Merge pull request #73 from Resaec/uart

Add UART register enumerators

exosphere/src/uart.c

@@ -17,37 +17,37 @@ void uart_init(UartDevice dev, uint32_t baud) {
 
     /* Set baud rate. */
     uint32_t rate = (8 * baud + 408000000) / (16 * baud);
-    uart->UART_LCR = 0x80; /* Enable DLAB. */
+    uart->UART_LCR = UART_LCR_DLAB; /* Enable DLAB. */
     uart->UART_THR_DLAB = (uint8_t)rate; /* Divisor latch LSB. */
     uart->UART_IER_DLAB = (uint8_t)(rate >> 8); /* Divisor latch MSB. */
     uart->UART_LCR = 0; /* Diable DLAB. */
 
     /* Setup UART in fifo mode. */
     uart->UART_IER_DLAB = 0;
-    uart->UART_IIR_FCR = 7; /* Enable and clear TX and RX FIFOs. */
+    uart->UART_IIR_FCR = UART_FCR_FCR_EN_FIFO | UART_FCR_RX_CLR | UART_FCR_TX_CLR; /* Enable and clear TX and RX FIFOs. */
     uart->UART_LSR;
     wait(3 * ((baud + 999999) / baud));
-    uart->UART_LCR = 3; /* Set word length 8. */
+    uart->UART_LCR = UART_LCR_WD_LENGTH_8; /* Set word length 8. */
     uart->UART_MCR = 0;
     uart->UART_MSR = 0;
     uart->UART_IRDA_CSR = 0;
-    uart->UART_RX_FIFO_CFG = 1;
+    uart->UART_RX_FIFO_CFG = 1; /* Set RX_FIFO trigger level */
     uart->UART_MIE = 0;
     uart->UART_ASR = 0;
 }
 
-void uart_wait_idle(UartDevice dev, uint32_t which) {
+/* This function blocks until the UART device (dev) is in the desired state (status). Make sure the desired state can be reached! */
-    while (!(get_uart_device(dev)->UART_VENDOR_STATUS & which)) {
+void uart_wait_idle(UartDevice dev, UartVendorStatus status) {
+    while (!(get_uart_device(dev)->UART_VENDOR_STATUS & status)) {
         /* Wait */
     }
 }
 
-void uart_send(UartDevice dev, const void *buf, size_t len)
+void uart_send(UartDevice dev, const void *buf, size_t len) {
-{
     volatile uart_t *uart = get_uart_device(dev);
 
     for (size_t i = 0; i < len; i++) {
-        while (uart->UART_LSR & UART_TX_FIFO_FULL) {
+        while (uart->UART_LSR & UART_LSR_TX_FIFO_FULL) {
             /* Wait until the TX FIFO isn't full */
         }
         uart->UART_THR_DLAB = *((const uint8_t *)buf + i);
@@ -58,9 +58,9 @@ void uart_recv(UartDevice dev, void *buf, size_t len) {
     volatile uart_t *uart = get_uart_device(dev);
 
     for (size_t i = 0; i < len; i++) {
-        while (uart->UART_LSR & UART_RX_FIFO_EMPTY) {
+        while (uart->UART_LSR & UART_LSR_RX_FIFO_EMPTY) {
             /* Wait until the RX FIFO isn't empty */
         }
-         *((uint8_t *)buf + i) = uart->UART_THR_DLAB;
+        *((uint8_t *)buf + i) = uart->UART_THR_DLAB;
     }
 }

exosphere/src/uart.h

@@ -13,6 +13,8 @@ static inline uintptr_t get_uart_base(void) {
 
 #define UART_BASE (get_uart_base())
 
+#define BAUD_115200 115200
+
 /* Exosphère: add the clkreset values for UART C,D,E */
 typedef enum {
     UART_A = 0,
@@ -22,12 +24,112 @@ typedef enum {
     UART_E = 4,
 } UartDevice;
 
-#define BAUD_115200 115200
+/* 36.3.12 UART_VENDOR_STATUS_0_0 */
+typedef enum {
+    UART_VENDOR_STATE_TX_IDLE = 1 << 0,
+    UART_VENDOR_STATE_RX_IDLE = 1 << 1,
 
-#define UART_TX_IDLE        0x00000001
+    /* This bit is set to 1 when a read is issued to an empty FIFO and gets cleared on register read (sticky bit until read)
-#define UART_RX_IDLE        0x00000002
+    0 = NO_UNDERRUN
-#define UART_TX_FIFO_FULL   0x100
+    1 = UNDERRUN
-#define UART_RX_FIFO_EMPTY  0x200
+    */
+    UART_VENDOR_STATE_RX_UNDERRUN = 1 << 2,
+
+    /* This bit is set to 1 when write data is issued to the TX FIFO when it is already full and gets cleared on register read (sticky bit until read)
+    0 = NO_OVERRUN
+    1 = OVERRUN
+    */
+    UART_VENDOR_STATE_TX_OVERRUN = 1 << 3,
+
+    UART_VENDOR_STATE_RX_FIFO_COUNTER = 0b111111 << 16, /* reflects number of current entries in RX FIFO */
+    UART_VENDOR_STATE_TX_FIFO_COUNTER = 0b111111 << 24 /* reflects number of current entries in TX FIFO */
+} UartVendorStatus;
+
+/* 36.3.6 UART_LSR_0 */
+typedef enum {
+    UART_LSR_RDR           = 1 << 0, /* Receiver Data Ready */
+    UART_LSR_OVRF          = 1 << 1, /* Receiver Overrun Error */
+    UART_LSR_PERR          = 1 << 2, /* Parity Error */
+    UART_LSR_FERR          = 1 << 3, /* Framing Error */
+    UART_LSR_BRK           = 1 << 4, /* BREAK condition detected on line */
+    UART_LSR_THRE          = 1 << 5, /* Transmit Holding Register is Empty -- OK to write data */
+    UART_LSR_TMTY          = 1 << 6, /* Transmit Shift Register empty status */
+    UART_LSR_FIFOE         = 1 << 7, /* Receive FIFO Error */
+    UART_LSR_TX_FIFO_FULL  = 1 << 8, /* Transmitter FIFO full status */
+    UART_LSR_RX_FIFO_EMPTY = 1 << 9, /* Receiver FIFO empty status */
+} UartLineStatus;
+
+/* 36.3.4 UART_LCR_0 */
+typedef enum {
+    UART_LCR_WD_LENGTH_5 = 0, /* word length 5 */
+    UART_LCR_WD_LENGTH_6 = 1, /* word length 6 */
+    UART_LCR_WD_LENGTH_7 = 2, /* word length 7 */
+    UART_LCR_WD_LENGTH_8 = 3, /* word length 8 */
+
+    /* STOP:
+    0 = Transmit 1 stop bit
+    1 = Transmit 2 stop bits (receiver always checks for 1 stop bit)
+    */
+    UART_LCR_STOP        = 1 << 2, 
+    UART_LCR_PAR         = 1 << 3, /* Parity enabled */
+    UART_LCR_EVEN        = 1 << 4, /* Even parity format. There will always be an even number of 1s in the binary representation (PAR = 1) */
+    UART_LCR_SET_P       = 1 << 5, /* Set (force) parity to value in LCR[4] */
+    UART_LCR_SET_B       = 1 << 6, /* Set BREAK condition -- Transmitter sends all zeroes to indicate BREAK */
+    UART_LCR_DLAB        = 1 << 7, /* Divisor Latch Access Bit (set to allow programming of the DLH, DLM Divisors) */
+} UartLineControl;
+
+/* 36.3.3 UART_IIR_FCR_0 */
+typedef enum {
+    UART_FCR_FCR_EN_FIFO = 1 << 0, /* Enable the transmit and receive FIFOs. This bit should be enabled */
+    UART_FCR_RX_CLR      = 1 << 1, /* Clears the contents of the receive FIFO and resets its counter logic to 0 (the receive shift register is not cleared or altered). This bit returns to 0 after clearing the FIFOs */
+    UART_FCR_TX_CLR      = 1 << 2, /* Clears the contents of the transmit FIFO and resets its counter logic to 0 (the transmit shift register is not cleared or altered). This bit returns to 0 after clearing the FIFOs */
+
+    /* DMA:
+    0 = DMA_MODE_0
+    1 = DMA_MODE_1
+    */
+    UART_FCR_DMA         = 1 << 3,
+
+    /* TX_TRIG
+    0 = FIFO_COUNT_GREATER_16
+    1 = FIFO_COUNT_GREATER_8
+    2 = FIFO_COUNT_GREATER_4
+    3 = FIFO_COUNT_GREATER_1
+    */
+    UART_FCR_TX_TRIG                       = 3 << 4,
+    UART_FCR_TX_TRIG_FIFO_COUNT_GREATER_16 = 0 << 4,
+    UART_FCR_TX_TRIG_FIFO_COUNT_GREATER_8  = 1 << 4,
+    UART_FCR_TX_TRIG_FIFO_COUNT_GREATER_4  = 2 << 4,
+    UART_FCR_TX_TRIG_FIFO_COUNT_GREATER_1  = 3 << 4,
+
+    /* RX_TRIG
+    0 = FIFO_COUNT_GREATER_1
+    1 = FIFO_COUNT_GREATER_4
+    2 = FIFO_COUNT_GREATER_8
+    3 = FIFO_COUNT_GREATER_16 
+    */
+    UART_FCR_RX_TRIG                       = 3 << 6,
+    UART_FCR_RX_TRIG_FIFO_COUNT_GREATER_1  = 0 << 6,
+    UART_FCR_RX_TRIG_FIFO_COUNT_GREATER_4  = 1 << 6,
+    UART_FCR_RX_TRIG_FIFO_COUNT_GREATER_8  = 2 << 6,
+    UART_FCR_RX_TRIG_FIFO_COUNT_GREATER_16 = 3 << 6,
+} UartFifoControl;
+
+/* 36.3.3 UART_IIR_FCR_0 */
+typedef enum {
+    UART_IIR_IS_STA  = 1 << 0, /* Interrupt Pending if ZERO */
+    UART_IIR_IS_PRI0 = 1 << 1, /* Encoded Interrupt ID Refer to IIR[3:0] table [36.3.3] */
+    UART_IIR_IS_PRI1 = 1 << 2, /* Encoded Interrupt ID Refer to IIR[3:0] table */
+    UART_IIR_IS_PRI2 = 1 << 3, /* Encoded Interrupt ID Refer to IIR[3:0] table */
+
+    /* FIFO Mode Status
+    0 = 16450 mode (no FIFO)
+    1 = 16550 mode (FIFO)
+    */
+    UART_IIR_EN_FIFO    = 3 << 6,
+    UART_IIR_MODE_16450 = 0 << 6,
+    UART_IIR_MODE_16550 = 1 << 6,
+} UartInterruptIdentification;
 
 typedef struct {
     /* 0x00 */ uint32_t UART_THR_DLAB;
@@ -48,7 +150,7 @@ typedef struct {
 
 void uart_select(UartDevice dev);
 void uart_init(UartDevice dev, uint32_t baud);
-void uart_wait_idle(UartDevice dev, uint32_t which);
+void uart_wait_idle(UartDevice dev, UartVendorStatus status);
 void uart_send(UartDevice dev, const void *buf, size_t len);
 void uart_recv(UartDevice dev, void *buf, size_t len);