diff options
Diffstat (limited to 'arch/arm/mach-bcm/board_bcm2835.c')
| -rw-r--r-- | arch/arm/mach-bcm/board_bcm2835.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm/board_bcm2835.c b/arch/arm/mach-bcm/board_bcm2835.c index bfc556f76720..91a758c61f48 100644 --- a/arch/arm/mach-bcm/board_bcm2835.c +++ b/arch/arm/mach-bcm/board_bcm2835.c @@ -5,13 +5,103 @@ #include <linux/init.h> #include <linux/irqchip.h> +#include <linux/mm.h> #include <linux/of_address.h> +#include <linux/of_fdt.h> +#include <asm/system_info.h> #include <asm/mach/arch.h> #include <asm/mach/map.h> +#include <asm/memory.h> +#include <asm/pgtable.h> #include "platsmp.h" +#define BCM2835_USB_VIRT_BASE (VMALLOC_START) +#define BCM2835_USB_VIRT_MPHI (VMALLOC_START + 0x10000) + +static void __init bcm2835_init(void) +{ + struct device_node *np = of_find_node_by_path("/system"); + u32 val; + u64 val64; + + if (!of_property_read_u32(np, "linux,revision", &val)) + system_rev = val; + if (!of_property_read_u64(np, "linux,serial", &val64)) + system_serial_low = val64; +} + +/* + * We need to map registers that are going to be accessed by the FIQ + * very early, before any kernel threads are spawned. Because if done + * later, the mapping tables are not updated instantly but lazily upon + * first access through a data abort handler. While that is fine + * when executing regular kernel code, if the first access in a specific + * thread happens while running FIQ code this will result in a panic. + * + * For more background see the following old mailing list thread: + * https://www.spinics.net/lists/arm-kernel/msg325250.html + */ +static int __init bcm2835_map_usb(unsigned long node, const char *uname, + int depth, void *data) +{ + struct map_desc map[2]; + const __be32 *reg; + int len; + unsigned long p2b_offset = *((unsigned long *) data); + + if (!of_flat_dt_is_compatible(node, "brcm,bcm2708-usb")) + return 0; + reg = of_get_flat_dt_prop(node, "reg", &len); + if (!reg || len != (sizeof(unsigned long) * 4)) + return 0; + + /* Use information about the physical addresses of the + * registers from the device tree, but use legacy + * iotable_init() static mapping function to map them, + * as ioremap() is not functional at this stage in boot. + */ + map[0].virtual = (unsigned long) BCM2835_USB_VIRT_BASE; + map[0].pfn = __phys_to_pfn(be32_to_cpu(reg[0]) - p2b_offset); + map[0].length = be32_to_cpu(reg[1]); + map[0].type = MT_DEVICE; + map[1].virtual = (unsigned long) BCM2835_USB_VIRT_MPHI; + map[1].pfn = __phys_to_pfn(be32_to_cpu(reg[2]) - p2b_offset); + map[1].length = be32_to_cpu(reg[3]); + map[1].type = MT_DEVICE; + iotable_init(map, 2); + + return 1; +} + +static void __init bcm2835_map_io(void) +{ + const __be32 *ranges, *address_cells; + unsigned long root, addr_cells; + int soc, len; + unsigned long p2b_offset; + + debug_ll_io_init(); + + root = of_get_flat_dt_root(); + /* Find out how to map bus to physical address first from soc/ranges */ + soc = of_get_flat_dt_subnode_by_name(root, "soc"); + if (soc < 0) + return; + address_cells = of_get_flat_dt_prop(root, "#address-cells", &len); + if (!address_cells || len < (sizeof(unsigned long))) + return; + addr_cells = be32_to_cpu(address_cells[0]); + ranges = of_get_flat_dt_prop(soc, "ranges", &len); + if (!ranges || len < (sizeof(unsigned long) * (2 + addr_cells))) + return; + p2b_offset = be32_to_cpu(ranges[0]) - be32_to_cpu(ranges[addr_cells]); + + /* Now search for bcm2708-usb node in device tree */ + of_scan_flat_dt(bcm2835_map_usb, &p2b_offset); +} + static const char * const bcm2835_compat[] = { #ifdef CONFIG_ARCH_MULTI_V6 "brcm,bcm2835", @@ -24,6 +114,25 @@ static const char * const bcm2835_compat[] = { }; DT_MACHINE_START(BCM2835, "BCM2835") + .map_io = bcm2835_map_io, + .init_machine = bcm2835_init, .dt_compat = bcm2835_compat, .smp = smp_ops(bcm2836_smp_ops), MACHINE_END + +static const char * const bcm2711_compat[] = { +#ifdef CONFIG_ARCH_MULTI_V7 + "brcm,bcm2711", +#endif + NULL +}; + +DT_MACHINE_START(BCM2711, "BCM2711") +#if defined(CONFIG_ZONE_DMA) && defined(CONFIG_ARM_LPAE) + .dma_zone_size = SZ_1G, +#endif + .map_io = bcm2835_map_io, + .init_machine = bcm2835_init, + .dt_compat = bcm2711_compat, + .smp = smp_ops(bcm2836_smp_ops), +MACHINE_END |