Initial Release

clocks/CMakeLists.txt

@@ -0,0 +1,5 @@
+if (NOT PICO_NO_HARDWARE)
+    add_subdirectory(hello_48MHz)
+    add_subdirectory(hello_gpout)
+    add_subdirectory(hello_resus)
+endif ()

clocks/hello_48MHz/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_executable(hello_48MHz
+        hello_48MHz.c
+        )
+
+# Pull in our pico_stdlib which pulls in commonly used features
+target_link_libraries(hello_48MHz pico_stdlib hardware_clocks)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(hello_48MHz)
+
+# add url via pico_set_program_url
+example_auto_set_url(hello_48MHz)

clocks/hello_48MHz/hello_48MHz.c

@@ -0,0 +1,68 @@
+/**
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/pll.h"
+#include "hardware/clocks.h"
+#include "hardware/structs/pll.h"
+#include "hardware/structs/clocks.h"
+
+void measure_freqs(void) {
+    uint f_pll_sys = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_PLL_SYS_CLKSRC_PRIMARY);
+    uint f_pll_usb = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_PLL_USB_CLKSRC_PRIMARY);
+    uint f_rosc = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_ROSC_CLKSRC);
+    uint f_clk_sys = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_SYS);
+    uint f_clk_peri = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_PERI);
+    uint f_clk_usb = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_USB);
+    uint f_clk_adc = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_ADC);
+    uint f_clk_rtc = frequency_count_khz(CLOCKS_FC0_SRC_VALUE_CLK_RTC);
+
+    printf("pll_sys  = %dkHz\n", f_pll_sys);
+    printf("pll_usb  = %dkHz\n", f_pll_usb);
+    printf("rosc     = %dkHz\n", f_rosc);
+    printf("clk_sys  = %dkHz\n", f_clk_sys);
+    printf("clk_peri = %dkHz\n", f_clk_peri);
+    printf("clk_usb  = %dkHz\n", f_clk_usb);
+    printf("clk_adc  = %dkHz\n", f_clk_adc);
+    printf("clk_rtc  = %dkHz\n", f_clk_rtc);
+
+    // Can't measure clk_ref / xosc as it is the ref
+}
+
+int main() {
+    stdio_init_all();
+
+    printf("Hello, world!\n");
+
+    measure_freqs();
+
+    // 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);
+
+    // Re init uart now that clk_peri has changed
+    stdio_init_all();
+
+    measure_freqs();
+    printf("Hello, 48MHz");
+
+    return 0;
+}

clocks/hello_gpout/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_executable(hello_gpout
+        hello_gpout.c
+        )
+
+# Pull in our pico_stdlib which pulls in commonly used features
+target_link_libraries(hello_gpout pico_stdlib)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(hello_gpout)
+
+# add url via pico_set_program_url
+example_auto_set_url(hello_gpout)

clocks/hello_gpout/hello_gpout.c

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) 2021 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/clocks.h"
+
+
+int main() {
+    stdio_init_all();
+    printf("Hello gpout\n");
+
+    // Output clk_sys / 10 to gpio 21, etc...
+    clock_gpio_init(21, CLOCKS_CLK_GPOUT0_CTRL_AUXSRC_VALUE_CLK_SYS, 10);
+    clock_gpio_init(23, CLOCKS_CLK_GPOUT0_CTRL_AUXSRC_VALUE_CLK_USB, 10);
+    clock_gpio_init(24, CLOCKS_CLK_GPOUT0_CTRL_AUXSRC_VALUE_CLK_ADC, 10);
+    clock_gpio_init(26, CLOCKS_CLK_GPOUT0_CTRL_AUXSRC_VALUE_CLK_RTC, 10);
+
+    return 0;
+}

clocks/hello_resus/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_executable(hello_resus
+        hello_resus.c
+        )
+
+# Pull in our pico_stdlib which pulls in commonly used features
+target_link_libraries(hello_resus pico_stdlib)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(hello_resus)
+
+# add url via pico_set_program_url
+example_auto_set_url(hello_resus)

clocks/hello_resus/hello_resus.c

@@ -0,0 +1,48 @@
+/**
+ * Copyright (c) 2021 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/clocks.h"
+#include "hardware/pll.h"
+
+volatile bool seen_resus;
+
+void resus_callback(void) {
+    // Reconfigure PLL sys back to the default state of 1500 / 6 / 2 = 125MHz
+    pll_init(pll_sys, 1, 1500 * MHZ, 6, 2);
+
+    // 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,
+                    125 * MHZ,
+                    125 * MHZ);
+
+    // Reconfigure uart as clocks have changed
+    stdio_init_all();
+    printf("Resus event fired\n");
+
+    // Wait for uart output to finish
+    uart_default_tx_wait_blocking();
+
+    seen_resus = true;
+}
+
+int main() {
+    stdio_init_all();
+    printf("Hello resus\n");
+
+    seen_resus = false;
+
+    clocks_enable_resus(&resus_callback);
+    // Break PLL sys
+    pll_deinit(pll_sys);
+
+    while(!seen_resus);
+
+    return 0;
+}