Revert "kernel: retrieve system timer clock frequency at runtime or static"

This reverts commit 7c03e5d.

zephyrproject-rtos#69705
Introduced a regression in main in which
tests/subsys/logging/log_timestamp
started failing. (See
zephyrproject-rtos#72344
for more info).
Let's revert the PR. It can be submitted after with the issue
fixed.

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

include/zephyr/sys_clock.h

@@ -146,9 +146,9 @@ typedef struct {
 
 /** @endcond */
 
-#if defined(CONFIG_SYS_CLOCK_EXISTS) && !defined(CONFIG_TIMER_READS_ITS_FREQUENCY_AT_RUNTIME)
-BUILD_ASSERT(CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC != 0,
-	"SYS_CLOCK_HW_CYCLES_PER_SEC must be non-zero!");
+#if defined(CONFIG_SYS_CLOCK_EXISTS) && \
+	(CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC == 0)
+#error "SYS_CLOCK_HW_CYCLES_PER_SEC must be non-zero!"
 #endif
 
 
@@ -164,7 +164,7 @@ BUILD_ASSERT(CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC != 0,
  * @{
  */
 
-#if defined(CONFIG_SYS_CLOCK_EXISTS) && !defined(CONFIG_TIMER_READS_ITS_FREQUENCY_AT_RUNTIME)
+#ifdef CONFIG_SYS_CLOCK_EXISTS
 
 #if defined(CONFIG_TIMER_READS_ITS_FREQUENCY_AT_RUNTIME) || \
 	(MSEC_PER_SEC % CONFIG_SYS_CLOCK_TICKS_PER_SEC) || \

kernel/Kconfig

@@ -799,7 +799,6 @@ config SYS_CLOCK_TICKS_PER_SEC
 
 config SYS_CLOCK_HW_CYCLES_PER_SEC
 	int "System clock's h/w timer frequency"
-	depends on !TIMER_READS_ITS_FREQUENCY_AT_RUNTIME
 	help
 	  This option specifies the frequency of the hardware timer used for the
 	  system clock (in Hz). This option is set by the SOC's or board's Kconfig file

kernel/timeout.c

@@ -25,7 +25,7 @@ static struct k_spinlock timeout_lock;
 static int announce_remaining;
 
 #if defined(CONFIG_TIMER_READS_ITS_FREQUENCY_AT_RUNTIME)
-int z_clock_hw_cycles_per_sec;
+int z_clock_hw_cycles_per_sec = CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC;
 
 #ifdef CONFIG_USERSPACE
 static inline int z_vrfy_sys_clock_hw_cycles_per_sec_runtime_get(void)