static void stm32l4_stdclockconfig(void)
{
uint32_t regval;
volatile int32_t timeout;
#ifdef STM32L4_BOARD_USEHSI
/* Enable Internal High-Speed Clock (HSI) */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_HSION; /* Enable HSI */
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the HSI is ready (or until a timeout elapsed) */
for (timeout = HSIRDY_TIMEOUT; timeout > 0; timeout--)
{
/* Check if the HSIRDY flag is the set in the CR */
if ((getreg32(STM32L4_RCC_CR) & RCC_CR_HSIRDY) != 0)
{
/* If so, then break-out with timeout > 0 */
break;
}
}
#elif defined(STM32L4_BOARD_USEMSI)
/* Enable Internal Multi-Speed Clock (MSI) */
# error STM32L4_BOARD_USEMSI not yet implemented in arch/arm/src/stm32l4/stm32l4x6xx_rcc.c
/* setting MSIRANGE */
/* setting MSIPLLEN */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_MSION; /* Enable MSI */
putreg32(regval, STM32L4_RCC_CR);
#elif defined(STM32L4_BOARD_USEHSE)
/* Enable External High-Speed Clock (HSE) */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_HSEON; /* Enable HSE */
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the HSE is ready (or until a timeout elapsed) */
for (timeout = HSERDY_TIMEOUT; timeout > 0; timeout--)
{
/* Check if the HSERDY flag is the set in the CR */
if ((getreg32(STM32L4_RCC_CR) & RCC_CR_HSERDY) != 0)
{
/* If so, then break-out with timeout > 0 */
break;
}
}
#else
# error stm32l4_stdclockconfig(), must have one of STM32L4_BOARD_USEHSI, STM32L4_BOARD_USEMSI, STM32L4_BOARD_USEHSE defined
#endif
/* Check for a timeout. If this timeout occurs, then we are hosed. We
* have no real back-up plan, although the following logic makes it look
* as though we do.
*/
if (timeout > 0)
{
#warning todo: regulator voltage according to clock freq
#if 0
/* Ensure Power control is enabled before modifying it. */
regval = getreg32(STM32L4_RCC_APB1ENR);
regval |= RCC_APB1ENR_PWREN;
putreg32(regval, STM32L4_RCC_APB1ENR);
/* Select regulator voltage output Scale 1 mode to support system
* frequencies up to 168 MHz.
*/
regval = getreg32(STM32L4_PWR_CR);
regval &= ~PWR_CR_VOS_MASK;
regval |= PWR_CR_VOS_SCALE_1;
putreg32(regval, STM32L4_PWR_CR);
#endif
/* Set the HCLK source/divider */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_HPRE_MASK;
regval |= STM32L4_RCC_CFGR_HPRE;
putreg32(regval, STM32L4_RCC_CFGR);
/* Set the PCLK2 divider */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_PPRE2_MASK;
regval |= STM32L4_RCC_CFGR_PPRE2;
putreg32(regval, STM32L4_RCC_CFGR);
/* Set the PCLK1 divider */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_PPRE1_MASK;
regval |= STM32L4_RCC_CFGR_PPRE1;
putreg32(regval, STM32L4_RCC_CFGR);
#ifdef CONFIG_RTC_HSECLOCK
/* Set the RTC clock divisor */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_RTCPRE_MASK;
regval |= RCC_CFGR_RTCPRE(HSE_DIVISOR);
putreg32(regval, STM32L4_RCC_CFGR);
#endif
/* Set the PLL source and main divider */
regval = getreg32(STM32L4_RCC_PLLCFG);
/* Configure Main PLL */
/* Set the PLL dividers and multipliers to configure the main PLL */
regval = (STM32L4_PLLCFG_PLLM | STM32L4_PLLCFG_PLLN | STM32L4_PLLCFG_PLLP
| STM32L4_PLLCFG_PLLQ | STM32L4_PLLCFG_PLLR);
#ifdef STM32L4_PLLCFG_PLLP_ENABLED
regval |= RCC_PLLCFG_PLLPEN;
#endif
#ifdef STM32L4_PLLCFG_PLLQ_ENABLED
regval |= RCC_PLLCFG_PLLQEN;
#endif
#ifdef STM32L4_PLLCFG_PLLR_ENABLED
regval |= RCC_PLLCFG_PLLREN;
#endif
/* XXX The choice of clock source to PLL (all three) is independent
* of the sys clock source choice, review the STM32L4_BOARD_USEHSI
* name; probably split it into two, one for PLL source and one
* for sys clock source.
*/
#ifdef STM32L4_BOARD_USEHSI
regval |= RCC_PLLCFG_PLLSRC_HSI;
#else /* if STM32L4_BOARD_USEHSE */
regval |= RCC_PLLCFG_PLLSRC_HSE;
#endif
putreg32(regval, STM32L4_RCC_PLLCFG);
/* Enable the main PLL */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_PLLON;
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the PLL is ready */
while ((getreg32(STM32L4_RCC_CR) & RCC_CR_PLLRDY) == 0)
{
}
#ifdef CONFIG_STM32L4_SAI1PLL
/* Configure SAI1 PLL */
regval = getreg32(STM32L4_RCC_PLLSAI1CFG);
/* Set the PLL dividers and multipliers to configure the SAI1 PLL */
regval = (STM32L4_PLLSAI1CFG_PLLN | STM32L4_PLLSAI1CFG_PLLP
| STM32L4_PLLSAI1CFG_PLLQ | STM32L4_PLLSAI1CFG_PLLR);
#ifdef STM32L4_PLLSAI1CFG_PLLP_ENABLED
regval |= RCC_PLLSAI1CFG_PLLPEN;
#endif
#ifdef STM32L4_PLLSAI1CFG_PLLQ_ENABLED
regval |= RCC_PLLSAI1CFG_PLLQEN;
#endif
#ifdef STM32L4_PLLSAI1CFG_PLLR_ENABLED
regval |= RCC_PLLSAI1CFG_PLLREN;
#endif
putreg32(regval, STM32L4_RCC_PLLSAI1CFG);
/* Enable the SAI1 PLL */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_PLLSAI1ON;
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the PLL is ready */
while ((getreg32(STM32L4_RCC_CR) & RCC_CR_PLLSAI1RDY) == 0)
{
}
#endif
#ifdef CONFIG_STM32L4_SAI2PLL
/* Configure SAI2 PLL */
regval = getreg32(STM32L4_RCC_PLLSAI2CFG);
/* Enable the SAI2 PLL */
/* Set the PLL dividers and multipliers to configure the SAI2 PLL */
regval = (STM32L4_PLLSAI2CFG_PLLN | STM32L4_PLLSAI2CFG_PLLP |
STM32L4_PLLSAI2CFG_PLLR);
#ifdef STM32L4_PLLSAI2CFG_PLLP_ENABLED
regval |= RCC_PLLSAI2CFG_PLLPEN;
#endif
#ifdef STM32L4_PLLSAI2CFG_PLLR_ENABLED
regval |= RCC_PLLSAI2CFG_PLLREN;
#endif
putreg32(regval, STM32L4_RCC_PLLSAI2CFG);
/* Enable the SAI1 PLL */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_PLLSAI2ON;
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the PLL is ready */
while ((getreg32(STM32L4_RCC_CR) & RCC_CR_PLLSAI2RDY) == 0)
{
}
#endif
/* Enable FLASH prefetch, instruction cache, data cache, and 5 wait states */
#ifdef CONFIG_STM32L4_FLASH_PREFETCH
regval = (FLASH_ACR_LATENCY_4 | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_PRFTEN);
#else
regval = (FLASH_ACR_LATENCY_4 | FLASH_ACR_ICEN | FLASH_ACR_DCEN);
#endif
putreg32(regval, STM32L4_FLASH_ACR);
/* Select the main PLL as system clock source */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_SW_MASK;
regval |= RCC_CFGR_SW_PLL;
putreg32(regval, STM32L4_RCC_CFGR);
/* Wait until the PLL source is used as the system clock source */
while ((getreg32(STM32L4_RCC_CFGR) & RCC_CFGR_SWS_MASK) != RCC_CFGR_SWS_PLL)
{
}
#if defined(CONFIG_STM32L4_IWDG) || defined(CONFIG_RTC_LSICLOCK)
/* Low speed internal clock source LSI */
stm32l4_rcc_enablelsi();
#endif
#if defined(STM32L4_USE_LSE)
/* Low speed external clock source LSE
*
* TODO: There is another case where the LSE needs to
* be enabled: if the MCO1 pin selects LSE as source.
* XXX and other cases, like automatic trimming of MSI for USB use
*/
/* ensure Power control is enabled since it is indirectly required
* to alter the LSE parameters.
*/
stm32l4_pwr_enableclk(true);
/* XXX other LSE settings must be made before turning on the oscillator
* and we need to ensure it is first off before doing so.
*/
/* turn on the LSE oscillator
* XXX this will almost surely get moved since we also want to use
* this for automatically trimming MSI, etc.
*/
stm32l4_rcc_enablelse();
#endif
#if defined(STM32L4_USE_CLK48)
/* XXX sanity if sdmmc1 or usb or rng, then we need to set the clk48 source
* and then we can also do away with STM32L4_USE_CLK48, and give better
* warning messages
*
* XXX sanity if our STM32L4_CLK48_SEL is YYY then we need to have already
* enabled ZZZ
*/
regval = getreg32(STM32L4_RCC_CCIPR);
regval &= RCC_CCIPR_CLK48SEL_MASK;
regval |= STM32L4_CLK48_SEL;
putreg32(regval, STM32L4_RCC_CCIPR);
#endif
}
}
void stm32l4_board_clockconfig(void)
{
uint32_t regval;
/* Enable Internal High-Speed Clock (HSI) */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_HSION; /* Enable HSI */
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the HSI is ready */
while ((getreg32(STM32L4_RCC_CR) & RCC_CR_HSIRDY) == 0)
{
}
/* Set the HCLK source/divider */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_HPRE_MASK;
regval |= STM32L4_RCC_CFGR_HPRE;
putreg32(regval, STM32L4_RCC_CFGR);
/* Set the PCLK2 divider */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_PPRE2_MASK;
regval |= STM32L4_RCC_CFGR_PPRE2;
putreg32(regval, STM32L4_RCC_CFGR);
/* Set the PCLK1 divider */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_PPRE1_MASK;
regval |= STM32L4_RCC_CFGR_PPRE1;
putreg32(regval, STM32L4_RCC_CFGR);
/* Set the PLL source and main divider */
regval = getreg32(STM32L4_RCC_PLLCFG);
/* Configure Main PLL */
/* Set the PLL dividers and multipliers to configure the main PLL */
regval = (STM32L4_PLLCFG_PLLM | STM32L4_PLLCFG_PLLN | STM32L4_PLLCFG_PLLP
| STM32L4_PLLCFG_PLLQ | STM32L4_PLLCFG_PLLR);
regval |= RCC_PLLCFG_PLLQEN;
regval |= RCC_PLLCFG_PLLREN;
/* XXX The choice of clock source to PLL (all three) is independent
* of the sys clock source choice, review the STM32L4_BOARD_USEHSI
* name; probably split it into two, one for PLL source and one
* for sys clock source.
*/
regval |= RCC_PLLCFG_PLLSRC_HSI;
putreg32(regval, STM32L4_RCC_PLLCFG);
/* Enable the main PLL */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_PLLON;
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the PLL is ready */
while ((getreg32(STM32L4_RCC_CR) & RCC_CR_PLLRDY) == 0)
{
}
/* Configure SAI1 PLL */
regval = getreg32(STM32L4_RCC_PLLSAI1CFG);
/* Set the PLL dividers and multipliers to configure the SAI1 PLL */
regval = (STM32L4_PLLSAI1CFG_PLLN | STM32L4_PLLSAI1CFG_PLLP |
STM32L4_PLLSAI1CFG_PLLQ | STM32L4_PLLSAI1CFG_PLLR);
regval |= RCC_PLLSAI1CFG_PLLQEN;
putreg32(regval, STM32L4_RCC_PLLSAI1CFG);
/* Enable the SAI1 PLL */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_PLLSAI1ON;
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the PLL is ready */
while ((getreg32(STM32L4_RCC_CR) & RCC_CR_PLLSAI1RDY) == 0)
{
}
/* Configure SAI2 PLL */
regval = getreg32(STM32L4_RCC_PLLSAI2CFG);
/* Enable the SAI2 PLL */
/* Set the PLL dividers and multipliers to configure the SAI2 PLL */
regval = (STM32L4_PLLSAI2CFG_PLLN | STM32L4_PLLSAI2CFG_PLLP |
STM32L4_PLLSAI2CFG_PLLR);
putreg32(regval, STM32L4_RCC_PLLSAI2CFG);
/* Enable the SAI1 PLL */
regval = getreg32(STM32L4_RCC_CR);
regval |= RCC_CR_PLLSAI2ON;
putreg32(regval, STM32L4_RCC_CR);
/* Wait until the PLL is ready */
while ((getreg32(STM32L4_RCC_CR) & RCC_CR_PLLSAI2RDY) == 0)
{
}
/* Enable FLASH prefetch, instruction cache, data cache, and 5 wait states */
#ifdef CONFIG_STM32L4_FLASH_PREFETCH
regval = (FLASH_ACR_LATENCY_4 | FLASH_ACR_ICEN | FLASH_ACR_DCEN |
FLASH_ACR_PRFTEN);
#else
regval = (FLASH_ACR_LATENCY_4 | FLASH_ACR_ICEN | FLASH_ACR_DCEN);
#endif
putreg32(regval, STM32L4_FLASH_ACR);
/* Select the main PLL as system clock source */
regval = getreg32(STM32L4_RCC_CFGR);
regval &= ~RCC_CFGR_SW_MASK;
regval |= RCC_CFGR_SW_PLL;
putreg32(regval, STM32L4_RCC_CFGR);
/* Wait until the PLL source is used as the system clock source */
while ((getreg32(STM32L4_RCC_CFGR) & RCC_CFGR_SWS_MASK) != RCC_CFGR_SWS_PLL)
{
}
#if defined(CONFIG_STM32L4_IWDG) || defined(CONFIG_RTC_LSICLOCK)
/* Low speed internal clock source LSI */
stm32l4_rcc_enablelsi();
#endif
#if defined(STM32L4_USE_LSE)
/* Low speed external clock source LSE
*
* TODO: There is another case where the LSE needs to
* be enabled: if the MCO1 pin selects LSE as source.
*/
stm32l4_pwr_enableclk(true);
stm32l4_rcc_enablelse();
#endif
/* XXX sanity if sdmmc1 or usb or rng, then we need to set the clk48 source
* and then we can also do away with STM32L4_USE_CLK48, and give better
* warning messages
*
* XXX sanity if our STM32L4_CLK48_SEL is YYY then we need to have already
* enabled ZZZ
*/
regval = getreg32(STM32L4_RCC_CCIPR);
regval &= RCC_CCIPR_CLK48SEL_MASK;
regval |= STM32L4_CLK48_SEL;
putreg32(regval, STM32L4_RCC_CCIPR);
}