Hi,
I'm having an issue with RTC module. getting an error due to no clock source is connected to rtc_ck:
[ 3.645423] stm32_rtc 5c004000.rtc: rtc_ck is slow
[ 3.749902] stm32_rtc 5c004000.rtc: Can't enter in init mode. Prescaler config failed.
[ 3.756489] stm32_rtc: probe of 5c004000.rtc failed with error -110
when I checked the clocks:
root@stm32mp1:~# cat /sys/kernel/debug/clk/clk_summary |grep rtc
rtcapb 0 0 0 66625000 0 0 50000 Y
ck_rtc 0 0 0 0 0 0 50000 Y
root@stm32mp1:~# cat /sys/kernel/debug/clk/clk_summary |grep lse
ck_lse 0 0 0 32768 0 0 50000 Y
Also checked the RCC_BDCR @ 0x50000400 and the returned value is 0x00100035 which means RTCSRC[1:0] register is 0. That means it is not selecting any other clock source (LSE, LSI and HSE/DIV). I have tried to change and select every clock source configuration from CubeMX using RTC Clock Mux, no luck. It doesn't choose a clock source and it stays conneted to 0.
I have read and tried to solve it using the sources below:
https://wiki.stmicroelectronics.cn/stm32mpu/index.php?title=RTC_device_tree_configuration&stable=1
https://wiki.st.com/stm32mpu/wiki/RCC_internal_peripheral
https://wiki.st.com/stm32mpu/wiki/Clock_device_tree_configuration
What might be the issue here?
Optee DT:
#include <dt-bindings/rtc/rtc-stm32.h>
/{ /* Root*/
clocks {
clk_hsi: clk-hsi {
clock-frequency = <64000000>;
};
clk_lse: clk-lse {
clock-frequency = <32768>;
st,drive = < LSEDRV_MEDIUM_HIGH >;
};
clk_hse: clk-hse {
clock-frequency = <24000000>;
};
clk_i2sin: clk-i2sin {
status = "disabled";
};
};
};
&rcc{
pinctrl-names = "default";
pinctrl-0 = <&rcc_pins_mx>;
status = "okay";
clocks = <&clk_hse>, <&clk_hsi>, <&clk_lse>, <&clk_lsi>, <&clk_csi>;
clock-names = "clk-hse", "clk-hsi", "clk-lse", "clk-lsi", "clk-csi";
st,clksrc=<
CLK_MPU_PLL1P
CLK_AXI_PLL2P
CLK_MLAHBS_PLL3
CLK_RTC_LSE
CLK_MCO1_LSE
CLK_MCO2_DISABLED
CLK_CKPER_HSE
CLK_ETH1_PLL4P
CLK_ETH2_PLL4P
CLK_SDMMC1_PLL4P
CLK_STGEN_HSE
CLK_USBPHY_HSE
CLK_I2C4_HSI
CLK_USBO_USBPHY
CLK_ADC1_CKPER
CLK_ADC2_CKPER
CLK_I2C12_HSI
CLK_I2C5_HSI
CLK_UART2_HSI
CLK_UART4_HSI
CLK_SAI1_PLL4Q
CLK_RNG1_PLL4R
CLK_SAES_AXI
CLK_LPTIM3_PCLK3
>;
st,clkdiv = <
DIV(DIV_MPU, 1)
DIV(DIV_AXI, 0)
DIV(DIV_MLAHB, 0)
DIV(DIV_APB1, 1)
DIV(DIV_APB2, 1)
DIV(DIV_APB3, 1)
DIV(DIV_APB4, 1)
DIV(DIV_APB5, 2)
DIV(DIV_APB6, 1)
DIV(DIV_RTC, 0)
DIV(DIV_MCO1, 0)
DIV(DIV_MCO2, 0)
>;
...
};&rtc{
pinctrl-names = "default";
pinctrl-0 = <&rtc_pins_mx>;
status = "okay";
/* USER CODE BEGIN rtc */
st,alarm = <RTC_OUT1>;
/* USER CODE END rtc */
};
