From 98a508629a8d0d444060d7df01818b3470cd84b5 Mon Sep 17 00:00:00 2001
From: Marshal Horn <kamocat@gmail.com>
Date: Thu, 16 Jul 2020 21:27:07 -0700
Subject: [PATCH] Moved speaker code to its own driver

It appears it will take some work to feed PWM with DMA.
---
 code/cfg/mcuconf.h     |  1 +
 code/drivers/speaker.c | 53 ++++++++++++++++++++++++++++++++++++++++++
 code/drivers/speaker.h |  6 +++++
 code/radio/rx.c        | 26 +--------------------
 code/radio/rx.h        | 18 +++++++++-----
 5 files changed, 73 insertions(+), 31 deletions(-)
 create mode 100644 code/drivers/speaker.c
 create mode 100644 code/drivers/speaker.h

diff --git a/code/cfg/mcuconf.h b/code/cfg/mcuconf.h
index 6ee4c69..7120675 100644
--- a/code/cfg/mcuconf.h
+++ b/code/cfg/mcuconf.h
@@ -166,6 +166,7 @@
 #define STM32_PWM_TIM1_IRQ_PRIORITY         3
 #define STM32_PWM_TIM2_IRQ_PRIORITY         3
 #define STM32_PWM_TIM3_IRQ_PRIORITY         3
+#define STM32_PWM_TIM3_DMA_STREAM           STM32_DMA_STREAM_ID(1, 4)
 
 /*
  * SERIAL driver system settings.
diff --git a/code/drivers/speaker.c b/code/drivers/speaker.c
new file mode 100644
index 0000000..01fe3fd
--- /dev/null
+++ b/code/drivers/speaker.c
@@ -0,0 +1,53 @@
+#include "speaker.h"
+
+
+static const DMAConfig spkr_dma = {
+  .stream = STM32_ICU1_CH1_DMA_STREAM,
+  .channel = STM32_ICU1_CH1_DMA_CHANNEL,
+  .dma_priority = STM32_ICU1_CH1_DMA_PRIORITY,
+  .irq_priority = STM32_ICU1_CH1_DMA_IRQ_PRIORITY,
+  .periph_addr = &TIM3->DMAR,
+  .direction = DMA_DIR_P2M,
+  .psize = 2,
+  .msize = 2,
+  .inc_peripheral_addr = false,
+  .inc_memory_addr = true,
+  .circular = true,
+  .error_cb = &error_cb,
+  .end_cb = &end_cb,
+  .mburst = 8,
+  .fifo = 4
+};
+
+//DMA channels is STM32_PWM_TIM3_DMA_STREAM
+
+void speakerUpdate(int16_t data, int len);
+
+/** Copies audio data to PWM
+ *
+ */
+void speaker_callback(PWMDriver * pwmp){
+//FIXME: Copy data into DMA buffer. Or interrupt every period.
+}
+
+static PWMConfig spkr = {
+  .frequency = 4096000,                                    /* 4MHz PWM clock frequency.   */
+  .period = 4096,                                      /* Initial PWM period 1ms.       */
+  .callback = speaker_callback,
+  .channels = {
+   {PWM_OUTPUT_ACTIVE_HIGH, NULL},
+   {PWM_OUTPUT_DISABLED, NULL},
+   {PWM_OUTPUT_DISABLED, NULL},
+   {PWM_OUTPUT_DISABLED, NULL}
+  },
+  .cr2 = 0,
+  .dier = STM32_TIM_DIER_CC1DE,   // DMA request on channel 1 compare match
+};
+
+void speakerStart(void){
+  pwmStart(&PWMD3, &spkr);
+}
+
+void speakerStop(void){
+  pwmStop(&PWMD3);
+}
diff --git a/code/drivers/speaker.h b/code/drivers/speaker.h
new file mode 100644
index 0000000..1049e0f
--- /dev/null
+++ b/code/drivers/speaker.h
@@ -0,0 +1,6 @@
+#include "hal.h"
+
+
+void speakerStart(void);
+void speakerStop(void);
+void speakerUpdate(int16_t data, int len);
diff --git a/code/radio/rx.c b/code/radio/rx.c
index 20ac1c4..b112dfd 100644
--- a/code/radio/rx.c
+++ b/code/radio/rx.c
@@ -7,6 +7,7 @@
 
 #include "rx.h"
 #include "ssb.h"
+#include "../drivers/speaker.h"
 
 /** Mailbox for received data */
 mailbox_t new_sample;
@@ -116,28 +117,3 @@ void adc_rx_init(void){
   adcStartConversion(&ADCD1, &qsd_in, samples, len);
 
 }
-
-/** Copies audio data to PWM
- *
- */
-void speaker_callback(PWMDriver * pwmp){
-//FIXME: Copy data into DMA buffer. Or interrupt every period.
-}
-
-static PWMConfig spkr = {
-  4096000,                                    /* 4MHz PWM clock frequency.   */
-  4096,                                      /* Initial PWM period 1ms.       */
-  speaker_callback,
-  {
-   {PWM_OUTPUT_ACTIVE_HIGH, NULL},
-   {PWM_OUTPUT_DISABLED, NULL},
-   {PWM_OUTPUT_DISABLED, NULL},
-   {PWM_OUTPUT_DISABLED, NULL}
-  },
-  0,
-  0
-};
-
-void speaker_init(void){
-
-}
diff --git a/code/radio/rx.h b/code/radio/rx.h
index ea2c9ba..2c6431b 100644
--- a/code/radio/rx.h
+++ b/code/radio/rx.h
@@ -11,12 +11,22 @@
 #include "hal.h"
 #include "ch.h"
 
+/** List of radio modes.
+ *
+ * This list will be expanded as more modes are supported
+ */
+enum radio_mode {
+  CW, //< Continuous wave, also known as morse code
+  USB,//< Upper Sideband, for frequencies above 10MHz
+  LSB,//< Lower sideband, for frequencies below 10MHz
+};
+
 /** Starts radio reception and demodulation
  *
  */
-void rxStart(uint8_t mode);
+void rxStart(enum radio_mode mode, float frequency);
 
-/* Pauses radio reception and demodulation
+/* Stops radio reception and demodulation
  *
  */
 void rxStop(void);
@@ -58,8 +68,4 @@ static void adccallback(ADCDriver *adcp);
  */
 void adc_rx_init(void);
 
-void speaker_init(void);
-
-void speaker_update(int16_t data, int len);
-
 #endif /* RX_H_ */