From 517f179f8d7960836e339d80e2e2b92384ede78c Mon Sep 17 00:00:00 2001
From: Sebastien Lorquet <sebastien@lorquet.fr>
Date: Tue, 17 May 2022 15:20:35 +0200
Subject: [PATCH] stm32h7: Adds the ability to choose the HSI divider, which
 must be indicated in board.h if used.

---
 arch/arm/src/stm32h7/stm32h7x3xx_rcc.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/src/stm32h7/stm32h7x3xx_rcc.c b/arch/arm/src/stm32h7/stm32h7x3xx_rcc.c
index c6a5f457b8..9462ae2352 100644
--- a/arch/arm/src/stm32h7/stm32h7x3xx_rcc.c
+++ b/arch/arm/src/stm32h7/stm32h7x3xx_rcc.c
@@ -98,6 +98,10 @@
 #  define USE_PLL3
 #endif
 
+#if defined(STM32_BOARD_USEHSI) && !defined(STM32_BOARD_HSIDIV)
+#error When HSI is used, you have to define STM32_BOARD_HSIDIV in board/include/board.h
+#endif
+
 /****************************************************************************
  * Private Data
  ****************************************************************************/
@@ -600,6 +604,11 @@ void stm32_stdclockconfig(void)
 
   regval  = getreg32(STM32_RCC_CR);
   regval |= RCC_CR_HSION;           /* Enable HSI */
+
+  /* Set HSI predivider to board specific value */
+
+  regval |= STM32_BOARD_HSIDIV;
+
   putreg32(regval, STM32_RCC_CR);
 
   /* Wait until the HSI is ready (or until a timeout elapsed) */