altos/stmf0: Leave power interface disabled until needed

[fw/altos] / src / stmf0 / ao_arch_funcs.h

diff --git a/src/stmf0/ao_arch_funcs.h b/src/stmf0/ao_arch_funcs.h
index 9233f0440eb9d8c6f49c62dee60281f9dfd8e273..591ca8a07576fb01a2888754d5f372fc9ab0ac47 100644 (file)
--- a/src/stmf0/ao_arch_funcs.h
+++ b/src/stmf0/ao_arch_funcs.h
@@ -447,6 +447,34 @@ static inline void ao_arch_restore_stack(void) {
        asm("pop {r0-r7,pc}\n");
 }
 
+static inline void ao_sleep_mode(void) {
+
+       /*
+         WFI (Wait for Interrupt) or WFE (Wait for Event) while:
+          – Set SLEEPDEEP in Cortex ® -M0 System Control register
+          – Set PDDS bit in Power Control register (PWR_CR)
+          – Clear WUF bit in Power Control/Status register (PWR_CSR)
+       */
+
+       ao_arch_block_interrupts();
+
+       /* Enable power interface clock */
+       stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_PWREN);
+       ao_arch_nop();
+       stm_scb.scr |= (1 << STM_SCB_SCR_SLEEPDEEP);
+       ao_arch_nop();
+       stm_pwr.cr |= (1 << STM_PWR_CR_PDDS) | (1 << STM_PWR_CR_LPDS);
+       ao_arch_nop();
+       stm_pwr.cr |= (1 << STM_PWR_CR_CWUF);
+       ao_arch_nop();
+       ao_arch_nop();
+       ao_arch_nop();
+       ao_arch_nop();
+       ao_arch_nop();
+       asm("wfi");
+       ao_arch_nop();
+}
+
 #ifndef HAS_SAMPLE_PROFILE
 #define HAS_SAMPLE_PROFILE 0
 #endif