xref: /linux/arch/arm/mach-tegra/reset.c (revision 4cb5d9eca143f7fbf8cc457be19a91914f978a00)
1 /*
2  * arch/arm/mach-tegra/reset.c
3  *
4  * Copyright (C) 2011,2012 NVIDIA Corporation.
5  *
6  * This software is licensed under the terms of the GNU General Public
7  * License version 2, as published by the Free Software Foundation, and
8  * may be copied, distributed, and modified under those terms.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  */
16 
17 #include <linux/bitops.h>
18 #include <linux/cpumask.h>
19 #include <linux/init.h>
20 #include <linux/io.h>
21 
22 #include <linux/firmware/trusted_foundations.h>
23 
24 #include <soc/tegra/fuse.h>
25 
26 #include <asm/cacheflush.h>
27 #include <asm/firmware.h>
28 #include <asm/hardware/cache-l2x0.h>
29 
30 #include "iomap.h"
31 #include "irammap.h"
32 #include "reset.h"
33 #include "sleep.h"
34 
35 #define TEGRA_IRAM_RESET_BASE (TEGRA_IRAM_BASE + \
36 				TEGRA_IRAM_RESET_HANDLER_OFFSET)
37 
38 static bool is_enabled;
39 
40 static void __init tegra_cpu_reset_handler_set(const u32 reset_address)
41 {
42 	void __iomem *evp_cpu_reset =
43 		IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE + 0x100);
44 	void __iomem *sb_ctrl = IO_ADDRESS(TEGRA_SB_BASE);
45 	u32 reg;
46 
47 	/*
48 	 * NOTE: This must be the one and only write to the EVP CPU reset
49 	 *       vector in the entire system.
50 	 */
51 	writel(reset_address, evp_cpu_reset);
52 	wmb();
53 	reg = readl(evp_cpu_reset);
54 
55 	/*
56 	 * Prevent further modifications to the physical reset vector.
57 	 *  NOTE: Has no effect on chips prior to Tegra30.
58 	 */
59 	reg = readl(sb_ctrl);
60 	reg |= 2;
61 	writel(reg, sb_ctrl);
62 	wmb();
63 }
64 
65 static void __init tegra_cpu_reset_handler_enable(void)
66 {
67 	void __iomem *iram_base = IO_ADDRESS(TEGRA_IRAM_RESET_BASE);
68 	const u32 reset_address = TEGRA_IRAM_RESET_BASE +
69 						tegra_cpu_reset_handler_offset;
70 	int err;
71 
72 	BUG_ON(is_enabled);
73 	BUG_ON(tegra_cpu_reset_handler_size > TEGRA_IRAM_RESET_HANDLER_SIZE);
74 
75 	memcpy(iram_base, (void *)__tegra_cpu_reset_handler_start,
76 			tegra_cpu_reset_handler_size);
77 
78 	err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
79 	switch (err) {
80 	case -ENOSYS:
81 		tegra_cpu_reset_handler_set(reset_address);
82 		/* pass-through */
83 	case 0:
84 		is_enabled = true;
85 		break;
86 	default:
87 		pr_crit("Cannot set CPU reset handler: %d\n", err);
88 		BUG();
89 	}
90 }
91 
92 void __init tegra_cpu_reset_handler_init(void)
93 {
94 	__tegra_cpu_reset_handler_data[TEGRA_RESET_TF_PRESENT] =
95 		trusted_foundations_registered();
96 
97 #ifdef CONFIG_SMP
98 	__tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_PRESENT] =
99 		*((u32 *)cpu_possible_mask);
100 	__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_SECONDARY] =
101 		__pa_symbol((void *)secondary_startup);
102 #endif
103 
104 #ifdef CONFIG_PM_SLEEP
105 	__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP1] =
106 		TEGRA_IRAM_LPx_RESUME_AREA;
107 	__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] =
108 		__pa_symbol((void *)tegra_resume);
109 #endif
110 
111 	tegra_cpu_reset_handler_enable();
112 }
113