xref: /openbmc/linux/arch/arm/mach-gemini/board-dt.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Gemini 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 #include <asm/system_misc.h>
12 #include <asm/proc-fns.h>
13 
14 #ifdef CONFIG_DEBUG_GEMINI
15 /* This is needed for LL-debug/earlyprintk/debug-macro.S */
16 static struct map_desc gemini_io_desc[] __initdata = {
17 	{
18 		.virtual = CONFIG_DEBUG_UART_VIRT,
19 		.pfn = __phys_to_pfn(CONFIG_DEBUG_UART_PHYS),
20 		.length = SZ_4K,
21 		.type = MT_DEVICE,
22 	},
23 };
24 
25 static void __init gemini_map_io(void)
26 {
27 	iotable_init(gemini_io_desc, ARRAY_SIZE(gemini_io_desc));
28 }
29 #else
30 #define gemini_map_io NULL
31 #endif
32 
33 static void gemini_idle(void)
34 {
35 	/*
36 	 * Because of broken hardware we have to enable interrupts or the CPU
37 	 * will never wakeup... Acctualy it is not very good to enable
38 	 * interrupts first since scheduler can miss a tick, but there is
39 	 * no other way around this. Platforms that needs it for power saving
40 	 * should enable it in init code, since by default it is
41 	 * disabled.
42 	 */
43 
44 	/* FIXME: Enabling interrupts here is racy! */
45 	local_irq_enable();
46 	cpu_do_idle();
47 }
48 
49 static void __init gemini_init_machine(void)
50 {
51 	arm_pm_idle = gemini_idle;
52 }
53 
54 static const char *gemini_board_compat[] = {
55 	"cortina,gemini",
56 	NULL,
57 };
58 
59 DT_MACHINE_START(GEMINI_DT, "Gemini (Device Tree)")
60 	.map_io		= gemini_map_io,
61 	.init_machine	= gemini_init_machine,
62 	.dt_compat	= gemini_board_compat,
63 MACHINE_END
64