aboutsummaryrefslogtreecommitdiff
path: root/lib/stm32/f1/rcc.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/stm32/f1/rcc.c')
-rw-r--r--lib/stm32/f1/rcc.c677
1 files changed, 677 insertions, 0 deletions
diff --git a/lib/stm32/f1/rcc.c b/lib/stm32/f1/rcc.c
new file mode 100644
index 0000000..689cabb
--- /dev/null
+++ b/lib/stm32/f1/rcc.c
@@ -0,0 +1,677 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2009 Federico Ruiz-Ugalde <memeruiz at gmail dot com>
+ * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopencm3/stm32/f1/rcc.h>
+#include <libopencm3/stm32/f1/flash.h>
+
+/* Set the default ppre1 and ppre2 peripheral clock frequencies after reset */
+u32 rcc_ppre1_frequency = 8000000;
+u32 rcc_ppre2_frequency = 8000000;
+
+void rcc_osc_ready_int_clear(osc_t osc)
+{
+ switch (osc) {
+ case PLL:
+ RCC_CIR |= RCC_CIR_PLLRDYC;
+ break;
+ case HSE:
+ RCC_CIR |= RCC_CIR_HSERDYC;
+ break;
+ case HSI:
+ RCC_CIR |= RCC_CIR_HSIRDYC;
+ break;
+ case LSE:
+ RCC_CIR |= RCC_CIR_LSERDYC;
+ break;
+ case LSI:
+ RCC_CIR |= RCC_CIR_LSIRDYC;
+ break;
+ }
+}
+
+void rcc_osc_ready_int_enable(osc_t osc)
+{
+ switch (osc) {
+ case PLL:
+ RCC_CIR |= RCC_CIR_PLLRDYIE;
+ break;
+ case HSE:
+ RCC_CIR |= RCC_CIR_HSERDYIE;
+ break;
+ case HSI:
+ RCC_CIR |= RCC_CIR_HSIRDYIE;
+ break;
+ case LSE:
+ RCC_CIR |= RCC_CIR_LSERDYIE;
+ break;
+ case LSI:
+ RCC_CIR |= RCC_CIR_LSIRDYIE;
+ break;
+ }
+}
+
+void rcc_osc_ready_int_disable(osc_t osc)
+{
+ switch (osc) {
+ case PLL:
+ RCC_CIR &= ~RCC_CIR_PLLRDYIE;
+ break;
+ case HSE:
+ RCC_CIR &= ~RCC_CIR_HSERDYIE;
+ break;
+ case HSI:
+ RCC_CIR &= ~RCC_CIR_HSIRDYIE;
+ break;
+ case LSE:
+ RCC_CIR &= ~RCC_CIR_LSERDYIE;
+ break;
+ case LSI:
+ RCC_CIR &= ~RCC_CIR_LSIRDYIE;
+ break;
+ }
+}
+
+int rcc_osc_ready_int_flag(osc_t osc)
+{
+ switch (osc) {
+ case PLL:
+ return ((RCC_CIR & RCC_CIR_PLLRDYF) != 0);
+ break;
+ case HSE:
+ return ((RCC_CIR & RCC_CIR_HSERDYF) != 0);
+ break;
+ case HSI:
+ return ((RCC_CIR & RCC_CIR_HSIRDYF) != 0);
+ break;
+ case LSE:
+ return ((RCC_CIR & RCC_CIR_LSERDYF) != 0);
+ break;
+ case LSI:
+ return ((RCC_CIR & RCC_CIR_LSIRDYF) != 0);
+ break;
+ }
+
+ /* Shouldn't be reached. */
+ return -1;
+}
+
+void rcc_css_int_clear(void)
+{
+ RCC_CIR |= RCC_CIR_CSSC;
+}
+
+int rcc_css_int_flag(void)
+{
+ return ((RCC_CIR & RCC_CIR_CSSF) != 0);
+}
+
+void rcc_wait_for_osc_ready(osc_t osc)
+{
+ switch (osc) {
+ case PLL:
+ while ((RCC_CR & RCC_CR_PLLRDY) == 0);
+ break;
+ case HSE:
+ while ((RCC_CR & RCC_CR_HSERDY) == 0);
+ break;
+ case HSI:
+ while ((RCC_CR & RCC_CR_HSIRDY) == 0);
+ break;
+ case LSE:
+ while ((RCC_BDCR & RCC_BDCR_LSERDY) == 0);
+ break;
+ case LSI:
+ while ((RCC_CSR & RCC_CSR_LSIRDY) == 0);
+ break;
+ }
+}
+
+void rcc_osc_on(osc_t osc)
+{
+ switch (osc) {
+ case PLL:
+ RCC_CR |= RCC_CR_PLLON;
+ break;
+ case HSE:
+ RCC_CR |= RCC_CR_HSEON;
+ break;
+ case HSI:
+ RCC_CR |= RCC_CR_HSION;
+ break;
+ case LSE:
+ RCC_BDCR |= RCC_BDCR_LSEON;
+ break;
+ case LSI:
+ RCC_CSR |= RCC_CSR_LSION;
+ break;
+ }
+}
+
+void rcc_osc_off(osc_t osc)
+{
+ switch (osc) {
+ case PLL:
+ RCC_CR &= ~RCC_CR_PLLON;
+ break;
+ case HSE:
+ RCC_CR &= ~RCC_CR_HSEON;
+ break;
+ case HSI:
+ RCC_CR &= ~RCC_CR_HSION;
+ break;
+ case LSE:
+ RCC_BDCR &= ~RCC_BDCR_LSEON;
+ break;
+ case LSI:
+ RCC_CSR &= ~RCC_CSR_LSION;
+ break;
+ }
+}
+
+void rcc_css_enable(void)
+{
+ RCC_CR |= RCC_CR_CSSON;
+}
+
+void rcc_css_disable(void)
+{
+ RCC_CR &= ~RCC_CR_CSSON;
+}
+
+void rcc_osc_bypass_enable(osc_t osc)
+{
+ switch (osc) {
+ case HSE:
+ RCC_CR |= RCC_CR_HSEBYP;
+ break;
+ case LSE:
+ RCC_BDCR |= RCC_BDCR_LSEBYP;
+ break;
+ case PLL:
+ case HSI:
+ case LSI:
+ /* Do nothing, only HSE/LSE allowed here. */
+ break;
+ }
+}
+
+void rcc_osc_bypass_disable(osc_t osc)
+{
+ switch (osc) {
+ case HSE:
+ RCC_CR &= ~RCC_CR_HSEBYP;
+ break;
+ case LSE:
+ RCC_BDCR &= ~RCC_BDCR_LSEBYP;
+ break;
+ case PLL:
+ case HSI:
+ case LSI:
+ /* Do nothing, only HSE/LSE allowed here. */
+ break;
+ }
+}
+
+void rcc_peripheral_enable_clock(volatile u32 *reg, u32 en)
+{
+ *reg |= en;
+}
+
+void rcc_peripheral_disable_clock(volatile u32 *reg, u32 en)
+{
+ *reg &= ~en;
+}
+
+void rcc_peripheral_reset(volatile u32 *reg, u32 reset)
+{
+ *reg |= reset;
+}
+
+void rcc_peripheral_clear_reset(volatile u32 *reg, u32 clear_reset)
+{
+ *reg &= ~clear_reset;
+}
+
+void rcc_set_sysclk_source(u32 clk)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~((1 << 1) | (1 << 0));
+ RCC_CFGR = (reg32 | clk);
+}
+
+void rcc_set_pll_multiplication_factor(u32 mul)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~((1 << 21) | (1 << 20) | (1 << 19) | (1 << 18));
+ RCC_CFGR = (reg32 | (mul << 18));
+}
+
+void rcc_set_pll_source(u32 pllsrc)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~(1 << 16);
+ RCC_CFGR = (reg32 | (pllsrc << 16));
+}
+
+void rcc_set_pllxtpre(u32 pllxtpre)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~(1 << 17);
+ RCC_CFGR = (reg32 | (pllxtpre << 17));
+}
+
+void rcc_set_adcpre(u32 adcpre)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~((1 << 14) | (1 << 15));
+ RCC_CFGR = (reg32 | (adcpre << 14));
+}
+
+void rcc_set_ppre2(u32 ppre2)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~((1 << 11) | (1 << 12) | (1 << 13));
+ RCC_CFGR = (reg32 | (ppre2 << 11));
+}
+
+void rcc_set_ppre1(u32 ppre1)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~((1 << 8) | (1 << 9) | (1 << 10));
+ RCC_CFGR = (reg32 | (ppre1 << 8));
+}
+
+void rcc_set_hpre(u32 hpre)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~((1 << 4) | (1 << 5) | (1 << 6) | (1 << 7));
+ RCC_CFGR = (reg32 | (hpre << 4));
+}
+
+void rcc_set_usbpre(u32 usbpre)
+{
+ u32 reg32;
+
+ reg32 = RCC_CFGR;
+ reg32 &= ~(1 << 22);
+ RCC_CFGR = (reg32 | (usbpre << 22));
+}
+
+u32 rcc_system_clock_source(void)
+{
+ /* Return the clock source which is used as system clock. */
+ return ((RCC_CFGR & 0x000c) >> 2);
+}
+
+/*
+ * These functions are setting up the whole clock system for the most common
+ * input clock and output clock configurations.
+ */
+void rcc_clock_setup_in_hsi_out_64mhz(void)
+{
+ /* Enable internal high-speed oscillator. */
+ rcc_osc_on(HSI);
+ rcc_wait_for_osc_ready(HSI);
+
+ /* Select HSI as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSICLK);
+
+ /*
+ * Set prescalers for AHB, ADC, ABP1, ABP2.
+ * Do this before touching the PLL (TODO: why?).
+ */
+ rcc_set_hpre(RCC_CFGR_HPRE_SYSCLK_NODIV); /* Set. 64MHz Max. 72MHz */
+ rcc_set_adcpre(RCC_CFGR_ADCPRE_PCLK2_DIV8); /* Set. 8MHz Max. 14MHz */
+ rcc_set_ppre1(RCC_CFGR_PPRE1_HCLK_DIV2); /* Set. 32MHz Max. 36MHz */
+ rcc_set_ppre2(RCC_CFGR_PPRE2_HCLK_NODIV); /* Set. 64MHz Max. 72MHz */
+
+ /*
+ * Sysclk is running with 64MHz -> 2 waitstates.
+ * 0WS from 0-24MHz
+ * 1WS from 24-48MHz
+ * 2WS from 48-72MHz
+ */
+ flash_set_ws(FLASH_LATENCY_2WS);
+
+ /*
+ * Set the PLL multiplication factor to 16.
+ * 8MHz (internal) * 16 (multiplier) / 2 (PLLSRC_HSI_CLK_DIV2) = 64MHz
+ */
+ rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_PLL_CLK_MUL16);
+
+ /* Select HSI/2 as PLL source. */
+ rcc_set_pll_source(RCC_CFGR_PLLSRC_HSI_CLK_DIV2);
+
+ /* Enable PLL oscillator and wait for it to stabilize. */
+ rcc_osc_on(PLL);
+ rcc_wait_for_osc_ready(PLL);
+
+ /* Select PLL as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_PLLCLK);
+
+ /* Set the peripheral clock frequencies used */
+ rcc_ppre1_frequency = 32000000;
+ rcc_ppre2_frequency = 64000000;
+}
+
+void rcc_clock_setup_in_hsi_out_48mhz(void)
+{
+ /* Enable internal high-speed oscillator. */
+ rcc_osc_on(HSI);
+ rcc_wait_for_osc_ready(HSI);
+
+ /* Select HSI as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSICLK);
+
+ /*
+ * Set prescalers for AHB, ADC, ABP1, ABP2.
+ * Do this before touching the PLL (TODO: why?).
+ */
+ rcc_set_hpre(RCC_CFGR_HPRE_SYSCLK_NODIV); /* Set. 48MHz Max. 72MHz */
+ rcc_set_adcpre(RCC_CFGR_ADCPRE_PCLK2_DIV8); /* Set. 6MHz Max. 14MHz */
+ rcc_set_ppre1(RCC_CFGR_PPRE1_HCLK_DIV2); /* Set. 24MHz Max. 36MHz */
+ rcc_set_ppre2(RCC_CFGR_PPRE2_HCLK_NODIV); /* Set. 48MHz Max. 72MHz */
+ rcc_set_usbpre(RCC_CFGR_USBPRE_PLL_CLK_NODIV); /* Set. 48MHz Max. 48MHz */
+
+ /*
+ * Sysclk runs with 48MHz -> 1 waitstates.
+ * 0WS from 0-24MHz
+ * 1WS from 24-48MHz
+ * 2WS from 48-72MHz
+ */
+ flash_set_ws(FLASH_LATENCY_1WS);
+
+ /*
+ * Set the PLL multiplication factor to 12.
+ * 8MHz (internal) * 12 (multiplier) / 2 (PLLSRC_HSI_CLK_DIV2) = 48MHz
+ */
+ rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_PLL_CLK_MUL12);
+
+ /* Select HSI/2 as PLL source. */
+ rcc_set_pll_source(RCC_CFGR_PLLSRC_HSI_CLK_DIV2);
+
+ /* Enable PLL oscillator and wait for it to stabilize. */
+ rcc_osc_on(PLL);
+ rcc_wait_for_osc_ready(PLL);
+
+ /* Select PLL as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_PLLCLK);
+
+ /* Set the peripheral clock frequencies used */
+ rcc_ppre1_frequency = 24000000;
+ rcc_ppre2_frequency = 48000000;
+}
+
+void rcc_clock_setup_in_hse_8mhz_out_24mhz(void)
+{
+ /* Enable internal high-speed oscillator. */
+ rcc_osc_on(HSI);
+ rcc_wait_for_osc_ready(HSI);
+
+ /* Select HSI as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSICLK);
+
+ /* Enable external high-speed oscillator 8MHz. */
+ rcc_osc_on(HSE);
+ rcc_wait_for_osc_ready(HSE);
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSECLK);
+
+ /*
+ * Set prescalers for AHB, ADC, ABP1, ABP2.
+ * Do this before touching the PLL (TODO: why?).
+ */
+ rcc_set_hpre(RCC_CFGR_HPRE_SYSCLK_NODIV); /* Set. 24MHz Max. 72MHz */
+ rcc_set_adcpre(RCC_CFGR_ADCPRE_PCLK2_DIV2); /* Set. 12MHz Max. 14MHz */
+ rcc_set_ppre1(RCC_CFGR_PPRE1_HCLK_NODIV); /* Set. 24MHz Max. 36MHz */
+ rcc_set_ppre2(RCC_CFGR_PPRE2_HCLK_NODIV); /* Set. 24MHz Max. 72MHz */
+
+ /*
+ * Sysclk runs with 24MHz -> 0 waitstates.
+ * 0WS from 0-24MHz
+ * 1WS from 24-48MHz
+ * 2WS from 48-72MHz
+ */
+ flash_set_ws(FLASH_LATENCY_0WS);
+
+ /*
+ * Set the PLL multiplication factor to 3.
+ * 8MHz (external) * 3 (multiplier) = 24MHz
+ */
+ rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_PLL_CLK_MUL3);
+
+ /* Select HSE as PLL source. */
+ rcc_set_pll_source(RCC_CFGR_PLLSRC_HSE_CLK);
+
+ /*
+ * External frequency undivided before entering PLL
+ * (only valid/needed for HSE).
+ */
+ rcc_set_pllxtpre(RCC_CFGR_PLLXTPRE_HSE_CLK);
+
+ /* Enable PLL oscillator and wait for it to stabilize. */
+ rcc_osc_on(PLL);
+ rcc_wait_for_osc_ready(PLL);
+
+ /* Select PLL as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_PLLCLK);
+
+ /* Set the peripheral clock frequencies used */
+ rcc_ppre1_frequency = 24000000;
+ rcc_ppre2_frequency = 24000000;
+}
+void rcc_clock_setup_in_hse_8mhz_out_72mhz(void)
+{
+ /* Enable internal high-speed oscillator. */
+ rcc_osc_on(HSI);
+ rcc_wait_for_osc_ready(HSI);
+
+ /* Select HSI as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSICLK);
+
+ /* Enable external high-speed oscillator 8MHz. */
+ rcc_osc_on(HSE);
+ rcc_wait_for_osc_ready(HSE);
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSECLK);
+
+ /*
+ * Set prescalers for AHB, ADC, ABP1, ABP2.
+ * Do this before touching the PLL (TODO: why?).
+ */
+ rcc_set_hpre(RCC_CFGR_HPRE_SYSCLK_NODIV); /* Set. 72MHz Max. 72MHz */
+ rcc_set_adcpre(RCC_CFGR_ADCPRE_PCLK2_DIV8); /* Set. 9MHz Max. 14MHz */
+ rcc_set_ppre1(RCC_CFGR_PPRE1_HCLK_DIV2); /* Set. 36MHz Max. 36MHz */
+ rcc_set_ppre2(RCC_CFGR_PPRE2_HCLK_NODIV); /* Set. 72MHz Max. 72MHz */
+
+ /*
+ * Sysclk runs with 72MHz -> 2 waitstates.
+ * 0WS from 0-24MHz
+ * 1WS from 24-48MHz
+ * 2WS from 48-72MHz
+ */
+ flash_set_ws(FLASH_LATENCY_2WS);
+
+ /*
+ * Set the PLL multiplication factor to 9.
+ * 8MHz (external) * 9 (multiplier) = 72MHz
+ */
+ rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_PLL_CLK_MUL9);
+
+ /* Select HSE as PLL source. */
+ rcc_set_pll_source(RCC_CFGR_PLLSRC_HSE_CLK);
+
+ /*
+ * External frequency undivided before entering PLL
+ * (only valid/needed for HSE).
+ */
+ rcc_set_pllxtpre(RCC_CFGR_PLLXTPRE_HSE_CLK);
+
+ /* Enable PLL oscillator and wait for it to stabilize. */
+ rcc_osc_on(PLL);
+ rcc_wait_for_osc_ready(PLL);
+
+ /* Select PLL as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_PLLCLK);
+
+ /* Set the peripheral clock frequencies used */
+ rcc_ppre1_frequency = 36000000;
+ rcc_ppre2_frequency = 72000000;
+}
+
+void rcc_clock_setup_in_hse_12mhz_out_72mhz(void)
+{
+ /* Enable internal high-speed oscillator. */
+ rcc_osc_on(HSI);
+ rcc_wait_for_osc_ready(HSI);
+
+ /* Select HSI as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSICLK);
+
+ /* Enable external high-speed oscillator 16MHz. */
+ rcc_osc_on(HSE);
+ rcc_wait_for_osc_ready(HSE);
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSECLK);
+
+ /*
+ * Set prescalers for AHB, ADC, ABP1, ABP2.
+ * Do this before touching the PLL (TODO: why?).
+ */
+ rcc_set_hpre(RCC_CFGR_HPRE_SYSCLK_NODIV); /* Set. 72MHz Max. 72MHz */
+ rcc_set_adcpre(RCC_CFGR_ADCPRE_PCLK2_DIV6); /* Set. 12MHz Max. 14MHz */
+ rcc_set_ppre1(RCC_CFGR_PPRE1_HCLK_DIV2); /* Set. 36MHz Max. 36MHz */
+ rcc_set_ppre2(RCC_CFGR_PPRE2_HCLK_NODIV); /* Set. 72MHz Max. 72MHz */
+
+ /*
+ * Sysclk runs with 72MHz -> 2 waitstates.
+ * 0WS from 0-24MHz
+ * 1WS from 24-48MHz
+ * 2WS from 48-72MHz
+ */
+ flash_set_ws(FLASH_LATENCY_2WS);
+
+ /*
+ * Set the PLL multiplication factor to 9.
+ * 12MHz (external) * 6 (multiplier) / 1 (PLLXTPRE_HSE_CLK) = 72MHz
+ */
+ rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_PLL_CLK_MUL6);
+
+ /* Select HSI as PLL source. */
+ rcc_set_pll_source(RCC_CFGR_PLLSRC_HSE_CLK);
+
+ /*
+ * Divide external frequency by 2 before entering PLL
+ * (only valid/needed for HSE).
+ */
+ rcc_set_pllxtpre(RCC_CFGR_PLLXTPRE_HSE_CLK);
+
+ /* Enable PLL oscillator and wait for it to stabilize. */
+ rcc_osc_on(PLL);
+ rcc_wait_for_osc_ready(PLL);
+
+ /* Select PLL as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_PLLCLK);
+
+ /* Set the peripheral clock frequencies used */
+ rcc_ppre1_frequency = 36000000;
+ rcc_ppre2_frequency = 72000000;
+}
+
+void rcc_clock_setup_in_hse_16mhz_out_72mhz(void)
+{
+ /* Enable internal high-speed oscillator. */
+ rcc_osc_on(HSI);
+ rcc_wait_for_osc_ready(HSI);
+
+ /* Select HSI as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSICLK);
+
+ /* Enable external high-speed oscillator 16MHz. */
+ rcc_osc_on(HSE);
+ rcc_wait_for_osc_ready(HSE);
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSECLK);
+
+ /*
+ * Set prescalers for AHB, ADC, ABP1, ABP2.
+ * Do this before touching the PLL (TODO: why?).
+ */
+ rcc_set_hpre(RCC_CFGR_HPRE_SYSCLK_NODIV); /* Set. 72MHz Max. 72MHz */
+ rcc_set_adcpre(RCC_CFGR_ADCPRE_PCLK2_DIV6); /* Set. 12MHz Max. 14MHz */
+ rcc_set_ppre1(RCC_CFGR_PPRE1_HCLK_DIV2); /* Set. 36MHz Max. 36MHz */
+ rcc_set_ppre2(RCC_CFGR_PPRE2_HCLK_NODIV); /* Set. 72MHz Max. 72MHz */
+
+ /*
+ * Sysclk runs with 72MHz -> 2 waitstates.
+ * 0WS from 0-24MHz
+ * 1WS from 24-48MHz
+ * 2WS from 48-72MHz
+ */
+ flash_set_ws(FLASH_LATENCY_2WS);
+
+ /*
+ * Set the PLL multiplication factor to 9.
+ * 16MHz (external) * 9 (multiplier) / 2 (PLLXTPRE_HSE_CLK_DIV2) = 72MHz
+ */
+ rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_PLL_CLK_MUL9);
+
+ /* Select HSI as PLL source. */
+ rcc_set_pll_source(RCC_CFGR_PLLSRC_HSE_CLK);
+
+ /*
+ * Divide external frequency by 2 before entering PLL
+ * (only valid/needed for HSE).
+ */
+ rcc_set_pllxtpre(RCC_CFGR_PLLXTPRE_HSE_CLK_DIV2);
+
+ /* Enable PLL oscillator and wait for it to stabilize. */
+ rcc_osc_on(PLL);
+ rcc_wait_for_osc_ready(PLL);
+
+ /* Select PLL as SYSCLK source. */
+ rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_PLLCLK);
+
+ /* Set the peripheral clock frequencies used */
+ rcc_ppre1_frequency = 36000000;
+ rcc_ppre2_frequency = 72000000;
+}
+
+void rcc_backupdomain_reset(void)
+{
+ /* Set the backup domain software reset. */
+ RCC_BDCR |= RCC_BDCR_BDRST;
+
+ /* Clear the backup domain software reset. */
+ RCC_BDCR &= ~RCC_BDCR_BDRST;
+}