xref: /openbmc/u-boot/arch/mips/mach-mscc/reset.c (revision 1895b87e)
1 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
2 /*
3  * Copyright (c) 2018 Microsemi Corporation
4  */
5 
6 #include <common.h>
7 
8 #include <asm/sections.h>
9 #include <asm/io.h>
10 
11 #include <asm/reboot.h>
12 
13 void _machine_restart(void)
14 {
15 #if defined(CONFIG_SOC_JR2) || defined(CONFIG_SOC_SERVALT)
16 	register u32 reg = readl(BASE_CFG + ICPU_GENERAL_CTRL);
17 	/* Set owner */
18 	reg &= ~ICPU_GENERAL_CTRL_IF_SI_OWNER_M;
19 	reg |= ICPU_GENERAL_CTRL_IF_SI_OWNER(1);
20 	/* Set boot mode */
21 	reg |= ICPU_GENERAL_CTRL_BOOT_MODE_ENA;
22 	writel(reg, BASE_CFG + ICPU_GENERAL_CTRL);
23 	/* Read back in order to make BOOT mode setting active */
24 	reg = readl(BASE_CFG + ICPU_GENERAL_CTRL);
25 	/* Reset CPU only - still executing _here_. but from cache */
26 	writel(readl(BASE_CFG + ICPU_RESET) |
27 	       ICPU_RESET_CORE_RST_CPU_ONLY |
28 	       ICPU_RESET_CORE_RST_FORCE,
29 	       BASE_CFG + ICPU_RESET);
30 #elif defined(CONFIG_SOC_SERVAL)
31 	register unsigned long i;
32 
33 	/* Prevent VCore-III from being reset with a global reset */
34 	writel(ICPU_RESET_CORE_RST_PROTECT, BASE_CFG + ICPU_RESET);
35 
36 	/* Do global reset */
37 	writel(PERF_SOFT_RST_SOFT_CHIP_RST, BASE_DEVCPU_GCB + PERF_SOFT_RST);
38 
39 	for (i = 0; i < 1000; i++)
40 		;
41 
42 	/* Power down DDR for clean DDR re-training */
43 	writel(readl(BASE_CFG + ICPU_MEMCTRL_CTRL) |
44 	       ICPU_MEMCTRL_CTRL_PWR_DOWN,
45 	       BASE_CFG + ICPU_MEMCTRL_CTRL);
46 
47 	while (!(readl(BASE_CFG + ICPU_MEMCTRL_STAT) &
48 		 ICPU_MEMCTRL_STAT_PWR_DOWN_ACK))
49 		;
50 
51 	/* Reset VCore-III, only. */
52 	writel(ICPU_RESET_CORE_RST_FORCE, BASE_CFG + ICPU_RESET);
53 #else		/* Luton || Ocelot */
54 	register u32 resetbits = PERF_SOFT_RST_SOFT_CHIP_RST;
55 	(void)readl(BASE_DEVCPU_GCB + PERF_SOFT_RST);
56 
57 	/* Make sure VCore is NOT protected from reset */
58 	clrbits_le32(BASE_CFG + ICPU_RESET, ICPU_RESET_CORE_RST_PROTECT);
59 
60 	/* Change to SPI bitbang for SPI reset workaround... */
61 	writel(ICPU_SW_MODE_SW_SPI_CS_OE(1) | ICPU_SW_MODE_SW_SPI_CS(1) |
62 	       ICPU_SW_MODE_SW_PIN_CTRL_MODE, BASE_CFG + ICPU_SW_MODE);
63 
64 	/* Do the global reset */
65 	writel(resetbits, BASE_DEVCPU_GCB + PERF_SOFT_RST);
66 #endif
67 
68 	while (1)
69 		; /* NOP */
70 }
71