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

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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
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65
lib/stm32/g0/rcc.c
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@@ -437,7 +437,7 @@ void rcc_set_mcopre(uint32_t mcopre)
* @param clock rcc_clock_scale with desired parameters
*/
void rcc_clock_setup(const struct rcc_clock_scale *clock)
{
{
if (clock->sysclock_source == RCC_PLL) {
enum rcc_osc pll_source;
@@ -547,4 +547,67 @@ void rcc_set_peripheral_clk_sel(uint32_t periph, uint32_t sel)
RCC_CCIPR = reg32 | (sel << shift);
}
static uint32_t rcc_get_clksel_freq(uint8_t shift) {
uint8_t clksel = (RCC_CCIPR >> shift) & RCC_CCIPR_USART1SEL_MASK;
uint8_t hpre = (RCC_CFGR >> RCC_CFGR_HPRE_SHIFT) & RCC_CFGR_HPRE_MASK;
switch (clksel) {
case RCC_CCIPR_USART1SEL_PCLK:
return rcc_apb1_frequency;
case RCC_CCIPR_USART1SEL_SYSCLK:
return rcc_ahb_frequency * rcc_get_div_from_hpre(hpre);
case RCC_CCIPR_USART1SEL_HSI16:
return 16000000U;
}
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_clksel_freq(RCC_CCIPR_USART1SEL_SHIFT);
} else if (usart == USART2_BASE) {
return rcc_get_clksel_freq(RCC_CCIPR_USART2SEL_SHIFT);
} else if (usart == LPUART1_BASE) {
return rcc_get_clksel_freq(RCC_CCIPR_LPUART1SEL_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 __attribute__((unused)))
{
if (i2c == I2C1_BASE) {
return rcc_get_clksel_freq(RCC_CCIPR_I2C1SEL_SHIFT);
} 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;
}
/**@}*/