/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * 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/io.h> #include <linux/of.h> #include <linux/printk.h> #include <linux/slab.h> #include <linux/types.h> #include <asm/bmips.h> /* * 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 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. */ struct bmips_dma_range { u32 child_addr; u32 parent_addr; u32 size; }; static struct bmips_dma_range *bmips_dma_ranges; #define FLUSH_RAC 0x100 dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t pa) { 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; } phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr) { 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; } void arch_sync_dma_for_cpu_all(struct device *dev) { void __iomem *cbr = BMIPS_GET_CBR(); u32 cfg; if (boot_cpu_type() != CPU_BMIPS3300 && boot_cpu_type() != CPU_BMIPS4350 && boot_cpu_type() != CPU_BMIPS4380) return; /* Flush stale data out of the readahead cache */ cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG); __raw_writel(cfg | 0x100, cbr + BMIPS_RAC_CONFIG); __raw_readl(cbr + BMIPS_RAC_CONFIG); } static int __init bmips_init_dma_ranges(void) { 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; 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 = kcalloc(len + 1, sizeof(struct bmips_dma_range), 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(bmips_init_dma_ranges);