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zephyr/drivers/clock_control/stm32_ll_clock.c
Erwan Gouriou d8ba007a8b drivers: clock_control: Add MSI as possible clock source for stm32 
Add MSI as potential SYSCLK direct source for L0 and L4.
It could be needed in some cases when an accurate clock
is required and no external clock is available.

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
2018-04-24 08:55:02 -05:00

391 lines
11 KiB
C
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/*
*
* Copyright (c) 2017 Linaro Limited.
* Copyright (c) 2017 RnDity Sp. z o.o.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <soc.h>
#include <soc_registers.h>
#include <clock_control.h>
#include <misc/util.h>
#include <clock_control/stm32_clock_control.h>
#include "stm32_ll_clock.h"
/* Macros to fill up prescaler values */
#define _ahb_prescaler(v) LL_RCC_SYSCLK_DIV_ ## v
#define ahb_prescaler(v) _ahb_prescaler(v)
#define _apb1_prescaler(v) LL_RCC_APB1_DIV_ ## v
#define apb1_prescaler(v) _apb1_prescaler(v)
#ifndef CONFIG_SOC_SERIES_STM32F0X
#define _apb2_prescaler(v) LL_RCC_APB2_DIV_ ## v
#define apb2_prescaler(v) _apb2_prescaler(v)
#endif /* CONFIG_SOC_SERIES_STM32F0X */
/**
* @brief fill in AHB/APB buses configuration structure
*/
static void config_bus_clk_init(LL_UTILS_ClkInitTypeDef *clk_init)
{
clk_init->AHBCLKDivider = ahb_prescaler(
CONFIG_CLOCK_STM32_AHB_PRESCALER);
clk_init->APB1CLKDivider = apb1_prescaler(
CONFIG_CLOCK_STM32_APB1_PRESCALER);
#ifndef CONFIG_SOC_SERIES_STM32F0X
clk_init->APB2CLKDivider = apb2_prescaler(
CONFIG_CLOCK_STM32_APB2_PRESCALER);
#endif /* CONFIG_SOC_SERIES_STM32F0X */
}
static u32_t get_bus_clock(u32_t clock, u32_t prescaler)
{
return clock / prescaler;
}
static inline int stm32_clock_control_on(struct device *dev,
clock_control_subsys_t sub_system)
{
struct stm32_pclken *pclken = (struct stm32_pclken *)(sub_system);
ARG_UNUSED(dev);
switch (pclken->bus) {
case STM32_CLOCK_BUS_AHB1:
LL_AHB1_GRP1_EnableClock(pclken->enr);
break;
#if defined(CONFIG_SOC_SERIES_STM32L4X) || defined(CONFIG_SOC_SERIES_STM32F4X)
case STM32_CLOCK_BUS_AHB2:
LL_AHB2_GRP1_EnableClock(pclken->enr);
break;
#endif /* CONFIG_SOC_SERIES_STM32L4X || CONFIG_SOC_SERIES_STM32F4X */
case STM32_CLOCK_BUS_APB1:
LL_APB1_GRP1_EnableClock(pclken->enr);
break;
#if defined(CONFIG_SOC_SERIES_STM32L4X) || defined(CONFIG_SOC_SERIES_STM32F0X)
case STM32_CLOCK_BUS_APB1_2:
LL_APB1_GRP2_EnableClock(pclken->enr);
break;
#endif /* CONFIG_SOC_SERIES_STM32L4X || CONFIG_SOC_SERIES_STM32F0X */
#ifndef CONFIG_SOC_SERIES_STM32F0X
case STM32_CLOCK_BUS_APB2:
LL_APB2_GRP1_EnableClock(pclken->enr);
break;
#endif /* CONFIG_SOC_SERIES_STM32F0X */
#ifdef CONFIG_SOC_SERIES_STM32L0X
case STM32_CLOCK_BUS_IOP:
LL_IOP_GRP1_EnableClock(pclken->enr);
break;
#endif /* CONFIG_SOC_SERIES_STM32L0X */
}
return 0;
}
static inline int stm32_clock_control_off(struct device *dev,
clock_control_subsys_t sub_system)
{
struct stm32_pclken *pclken = (struct stm32_pclken *)(sub_system);
ARG_UNUSED(dev);
switch (pclken->bus) {
case STM32_CLOCK_BUS_AHB1:
LL_AHB1_GRP1_DisableClock(pclken->enr);
break;
#if defined(CONFIG_SOC_SERIES_STM32L4X) || defined(CONFIG_SOC_SERIES_STM32F4X)
case STM32_CLOCK_BUS_AHB2:
LL_AHB2_GRP1_DisableClock(pclken->enr);
break;
#endif /* CONFIG_SOC_SERIES_STM32L4X || CONFIG_SOC_SERIES_STM32F4X */
case STM32_CLOCK_BUS_APB1:
LL_APB1_GRP1_DisableClock(pclken->enr);
break;
#if defined(CONFIG_SOC_SERIES_STM32L4X) || defined(CONFIG_SOC_SERIES_STM32F0X)
case STM32_CLOCK_BUS_APB1_2:
LL_APB1_GRP2_DisableClock(pclken->enr);
break;
#endif /* CONFIG_SOC_SERIES_STM32L4X || CONFIG_SOC_SERIES_STM32F0X */
#ifndef CONFIG_SOC_SERIES_STM32F0X
case STM32_CLOCK_BUS_APB2:
LL_APB2_GRP1_DisableClock(pclken->enr);
break;
#endif /* CONFIG_SOC_SERIES_STM32F0X */
#ifdef CONFIG_SOC_SERIES_STM32L0X
case STM32_CLOCK_BUS_IOP:
LL_IOP_GRP1_DisableClock(pclken->enr);
break;
#endif /* CONFIG_SOC_SERIES_STM32L0X */
}
return 0;
}
static int stm32_clock_control_get_subsys_rate(struct device *clock,
clock_control_subsys_t sub_system,
u32_t *rate)
{
struct stm32_pclken *pclken = (struct stm32_pclken *)(sub_system);
/*
* Get AHB Clock (= SystemCoreClock = SYSCLK/prescaler)
* SystemCoreClock is preferred to CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC
* since it will be updated after clock configuration and hence
* more likely to contain actual clock speed
*/
u32_t ahb_clock = SystemCoreClock;
u32_t apb1_clock = get_bus_clock(ahb_clock,
CONFIG_CLOCK_STM32_APB1_PRESCALER);
#ifndef CONFIG_SOC_SERIES_STM32F0X
u32_t apb2_clock = get_bus_clock(ahb_clock,
CONFIG_CLOCK_STM32_APB2_PRESCALER);
#endif /* CONFIG_SOC_SERIES_STM32F0X */
ARG_UNUSED(clock);
switch (pclken->bus) {
case STM32_CLOCK_BUS_AHB1:
case STM32_CLOCK_BUS_AHB2:
#ifdef CONFIG_SOC_SERIES_STM32L0X
case STM32_CLOCK_BUS_IOP:
#endif /* CONFIG_SOC_SERIES_STM32L0X */
*rate = ahb_clock;
break;
case STM32_CLOCK_BUS_APB1:
#if defined(CONFIG_SOC_SERIES_STM32L4X) || defined(CONFIG_SOC_SERIES_STM32F0X)
case STM32_CLOCK_BUS_APB1_2:
#endif /* CONFIG_SOC_SERIES_STM32L4X || CONFIG_SOC_SERIES_STM32F0X */
*rate = apb1_clock;
break;
#ifndef CONFIG_SOC_SERIES_STM32F0X
case STM32_CLOCK_BUS_APB2:
*rate = apb2_clock;
break;
#endif /* CONFIG_SOC_SERIES_STM32F0X */
}
return 0;
}
static struct clock_control_driver_api stm32_clock_control_api = {
.on = stm32_clock_control_on,
.off = stm32_clock_control_off,
.get_rate = stm32_clock_control_get_subsys_rate,
};
/*
* Unconditionally switch the system clock source to HSI.
*/
__unused
static void stm32_clock_switch_to_hsi(u32_t ahb_prescaler)
{
/* Enable HSI if not enabled */
if (LL_RCC_HSI_IsReady() != 1) {
/* Enable HSI */
LL_RCC_HSI_Enable();
while (LL_RCC_HSI_IsReady() != 1) {
/* Wait for HSI ready */
}
}
/* Set HSI as SYSCLCK source */
LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_HSI);
LL_RCC_SetAHBPrescaler(ahb_prescaler);
while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_HSI) {
}
}
static int stm32_clock_control_init(struct device *dev)
{
LL_UTILS_ClkInitTypeDef s_ClkInitStruct;
ARG_UNUSED(dev);
/* configure clock for AHB/APB buses */
config_bus_clk_init((LL_UTILS_ClkInitTypeDef *)&s_ClkInitStruct);
/* Some clocks would be activated by default */
config_enable_default_clocks();
#ifdef CONFIG_CLOCK_STM32_SYSCLK_SRC_PLL
LL_UTILS_PLLInitTypeDef s_PLLInitStruct;
/* configure PLL input settings */
config_pll_init(&s_PLLInitStruct);
/*
* Switch to HSI and disable the PLL before configuration.
* (Switching to HSI makes sure we have a SYSCLK source in
* case we're currently running from the PLL we're about to
* turn off and reconfigure.)
*
* Don't use s_ClkInitStruct.AHBCLKDivider as the AHB
* prescaler here. In this configuration, that's the value to
* use when the SYSCLK source is the PLL, not HSI.
*/
stm32_clock_switch_to_hsi(LL_RCC_SYSCLK_DIV_1);
LL_RCC_PLL_Disable();
#ifdef CONFIG_CLOCK_STM32_PLL_Q_DIVISOR
MODIFY_REG(RCC->PLLCFGR, RCC_PLLCFGR_PLLQ,
CONFIG_CLOCK_STM32_PLL_Q_DIVISOR
<< POSITION_VAL(RCC_PLLCFGR_PLLQ));
#endif /* CONFIG_CLOCK_STM32_PLL_Q_DIVISOR */
#ifdef CONFIG_CLOCK_STM32_PLL_SRC_MSI
/* Switch to PLL with MSI as clock source */
LL_PLL_ConfigSystemClock_MSI(&s_PLLInitStruct, &s_ClkInitStruct);
/* Disable other clocks */
LL_RCC_HSI_Disable();
LL_RCC_HSE_Disable();
#elif CONFIG_CLOCK_STM32_PLL_SRC_HSI
/* Switch to PLL with HSI as clock source */
LL_PLL_ConfigSystemClock_HSI(&s_PLLInitStruct, &s_ClkInitStruct);
/* Disable other clocks */
LL_RCC_HSE_Disable();
LL_RCC_MSI_Disable();
#elif CONFIG_CLOCK_STM32_PLL_SRC_HSE
int hse_bypass = LL_UTILS_HSEBYPASS_OFF;
#ifdef CONFIG_CLOCK_STM32_HSE_BYPASS
hse_bypass = LL_UTILS_HSEBYPASS_ON;
#endif /* CONFIG_CLOCK_STM32_HSE_BYPASS */
/* Switch to PLL with HSE as clock source */
LL_PLL_ConfigSystemClock_HSE(CONFIG_CLOCK_STM32_HSE_CLOCK, hse_bypass,
&s_PLLInitStruct,
&s_ClkInitStruct);
/* Disable other clocks */
LL_RCC_HSI_Disable();
LL_RCC_MSI_Disable();
#endif /* CONFIG_CLOCK_STM32_PLL_SRC_... */
#elif CONFIG_CLOCK_STM32_SYSCLK_SRC_HSE
/* Enable HSE if not enabled */
if (LL_RCC_HSE_IsReady() != 1) {
/* Check if need to enable HSE bypass feature or not */
#ifdef CONFIG_CLOCK_STM32_HSE_BYPASS
LL_RCC_HSE_EnableBypass();
#else
LL_RCC_HSE_DisableBypass();
#endif /* CONFIG_CLOCK_STM32_HSE_BYPASS */
/* Enable HSE */
LL_RCC_HSE_Enable();
while (LL_RCC_HSE_IsReady() != 1) {
/* Wait for HSE ready */
}
}
/* Set HSE as SYSCLCK source */
LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_HSE);
LL_RCC_SetAHBPrescaler(s_ClkInitStruct.AHBCLKDivider);
while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_HSE) {
}
/* Update SystemCoreClock variable */
LL_SetSystemCoreClock(__LL_RCC_CALC_HCLK_FREQ(
CONFIG_CLOCK_STM32_HSE_CLOCK,
s_ClkInitStruct.AHBCLKDivider));
/* Set APB1 & APB2 prescaler*/
LL_RCC_SetAPB1Prescaler(s_ClkInitStruct.APB1CLKDivider);
#ifndef CONFIG_SOC_SERIES_STM32F0X
LL_RCC_SetAPB2Prescaler(s_ClkInitStruct.APB2CLKDivider);
#endif /* CONFIG_SOC_SERIES_STM32F0X */
/* Set flash latency */
/* HSI used as SYSCLK, set latency to 0 */
LL_FLASH_SetLatency(LL_FLASH_LATENCY_0);
/* Disable other clocks */
LL_RCC_HSI_Disable();
LL_RCC_MSI_Disable();
LL_RCC_PLL_Disable();
#elif CONFIG_CLOCK_STM32_SYSCLK_SRC_MSI
/* Set MSI Range */
LL_RCC_MSI_SetRange(LL_RCC_MSIRANGE_8);
/* Enable MSI if not enabled */
if (LL_RCC_MSI_IsReady() != 1) {
/* Enable HSI */
LL_RCC_MSI_Enable();
while (LL_RCC_MSI_IsReady() != 1) {
/* Wait for HSI ready */
}
}
/* Set MSI as SYSCLCK source */
LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_MSI);
LL_RCC_SetAHBPrescaler(s_ClkInitStruct.AHBCLKDivider);
while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_MSI) {
}
/* Update SystemCoreClock variable */
LL_SetSystemCoreClock(__LL_RCC_CALC_HCLK_FREQ(MSI_VALUE,
s_ClkInitStruct.AHBCLKDivider));
/* Set APB1 & APB2 prescaler*/
LL_RCC_SetAPB1Prescaler(s_ClkInitStruct.APB1CLKDivider);
LL_RCC_SetAPB2Prescaler(s_ClkInitStruct.APB2CLKDivider);
/* Set flash latency */
/* MSI used as SYSCLK (16MHz), set latency to 0 */
LL_FLASH_SetLatency(LL_FLASH_LATENCY_0);
/* Disable other clocks */
LL_RCC_HSE_Disable();
LL_RCC_HSI_Disable();
LL_RCC_PLL_Disable();
#elif CONFIG_CLOCK_STM32_SYSCLK_SRC_HSI
stm32_clock_switch_to_hsi(s_ClkInitStruct.AHBCLKDivider);
/* Update SystemCoreClock variable */
LL_SetSystemCoreClock(__LL_RCC_CALC_HCLK_FREQ(HSI_VALUE,
s_ClkInitStruct.AHBCLKDivider));
/* Set APB1 & APB2 prescaler*/
LL_RCC_SetAPB1Prescaler(s_ClkInitStruct.APB1CLKDivider);
#ifndef CONFIG_SOC_SERIES_STM32F0X
LL_RCC_SetAPB2Prescaler(s_ClkInitStruct.APB2CLKDivider);
#endif /* CONFIG_SOC_SERIES_STM32F0X */
/* Set flash latency */
/* HSI used as SYSCLK, set latency to 0 */
LL_FLASH_SetLatency(LL_FLASH_LATENCY_0);
/* Disable other clocks */
LL_RCC_HSE_Disable();
LL_RCC_MSI_Disable();
LL_RCC_PLL_Disable();
#endif /* CONFIG_CLOCK_STM32_SYSCLK_SRC_... */
return 0;
}
/**
* @brief RCC device, note that priority is intentionally set to 1 so
* that the device init runs just after SOC init
*/
DEVICE_AND_API_INIT(rcc_stm32, STM32_CLOCK_CONTROL_NAME,
&stm32_clock_control_init,
NULL, NULL,
PRE_KERNEL_1,
CONFIG_CLOCK_CONTROL_STM32_DEVICE_INIT_PRIORITY,
&stm32_clock_control_api);
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