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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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52
lib/stm32/l1/rcc.c
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@@ -39,6 +39,7 @@ system clock. Not all possible configurations are included.
*/
/**@{*/
#include <libopencm3/cm3/assert.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/flash.h>
#include <libopencm3/stm32/pwr.h>
@@ -555,4 +556,55 @@ void rcc_clock_setup_pll(const struct rcc_clock_scale *clock)
rcc_apb2_frequency = clock->apb2_frequency;
}
/*---------------------------------------------------------------------------*/
/** @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_apb2_frequency;
} 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)
{
/* Handle APB1 timers, and apply multiplier if necessary. */
if (timer >= TIM2_BASE && timer <= TIM7_BASE) {
uint8_t ppre1 = (RCC_CFGR >> RCC_CFGR_PPRE1_SHIFT) & RCC_CFGR_PPRE1_MASK;
return (ppre1 == RCC_CFGR_PPRE1_HCLK_NODIV) ? rcc_apb1_frequency
: 2 * rcc_apb1_frequency;
} else {
uint8_t ppre2 = (RCC_CFGR >> RCC_CFGR_PPRE2_SHIFT) & RCC_CFGR_PPRE2_MASK;
return (ppre2 == RCC_CFGR_PPRE2_HCLK_NODIV) ? rcc_apb2_frequency
: 2 * rcc_apb2_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)))
{
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) {
if (spi == SPI1_BASE) {
return rcc_apb2_frequency;
} else {
return rcc_apb1_frequency;
}
}
/**@}*/