1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * (C) Copyright 2012 Stephen Warren
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  */
8 
9 #include <common.h>
10 #include <cpu_func.h>
11 #include <asm/io.h>
12 #include <asm/arch/base.h>
13 #include <asm/arch/wdog.h>
14 #include <efi_loader.h>
15 
16 #define RESET_TIMEOUT 10
17 
18 /*
19  * The Raspberry Pi firmware uses the RSTS register to know which partiton
20  * to boot from. The partiton value is spread into bits 0, 2, 4, 6, 8, 10.
21  * Partiton 63 is a special partition used by the firmware to indicate halt.
22  */
23 #define BCM2835_WDOG_RSTS_RASPBERRYPI_HALT	0x555
24 
25 /* max ticks timeout */
26 #define BCM2835_WDOG_MAX_TIMEOUT	0x000fffff
27 
hw_watchdog_disable(void)28 void hw_watchdog_disable(void) {}
29 
30 __efi_runtime_data struct bcm2835_wdog_regs *wdog_regs;
31 
32 static void __efi_runtime
__reset_cpu(struct bcm2835_wdog_regs * wdog_regs,ulong ticks)33 __reset_cpu(struct bcm2835_wdog_regs *wdog_regs, ulong ticks)
34 {
35 	uint32_t rstc, timeout;
36 
37 	if (ticks == 0) {
38 		hw_watchdog_disable();
39 		timeout = RESET_TIMEOUT;
40 	} else
41 		timeout = ticks & BCM2835_WDOG_MAX_TIMEOUT;
42 
43 	rstc = readl(&wdog_regs->rstc);
44 	rstc &= ~BCM2835_WDOG_RSTC_WRCFG_MASK;
45 	rstc |= BCM2835_WDOG_RSTC_WRCFG_FULL_RESET;
46 
47 	writel(BCM2835_WDOG_PASSWORD | timeout, &wdog_regs->wdog);
48 	writel(BCM2835_WDOG_PASSWORD | rstc, &wdog_regs->rstc);
49 }
50 
reset_cpu(ulong ticks)51 void reset_cpu(ulong ticks)
52 {
53 	struct bcm2835_wdog_regs *regs =
54 		(struct bcm2835_wdog_regs *)BCM2835_WDOG_PHYSADDR;
55 
56 	__reset_cpu(regs, 0);
57 }
58 
59 #ifdef CONFIG_EFI_LOADER
60 
efi_reset_system(enum efi_reset_type reset_type,efi_status_t reset_status,unsigned long data_size,void * reset_data)61 void __efi_runtime EFIAPI efi_reset_system(
62 			enum efi_reset_type reset_type,
63 			efi_status_t reset_status,
64 			unsigned long data_size, void *reset_data)
65 {
66 	u32 val;
67 
68 	if (reset_type == EFI_RESET_COLD ||
69 	    reset_type == EFI_RESET_WARM ||
70 	    reset_type == EFI_RESET_PLATFORM_SPECIFIC) {
71 		__reset_cpu(wdog_regs, 0);
72 	} else if (reset_type == EFI_RESET_SHUTDOWN) {
73 		/*
74 		 * We set the watchdog hard reset bit here to distinguish this reset
75 		 * from the normal (full) reset. bootcode.bin will not reboot after a
76 		 * hard reset.
77 		 */
78 		val = readl(&wdog_regs->rsts);
79 		val |= BCM2835_WDOG_PASSWORD;
80 		val |= BCM2835_WDOG_RSTS_RASPBERRYPI_HALT;
81 		writel(val, &wdog_regs->rsts);
82 		__reset_cpu(wdog_regs, 0);
83 	}
84 
85 	while (1) { }
86 }
87 
efi_reset_system_init(void)88 efi_status_t efi_reset_system_init(void)
89 {
90 	wdog_regs = (struct bcm2835_wdog_regs *)BCM2835_WDOG_PHYSADDR;
91 	return efi_add_runtime_mmio(&wdog_regs, sizeof(*wdog_regs));
92 }
93 
94 #endif
95