zephyr/soc/st/stm32/stm32c0/soc.c

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/*
* Copyright (c) 2023 Benjamin Björnsson <benjamin.bjornsson@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief System/hardware module for STM32C0 processor
*/
#include <zephyr/device.h>
#include <zephyr/init.h>
#include <zephyr/linker/linker-defs.h>
#include <string.h>
#include <cmsis_core.h>
/**
* @brief Perform basic hardware initialization at boot.
*
* This needs to be run from the very beginning.
* So the init priority has to be 0 (zero).
*
* @return 0
*/
init: remove the need for a dummy device pointer in SYS_INIT functions The init infrastructure, found in `init.h`, is currently used by: - `SYS_INIT`: to call functions before `main` - `DEVICE_*`: to initialize devices They are all sorted according to an initialization level + a priority. `SYS_INIT` calls are really orthogonal to devices, however, the required function signature requires a `const struct device *dev` as a first argument. The only reason for that is because the same init machinery is used by devices, so we have something like: ```c struct init_entry { int (*init)(const struct device *dev); /* only set by DEVICE_*, otherwise NULL */ const struct device *dev; } ``` As a result, we end up with such weird/ugly pattern: ```c static int my_init(const struct device *dev) { /* always NULL! add ARG_UNUSED to avoid compiler warning */ ARG_UNUSED(dev); ... } ``` This is really a result of poor internals isolation. This patch proposes a to make init entries more flexible so that they can accept sytem initialization calls like this: ```c static int my_init(void) { ... } ``` This is achieved using a union: ```c union init_function { /* for SYS_INIT, used when init_entry.dev == NULL */ int (*sys)(void); /* for DEVICE*, used when init_entry.dev != NULL */ int (*dev)(const struct device *dev); }; struct init_entry { /* stores init function (either for SYS_INIT or DEVICE*) union init_function init_fn; /* stores device pointer for DEVICE*, NULL for SYS_INIT. Allows * to know which union entry to call. */ const struct device *dev; } ``` This solution **does not increase ROM usage**, and allows to offer clean public APIs for both SYS_INIT and DEVICE*. Note that however, init machinery keeps a coupling with devices. **NOTE**: This is a breaking change! All `SYS_INIT` functions will need to be converted to the new signature. See the script offered in the following commit. Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no> init: convert SYS_INIT functions to the new signature Conversion scripted using scripts/utils/migrate_sys_init.py. Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no> manifest: update projects for SYS_INIT changes Update modules with updated SYS_INIT calls: - hal_ti - lvgl - sof - TraceRecorderSource Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no> tests: devicetree: devices: adjust test Adjust test according to the recently introduced SYS_INIT infrastructure. Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no> tests: kernel: threads: adjust SYS_INIT call Adjust to the new signature: int (*init_fn)(void); Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
2022-10-19 15:33:44 +08:00
static int stm32c0_init(void)
{
/* Update CMSIS SystemCoreClock variable (HCLK) */
/* At reset, system core clock is set to 48 MHz from HSI */
SystemCoreClock = 48000000;
return 0;
}
SYS_INIT(stm32c0_init, PRE_KERNEL_1, 0);