xref: /openbmc/linux/arch/arm/mach-ixp4xx/ixp4xx-of.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * IXP4xx Device Tree boot support
4  */
5 #include <linux/kernel.h>
6 #include <linux/init.h>
7 #include <linux/io.h>
8 
9 #include <asm/mach/arch.h>
10 #include <asm/mach/map.h>
11 
12 /*
13  * These are the only fixed phys to virt mappings we ever need
14  * we put it right after the UART mapping at 0xffc80000-0xffc81fff
15  */
16 #define IXP4XX_EXP_CFG_BASE_PHYS	0xC4000000
17 #define IXP4XX_EXP_CFG_BASE_VIRT	0xFEC14000
18 
19 static struct map_desc ixp4xx_of_io_desc[] __initdata = {
20 	/*
21 	 * This is needed for runtime system configuration checks,
22 	 * such as reading if hardware so-and-so is present. This
23 	 * could eventually be converted into a syscon once all boards
24 	 * are converted to device tree.
25 	 */
26 	{
27 		.virtual = IXP4XX_EXP_CFG_BASE_VIRT,
28 		.pfn = __phys_to_pfn(IXP4XX_EXP_CFG_BASE_PHYS),
29 		.length = SZ_4K,
30 		.type = MT_DEVICE,
31 	},
32 #ifdef CONFIG_DEBUG_UART_8250
33 	/* This is needed for LL-debug/earlyprintk/debug-macro.S */
34 	{
35 		.virtual = CONFIG_DEBUG_UART_VIRT,
36 		.pfn = __phys_to_pfn(CONFIG_DEBUG_UART_PHYS),
37 		.length = SZ_4K,
38 		.type = MT_DEVICE,
39 	},
40 #endif
41 };
42 
43 static void __init ixp4xx_of_map_io(void)
44 {
45 	iotable_init(ixp4xx_of_io_desc, ARRAY_SIZE(ixp4xx_of_io_desc));
46 }
47 
48 /*
49  * We handle 4 differen SoC families. These compatible strings are enough
50  * to provide the core so that different boards can add their more detailed
51  * specifics.
52  */
53 static const char *ixp4xx_of_board_compat[] = {
54 	"intel,ixp42x",
55 	"intel,ixp43x",
56 	"intel,ixp45x",
57 	"intel,ixp46x",
58 	NULL,
59 };
60 
61 DT_MACHINE_START(IXP4XX_DT, "IXP4xx (Device Tree)")
62 	.map_io		= ixp4xx_of_map_io,
63 	.dt_compat	= ixp4xx_of_board_compat,
64 MACHINE_END
65