altos/stmf0: Leave power interface disabled until needed

We only need the power interface when placing the chip in the lowest
power state, so don't power up the power interface clock at startup,
instead wait until later.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/stmf0/ao_arch_funcs.h b/src/stmf0/ao_arch_funcs.h
index a0c6e08876cbb012e350b18dc585e02346db9c7c..591ca8a07576fb01a2888754d5f372fc9ab0ac47 100644 (file)
--- a/src/stmf0/ao_arch_funcs.h
+++ b/src/stmf0/ao_arch_funcs.h
@@ -458,6 +458,9 @@ static inline void ao_sleep_mode(void) {
 
        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);

diff --git a/src/stmf0/ao_timer.c b/src/stmf0/ao_timer.c
index 58e52995cf32f35cbb4146b092f60e6217771972..be333754cfa37298d669f57572eb4783d4999093 100644 (file)
--- a/src/stmf0/ao_timer.c
+++ b/src/stmf0/ao_timer.c
@@ -294,9 +294,6 @@ ao_clock_init(void)
        /* Enable 1 wait state so the CPU can run at 48MHz */
        stm_flash.acr |= (STM_FLASH_ACR_LATENCY_1 << STM_FLASH_ACR_LATENCY);
 
-       /* Enable power interface clock */
-       stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_PWREN);
-
        /* HCLK to 48MHz -> AHB prescaler = /1 */
        cfgr = stm_rcc.cfgr;
        cfgr &= ~(STM_RCC_CFGR_HPRE_MASK << STM_RCC_CFGR_HPRE);