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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 <gregkh@linuxfoundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
hifive-unleashed-5.1
Santosh Shilimkar 2014-04-24 11:30:04 -04:00
parent 92ea637ede
commit 591c1ee465
2 changed files with 66 additions and 6 deletions
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65
drivers/of/platform.c
View File

@ -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;

7
include/linux/dma-mapping.h
View File

@ -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;