From: Keith Packard <keithp@keithp.com>
Date: Tue, 16 Jul 2019 18:10:36 +0000 (-0700)
Subject: altos/micropeak-v2.0: Reduce power usage
X-Git-Tag: 1.9.1~1^2~58
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=c37cd66b7c11f904b528c5ff7e80e18c5e0d26e5

altos/micropeak-v2.0: Reduce power usage

This gets power consumption down under 1mA on the pad. Not really low
enough to sell, but I think this is about as low as the chip will go.

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

diff --git a/src/micropeak-v2.0/ao_micropeak.c b/src/micropeak-v2.0/ao_micropeak.c
index 0b9972e9..1bf0999e 100644
--- a/src/micropeak-v2.0/ao_micropeak.c
+++ b/src/micropeak-v2.0/ao_micropeak.c
@@ -272,9 +272,6 @@ ao_hsi_init(void)
 	/* Enable prefetch */
 	stm_flash.acr |= (1 << STM_FLASH_ACR_PRFTBE);
 
-	/* 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);
@@ -314,7 +311,6 @@ main(void)
 	ao_led_init();
 	ao_task_init();
 	ao_timer_init();
-	ao_serial_init();
 	stm_moder_set(&stm_gpioa, 2, STM_MODER_OUTPUT);
 	ao_dma_init();
 	ao_spi_init();
@@ -325,6 +321,12 @@ main(void)
 	ao_ms5607_init();
 	ao_storage_init();
 
+	/* Let FLITF clock turn off in sleep mode */
+	stm_rcc.ahbenr &= ~(1 << STM_RCC_AHBENR_FLITFEN);
+
+	/* Le SRAM clock turn off in sleep mode */
+	stm_rcc.ahbenr &= ~(1 << STM_RCC_AHBENR_SRAMEN);
+
 	if (ao_on_battery) {
 		/* On battery power, run the flight code */
 		ao_add_task(&mp_task, ao_micropeak, "micropeak");
diff --git a/src/micropeak-v2.0/ao_pins.h b/src/micropeak-v2.0/ao_pins.h
index 9dba26bd..d3bd2281 100644
--- a/src/micropeak-v2.0/ao_pins.h
+++ b/src/micropeak-v2.0/ao_pins.h
@@ -43,8 +43,8 @@ extern uint8_t ao_on_battery;
 #define AO_RCC_CFGR_HPRE_DIV	(ao_on_battery ? STM_RCC_CFGR_HPRE_DIV_16 : STM_RCC_CFGR_HPRE_DIV_1)
 
 /* APB = 12MHz usb / 2MHz battery */
-#define AO_APB_PRESCALER	1
-#define AO_RCC_CFGR_PPRE_DIV	STM_RCC_CFGR_PPRE_DIV_1
+#define AO_APB_PRESCALER	(ao_on_battery ? 2 : 1)
+#define AO_RCC_CFGR_PPRE_DIV	(ao_on_battery ? STM_RCC_CFGR_PPRE_DIV_2 : STM_RCC_CFGR_PPRE_DIV_1)
 
 #define HAS_USB			1
 #define AO_PA11_PA12_RMP	1
@@ -86,6 +86,7 @@ extern uint8_t ao_on_battery;
 
 /* SPI */
 #define HAS_SPI_1		1
+#define SPI_1_POWER_MANAGE	1
 #define SPI_1_PA5_PA6_PA7	1
 #define SPI_1_PB3_PB4_PB5	0
 #define SPI_1_OSPEEDR		STM_OSPEEDR_MEDIUM
@@ -128,9 +129,11 @@ void ao_delay_until(uint16_t target);
 #define ao_async_stop() do {					\
 		ao_serial2_drain();				\
 		stm_moder_set(&stm_gpioa, 2, STM_MODER_OUTPUT); \
+		ao_serial_shutdown();				\
 	} while (0)
 
 #define ao_async_start() do {						\
+		ao_serial_init();					\
 		stm_moder_set(&stm_gpioa, 2, STM_MODER_ALTERNATE);	\
 		ao_delay(AO_MS_TO_TICKS(100));				\
 	} while (0)