diff options
Diffstat (limited to '02.5-collatz/src/clock.c')
-rw-r--r-- | 02.5-collatz/src/clock.c | 106 |
1 files changed, 0 insertions, 106 deletions
diff --git a/02.5-collatz/src/clock.c b/02.5-collatz/src/clock.c deleted file mode 100644 index 75bac97..0000000 --- a/02.5-collatz/src/clock.c +++ /dev/null @@ -1,106 +0,0 @@ -/* - * This file sets the system clock to its full glory of 80Mhz - */ - -#include "clock.h" -#include <stdint.h> -#include "flash.h" -#include "gpio.h" -#include "spin.h" - -#define TIMEOUT 10000 - -int pll_off() -{ - uint32_t c; - - RCC.c_r &= ~BIT(24); /* Turn off pll. */ - for (c = 0; c < TIMEOUT && RCC.c_r & BIT(25); ++c) - ; /* Wait for OFF. */ - - if (c == TIMEOUT) { - return E_TIMEOUT; - } - - return 0; -} - -int pll_on() -{ - uint32_t c; - - RCC.c_r |= BIT(24); /* Turn on PLL. */ - for (c = 0; c < TIMEOUT && !(RCC.c_r & BIT(25)); ++c) - ; /* Wait for RDY. */ - - if (c == TIMEOUT) { - return E_TIMEOUT; - } - - return 0; -} - -int configure_pll( - uint8_t pllp_div_factor, pll_divisor_t pllr, /* System clock divisor. */ - pll_divisor_t pllq, /* Divison factor for PLL48M1CLK. */ - pllp_divisor_t pllp, /* Divison factor for PLLSAI2CLK. */ - uint8_t plln, /* PLL numerator. */ - pllm_divisor_t pllm, /* PLL denominator. */ - pll_src_t pllsrc /* PLL source */) -{ - if (RCC.c_r & BIT(25)) { - /* PLL must be off to configure it. */ - return E_NOT_OFF; - } - - /* Make sure inputs are valid. */ - if (pllp_div_factor == 1 || pllp_div_factor > 31) { - return E_BADPLLP_DIV; - } - if (plln < 8 || plln > 86) { - return E_BADPLLN; - } - - RCC.pllcfg_r = (pllp_div_factor << 27) | (pllr << 24) | (pllq << 20) | - (pllp << 16) | (plln << 8) | (pllm << 4) | (pllsrc << 0); - - return 0; -} - -int set_system_clock_MHz(uint8_t mhz) -{ - /* Set the source of the system colck to MSI temporarily. */ - set_system_clock_src(SYSTEM_CLOCK_SRC_MSI); - - if (mhz <= 8 || mhz > 80) { - return E_BAD_ARG; - } - - pll_off(); - - configure_pll( - 0 /* pllp_div_factor */, PLL_DIVISOR_4 /* pllr: VCO / 4 = mhz MHz. */, - PLL_DIVISOR_4 /* pllq: VCO / 4 = mhz MHz */, PLLP_DIVISOR_7 /* pllp */, - - /* The following set the frequency of VCO to (mhz*4)MHz: mhz * 1 * 4MHz. - */ - mhz /* plln | mhz */, PLLM_DIVISOR_1 /* pllm | 01 */, - PLL_SRC_MSI /* pll src | 04 Mhz */); - - pll_on(); - - /* Configure the flash to have 4 wait states. This is required at - * 80 MHz. */ - FLASH.ac_r &= ~0x07; - FLASH.ac_r |= 0x04; - - /* Set the source of the system colck to PLL. */ - set_system_clock_src(SYSTEM_CLOCK_SRC_PLL); - return 0; -} - -int set_system_clock_src(system_clock_src_t src) -{ - uint8_t value = RCC.cfg_r & ~0x03; - RCC.cfg_r = value | src; -} |