soc: sam0: samd5x: xosc32 configurable startup time

Adds Kconfig option to configure the startup time of the external
32KHz crystal oscillator.

Signed-off-by: Thomas Schranz <[email protected]>
(cherry picked from commit cd20154)

Author: Thomas Schranz

soc/atmel/sam0/common/Kconfig.samd5x

@@ -10,6 +10,14 @@ config SOC_ATMEL_SAMD5X_XOSC32K
 	  startup.  This can then be selected as the main clock source
 	  for the SOC.
 
+config SOC_ATMEL_SAMD5X_XOSC32K_STARTUP
+	depends on SOC_ATMEL_SAMD5X_XOSC32K
+	hex "Startup time external 32 kHz crystal oscillator"
+	range 0x0 0x6
+	default 0x1
+	help
+	  Selects the startup time for the external 32 kHz crystal oscillator.
+
 choice
 	prompt "Main clock source"
 	default SOC_ATMEL_SAMD5X_DEFAULT_AS_MAIN

soc/atmel/sam0/common/soc_samd5x.c

@@ -18,13 +18,18 @@
 #define SAM0_DFLL_FREQ_HZ		(48000000U)
 #define SAM0_DPLL_FREQ_MIN_HZ		(96000000U)
 #define SAM0_DPLL_FREQ_MAX_HZ		(200000000U)
+#define SAM0_XOSC32K_STARTUP_TIME	CONFIG_SOC_ATMEL_SAMD5X_XOSC32K_STARTUP
 
 #if CONFIG_SOC_ATMEL_SAMD5X_XOSC32K_AS_MAIN
 static void osc32k_init(void)
 {
-	OSC32KCTRL->XOSC32K.reg = OSC32KCTRL_XOSC32K_ENABLE | OSC32KCTRL_XOSC32K_XTALEN
-				| OSC32KCTRL_XOSC32K_EN32K | OSC32KCTRL_XOSC32K_RUNSTDBY
-				| OSC32KCTRL_XOSC32K_STARTUP(0) | OSC32KCTRL_XOSC32K_CGM_XT;
+	OSC32KCTRL->XOSC32K.reg = OSC32KCTRL_XOSC32K_ENABLE
+				| OSC32KCTRL_XOSC32K_XTALEN
+				| OSC32KCTRL_XOSC32K_CGM_XT
+				| OSC32KCTRL_XOSC32K_EN32K
+				| OSC32KCTRL_XOSC32K_RUNSTDBY
+				| OSC32KCTRL_XOSC32K_STARTUP(SAM0_XOSC32K_STARTUP_TIME)
+				;
 
 	while (!OSC32KCTRL->STATUS.bit.XOSC32KRDY) {
 	}