Commit 591c1ee4 authored by Santosh Shilimkar's avatar Santosh Shilimkar
Browse files

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: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
parent 92ea637e

drivers/of/platform.c

+59 −6
Original line number Diff line number Diff line
@@ -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;

include/linux/dma-mapping.h

+7 −0
Original line number Diff line number Diff line
@@ -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;

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