dma_ops. Otherwise, set_arch_dma_coherent_ops() is declared as nop. Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- drivers/of/platform.c | 65 ++++++++++++++++++++++++++++++++++++++++----- include/linux/dma-mapping.h | 7 +++++ 2 files changed, 66 insertions(+), 6 deletions(-) (limited to 'drivers') diff --git a/drivers/of/platform.c b/drivers/of/platform.c index 404d1daebefa..91fa9838b56f 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -186,6 +186,64 @@ struct platform_device *of_device_alloc(struct device_node *np, } EXPORT_SYMBOL(of_device_alloc); +/** + * of_dma_configure - Setup DMA configuration + * @dev: Device to apply DMA configuration + * + * Try to get devices's DMA configuration from DT and update it + * accordingly. + * + * In case if platform code need to use own special DMA configuration,it + * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event + * to fix up DMA configuration. + */ +static void of_dma_configure(struct platform_device *pdev) +{ + u64 dma_addr, paddr, size; + int ret; + struct device *dev = &pdev->dev; + +#if defined(CONFIG_MICROBLAZE) + pdev->archdata.dma_mask = 0xffffffffUL; +#endif + + /* + * Set default dma-mask to 32 bit. Drivers are expected to setup + * the correct supported dma_mask. + */ + dev->coherent_dma_mask = DMA_BIT_MASK(32); + + /* + * Set it to coherent_dma_mask by default if the architecture + * code has not set it. + */ + if (!dev->dma_mask) + dev->dma_mask = &dev->coherent_dma_mask; + + /* + * if dma-coherent property exist, call arch hook to setup + * dma coherent operations. + */ + if (of_dma_is_coherent(dev->of_node)) { + set_arch_dma_coherent_ops(dev); + dev_dbg(dev, "device is dma coherent\n"); + } + + /* + * if dma-ranges property doesn't exist - just return else + * setup the dma offset + */ + ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size); + if (ret < 0) { + dev_dbg(dev, "no dma range information to setup\n"); + return; + } + + /* DMA ranges found. Calculate and set dma_pfn_offset */ + dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr); + dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset); +} + /** * of_platform_device_create_pdata - Alloc, initialize and register an of_device * @np: pointer to node to create device for @@ -211,12 +269,7 @@ static struct platform_device *of_platform_device_create_pdata( if (!dev) return NULL; -#if defined(CONFIG_MICROBLAZE) - dev->archdata.dma_mask = 0xffffffffUL; -#endif - dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); - if (!dev->dev.dma_mask) - dev->dev.dma_mask = &dev->dev.coherent_dma_mask; + of_dma_configure(dev); dev->dev.bus = &platform_bus_type; dev->dev.platform_data = platform_data; diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index fd4aee29ad10..c7d9b1b14ce7 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -123,6 +123,13 @@ static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask) extern u64 dma_get_required_mask(struct device *dev); +#ifndef set_arch_dma_coherent_ops +static inline int set_arch_dma_coherent_ops(struct device *dev) +{ + return 0; +} +#endif + static inline unsigned int dma_get_max_seg_size(struct device *dev) { return dev->dma_parms ? dev->dma_parms->max_segment_size : 65536; -- cgit v1.2.3-58-ga151