1 /******************************************************************************
2 *
3 * Copyright (C) 2022-2023 Maxim Integrated Products, Inc. (now owned by
4 * Analog Devices, Inc.),
5 * Copyright (C) 2023-2024 Analog Devices, Inc.
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 *
19 ******************************************************************************/
20
21 #include <string.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include "max32655.h"
25 #include "gcr_regs.h"
26 #include "mxc_sys.h"
27 #include "flc_regs.h"
28 #include "icc.h"
29 #include "simo.h"
30
31 extern void (*const __isr_vector[])(void);
32
33 uint32_t SystemCoreClock = HIRC_FREQ;
34
35 /*
36 The libc implementation from GCC 11+ depends on _getpid and _kill in some places.
37 There is no concept of processes/PIDs in the baremetal PeriphDrivers, therefore
38 we implement stub functions that return an error code to resolve linker warnings.
39 */
_getpid(void)40 __weak int _getpid(void)
41 {
42 return E_NOT_SUPPORTED;
43 }
44
_kill(void)45 __weak int _kill(void)
46 {
47 return E_NOT_SUPPORTED;
48 }
49
SystemCoreClockUpdate(void)50 __weak void SystemCoreClockUpdate(void)
51 {
52 uint32_t base_freq, div, clk_src;
53
54 // Get the clock source and frequency
55 clk_src = (MXC_GCR->clkctrl & MXC_F_GCR_CLKCTRL_SYSCLK_SEL);
56 switch (clk_src) {
57 case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_EXTCLK:
58 base_freq = EXTCLK_FREQ;
59 break;
60 case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_ERFO:
61 base_freq = ERFO_FREQ;
62 break;
63 case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_INRO:
64 base_freq = INRO_FREQ;
65 break;
66 case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_IPO:
67 base_freq = IPO_FREQ;
68 break;
69 case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_ISO:
70 base_freq = ISO_FREQ;
71 break;
72 case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_IBRO:
73 base_freq = IBRO_FREQ;
74 break;
75 case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_ERTCO:
76 base_freq = ERTCO_FREQ;
77 break;
78 default:
79 // Codes 001 and 111 are reserved.
80 // This code should never execute, however, initialize to safe value.
81 base_freq = HIRC_FREQ;
82 break;
83 }
84
85 // Get the clock divider
86 div = (MXC_GCR->clkctrl & MXC_F_GCR_CLKCTRL_SYSCLK_DIV) >> MXC_F_GCR_CLKCTRL_SYSCLK_DIV_POS;
87
88 SystemCoreClock = base_freq >> div;
89 }
90
91 /* This function is called before C runtime initialization and can be
92 * implemented by the application for early initializations. If a value other
93 * than '0' is returned, the C runtime initialization will be skipped.
94 *
95 * You may over-ride this function in your program by defining a custom
96 * PreInit(), but care should be taken to reproduce the initialization steps
97 * or a non-functional system may result.
98 */
PreInit(void)99 __weak int PreInit(void)
100 {
101 uint32_t psc = MXC_GCR->clkctrl & MXC_F_GCR_CLKCTRL_SYSCLK_DIV;
102
103 /* Divide down system clock until SIMO is ready */
104 MXC_GCR->clkctrl = (MXC_GCR->clkctrl & ~(MXC_F_GCR_CLKCTRL_SYSCLK_DIV)) |
105 (MXC_S_GCR_CLKCTRL_SYSCLK_DIV_DIV128);
106
107 while (!(MXC_SIMO->buck_out_ready & MXC_F_SIMO_BUCK_OUT_READY_BUCKOUTRDYA)) {}
108 while (!(MXC_SIMO->buck_out_ready & MXC_F_SIMO_BUCK_OUT_READY_BUCKOUTRDYB)) {}
109 while (!(MXC_SIMO->buck_out_ready & MXC_F_SIMO_BUCK_OUT_READY_BUCKOUTRDYC)) {}
110
111 /* Restore system clock divider */
112 MXC_GCR->clkctrl = (MXC_GCR->clkctrl & ~(MXC_F_GCR_CLKCTRL_SYSCLK_DIV)) | (psc);
113
114 return 0;
115 }
116
117 /* This function can be implemented by the application to initialize the board */
Board_Init(void)118 __weak int Board_Init(void)
119 {
120 /* Do nothing */
121 return 0;
122 }
123
PalSysInit(void)124 __weak void PalSysInit(void) {}
125
126 /* This function is called just before control is transferred to main().
127 *
128 * You may over-ride this function in your program by defining a custom
129 * SystemInit(), but care should be taken to reproduce the initialization
130 * steps or a non-functional system may result.
131 */
SystemInit(void)132 __weak void SystemInit(void)
133 {
134 /* Configure the interrupt controller to use the application vector table in */
135 /* the application space */
136 #if defined(__CC_ARM) || defined(__GNUC__)
137 /* IAR sets the VTOR pointer incorrectly and causes stack corruption */
138 SCB->VTOR = (uint32_t)__isr_vector;
139 #endif /* __CC_ARM || __GNUC__ */
140
141 /* Make sure interrupts are enabled. */
142 __enable_irq();
143
144 /* Enable instruction cache */
145 MXC_ICC_Enable(MXC_ICC0);
146
147 /* Enable FPU on Cortex-M4, which occupies coprocessor slots 10 & 11 */
148 /* Grant full access, per "Table B3-24 CPACR bit assignments". */
149 /* DDI0403D "ARMv7-M Architecture Reference Manual" */
150 SCB->CPACR |= SCB_CPACR_CP10_Msk | SCB_CPACR_CP11_Msk;
151 __DSB();
152 __ISB();
153
154 /* Setup the SIMO voltages */
155 MXC_SIMO_SetVregO_A(1750);
156 while (MXC_SIMO_GetOutReadyA() != E_NO_ERROR) {}
157 MXC_SIMO_SetVregO_B(1100);
158 while (MXC_SIMO_GetOutReadyB() != E_NO_ERROR) {}
159 MXC_SIMO_SetVregO_C(1100);
160 while (MXC_SIMO_GetOutReadyC() != E_NO_ERROR) {}
161
162 /* Change system clock source to the main high-speed clock */
163 MXC_SYS_Clock_Select(MXC_SYS_CLOCK_IPO);
164 MXC_SYS_SetClockDiv(MXC_SYS_CLOCK_DIV_1);
165 SystemCoreClockUpdate();
166
167 Board_Init();
168
169 PalSysInit();
170 }
171
172 #if defined(__CC_ARM)
173 /* Global variable initialization does not occur until post scatterload in Keil tools.*/
174
175 /* External function called after our post scatterload function implementation. */
176 extern void $Super$$__main_after_scatterload(void);
177
178 /**
179 * @brief Initialization function for SystemCoreClock and Board_Init.
180 * @details $Sub$$__main_after_scatterload is called during system startup in the Keil
181 * toolset. Global variable and static variable space must be set up by the compiler
182 * prior to using these memory spaces. Setting up the SystemCoreClock and Board_Init
183 * require global memory for variable storage and are called from this function in
184 * the Keil tool chain.
185 */
$Sub$$__main_after_scatterload(void)186 void $Sub$$__main_after_scatterload(void)
187 {
188 SystemInit();
189 $Super$$__main_after_scatterload();
190 while (1) {}
191 }
192 #endif /* __CC_ARM */
193
