From 410e55d912e2b79037ae839b8c34f767c8f457b2 Mon Sep 17 00:00:00 2001
From: Joshua DeWeese <josh.deweese@gmail.com>
Date: Fri, 10 May 2024 21:40:47 -0400
Subject: [PATCH] cpu/{gd32v,stm32}/periph/adc: ensure max ADC speed is honored

This patch ensures that the ADC's max clock speed is not exceded.
---
 cpu/gd32v/periph/adc.c       | 2 ++
 cpu/stm32/periph/adc_f1.c    | 2 ++
 cpu/stm32/periph/adc_f2.c    | 2 ++
 cpu/stm32/periph/adc_f4_f7.c | 2 ++
 4 files changed, 8 insertions(+)

diff --git a/cpu/gd32v/periph/adc.c b/cpu/gd32v/periph/adc.c
index a1868bf72f..88b15a1c32 100644
--- a/cpu/gd32v/periph/adc.c
+++ b/cpu/gd32v/periph/adc.c
@@ -22,6 +22,7 @@
  * @}
  */
 
+#include "compiler_hints.h"
 #include "cpu.h"
 #include "macros/units.h"
 #include "mutex.h"
@@ -128,6 +129,7 @@ int adc_init(adc_t line)
             break;
         }
     }
+    assume((periph_apb_clk(APB2) / clk_div) <= ADC_CLK_MAX);
     RCU->CFG0 &= ~(RCU_CFG0_ADCPSC_2_Msk);
     RCU->CFG0 |= ((clk_div / 2) - 1) << RCU_CFG0_ADCPSC_2_Pos;
 
diff --git a/cpu/stm32/periph/adc_f1.c b/cpu/stm32/periph/adc_f1.c
index 5753eeda90..4382f72aee 100644
--- a/cpu/stm32/periph/adc_f1.c
+++ b/cpu/stm32/periph/adc_f1.c
@@ -20,6 +20,7 @@
  * @}
  */
 
+#include "compiler_hints.h"
 #include "cpu.h"
 #include "mutex.h"
 #include "periph/adc.h"
@@ -99,6 +100,7 @@ int adc_init(adc_t line)
             break;
         }
     }
+    assume((periph_apb_clk(APB2) / clk_div) <= ADC_CLK_MAX);
     RCC->CFGR &= ~(RCC_CFGR_ADCPRE);
     RCC->CFGR |= ((clk_div / 2) - 1) << 14;
 
diff --git a/cpu/stm32/periph/adc_f2.c b/cpu/stm32/periph/adc_f2.c
index dd8b6b1f5c..48a7bb1b6e 100644
--- a/cpu/stm32/periph/adc_f2.c
+++ b/cpu/stm32/periph/adc_f2.c
@@ -20,6 +20,7 @@
  * @}
  */
 
+#include "compiler_hints.h"
 #include "cpu.h"
 #include "mutex.h"
 #include "periph/adc.h"
@@ -92,6 +93,7 @@ int adc_init(adc_t line)
             break;
         }
     }
+    assume((periph_apb_clk(APB2) / clk_div) <= ADC_CLK_MAX);
     ADC->CCR = ((clk_div / 2) - 1) << 16;
 
     /* enable the ADC module */
diff --git a/cpu/stm32/periph/adc_f4_f7.c b/cpu/stm32/periph/adc_f4_f7.c
index ef707b3b47..e946c1e2a7 100644
--- a/cpu/stm32/periph/adc_f4_f7.c
+++ b/cpu/stm32/periph/adc_f4_f7.c
@@ -19,6 +19,7 @@
  * @}
  */
 
+#include "compiler_hints.h"
 #include "cpu.h"
 #include "irq.h"
 #include "mutex.h"
@@ -101,6 +102,7 @@ int adc_init(adc_t line)
             break;
         }
     }
+    assume((periph_apb_clk(APB2) / clk_div) <= ADC_CLK_MAX);
     ADC->CCR = ((clk_div / 2) - 1) << 16;
     /* set sampling time to the maximum */
     unsigned irq_state = irq_disable();