xref: /openbmc/u-boot/arch/arm/mach-bcm283x/reset.c (revision 87a62bce)
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 <asm/io.h>
11 #include <asm/arch/wdog.h>
12 #include <efi_loader.h>
13 
14 #define RESET_TIMEOUT 10
15 
16 /*
17  * The Raspberry Pi firmware uses the RSTS register to know which partiton
18  * to boot from. The partiton value is spread into bits 0, 2, 4, 6, 8, 10.
19  * Partiton 63 is a special partition used by the firmware to indicate halt.
20  */
21 #define BCM2835_WDOG_RSTS_RASPBERRYPI_HALT	0x555
22 
23 /* max ticks timeout */
24 #define BCM2835_WDOG_MAX_TIMEOUT	0x000fffff
25 
26 #ifdef CONFIG_BCM2835_WDT
27 extern void hw_watchdog_disable(void);
28 #else
29 void hw_watchdog_disable(void) {}
30 #endif
31 
32 __efi_runtime_data struct bcm2835_wdog_regs *wdog_regs =
33 	(struct bcm2835_wdog_regs *)BCM2835_WDOG_PHYSADDR;
34 
35 void __efi_runtime reset_cpu(ulong ticks)
36 {
37 	uint32_t rstc, timeout;
38 
39 	if (ticks == 0) {
40 		hw_watchdog_disable();
41 		timeout = RESET_TIMEOUT;
42 	} else
43 		timeout = ticks & BCM2835_WDOG_MAX_TIMEOUT;
44 
45 	rstc = readl(&wdog_regs->rstc);
46 	rstc &= ~BCM2835_WDOG_RSTC_WRCFG_MASK;
47 	rstc |= BCM2835_WDOG_RSTC_WRCFG_FULL_RESET;
48 
49 	writel(BCM2835_WDOG_PASSWORD | timeout, &wdog_regs->wdog);
50 	writel(BCM2835_WDOG_PASSWORD | rstc, &wdog_regs->rstc);
51 }
52 
53 #ifdef CONFIG_EFI_LOADER
54 
55 void __efi_runtime EFIAPI efi_reset_system(
56 			enum efi_reset_type reset_type,
57 			efi_status_t reset_status,
58 			unsigned long data_size, void *reset_data)
59 {
60 	u32 val;
61 
62 	switch (reset_type) {
63 	case EFI_RESET_COLD:
64 	case EFI_RESET_WARM:
65 	case EFI_RESET_PLATFORM_SPECIFIC:
66 		reset_cpu(0);
67 		break;
68 	case EFI_RESET_SHUTDOWN:
69 		/*
70 		 * We set the watchdog hard reset bit here to distinguish this reset
71 		 * from the normal (full) reset. bootcode.bin will not reboot after a
72 		 * hard reset.
73 		 */
74 		val = readl(&wdog_regs->rsts);
75 		val |= BCM2835_WDOG_PASSWORD;
76 		val |= BCM2835_WDOG_RSTS_RASPBERRYPI_HALT;
77 		writel(val, &wdog_regs->rsts);
78 		reset_cpu(0);
79 		break;
80 	}
81 
82 	while (1) { }
83 }
84 
85 efi_status_t efi_reset_system_init(void)
86 {
87 	return efi_add_runtime_mmio(&wdog_regs, sizeof(*wdog_regs));
88 }
89 
90 #endif
91