Large reorganization.

What was in core/ is now moved to arch/stm34l4xxx/peripherals.  This new
directory is *supposed to* to contain raw header files defining just the
pertinent register structures for the various peripherals.  Peripheral
management belongs somewhere in the new `kern/..` directories. This is
not completely the case at the moment, so more refactoring needs to be
done.

What was sitting in the root has now been moved into the kern/
directory. The kern/ directory is to contain everything else
other than raw device register definitions. The root of the kern/
tree is reserved for standard library-esque headers.

The kern/<peripheral> directory contains management systems for that
peripheral. (At the moment DMA is the only peripheral with a decent
management system.) Preferably these peripheral systems should only
include their correlating header in arch/stm34l4xxx/peripherals, and
use other management systems for handling other peripherals rather
than manipulating their raw registers directly. (Though this ideal
will require much more critical mass of management systems.)

1 files changed, 149 insertions, 0 deletions

diff --git a/02-usart/include/arch/stm32l4xxx/peripherals/dma.h b/02-usart/include/arch/stm32l4xxx/peripherals/dma.h
new file mode 100644
index 0000000..f62a92b
--- /dev/null
+++ b/02-usart/include/arch/stm32l4xxx/peripherals/dma.h
@@ -0,0 +1,149 @@
+#ifndef CORE_DMA_H_
+#define CORE_DMA_H_
+
+/*
+ * Header file for definining the DMA (Direct Memory Access).
+ *
+ * A DMA is used to perform data transfers between segments of memory
+ * or between memory and peripherals.
+ *
+ * There are 2 DMA's on the chip. Each with 7 channels.
+ */
+
+#include "kern/common.h"
+#include <arch.h>
+#include <stdint.h>
+
+#define DMA1 (* (dma_t*) DMA1_BASE)
+#define DMA2 (* (dma_t*) DMA2_BASE)
+
+typedef enum {
+  DMA_SIZE_8_BITS = 0,
+  DMA_SIZE_16_BITS = 1,
+  DMA_SIZE_32_BITS = 2,
+} dma_size_t;
+
+typedef enum {
+  DMA_PRIORITY_LEVEL_LOW = 0,
+  DMA_PRIORITY_LEVEL_MEDIUM = 1,
+  DMA_PRIORITY_LEVEL_HIGH = 2,
+  DMA_PRIORITY_LEVEL_VERY_HIGH = 3
+} dma_priority_level_t;
+
+typedef enum {
+  READ_FROM_PERIPHERAL = 0,
+  READ_FROM_MEMORY = 1,
+} dma_dir_t;
+
+typedef struct {
+
+#define dma_cc_en       (1 <<  0) // channel enable
+#define dma_cc_tcie     (1 <<  1) // transfer complete interrupt enable
+#define dma_cc_htie     (1 <<  2) // half transfer interrupt enable
+#define dma_cc_teie     (1 <<  3) // transfer error interrupt enable
+#define dma_cc_dir      (1 <<  4) // data transfer direction
+#define dma_cc_circ     (1 <<  5) // circular mode
+#define dma_cc_pinc     (1 <<  6) // peripheral increment mode
+#define dma_cc_minc     (1 <<  7) // memory increment mode
+#define dma_cc_psize    (3 <<  8) // Peripheral size
+#define dma_cc_msize    (3 << 10) // Memory size
+#define dma_cc_pl       (3 << 12) // Priority level
+#define dma_cc_mem2mem  (1 << 14) // Memory to memory mode
+
+  __IO uint32_t cc_r;
+
+  /* Number of data to transfer. Can only store a short. */
+  __IO uint32_t cndt_r;
+
+  /* DMA channel peripheral address register.
+   * Defines a memory address if mem2mem is set. */
+  __IO uint32_t cpa_r;
+
+  /* DMA channel memory address register.
+   * Defines another perpipheral address if peripheral-periphal mode is set. */
+  __IO uint32_t cma_r;
+
+  __IO uint32_t reserved;
+} dma_channel_config_t;
+
+typedef struct {
+  // DMA Interrupt status register.
+#define dma_gif1  (1 <<  0) // global interrupt flag for channel 1
+#define dma_tcif1 (1 <<  1) // transfer complete (TC) flag for channel 1
+#define dma_htif1 (1 <<  2) // half transfer (HT) flag for channel 1
+#define dma_teif1 (1 <<  3) // transfer error (TE) flag for channel 1
+#define dma_gif2  (1 <<  4) // global interrupt flag for channel 2
+#define dma_tcif2 (1 <<  5) // transfer complete (TC) flag for channel 2
+#define dma_htif2 (1 <<  6) // half transfer (HT) flag for channel 2
+#define dma_teif2 (1 <<  7) // transfer error (TE) flag for channel 2
+#define dma_gif3  (1 <<  8) // global interrupt flag for channel 3
+#define dma_tcif3 (1 <<  9) // transfer complete (TC) flag for channel 3
+#define dma_htif3 (1 << 10) // half transfer (HT) flag for channel 3
+#define dma_teif3 (1 << 11) // transfer error (TE) flag for channel 3
+#define dma_gif4  (1 << 12) // global interrupt flag for channel 4
+#define dma_tcif4 (1 << 13) // transfer complete (TC) flag for channel 4
+#define dma_htif4 (1 << 14) // half transfer (HT) flag for channel 4
+#define dma_teif4 (1 << 15) // transfer error (TE) flag for channel 4
+#define dma_gif5  (1 << 16) // global interrupt flag for channel 5
+#define dma_tcif5 (1 << 17) // transfer complete (TC) flag for channel 5
+#define dma_htif5 (1 << 18) // half transfer (HT) flag for channel 5
+#define dma_teif5 (1 << 19) // transfer error (TE) flag for channel 5
+#define dma_gif6  (1 << 20) // global interrupt flag for channel 6
+#define dma_tcif6 (1 << 21) // transfer complete (TC) flag for channel 6
+#define dma_htif6 (1 << 22) // half transfer (HT) flag for channel 6
+#define dma_teif6 (1 << 23) // transfer error (TE) flag for channel 6
+#define dma_gif7  (1 << 24) // global interrupt flag for channel 7
+#define dma_tcif7 (1 << 25) // transfer complete (TC) flag for channel 7
+#define dma_htif7 (1 << 26) // half transfer (HT) flag for channel 7
+#define dma_teif7 (1 << 27) // transfer error (TE) flag for channel 7
+  __IO uint32_t is_r;
+
+  // DMA Interrupt flag clear register
+#define dma_cgif1  (1 <<  0) // global interrupt flag clear for channel 1
+#define dma_ctcif1 (1 <<  1) // transfer complete flag clear for channel 1
+#define dma_chtif1 (1 <<  2) // half transfer flag clear for channel 1
+#define dma_cteif1 (1 <<  3) // transfer error flag clear for channel 1
+#define dma_cgif2  (1 <<  4) // global interrupt flag clear for channel 2
+#define dma_ctcif2 (1 <<  5) // transfer complete flag clear for channel 2
+#define dma_chtif2 (1 <<  6) // half transfer flag clear for channel 2
+#define dma_cteif2 (1 <<  7) // transfer error flag clear for channel 2
+#define dma_cgif3  (1 <<  8) // global interrupt flag clear for channel 3
+#define dma_ctcif3 (1 <<  9) // transfer complete flag clear for channel 3
+#define dma_chtif3 (1 << 10) // half transfer flag clear for channel 3
+#define dma_cteif3 (1 << 11) // transfer error flag clear for channel 3
+#define dma_cgif4  (1 << 12) // global interrupt flag clear for channel 4
+#define dma_ctcif4 (1 << 13) // transfer complete flag clear for channel 4
+#define dma_chtif4 (1 << 14) // half transfer flag clear for channel 4
+#define dma_cteif4 (1 << 15) // transfer error flag clear for channel 4
+#define dma_cgif5  (1 << 16) // global interrupt flag clear for channel 5
+#define dma_ctcif5 (1 << 17) // transfer complete flag clear for channel 5
+#define dma_chtif5 (1 << 18) // half transfer flag clear for channel 5
+#define dma_cteif5 (1 << 19) // transfer error flag clear for channel 5
+#define dma_cgif6  (1 << 20) // global interrupt flag clear for channel 6
+#define dma_ctcif6 (1 << 21) // transfer complete flag clear for channel 6
+#define dma_chtif6 (1 << 22) // half transfer flag clear for channel 6
+#define dma_cteif6 (1 << 23) // transfer error flag clear for channel 6
+#define dma_cgif7  (1 << 24) // global interrupt flag clear for channel 7
+#define dma_ctcif7 (1 << 25) // transfer complete flag clear for channel 7
+#define dma_chtif7 (1 << 26) // half transfer flag clear for channel 7
+#define dma_cteif7 (1 << 27) // transfer error flag clear for channel 7
+  __IO uint32_t ifc_r;
+
+  dma_channel_config_t channel_config[7];
+
+  __IO uint32_t reserved[5];
+
+  /* DMA channel selection register. */
+#define dma_c1s (0xF <<  0) // DMA channel 1 selection.
+#define dma_c2s (0xF <<  4) // DMA channel 2 selection.
+#define dma_c3s (0xF <<  8) // DMA channel 3 selection.
+#define dma_c4s (0xF << 12) // DMA channel 4 selection.
+#define dma_c5s (0xF << 16) // DMA channel 5 selection.
+#define dma_c6s (0xF << 20) // DMA channel 6 selection.
+#define dma_c7s (0xF << 24) // DMA channel 7 selection.
+  __IO uint32_t csel_r;
+} dma_t;
+
+static_assert(offsetof(dma_t, csel_r) == 0xA8, "Offset check failed.");
+
+#endif /* CORE_DMA_H_ */