1 /*
2 * Copyright (c) 2017-2019, STMicroelectronics - All Rights Reserved
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <assert.h>
8 #include <errno.h>
9 #include <string.h>
10
11 #include <libfdt.h>
12
13 #include <platform_def.h>
14
15 #include <arch_helpers.h>
16 #include <common/debug.h>
17 #include <drivers/arm/gicv2.h>
18 #include <drivers/delay_timer.h>
19 #include <drivers/st/stm32_iwdg.h>
20 #include <drivers/st/stm32mp_clkfunc.h>
21 #include <lib/mmio.h>
22 #include <lib/utils.h>
23 #include <plat/common/platform.h>
24
25 /* IWDG registers offsets */
26 #define IWDG_KR_OFFSET 0x00U
27
28 /* Registers values */
29 #define IWDG_KR_RELOAD_KEY 0xAAAA
30
31 struct stm32_iwdg_instance {
32 uintptr_t base;
33 unsigned long clock;
34 uint8_t flags;
35 int num_irq;
36 };
37
38 static struct stm32_iwdg_instance stm32_iwdg[IWDG_MAX_INSTANCE];
39
stm32_iwdg_get_dt_node(struct dt_node_info * info,int offset)40 static int stm32_iwdg_get_dt_node(struct dt_node_info *info, int offset)
41 {
42 int node;
43
44 node = dt_get_node(info, offset, DT_IWDG_COMPAT);
45 if (node < 0) {
46 if (offset == -1) {
47 VERBOSE("%s: No IDWG found\n", __func__);
48 }
49 return -FDT_ERR_NOTFOUND;
50 }
51
52 return node;
53 }
54
stm32_iwdg_refresh(void)55 void stm32_iwdg_refresh(void)
56 {
57 uint8_t i;
58
59 for (i = 0U; i < IWDG_MAX_INSTANCE; i++) {
60 struct stm32_iwdg_instance *iwdg = &stm32_iwdg[i];
61
62 /* 0x00000000 is not a valid address for IWDG peripherals */
63 if (iwdg->base != 0U) {
64 stm32mp_clk_enable(iwdg->clock);
65
66 mmio_write_32(iwdg->base + IWDG_KR_OFFSET,
67 IWDG_KR_RELOAD_KEY);
68
69 stm32mp_clk_disable(iwdg->clock);
70 }
71 }
72 }
73
stm32_iwdg_init(void)74 int stm32_iwdg_init(void)
75 {
76 int node = -1;
77 struct dt_node_info dt_info;
78 void *fdt;
79 uint32_t __unused count = 0;
80
81 if (fdt_get_address(&fdt) == 0) {
82 panic();
83 }
84
85 for (node = stm32_iwdg_get_dt_node(&dt_info, node);
86 node != -FDT_ERR_NOTFOUND;
87 node = stm32_iwdg_get_dt_node(&dt_info, node)) {
88 struct stm32_iwdg_instance *iwdg;
89 uint32_t hw_init;
90 uint32_t idx;
91
92 count++;
93
94 idx = stm32_iwdg_get_instance(dt_info.base);
95 iwdg = &stm32_iwdg[idx];
96 iwdg->base = dt_info.base;
97 iwdg->clock = (unsigned long)dt_info.clock;
98
99 /* DT can specify low power cases */
100 if (fdt_getprop(fdt, node, "stm32,enable-on-stop", NULL) ==
101 NULL) {
102 iwdg->flags |= IWDG_DISABLE_ON_STOP;
103 }
104
105 if (fdt_getprop(fdt, node, "stm32,enable-on-standby", NULL) ==
106 NULL) {
107 iwdg->flags |= IWDG_DISABLE_ON_STANDBY;
108 }
109
110 /* Explicit list of supported bit flags */
111 hw_init = stm32_iwdg_get_otp_config(idx);
112
113 if ((hw_init & IWDG_HW_ENABLED) != 0) {
114 if (dt_info.status == DT_DISABLED) {
115 ERROR("OTP enabled but iwdg%u DT-disabled\n",
116 idx + 1U);
117 panic();
118 }
119 iwdg->flags |= IWDG_HW_ENABLED;
120 }
121
122 if (dt_info.status == DT_DISABLED) {
123 zeromem((void *)iwdg,
124 sizeof(struct stm32_iwdg_instance));
125 continue;
126 }
127
128 if ((hw_init & IWDG_DISABLE_ON_STOP) != 0) {
129 iwdg->flags |= IWDG_DISABLE_ON_STOP;
130 }
131
132 if ((hw_init & IWDG_DISABLE_ON_STANDBY) != 0) {
133 iwdg->flags |= IWDG_DISABLE_ON_STANDBY;
134 }
135
136 VERBOSE("IWDG%u found, %ssecure\n", idx + 1U,
137 ((dt_info.status & DT_NON_SECURE) != 0) ?
138 "non-" : "");
139
140 if ((dt_info.status & DT_NON_SECURE) != 0) {
141 stm32mp_register_non_secure_periph_iomem(iwdg->base);
142 } else {
143 stm32mp_register_secure_periph_iomem(iwdg->base);
144 }
145
146 #if defined(IMAGE_BL2)
147 if (stm32_iwdg_shadow_update(idx, iwdg->flags) != BSEC_OK) {
148 return -1;
149 }
150 #endif
151 }
152
153 VERBOSE("%u IWDG instance%s found\n", count, (count > 1U) ? "s" : "");
154
155 return 0;
156 }
157