From 3868a7fa100f72137063bc2aed4f07284422ebd6 Mon Sep 17 00:00:00 2001
From: Marian Buschsieweke <marian.buschsieweke@ovgu.de>
Date: Thu, 27 Apr 2023 17:52:03 +0200
Subject: [PATCH] cpu/stm32: implement periph_timer_query_freqs

---
 cpu/stm32/Kconfig           |  1 +
 cpu/stm32/Makefile.features |  1 +
 cpu/stm32/periph/timer.c    | 17 +++++++++++++++++
 3 files changed, 19 insertions(+)

diff --git a/cpu/stm32/Kconfig b/cpu/stm32/Kconfig
index e714eca3c378..f6a0c4bba788 100644
--- a/cpu/stm32/Kconfig
+++ b/cpu/stm32/Kconfig
@@ -12,6 +12,7 @@ config CPU_STM32
     select HAS_PERIPH_GPIO
     select HAS_PERIPH_GPIO_IRQ
     select HAS_PERIPH_TIMER_PERIODIC
+    select HAS_PERIPH_TIMER_QUERY_FREQS
     select HAS_PERIPH_RTT_OVERFLOW
     select HAS_PERIPH_UART_MODECFG
     select HAS_PERIPH_UART_NONBLOCKING
diff --git a/cpu/stm32/Makefile.features b/cpu/stm32/Makefile.features
index db958253163d..aa93e3cef57f 100644
--- a/cpu/stm32/Makefile.features
+++ b/cpu/stm32/Makefile.features
@@ -8,6 +8,7 @@ FEATURES_PROVIDED += cpu_stm32$(CPU_FAM)
 FEATURES_PROVIDED += periph_cpuid
 FEATURES_PROVIDED += periph_gpio periph_gpio_irq
 FEATURES_PROVIDED += periph_timer_periodic
+FEATURES_PROVIDED += periph_timer_query_freqs
 FEATURES_PROVIDED += periph_rtt_overflow
 FEATURES_PROVIDED += periph_uart_modecfg
 FEATURES_PROVIDED += periph_uart_nonblocking
diff --git a/cpu/stm32/periph/timer.c b/cpu/stm32/periph/timer.c
index 3ea8fb85e77a..edf80488c43d 100644
--- a/cpu/stm32/periph/timer.c
+++ b/cpu/stm32/periph/timer.c
@@ -161,6 +161,23 @@ int timer_set_absolute(tim_t tim, int channel, unsigned int value)
     return 0;
 }
 
+uword_t timer_query_freqs_numof(tim_t dev)
+{
+    (void)dev;
+    /* Prescaler values from 0 to UINT16_MAX are supported */
+    return UINT16_MAX + 1;
+}
+
+uint32_t timer_query_freqs(tim_t dev, uword_t index)
+{
+
+    if (index > UINT16_MAX) {
+        return 0;
+    }
+
+    return periph_timer_clk(timer_config[dev].bus) / (index + 1);
+}
+
 int timer_set(tim_t tim, int channel, unsigned int timeout)
 {
     unsigned value = (dev(tim)->CNT + timeout) & timer_config[tim].max;