From 93625ee7c24d7b5f7f33fee291ce58a6065c7259 Mon Sep 17 00:00:00 2001
From: David Barksdale <amatus@amatus.name>
Date: Mon, 4 Jul 2016 13:39:26 -0500
Subject: Add some radio code

---
 laser-tag software/CMakeLists.txt |  1 +
 laser-tag software/main.c         |  6 +++
 laser-tag software/radio.c        | 88 +++++++++++++++++++++++++++++++++++++++
 laser-tag software/radio.h        |  6 +++
 4 files changed, 101 insertions(+)
 create mode 100644 laser-tag software/radio.c
 create mode 100644 laser-tag software/radio.h

diff --git a/laser-tag software/CMakeLists.txt b/laser-tag software/CMakeLists.txt
index 92bc6d1..fa8937d 100644
--- a/laser-tag software/CMakeLists.txt	
+++ b/laser-tag software/CMakeLists.txt	
@@ -101,6 +101,7 @@ ADD_EXECUTABLE(hello_world
     "${ProjDirPath}/main.c"
     "${ProjDirPath}/epaper.c"
     "${ProjDirPath}/text.c"
+    "${ProjDirPath}/radio.c"
 )
 SET_TARGET_PROPERTIES(hello_world PROPERTIES OUTPUT_NAME "hello_world.elf")
 
diff --git a/laser-tag software/main.c b/laser-tag software/main.c
index 0dfbac2..8eee6c5 100644
--- a/laser-tag software/main.c	
+++ b/laser-tag software/main.c	
@@ -31,6 +31,7 @@
 
 #include "epaper.h"
 #include "text.h"
+#include "radio.h"
 #include "fsl_clock_manager.h"
 #include "fsl_cmp_driver.h"
 #include "fsl_dac_driver.h"
@@ -583,6 +584,11 @@ int main (void)
     }
     blank_led = 30;
 
+    ret = radio_init();
+    if (0 == ret) {
+        led(0x22, 0x00, 0x22);
+    }
+
     /* We're done, everything else is triggered through interrupts */
     for(;;) {
         if (cue_next_image) {
diff --git a/laser-tag software/radio.c b/laser-tag software/radio.c
new file mode 100644
index 0000000..0915a29
--- /dev/null
+++ b/laser-tag software/radio.c	
@@ -0,0 +1,88 @@
+#include "radio.h"
+#include "fsl_gpio_driver.h"
+#include "fsl_spi_master_driver.h"
+
+static const gpio_output_pin_user_config_t pinReset = {
+    .pinName = GPIO_MAKE_PIN(GPIOC_IDX, 8),
+    .config.outputLogic = 1,
+};
+
+static const spi_master_user_config_t spiConfig = {
+    .bitsPerSec = 2000000, /* 2 MHz, max is 10 MHz */
+    .polarity = kSpiClockPolarity_ActiveHigh,
+    .phase = kSpiClockPhase_FirstEdge,
+    .direction = kSpiMsbFirst,
+    .bitCount = kSpi16BitMode,
+};
+
+static spi_master_state_t spiState;
+
+static spi_status_t SPI_Transfer(const uint8_t *tx, uint8_t *rx, size_t count)
+{
+    spi_status_t rc;
+
+    rc = SPI_DRV_MasterTransfer(0, NULL, tx, rx, count);
+    if (rc != kStatus_SPI_Success) {
+        return rc;
+    }
+    int i, timeout = (count + 127) / 128 + 1;
+    for (i = 0; i < timeout; ++i) {
+        rc = SPI_DRV_MasterGetTransferStatus(0, NULL);
+        if (rc == kStatus_SPI_Success) {
+            return rc;
+        }
+    }
+    return rc;
+}
+
+static uint8_t read_reg(uint8_t reg)
+{
+	uint8_t tx[2] = { 0, reg & 0x7f };
+	uint8_t rx[2] = { 0, 0 };
+
+    SPI_Transfer(tx, rx, 2);
+	return rx[0];
+}
+
+static void write_reg(uint8_t reg, uint8_t val)
+{
+	uint8_t tx[2] = { val, reg | 0x80 };
+
+    SPI_Transfer(tx, NULL, 2);
+}
+
+static void delay(uint32_t ms)
+{
+    for (; ms > 0; --ms) {
+        /* XXX This is really stupid */
+        volatile int i;
+        for (i = 0; i < 306; ++i);
+    }
+}
+
+int radio_init()
+{
+    PORT_HAL_SetMuxMode(g_portBase[GPIOC_IDX], 4, kPortMuxAlt2);
+    PORT_HAL_SetMuxMode(g_portBase[GPIOC_IDX], 5, kPortMuxAlt2);
+    PORT_HAL_SetMuxMode(g_portBase[GPIOC_IDX], 6, kPortMuxAlt2);
+    PORT_HAL_SetMuxMode(g_portBase[GPIOC_IDX], 7, kPortMuxAlt2);
+    PORT_HAL_SetMuxMode(g_portBase[GPIOC_IDX], 8, kPortMuxAsGpio);
+    GPIO_DRV_OutputPinInit(&pinReset);
+    delay(1);
+    GPIO_DRV_WritePinOutput(pinReset.pinName, 0);
+    delay(5);
+
+    /* Configure DMA channel */
+    SPI_DRV_MasterInit(0, &spiState);
+    uint32_t calculatedBaudRate;
+    SPI_DRV_MasterConfigureBus(0, &spiConfig, &calculatedBaudRate);
+
+	write_reg(0x2f, 0xaa);
+	uint32_t reg = read_reg(0x2f);
+	if (reg != 0xaa) {
+		return -1;
+	}
+	return 0;
+}
+
+/* vim: set expandtab ts=4 sw=4: */
diff --git a/laser-tag software/radio.h b/laser-tag software/radio.h
new file mode 100644
index 0000000..de36dd0
--- /dev/null
+++ b/laser-tag software/radio.h	
@@ -0,0 +1,6 @@
+#ifndef _RADIO_H_
+#define _RADIO_H_
+
+int radio_init();
+
+#endif
-- 
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