arch/esp32: Introduce the ESP32_RTC option.

Signed-off-by: Abdelatif Guettouche <abdelatif.guettouche@espressif.com>

arch/xtensa/src/esp32/Kconfig

@@ -211,44 +211,6 @@ config ESP32_XTAL_26MHz
 
 endchoice # On-board Crystal Frequency
 
-choice ESP32_RTC_CLK_SRC
-	prompt "RTC clock source"
-	default ESP32_RTC_CLK_SRC_INT_RC
-	---help---
-		Choose which clock is used as RTC clock source.
-
-		- "Internal 150kHz oscillator" option provides lowest deep sleep current
-			consumption, and does not require extra external components. However
-			frequency stability with respect to temperature is poor, so time may
-			drift in deep/light sleep modes.
-		- "External 32kHz crystal" provides better frequency stability, at the
-			expense of slightly higher (1uA) deep sleep current consumption.
-		- "External 32kHz oscillator" allows using 32kHz clock generated by an
-			external circuit. In this case, external clock signal must be connected
-			to 32K_XN pin. Amplitude should be <1.2V in case of sine wave signal,
-			and <1V in case of square wave signal. Common mode voltage should be
-			0.1 < Vcm < 0.5Vamp, where Vamp is the signal amplitude.
-			Additionally, 1nF capacitor must be connected between 32K_XP pin and
-			ground. 32K_XP pin can not be used as a GPIO in this case.
-		- "Internal 8.5MHz oscillator divided by 256" option results in higher
-			deep sleep current (by 5uA) but has better frequency stability than
-			the internal 150kHz oscillator. It does not require external components.
-
-	config ESP32_RTC_CLK_SRC_INT_RC
-		bool "Internal 150kHz RC oscillator"
-
-	config ESP32_RTC_CLK_SRC_EXT_XTAL
-		bool "External 32kHz crystal"
-		select ESP_SYSTEM_RTC_EXT_XTAL
-
-	config ESP32_RTC_CLK_SRC_EXT_OSC
-		bool "External 32kHz oscillator at 32K_XN pin"
-
-	config ESP32_RTC_CLK_SRC_INT_8MD256
-		bool "Internal 8.5MHz oscillator, divided by 256 (~33kHz)"
-
-endchoice
-
 config ESP32_RT_TIMER
 	bool "Real-time Timer"
 	default n
@@ -483,6 +445,10 @@ config ESP32_RWDT
 		to have the RTC module reset, please, use the Timers' Module WDTs.
 		They will only reset Main System.
 
+config ESP32_RTC
+	bool "Real Time Clock (RTC)"
+	default y
+
 config ESP32_UART0
 	bool "UART 0"
 	default n
@@ -1430,6 +1396,48 @@ config ESP32_FREERUN
 endmenu # Timer/counter Configuration
 endif # ESP32_TIMER
 
+menu "RTC Configuration"
+	depends on ESP32_RTC
+
+choice ESP32_RTC_CLK_SRC
+	prompt "RTC clock source"
+	default ESP32_RTC_CLK_SRC_INT_RC
+	---help---
+		Choose which clock is used as RTC clock source.
+
+		- "Internal 150kHz oscillator" option provides lowest deep sleep current
+			consumption, and does not require extra external components. However
+			frequency stability with respect to temperature is poor, so time may
+			drift in deep/light sleep modes.
+		- "External 32kHz crystal" provides better frequency stability, at the
+			expense of slightly higher (1uA) deep sleep current consumption.
+		- "External 32kHz oscillator" allows using 32kHz clock generated by an
+			external circuit. In this case, external clock signal must be connected
+			to 32K_XN pin. Amplitude should be <1.2V in case of sine wave signal,
+			and <1V in case of square wave signal. Common mode voltage should be
+			0.1 < Vcm < 0.5Vamp, where Vamp is the signal amplitude.
+			Additionally, 1nF capacitor must be connected between 32K_XP pin and
+			ground. 32K_XP pin can not be used as a GPIO in this case.
+		- "Internal 8.5MHz oscillator divided by 256" option results in higher
+			deep sleep current (by 5uA) but has better frequency stability than
+			the internal 150kHz oscillator. It does not require external components.
+
+config ESP32_RTC_CLK_SRC_INT_RC
+	bool "Internal 150kHz RC oscillator"
+
+config ESP32_RTC_CLK_SRC_EXT_XTAL
+	bool "External 32kHz crystal"
+	select ESP_SYSTEM_RTC_EXT_XTAL
+
+config ESP32_RTC_CLK_SRC_EXT_OSC
+	bool "External 32kHz oscillator at 32K_XN pin"
+
+config ESP32_RTC_CLK_SRC_INT_8MD256
+	bool "Internal 8.5MHz oscillator, divided by 256 (~33kHz)"
+
+endchoice
+endmenu # "RTC Configuration"
+
 menu "LEDC configuration"
 	depends on ESP32_LEDC
 

arch/xtensa/src/esp32/Make.defs

@@ -58,8 +58,6 @@ endif
 CHIP_CSRCS += esp32_pm.c
 endif
 
-CHIP_CSRCS += esp32_rtc.c
-
 ifeq ($(CONFIG_XTENSA_IMEM_USE_SEPARATE_HEAP),y)
 CHIP_CSRCS += esp32_imm.c
 endif
@@ -177,9 +175,12 @@ ifeq ($(CONFIG_ESP32_AES_ACCELERATOR),y)
 CHIP_CSRCS += esp32_aes.c
 endif
 
+ifeq ($(CONFIG_ESP32_RTC),y)
+CHIP_CSRCS += esp32_rtc.c
 ifeq ($(CONFIG_RTC_DRIVER),y)
 CHIP_CSRCS += esp32_rtc_lowerhalf.c
 endif
+endif
 
 ifeq ($(CONFIG_ESP32_WIRELESS),y)
 WIRELESS_DRV_UNPACK  = esp-wireless-drivers-3rdparty

arch/xtensa/src/esp32/esp32_rtc.c

@@ -157,13 +157,11 @@
   .fe_pd = (val), \
 }
 
-#ifdef CONFIG_RTC_DRIVER
 /* The magic data for the struct esp32_rtc_backup_s that is in RTC slow
  * memory.
  */
 
-#  define MAGIC_RTC_SAVE (UINT64_C(0x11223344556677))
+#define MAGIC_RTC_SAVE UINT64_C(0x11223344556677)
-#endif
 
 /* RTC Memory & Store Register usage */
 
@@ -228,8 +226,6 @@ struct esp32_rtc_sleep_pd_config_s
   uint32_t fe_pd : 1;     /* Set to 1 to power down Wi-Fi in sleep */
 };
 
-#ifdef CONFIG_RTC_DRIVER
-
 #ifdef CONFIG_RTC_ALARM
 struct alm_cbinfo_s
 {
@@ -248,8 +244,6 @@ struct esp32_rtc_backup_s
   int64_t  reserved0;
 };
 
-#endif
-
 /****************************************************************************
  * Private Function Prototypes
  ****************************************************************************/
@@ -268,7 +262,7 @@ static void esp32_rtc_clk_32k_enable(int ac, int res, int bias);
 static void IRAM_ATTR esp32_rtc_clk_8m_enable(bool clk_8m_en, bool d256_en);
 static uint32_t IRAM_ATTR esp32_rtc_clk_slow_freq_get_hz(void);
 
-#ifdef CONFIG_RTC_DRIVER
+#ifdef CONFIG_RTC_ALARM
 static void IRAM_ATTR esp32_rt_cb_handler(void *arg);
 #endif
 
@@ -286,8 +280,6 @@ static struct esp32_rtc_priv_s esp32_rtc_priv =
   .rtc_dboost_fpd = 1
 };
 
-#ifdef CONFIG_RTC_DRIVER
-
 /* Callback to use when the alarm expires */
 
 #ifdef CONFIG_RTC_ALARM
@@ -301,15 +293,11 @@ static RTC_DATA_ATTR struct esp32_rtc_backup_s rtc_saved_data;
 static struct esp32_rtc_backup_s *g_rtc_save;
 static bool g_rt_timer_enabled = false;
 
-#endif
-
 /****************************************************************************
  * Public Data
  ****************************************************************************/
 
-#ifdef CONFIG_RTC_DRIVER
 volatile bool g_rtc_enabled = false;
-#endif
 
 /****************************************************************************
  * Private Functions
@@ -747,7 +735,7 @@ static void esp32_select_rtc_slow_clk(enum esp32_slow_clk_sel_e slow_clk)
   putreg32((uint32_t)cal_val, RTC_SLOW_CLK_CAL_REG);
 }
 
-#ifdef CONFIG_RTC_DRIVER
+#ifdef CONFIG_RTC_ALARM
 
 /****************************************************************************
  * Name: esp32_rt_cb_handler
@@ -788,7 +776,7 @@ static void IRAM_ATTR esp32_rt_cb_handler(void *arg)
     }
 }
 
-#endif /* CONFIG_RTC_DRIVER */
+#endif /* CONFIG_RTC_ALARM */
 
 /****************************************************************************
  * Public Functions
@@ -1884,8 +1872,6 @@ uint64_t IRAM_ATTR esp32_rtc_get_boot_time(void)
         + (((uint64_t)getreg32(RTC_BOOT_TIME_HIGH_REG)) << 32);
 }
 
-#ifdef CONFIG_RTC_DRIVER
-
 /****************************************************************************
  * Name: up_rtc_time
  *
@@ -2271,5 +2257,3 @@ int up_rtc_timer_init(void)
 
   return OK;
 }
-
-#endif /* CONFIG_RTC_DRIVER */