1 files changed, 88 insertions, 0 deletions
diff --git a/fw/src/usart_helpers.h b/fw/src/usart_helpers.h
new file mode 100644
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--- /dev/null
+++ b/fw/src/usart_helpers.h
@@ -0,0 +1,88 @@
+/*
+ * This file is part of the libusbhost library
+ * hosted at http://github.com/libusbhost/libusbhost
+ *
+ * Copyright (C) 2015 Amir Hammad <amir.hammad@hotmail.com>
+ *
+ *
+ * libusbhost is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef USBH_USART_HELPERS_H
+#define USBH_USART_HELPERS_H
+
+#include "usbh_core.h"
+#include <stdint.h>
+#include <stdarg.h>
+#include <errno.h>
+
+BEGIN_DECLS
+
+struct dma_buf {
+    uint32_t xfr_start; /* Start index of running DMA transfer */
+    uint32_t xfr_end; /* End index of running DMA transfer plus one */
+    uint32_t wr_pos; /* Next index to be written */
+    uint32_t len;
+    uint8_t data[0];
+};
+
+struct dma_usart_file {
+    uint32_t usart;
+    uint32_t baudrate;
+    uint32_t dma;
+    uint8_t stream;
+    uint8_t channel;
+    uint8_t irqn;
+    volatile struct dma_buf *buf;
+};
+
+
+extern struct dma_usart_file *debug_out;
+
+
+void usart_init(uint32_t usart, uint32_t baudrate);
+void usart_fprintf(struct dma_usart_file *f, const char *str, ...);
+void usart_fifo_push(uint8_t c);
+
+void usart_dma_init(struct dma_usart_file *f);
+void usart_kickoff_dma(uint32_t dma, uint8_t stream, volatile uint8_t *buf, size_t len);
+void schedule_dma(volatile struct dma_usart_file *f);
+int dma_fifo_push(volatile struct dma_buf *buf, char c);
+int putf(void *file, char c);
+int putb(void *file, const uint8_t *buf, size_t len);
+void flush(void *file);
+
+/* This macro abomination templates a bunch of dma-specific register/constant names from preprocessor macros passed in
+ * from cmake. */
+#define DMA_PASTE(num) DMA ## num
+#define DMA(num) DMA_PASTE(num)
+
+#define NVIC_DMA_IRQ_PASTE(dma, stream) NVIC_ ## DMA ## dma ## _ ## STREAM ## stream ## _IRQ
+#define NVIC_DMA_IRQ(dma, stream) NVIC_DMA_IRQ_PASTE(dma, stream)
+
+#define DMA_ISR_PASTE(dma, stream) DMA ## dma ## _ ## STREAM ## stream ## _IRQHandler
+#define DMA_ISR(dma, stream) DMA_ISR_PASTE(dma, stream)
+
+#ifdef USART_DEBUG
+#define LOG_PRINTF(format, ...) usart_fprintf(debug_out, format, ##__VA_ARGS__);
+#else
+#define LOG_PRINTF(dummy, ...) ((void)dummy)
+#endif
+
+#define UNUSED(var) ((void)var)
+
+END_DECLS
+
+#endif