From df2ea2527f5b873af84b768c300ea00e6389d1af Mon Sep 17 00:00:00 2001
From: KonstantinKondrashov <konstantin@espressif.com>
Date: Tue, 10 Mar 2020 19:24:28 +0800
Subject: [PATCH] esp32s2: Add a Kconfig option- Number of attempts to repeat
 32k XTAL calibration

---
 components/esp32s2/Kconfig | 10 ++++++++++
 components/esp32s2/clk.c   | 12 +++++++-----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/components/esp32s2/Kconfig b/components/esp32s2/Kconfig
index 04aa92425f..22f37f0691 100644
--- a/components/esp32s2/Kconfig
+++ b/components/esp32s2/Kconfig
@@ -457,6 +457,16 @@ menu "ESP32S2-specific"
               In case more value will help improve the definition of the launch of the crystal.
               If the crystal could not start, it will be switched to internal RC.
 
+    config ESP32S2_RTC_XTAL_CAL_RETRY
+        int "Number of attempts to repeat 32k XTAL calibration"
+        default 3
+        depends on ESP32S2_RTC_CLK_SRC_EXT_CRYS
+        help
+            Number of attempts to repeat 32k XTAL calibration
+            before giving up and switching to the internal RC.
+            Increase this option if the 32k crystal oscillator
+            does not start and switches to internal RC.
+
     config ESP32S2_DISABLE_BASIC_ROM_CONSOLE
         bool "Permanently disable BASIC ROM Console"
         default n
diff --git a/components/esp32s2/clk.c b/components/esp32s2/clk.c
index f698eb29db..49b8ec1355 100644
--- a/components/esp32s2/clk.c
+++ b/components/esp32s2/clk.c
@@ -42,6 +42,12 @@
  */
 #define SLOW_CLK_CAL_CYCLES     CONFIG_ESP32S2_RTC_CLK_CAL_CYCLES
 
+#ifdef CONFIG_ESP32S2_RTC_XTAL_CAL_RETRY
+#define RTC_XTAL_CAL_RETRY CONFIG_ESP32S2_RTC_XTAL_CAL_RETRY
+#else
+#define RTC_XTAL_CAL_RETRY 1
+#endif
+
 #define MHZ (1000000)
 
 /* Lower threshold for a reasonably-looking calibration value for a 32k XTAL.
@@ -148,11 +154,7 @@ static void select_rtc_slow_clk(slow_clk_sel_t slow_clk)
     /* number of times to repeat 32k XTAL calibration
      * before giving up and switching to the internal RC
      */
-#ifdef CONFIG_IDF_TARGET_ESP32
-    int retry_32k_xtal = 1;     /* don't change the behavior for the ESP32 */
-#else
-    int retry_32k_xtal = 3;
-#endif
+    int retry_32k_xtal = RTC_XTAL_CAL_RETRY;
 
     do {
         if (rtc_slow_freq == RTC_SLOW_FREQ_32K_XTAL) {