freertos: deprecate XT_CLOCK_FREQ

- freertos: add deprecated definition for XT_CLOCK_FREQ
- flash_ops: don't use XT_CLOCK_FREQ
- unity: don't use XT_CLOCK_FREQ
- hw_random: don't use XT_CLOCK_FREQ
- core_dump: don't use XT_CLOCK_FREQ
- app_trace: don't use XT_CLOCK_FREQ
- xtensa_init: init xt_tick_divisor

components/esp32/core_dump.c

@@ -23,6 +23,7 @@
 
 #include "esp_panic.h"
 #include "esp_partition.h"
+#include "esp_clk.h"
 
 #if CONFIG_ESP32_ENABLE_COREDUMP
 #define LOG_LOCAL_LEVEL CONFIG_ESP32_CORE_DUMP_LOG_LEVEL
@@ -522,10 +523,11 @@ void esp_core_dump_to_uart(XtExcFrame *frame)
     PIN_FUNC_SELECT(PERIPHS_IO_MUX_U0TXD_U, FUNC_U0TXD_U0TXD);
 
     ESP_COREDUMP_LOGI("Press Enter to print core dump to UART...");
-    tm_end = xthal_get_ccount() / (XT_CLOCK_FREQ / 1000) + CONFIG_ESP32_CORE_DUMP_UART_DELAY;
+    const int cpu_ticks_per_ms = esp_clk_cpu_freq() / 1000;
+    tm_end = xthal_get_ccount() / cpu_ticks_per_ms + CONFIG_ESP32_CORE_DUMP_UART_DELAY;
     ch = esp_core_dump_uart_get_char();
     while (!(ch == '\n' || ch == '\r')) {
-        tm_cur = xthal_get_ccount() / (XT_CLOCK_FREQ / 1000);
+        tm_cur = xthal_get_ccount() / cpu_ticks_per_ms;
         if (tm_cur >= tm_end)
             break;
         ch = esp_core_dump_uart_get_char();

components/esp32/hw_random.c

@@ -17,6 +17,7 @@
 #include <stddef.h>
 #include <string.h>
 #include "esp_attr.h"
+#include "esp_clk.h"
 #include "soc/wdev_reg.h"
 #include "freertos/FreeRTOSConfig.h"
 #include "xtensa/core-macros.h"
@@ -35,13 +36,21 @@ uint32_t IRAM_ATTR esp_random(void)
      * WDEV_RND_REG reads while waiting.
      */
 
+    /* This code does not run in a critical section, so CPU frequency switch may
+     * happens while this code runs (this will not happen in the current
+     * implementation, but possible in the future). However if that happens,
+     * the number of cycles spent on frequency switching will certainly be more
+     * than the number of cycles we need to wait here.
+     */
+    uint32_t cpu_to_apb_freq_ratio = esp_clk_cpu_freq() / esp_clk_apb_freq();
+
     static uint32_t last_ccount = 0;
     uint32_t ccount;
     uint32_t result = 0;
     do {
         ccount = XTHAL_GET_CCOUNT();
         result ^= REG_READ(WDEV_RND_REG);
-    } while (ccount - last_ccount < XT_CLOCK_FREQ / APB_CLK_FREQ * 16);
+    } while (ccount - last_ccount < cpu_to_apb_freq_ratio * 16);
     last_ccount = ccount;
     return result ^ REG_READ(WDEV_RND_REG);
 }