1 /*
2 * SPDX-FileCopyrightText: 2018-2023 Espressif Systems (Shanghai) CO LTD
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include "esp_system.h"
8 #include "esp_rom_sys.h"
9 #include "esp_private/system_internal.h"
10 #include "soc/rtc_periph.h"
11 #include "esp32/rom/rtc.h"
12
13 static void esp_reset_reason_clear_hint(void);
14
15 static esp_reset_reason_t s_reset_reason;
16
get_reset_reason(uint32_t rtc_reset_reason,esp_reset_reason_t reset_reason_hint)17 static esp_reset_reason_t get_reset_reason(uint32_t rtc_reset_reason, esp_reset_reason_t reset_reason_hint)
18 {
19 switch (rtc_reset_reason) {
20 case RESET_REASON_CHIP_POWER_ON:
21 return ESP_RST_POWERON;
22
23 case RESET_REASON_CPU0_SW:
24 case RESET_REASON_CORE_SW:
25 if (reset_reason_hint == ESP_RST_PANIC ||
26 reset_reason_hint == ESP_RST_BROWNOUT ||
27 reset_reason_hint == ESP_RST_TASK_WDT ||
28 reset_reason_hint == ESP_RST_INT_WDT) {
29 return reset_reason_hint;
30 }
31 return ESP_RST_SW;
32
33 case RESET_REASON_CORE_DEEP_SLEEP:
34 return ESP_RST_DEEPSLEEP;
35
36 case RESET_REASON_CORE_MWDT0:
37 return ESP_RST_TASK_WDT;
38
39 case RESET_REASON_CORE_MWDT1:
40 return ESP_RST_INT_WDT;
41
42 case RESET_REASON_CORE_RTC_WDT:
43 case RESET_REASON_SYS_RTC_WDT:
44 case RESET_REASON_CPU0_RTC_WDT:
45 case RESET_REASON_CPU0_MWDT0:
46 return ESP_RST_WDT;
47
48 case RESET_REASON_SYS_BROWN_OUT:
49 return ESP_RST_BROWNOUT;
50
51 case RESET_REASON_CORE_SDIO:
52 return ESP_RST_SDIO;
53
54 default:
55 return ESP_RST_UNKNOWN;
56 }
57 }
58
esp_reset_reason_init(void)59 void esp_reset_reason_init(void)
60 {
61 esp_reset_reason_t hint = esp_reset_reason_get_hint();
62 s_reset_reason = get_reset_reason(esp_rom_get_reset_reason(PRO_CPU_NUM), hint);
63 if (hint != ESP_RST_UNKNOWN) {
64 esp_reset_reason_clear_hint();
65 }
66 }
67
esp_reset_reason(void)68 esp_reset_reason_t esp_reset_reason(void)
69 {
70 return s_reset_reason;
71 }
72
73 /* Reset reason hint is stored in RTC_RESET_CAUSE_REG, a.k.a. RTC_CNTL_STORE6_REG,
74 * a.k.a. RTC_ENTRY_ADDR_REG. It is safe to use this register both for the
75 * deep sleep wake stub entry address and for reset reason hint, since wake stub
76 * is only used for deep sleep reset, and in this case the reason provided by
77 * esp_rom_get_reset_reason is unambiguous.
78 *
79 * Same layout is used as for RTC_APB_FREQ_REG (a.k.a. RTC_CNTL_STORE5_REG):
80 * the value is replicated in low and high half-words. In addition to that,
81 * MSB is set to 1, which doesn't happen when RTC_CNTL_STORE6_REG contains
82 * deep sleep wake stub address.
83 */
84
85 #define RST_REASON_BIT 0x80000000
86 #define RST_REASON_MASK 0x7FFF
87 #define RST_REASON_SHIFT 16
88
89 /* in IRAM, can be called from panic handler */
esp_reset_reason_set_hint(esp_reset_reason_t hint)90 void IRAM_ATTR esp_reset_reason_set_hint(esp_reset_reason_t hint)
91 {
92 assert((hint & (~RST_REASON_MASK)) == 0);
93 uint32_t val = hint | (hint << RST_REASON_SHIFT) | RST_REASON_BIT;
94 REG_WRITE(RTC_RESET_CAUSE_REG, val);
95 }
96
97 /* in IRAM, can be called from panic handler */
esp_reset_reason_get_hint(void)98 esp_reset_reason_t esp_reset_reason_get_hint(void)
99 {
100 uint32_t reset_reason_hint = REG_READ(RTC_RESET_CAUSE_REG);
101 uint32_t high = (reset_reason_hint >> RST_REASON_SHIFT) & RST_REASON_MASK;
102 uint32_t low = reset_reason_hint & RST_REASON_MASK;
103 if ((reset_reason_hint & RST_REASON_BIT) == 0 || high != low) {
104 return ESP_RST_UNKNOWN;
105 }
106 return (esp_reset_reason_t) low;
107 }
esp_reset_reason_clear_hint(void)108 static void esp_reset_reason_clear_hint(void)
109 {
110 REG_WRITE(RTC_RESET_CAUSE_REG, 0);
111 }
112
