EMTime/libopencm3
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

stm32: added peripheral clock get helpers for all stm32 platforms.

Browse Source 
Allows for abstraction for code that's dependent on knowing the source clock
for a peripheral. Implemented a few core peripherals that tend to have clock
tree differences between platforms (USART, timers, I2C, SPI).
This commit is contained in:
Brian Viele
2020-03-06 00:57:21 -05:00
committed by Karl Palsson
parent df55d45cc1
commit e41ac6ea71
24 changed files with 860 additions and 94 deletions
Download Patch File Download Diff File Expand all files Collapse all files

68
lib/stm32/f0/rcc.c
View File

@@ -625,5 +625,73 @@ void rcc_clock_setup_in_hsi48_out_48mhz(void)
rcc_apb1_frequency = 48000000;
rcc_ahb_frequency = 48000000;
}
static uint32_t rcc_get_usart_clksel_freq(uint8_t shift) {
uint8_t clksel = (RCC_CFGR3 >> shift) & RCC_CFGR3_USARTxSW_MASK;
uint8_t hpre = (RCC_CFGR >> RCC_CFGR_HPRE_SHIFT) & RCC_CFGR_HPRE_MASK;
switch (clksel) {
case RCC_CFGR3_USART1SW_PCLK:
return rcc_apb1_frequency;
case RCC_CFGR3_USART1SW_SYSCLK:
return rcc_ahb_frequency * rcc_get_div_from_hpre(hpre);
case RCC_CFGR3_USART1SW_HSI:
return 8000000U;
}
cm3_assert_not_reached();
}
/*---------------------------------------------------------------------------*/
/** @brief Get the peripheral clock speed for the USART at base specified.
* @param usart Base address of USART to get clock frequency for.
*/
uint32_t rcc_get_usart_clk_freq(uint32_t usart)
{
if (usart == USART1_BASE) {
return rcc_get_usart_clksel_freq(RCC_CFGR3_USART1SW_SHIFT);
} else if (usart == USART2_BASE) {
return rcc_get_usart_clksel_freq(RCC_CFGR3_USART2SW_SHIFT);
} else if (usart == USART3_BASE) {
return rcc_get_usart_clksel_freq(RCC_CFGR3_USART3SW_SHIFT);
} else {
return rcc_apb1_frequency;
}
}
/*---------------------------------------------------------------------------*/
/** @brief Get the peripheral clock speed for the Timer at base specified.
* @param timer Base address of TIM to get clock frequency for.
*/
uint32_t rcc_get_timer_clk_freq(uint32_t timer __attribute__((unused)))
{
uint8_t ppre = (RCC_CFGR >> RCC_CFGR_PPRE_SHIFT) & RCC_CFGR_PPRE_MASK;
return (ppre == RCC_CFGR_PPRE_NODIV) ? rcc_apb1_frequency
: 2 * rcc_apb1_frequency;
}
/*---------------------------------------------------------------------------*/
/** @brief Get the peripheral clock speed for the I2C device at base specified.
* @param i2c Base address of I2C to get clock frequency for.
*/
uint32_t rcc_get_i2c_clk_freq(uint32_t i2c)
{
if (i2c == I2C1_BASE) {
if (RCC_CFGR3 & RCC_CFGR3_I2C1SW) {
uint8_t hpre = (RCC_CFGR >> RCC_CFGR_HPRE_SHIFT) & RCC_CFGR_HPRE_MASK;
return rcc_ahb_frequency * rcc_get_div_from_hpre(hpre);
} else {
return 8000000U;
}
} else {
return rcc_apb1_frequency;
}
}
/*---------------------------------------------------------------------------*/
/** @brief Get the peripheral clock speed for the SPI device at base specified.
* @param spi Base address of SPI device to get clock frequency for (e.g. SPI1_BASE).
*/
uint32_t rcc_get_spi_clk_freq(uint32_t spi __attribute__((unused))) {
return rcc_apb1_frequency;
}
/**@}*/