stm32f1: It's only necessary to program the CR1 register during SPI init

Only set the CR1 register during spi_prepare().

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

3 files changed, 9 insertions, 11 deletions

diff --git a/src/stm32f1/gpio.h b/src/stm32f1/gpio.h
index a4a3c121..8aba2f85 100644
--- a/src/stm32f1/gpio.h
+++ b/src/stm32f1/gpio.h
@@ -33,7 +33,7 @@ uint16_t gpio_adc_read(struct gpio_adc g);
 void gpio_adc_cancel_sample(struct gpio_adc g);
 
 struct spi_config {
-    SPI_TypeDef config;
+    uint32_t spi_cr1;
 };
 struct spi_config spi_setup(uint32_t bus, uint8_t mode, uint32_t rate);
 void spi_prepare(struct spi_config config);
diff --git a/src/stm32f1/main.c b/src/stm32f1/main.c
index b91d4dd0..e7a0cd91 100644
--- a/src/stm32f1/main.c
+++ b/src/stm32f1/main.c
@@ -112,8 +112,6 @@ void adc_config(void)
 void spi_config(void)
 {
     LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_SPI2);
-    LL_SPI_SetNSSMode(SPI2, LL_SPI_NSS_SOFT);
-    LL_SPI_SetMode(SPI2, LL_SPI_MODE_MASTER);
 }
 
 void io_config(void)
diff --git a/src/stm32f1/spi.c b/src/stm32f1/spi.c
index a90a030a..5ce81fb9 100644
--- a/src/stm32f1/spi.c
+++ b/src/stm32f1/spi.c
@@ -70,24 +70,24 @@ static void spi_init_pins(void)
 struct spi_config
 spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
 {
-    struct spi_config config;
-    config.config = *SPI2;
-
     if (bus > 0 || !rate)
         shutdown("Invalid spi_setup parameters");
 
     spi_init_pins();
-    spi_set_mode(&config.config, mode);
-    spi_set_baudrate(&config.config, rate);
+    SPI_TypeDef spi_hw = { };
+    LL_SPI_SetNSSMode(&spi_hw, LL_SPI_NSS_SOFT);
+    LL_SPI_SetMode(&spi_hw, LL_SPI_MODE_MASTER);
+    spi_set_mode(&spi_hw, mode);
+    spi_set_baudrate(&spi_hw, rate);
+    LL_SPI_Enable(&spi_hw);
 
-    return config;
+    return (struct spi_config){ .spi_cr1 = spi_hw.CR1 };
 }
 
 void
 spi_prepare(struct spi_config config)
 {
-    *SPI2 = config.config;
-    LL_SPI_Enable(SPI2);
+    SPI2->CR1 = config.spi_cr1;
 }
 
 void