From: Ivan Grokhotkov <ivan@espressif.com>
Date: Mon, 21 Aug 2017 14:33:52 +0000 (+0800)
Subject: soc/rtc: round APB clock frequency to nearest MHz
X-Git-Tag: v3.1-dev~333^2~4
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c743bdac885ba63fc1de3a3995dbc76741fa1da6;p=esp-idf

soc/rtc: round APB clock frequency to nearest MHz
---

diff --git a/components/soc/esp32/rtc_clk.c b/components/soc/esp32/rtc_clk.c
index 7f6d992919..aee0a39ff1 100644
--- a/components/soc/esp32/rtc_clk.c
+++ b/components/soc/esp32/rtc_clk.c
@@ -500,7 +500,11 @@ void rtc_clk_apb_freq_update(uint32_t apb_freq)
 
 uint32_t rtc_clk_apb_freq_get()
 {
-    return reg_val_to_clk_val(READ_PERI_REG(RTC_APB_FREQ_REG)) << 12;
+    uint32_t freq_hz = reg_val_to_clk_val(READ_PERI_REG(RTC_APB_FREQ_REG)) << 12;
+    // round to the nearest MHz
+    freq_hz += MHZ / 2;
+    uint32_t remainder = freq_hz % MHZ;
+    return freq_hz - remainder;
 }