michaelh/zephyr
1
0
Fork 0
Code Releases Activity

drivers: usb_dc_stm32: use HSI48 if available

Browse source 
This clock was designed to power crystal-less usb if available.

Signed-off-by: Pushpal Sidhu <psidhu.devel@gmail.com>
This commit is contained in:
Pushpal Sidhu 2018-04-13 14:25:30 -07:00 • committed by Kumar Gala
commit b1478518c0
1 changed files with 14 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

20
drivers/usb/device/usb_dc_stm32.c
View file

@ -210,18 +210,26 @@ static int usb_dc_stm32_clock_enable(void)
};
/*
* Some SoCs in STM32F0/L0/L4 series disable USB clock by default.
* We force USB clock source to PLL clock for this SoCs.
* Example reference manual RM0360 for STM32F030x4/x6/x8/xC and
* STM32F070x6/xB.
* Some SoCs in STM32F0/L0/L4 series disable USB clock by
* default. We force USB clock source to PLL clock for this
* SoCs. However, if these parts have an HSI48 clock, use
* that instead. Example reference manual RM0360 for
* STM32F030x4/x6/x8/xC and STM32F070x6/xB.
*/
#ifdef LL_RCC_USB_CLKSOURCE_NONE
#if defined(RCC_HSI48_SUPPORT)
LL_RCC_HSI48_Enable();
while (!LL_RCC_HSI48_IsReady()) {
/* Wait for HSI48 to become ready */
}
LL_RCC_SetUSBClockSource(LL_RCC_USB_CLKSOURCE_HSI48);
#elif defined(LL_RCC_USB_CLKSOURCE_NONE)
if (LL_RCC_PLL_IsReady()) {
LL_RCC_SetUSBClockSource(LL_RCC_USB_CLKSOURCE_PLL);
} else {
SYS_LOG_ERR("Unable to set USB clock source to PLL.");
}
#endif /* LL_RCC_USB_CLKSOURCE_NONE */
#endif /* RCC_HSI48_SUPPORT / LL_RCC_USB_CLKSOURCE_NONE */
clock_control_on(clk, (clock_control_subsys_t *)&pclken);