MIPS: BMIPS: Rewrite DMA code to use "dma-ranges" property

 * Copyright (C) 2014 Kevin Cernekee <cernekee@gmail.com>

 */

#define pr_fmt(fmt)		"bmips-dma: " fmt

#include <linux/device.h>

#include <linux/dma-direction.h>

#include <linux/dma-mapping.h>

#include <linux/init.h>

#include <linux/mm.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/pci.h>

#include <linux/printk.h>

#include <linux/slab.h>

#include <linux/types.h>

#include <dma-coherence.h>

/*

 * BCM3384 has configurable address translation windows which allow the

 * BCM338x has configurable address translation windows which allow the

 * peripherals' DMA addresses to be different from the Zephyr-visible

 * physical addresses.  e.g. usb_dma_addr = zephyr_pa ^ 0x08000000

 *

 * If our DT "memory" node has a "dma-xor-mask" property we will enable this

 * translation using the provided offset.

 * If the "brcm,ubus" node has a "dma-ranges" property we will enable this

 * translation globally using the provided information.  This implements a

 * very limited subset of "dma-ranges" support and it will probably be

 * replaced by a more generic version later.

 */

static u32 bcm3384_dma_xor_mask;

static u32 bcm3384_dma_xor_limit = 0xffffffff;

/*

 * PCI collapses the memory hole at 0x10000000 - 0x1fffffff.

 * On systems with a dma-xor-mask, this range is guaranteed to live above

 * the dma-xor-limit.

 */

#define BCM3384_MEM_HOLE_PA	0x10000000

#define BCM3384_MEM_HOLE_SIZE	0x10000000

struct bmips_dma_range {

	u32			child_addr;

	u32			parent_addr;

	u32			size;

};

static struct bmips_dma_range *bmips_dma_ranges;

static dma_addr_t bcm3384_phys_to_dma(struct device *dev, phys_addr_t pa)

#define FLUSH_RAC		0x100

static dma_addr_t bmips_phys_to_dma(struct device *dev, phys_addr_t pa)

{

	if (dev && dev_is_pci(dev) &&

	    pa >= (BCM3384_MEM_HOLE_PA + BCM3384_MEM_HOLE_SIZE))

		return pa - BCM3384_MEM_HOLE_SIZE;

	if (pa <= bcm3384_dma_xor_limit)

		return pa ^ bcm3384_dma_xor_mask;

	struct bmips_dma_range *r;

	for (r = bmips_dma_ranges; r && r->size; r++) {

		if (pa >= r->child_addr &&

		    pa < (r->child_addr + r->size))

			return pa - r->child_addr + r->parent_addr;

	}

	return pa;

}

dma_addr_t plat_map_dma_mem(struct device *dev, void *addr, size_t size)

{

	return bcm3384_phys_to_dma(dev, virt_to_phys(addr));

	return bmips_phys_to_dma(dev, virt_to_phys(addr));

}

dma_addr_t plat_map_dma_mem_page(struct device *dev, struct page *page)

{

	return bcm3384_phys_to_dma(dev, page_to_phys(page));

	return bmips_phys_to_dma(dev, page_to_phys(page));

}

unsigned long plat_dma_addr_to_phys(struct device *dev, dma_addr_t dma_addr)

{

	if (dev && dev_is_pci(dev) &&

	    dma_addr >= BCM3384_MEM_HOLE_PA)

		return dma_addr + BCM3384_MEM_HOLE_SIZE;

	if ((dma_addr ^ bcm3384_dma_xor_mask) <= bcm3384_dma_xor_limit)

		return dma_addr ^ bcm3384_dma_xor_mask;

	struct bmips_dma_range *r;

	for (r = bmips_dma_ranges; r && r->size; r++) {

		if (dma_addr >= r->parent_addr &&

		    dma_addr < (r->parent_addr + r->size))

			return dma_addr - r->parent_addr + r->child_addr;

	}

	return dma_addr;

}

static int __init bcm3384_init_dma_xor(void)

static int __init bmips_init_dma_ranges(void)

{

	struct device_node *np = of_find_node_by_type(NULL, "memory");

	struct device_node *np =

		of_find_compatible_node(NULL, NULL, "brcm,ubus");

	const __be32 *data;

	struct bmips_dma_range *r;

	int len;

	if (!np)

		return 0;

	of_property_read_u32(np, "dma-xor-mask", &bcm3384_dma_xor_mask);

	of_property_read_u32(np, "dma-xor-limit", &bcm3384_dma_xor_limit);

	data = of_get_property(np, "dma-ranges", &len);

	if (!data)

		goto out_good;

	len /= sizeof(*data) * 3;

	if (!len)

		goto out_bad;

	/* add a dummy (zero) entry at the end as a sentinel */

	bmips_dma_ranges = kzalloc(sizeof(struct bmips_dma_range) * (len + 1),

				   GFP_KERNEL);

	if (!bmips_dma_ranges)

		goto out_bad;

	for (r = bmips_dma_ranges; len; len--, r++) {

		r->child_addr = be32_to_cpup(data++);

		r->parent_addr = be32_to_cpup(data++);

		r->size = be32_to_cpup(data++);

	}

out_good:

	of_node_put(np);

	return 0;

out_bad:

	pr_err("error parsing dma-ranges property\n");

	of_node_put(np);

	return -EINVAL;

}

arch_initcall(bcm3384_init_dma_xor);

arch_initcall(bmips_init_dma_ranges);