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[STM32F0] Add support functions for USB clock setup in F072 chips.

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There is remaining an issue with PREDIV connected just after clock multiplexer (only F072). This should be fixed in another commit.
This commit is contained in:
Kuldeep Singh Dhaka 2014-03-20 23:06:25 +01:00 committed by Frantisek Burian
parent 331acce4fc
commit 342ec6e9e3
2 changed files with 52 additions and 0 deletions
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3
include/libopencm3/stm32/f0/rcc.h
View File

@ -501,18 +501,21 @@ void rcc_css_disable(void);
void rcc_css_int_clear(void);
int rcc_css_int_flag(void);
void rcc_set_sysclk_source(enum rcc_osc clk);
void rcc_set_usbclk_source(enum rcc_osc clk);
void rcc_set_pll_multiplication_factor(uint32_t mul);
void rcc_set_ppre(uint32_t ppre);
void rcc_set_hpre(uint32_t hpre);
void rcc_set_prediv(uint32_t prediv);
void rcc_set_mco(uint32_t mcosrc);
enum rcc_osc rcc_system_clock_source(void);
enum rcc_osc rcc_usb_clock_source(void);
void rcc_clock_setup_in_hsi_out_8mhz(void);
void rcc_clock_setup_in_hsi_out_16mhz(void);
void rcc_clock_setup_in_hsi_out_24mhz(void);
void rcc_clock_setup_in_hsi_out_32mhz(void);
void rcc_clock_setup_in_hsi_out_40mhz(void);
void rcc_clock_setup_in_hsi_out_48mhz(void);
void rcc_clock_setup_in_hsi48_out_48mhz(void);
END_DECLS

49
lib/stm32/f0/rcc.c
View File

@ -420,6 +420,29 @@ void rcc_set_sysclk_source(enum rcc_osc clk)
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the Source for the USB Clock.
*
* @param[in] osc enum ::osc_t. Oscillator ID. Only HSI48 or PLL have
* effect.
*/
void rcc_set_usbclk_source(enum rcc_osc clk)
{
switch (clk) {
case PLL:
RCC_CFGR3 |= RCC_CFGR3_USBSW;
case HSI48:
RCC_CFGR3 &= ~RCC_CFGR3_USBSW;
case HSI:
case HSE:
case LSI:
case LSE:
case HSI14:
/* do nothing */
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the PLL Multiplication Factor.
*
@ -493,6 +516,17 @@ enum rcc_osc rcc_system_clock_source(void)
cm3_assert_not_reached();
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Get the USB Clock Source.
*
* @returns ::osc_t USB clock source:
*/
enum rcc_osc rcc_usb_clock_source(void)
{
return (RCC_CFGR3 & RCC_CFGR3_USBSW) ? PLL : HSI48;
}
void rcc_clock_setup_in_hsi_out_8mhz(void)
{
rcc_osc_on(HSI);
@ -629,5 +663,20 @@ void rcc_clock_setup_in_hsi_out_48mhz(void)
rcc_ahb_frequency = 48000000;
}
void rcc_clock_setup_in_hsi48_out_48mhz(void)
{
rcc_osc_on(HSI48);
rcc_wait_for_osc_ready(HSI48);
rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
rcc_set_sysclk_source(HSI48);
rcc_apb1_frequency = 48000000;
rcc_ahb_frequency = 48000000;
}
/**@}*/