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/*
* Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include "pico/stdlib.h"
#include "hardware/pll.h"
#include "hardware/clocks.h"
#if LIB_PICO_STDIO_UART
#include "pico/stdio_uart.h"
#else
#include "pico/binary_info.h"
#endif
// everything running off the USB oscillator
void set_sys_clock_48mhz() {
if (!running_on_fpga()) {
// Change clk_sys to be 48MHz. The simplest way is to take this from PLL_USB
// which has a source frequency of 48MHz
clock_configure(clk_sys,
CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLKSRC_CLK_SYS_AUX,
CLOCKS_CLK_SYS_CTRL_AUXSRC_VALUE_CLKSRC_PLL_USB,
48 * MHZ,
48 * MHZ);
// Turn off PLL sys for good measure
pll_deinit(pll_sys);
// CLK peri is clocked from clk_sys so need to change clk_peri's freq
clock_configure(clk_peri,
0,
CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLK_SYS,
48 * MHZ,
48 * MHZ);
}
}
void set_sys_clock_pll(uint32_t vco_freq, uint post_div1, uint post_div2) {
if (!running_on_fpga()) {
clock_configure(clk_sys,
CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLKSRC_CLK_SYS_AUX,
CLOCKS_CLK_SYS_CTRL_AUXSRC_VALUE_CLKSRC_PLL_USB,
48 * MHZ,
48 * MHZ);
pll_init(pll_sys, 1, vco_freq, post_div1, post_div2);
uint32_t freq = vco_freq / (post_div1 * post_div2);
// Configure clocks
// CLK_REF = XOSC (12MHz) / 1 = 12MHz
clock_configure(clk_ref,
CLOCKS_CLK_REF_CTRL_SRC_VALUE_XOSC_CLKSRC,
0, // No aux mux
12 * MHZ,
12 * MHZ);
// CLK SYS = PLL SYS (125MHz) / 1 = 125MHz
clock_configure(clk_sys,
CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLKSRC_CLK_SYS_AUX,
CLOCKS_CLK_SYS_CTRL_AUXSRC_VALUE_CLKSRC_PLL_SYS,
freq, freq);
clock_configure(clk_peri,
0, // Only AUX mux on ADC
CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLKSRC_PLL_USB,
48 * MHZ,
48 * MHZ);
}
}
bool check_sys_clock_khz(uint32_t freq_khz, uint *vco_out, uint *postdiv1_out, uint *postdiv_out) {
uint crystal_freq_khz = clock_get_hz(clk_ref) / 1000;
for (uint fbdiv = 320; fbdiv >= 16; fbdiv--) {
uint vco = fbdiv * crystal_freq_khz;
if (vco < 400000 || vco > 1600000) continue;
for (uint postdiv1 = 7; postdiv1 >= 1; postdiv1--) {
for (uint postdiv2 = postdiv1; postdiv2 >= 1; postdiv2--) {
uint out = vco / (postdiv1 * postdiv2);
if (out == freq_khz && !(vco % (postdiv1 * postdiv2))) {
*vco_out = vco * 1000;
*postdiv1_out = postdiv1;
*postdiv_out = postdiv2;
return true;
}
}
}
}
return false;
}
void setup_default_uart() {
#if LIB_PICO_STDIO_UART
stdio_uart_init();
#elif defined(PICO_DEFAULT_UART_BAUD_RATE) && defined(PICO_DEFAULT_UART_TX_PIN) && defined(PICO_DEFAULT_UART_RX_PIN)
// this is mostly for backwards compatibility - stdio_uart_init is a bit more nuanced, and usually likely to be present
uart_init(uart_default, PICO_DEFAULT_UART_BAUD_RATE);
if (PICO_DEFAULT_UART_TX_PIN >= 0)
gpio_set_function(PICO_DEFAULT_UART_TX_PIN, GPIO_FUNC_UART);
if (PICO_DEFAULT_UART_RX_PIN >= 0)
gpio_set_function(PICO_DEFAULT_UART_RX_PIN, GPIO_FUNC_UART);
bi_decl_if_func_used(bi_2pins_with_func(PICO_DEFAULT_UART_RX_PIN, PICO_DEFAULT_UART_TX_PIN, GPIO_FUNC_UART));
#endif
}
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