diff options
Diffstat (limited to 'include/x86/uart.h')
| -rw-r--r-- | include/x86/uart.h | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/include/x86/uart.h b/include/x86/uart.h new file mode 100644 index 0000000..0c6194b --- /dev/null +++ b/include/x86/uart.h @@ -0,0 +1,349 @@ +/* +** @file uart.h +** +** @author M. Reek +** @authors K. Reek, Warren R. Carithers +** +** Definitions for a 16540/16550 compatible UART. Definitions are taken +** from datasheets for the National Semiconductor INS8250, NS16450, and +** NS16550 UART chips, and the PC87309 Super I/O legacy peripheral chip. +** +** The naming convention is UAx_yyy_zzzzz. "x" is either 4 or 5 (see below), +** "yyy" is the name of the register to which this value applies, and +** "zzzzz" is the name of the value or field. +** +** The UA4 prefix denotes 16540 compatible functions, available in both +** chips. The UA5 prefix denotes 16550-only functions (primarily the FIFOs). +** +** For many items there are two names: one short one that matches the name +** in the chip manual, and another that is more readable. +*/ + +#ifndef UART_H +#define UART_H + +/********************************************************************* +***************************** I/O PORTS ****************************** +*********************************************************************/ + +/* +** Base port number assigned to the device +*/ +#define UA4_COM1_PORT 0x3f8 +#define UA4_COM2_PORT 0x2f8 +#define UA4_COM3_PORT 0x3e8 +#define UA4_COM4_PORT 0x2e8 + +// short name for the one we'll use +#define UA4_PORT UA4_COM1_PORT +#define UA5_PORT UA4_COM1_PORT + +/* +** Registers +** +** The 164x0 chips have the following registers. The (RO) and (WO) +** suffixes indicate read-only and write-only access. +** +** Index Register(s) +** ===== ========================================= +** 0 Receiver Data (RO), Transmitter Data (WO) +** 1 Interrupt Enable +** 2 Interrupt ID (RO), FIFO Control (WO) +** 3 Line Control, Divisor Latch +** 4 Modem Control +** 5 Line Status +** 6 Modem Status +** 7 Scratch +** +** Registers indices are relative to the base I/O port for the +** specific UART port being used (e.g., for COM1, the port addresses +** are 0x3f8 through 0x3ff). When two registers share a port and have +** different access methods (RO vs. WO), a read from the port accesses +** the RO register and a write to the port access the WO register. +** +** The Line Control and Divisor Latch registers are accessed by writing +** a byte to the port; the high-order bit determines which register is +** accessed (0 selects Line Control, 1 selects Divisor Latch), with the +** remaining bits selecting fields within the indicated register. +*/ + +/* +** Receiver Data Register (read-only) +*/ +#define UA4_RXD (UA4_PORT+0) +# define UA4_RX_DATA UA4_RXD + +/* +** Transmitter Data Register (write-only) +*/ +#define UA4_TXD (UA4_PORT+0) +# define UA4_TX_DATA UA4_TXD + +/* +** Interrupt Enable Register +*/ +#define UA4_IER (UA4_PORT+1) +# define UA4_INT_ENABLE_REG UA4_IER + +// fields +#define UA4_IER_RX_IE 0x01 // Rcvr High-Data-Level Int Enable +#define UA4_IER_TX_IE 0x02 // Xmitter Low-data-level Int Enable +#define UA4_IER_LS_IE 0x04 // Line Status Int Enable +#define UA4_IER_MS_IE 0x08 // Modem Status Int Enable + +// aliases +#define UA4_IER_RX_INT_ENABLE UA4_IER_RX_IE +#define UA4_IER_TX_INT_ENABLE UA4_IER_TX_IE +#define UA4_IER_LINE_STATUS_INT_ENABLE UA4_IER_LS_IE +#define UA4_IER_MODEM_STATUS_INT_ENABLE UA4_IER_MS_IE + +/* +** Interrupt Identification Register (read-only) +** +** a.k.a. Event Identification Register +*/ +#define UA4_IIR (UA4_PORT+2) +# define UA4_EVENT_ID UA4_IIR + +// fields +#define UA4_IIR_IPF 0x01 // Interrupt Pending flag + +#define UA4_IIR_IPR_MASK 0x06 // Interrupt Priority mask +# define UA4_IIR_IPR0_MASK 0x02 // IPR bit 0 mask +# define UA4_IIR_IPR1_MASK 0x04 // IPR bit 1 mask + +#define UA5_IIR_RXFT 0x08 // RX_FIFO Timeout +#define UA5_IIR_FEN0 0x40 // FIFOs Enabled +#define UA5_IIR_FEN1 0x80 // FIFOs Enabled + +// aliases +#define UA4_IIR_INT_PENDING UA4_IIR_IPF +#define UA4_IIR_INT_PRIORITY UA4_IIR_IPR +#define UA5_IIR_RX_FIFO_TIMEOUT UA5_IIR_RXFT +#define UA5_IIR_FIFO_ENABLED_0 UA5_IIR_FEN0 +#define UA5_IIR_FIFO_ENABLED_1 UA5_IIR_FEN1 + +// IIR interrupt priorities (four-bit values) +#define UA4_IIR_INT_PRI_MASK 0x0f // Mask for extracting int priority +# define UA4_IIR_NO_INT 0x01 // no interrupt +# define UA4_IIR_LINE_STATUS 0x06 // line status interrupt +# define UA4_IIR_RX 0x04 // Receiver High Data Level +# define UA5_IIR_RX_FIFO 0x0c // Receiver FIFO timeout (16550) +# define UA4_IIR_TX 0x02 // Transmitter Low Data level +# define UA4_IIR_MODEM_STATUS 0x00 // Modem Status + +// aliases +#define UA4_IIR_NO_INT_PENDING UA4_IIR_NO_INT +#define UA4_IIR_LINE_STATUS_INT_PENDING UA4_IIR_LINE_STATUS +#define UA4_IIR_RX_INT_PENDING UA4_IIR_RX +#define UA5_IIR_RX_FIFO_TIMEOUT_INT_PENDING UA5_IIR_RX_FIFO +#define UA4_IIR_TX_INT_PENDING UA4_IIR_TX +#define UA4_IIR_MODEM_STATUS_INT_PENDING UA4_IIR_MODEM_STATUS + +/* +** FIFO Control Register (16550 only, write-only) +*/ +#define UA5_FCR (UA5_PORT+2) +# define UA5_FIFO_CTL UA5_FCR + +#define UA5_FCR_FIFO_RESET 0x00 // Reset the FIFO +#define UA5_FCR_FIFO_EN 0x01 // FIFO Enable +#define UA5_FCR_RXSR 0x02 // Receiver Soft Reset +#define UA5_FCR_TXSR 0x04 // Transmitter Soft Reset + +#define UA5_FCR_TXFT_MASK 0x30 // TX_FIFO threshold level mask +# define UA5_FCR_TXFT0_MASK 0x10 // TXFT bit 0 mask +# define UA5_FCR_TXFT1_MASK 0x20 // TXFT bit 1 mask +# define UA5_FCR_TX_FIFO_1 0x00 // 1 char +# define UA5_FCR_TX_FIFO_3 0x10 // 3 char +# define UA5_FCR_TX_FIFO_9 0x20 // 9 char +# define UA5_FCR_TX_FIFO_13 0x30 // 13 char + +#define UA5_FCR_RXFT_MASK 0xc0 // RX_FIFO threshold level mask +# define UA5_FCR_RXFT0_MASK 0x40 // RXFT bit 0 mask +# define UA5_FCR_RXFT1_MASK 0x80 // RXFT bit 1 mask +# define UA5_FCR_RX_FIFO_1 0x00 // 1 char +# define UA5_FCR_RX_FIFO_4 0x40 // 4 char +# define UA5_FCR_RX_FIFO_8 0x80 // 8 char +# define UA5_FCR_RX_FIFO_14 0xc0 // 14 char + +// aliases +#define UA5_FCR_FIFO_ENABLED UA5_FCR_FIFO_EN +#define UA5_FCR_RX_SOFT_RESET UA5_FCR_RXSR +#define UA5_FCR_TX_SOFT_RESET UA5_FCR_TXSR +#define UA5_FCR_TX_FIFO_1_CHAR UA5_FCR_TX_FIFO_1 +#define UA5_FCR_TX_FIFO_3_CHAR UA5_FCR_TX_FIFO_3 +#define UA5_FCR_TX_FIFO_9_CHAR UA5_FCR_TX_FIFO_9 +#define UA5_FCR_TX_FIFO_13_CHAR UA5_FCR_TX_FIFO_13 +#define UA5_FCR_RX_FIFO_1_CHAR UA5_FCR_RX_FIFO_1 +#define UA5_FCR_RX_FIFO_4_CHAR UA5_FCR_RX_FIFO_4 +#define UA5_FCR_RX_FIFO_8_CHAR UA5_FCR_RX_FIFO_8 +#define UA5_FCR_RX_FIFO_14_CHAR UA5_FCR_RX_FIFO_14 + +/* +** Line Control Register (available in all banks) +** +** Selected when bit 7 of the value written to the port is a 0. +*/ +#define UA4_LCR (UA4_PORT+3) +# define UA4_LINE_CTL UA4_LCR + +#define UA4_LCR_WLS_MASK 0x03 // Word Length Select mask +# define UA4_LCR_WLS0_MASK 0x01 // WLS bit 0 mask +# define UA4_LCR_WLS1_MASK 0x02 // WLS bit 1 mask +# define UA4_LCR_WLS_5 0x00 // 5 bits per char +# define UA4_LCR_WLS_6 0x01 // 6 bits per char +# define UA4_LCR_WLS_7 0x02 // 7 bits per char +# define UA4_LCR_WLS_8 0x03 // 8 bits per char + +#define UA4_LCR_STB 0x04 // Stop Bits +# define UA4_LCR_1_STOP_BIT 0x00 +# define UA4_LCR_2_STOP_BIT 0x04 + +#define UA4_LCR_PEN 0x08 // Parity Enable +#define UA4_LCR_EPS 0x10 // Even Parity Select +#define UA4_LCR_STKP 0x20 // Sticky Parity +# define UA4_LCR_NO_PARITY 0x00 +# define UA4_LCR_ODD_PARITY UA4_LCR_PEN +# define UA4_LCR_EVEN_PARITY (UA4_LCR_PEN|UA4_LCR_EPS) +# define UA4_LCR_PARITY_LOGIC_1 (UA4_LCR_PEN|UA4_LCR_STKP) +# define UA4_LCR_PARITY_LOGIC_0 (UA4_LCR_PEN|UA4_LCR_EPS|UA4_LCR_STKP) + +#define UA4_LCR_SBRK 0x40 // Set Break +#define UA4_LCR_DLAB 0x80 // Divisor Latch select bit + +// aliases +# define UA4_LCR_STOP_BITS UA4_LCR_STB +# define UA4_LCR_PARITY_ENABLE UA4_LCR_PEN +# define UA4_LCR_SET_BREAK UA4_LCR_SBRK +# define UA4_LCR_BANK_SELECT_ENABLE UA4_LCR_BKSE + +/* +** Divisor Latch Registers +** Divisor Latch Least Significant (DLL) +** Divisor Latch Most Significant (DLM) +** +** These contain the lower and upper halves of the 16-bit divisor for +** baud rate generation. +** +** Accessing them requires sending a command to LCR with the most +** significant bit (0x80, the DLAB field) set. This "unlocks" the +** Divisor Latch registers, which are accessed at UA4_PORT+0 and +** UA4_PORT+1 (i.e., in place of the RXD/TXD and IE registers). To +** "re-lock" the Divisor Latch registers, write a command byte to +** LCR with 0 in the DLAB bit. +*/ +#define UA4_DLL (UA4_PORT+0) // Divisor Latch (least sig.) +#define UA4_DLM (UA4_PORT+1) // Divisor Latch (most sig.) + +// aliases +#define UA4_DIVISOR_LATCH_LS UA4_DLL +#define UA4_DIVISOR_LATCH_MS UA4_DLM + +// Baud rate divisor high and low bytes +#define BAUD_HIGH_BYTE(x) (((x) >> 8) & 0xff) +#define BAUD_LOW_BYTE(x) ((x) & 0xff) + +// Baud rate divisors +#define DL_BAUD_50 2304 +#define DL_BAUD_75 1536 +#define DL_BAUD_110 1047 +#define DL_BAUD_150 768 +#define DL_BAUD_300 384 +#define DL_BAUD_600 192 +#define DL_BAUD_1200 96 +#define DL_BAUD_1800 64 +#define DL_BAUD_2000 58 +#define DL_BAUD_2400 48 +#define DL_BAUD_3600 32 +#define DL_BAUD_4800 24 +#define DL_BAUD_7200 16 +#define DL_BAUD_9600 12 +#define DL_BAUD_14400 8 +#define DL_BAUD_19200 6 +#define DL_BAUD_28800 4 +#define DL_BAUD_38400 3 +#define DL_BAUD_57600 2 +#define DL_BAUD_115200 1 + +/* +** Modem Control Register +*/ +#define UA4_MCR (UA4_PORT+4) +# define UA4_MODEM_CTL UA4_MCR + +#define UA4_MCR_DTR 0x01 // Data Terminal Ready +#define UA4_MCR_RTS 0x02 // Ready to Send +#define UA4_MCR_RILP 0x04 // Loopback Interrupt Request +#define UA4_MCR_ISEN 0x08 // Interrupt Signal Enable +#define UA4_MCR_DCDLP 0x08 // DCD Loopback +#define UA4_MCR_LOOP 0x10 // Loopback Enable + +// aliases +#define UA4_MCR_DATA_TERMINAL_READY UA4_MCR_DTR +#define UA4_MCR_READY_TO_SEND UA4_MCR_RTS +#define UA4_MCR_LOOPBACK_INT_REQ UA4_MCR_RILP +#define UA4_MCR_INT_SIGNAL_ENABLE UA4_MCR_ISEN +#define UA4_MCR_LOOPBACK_DCD UA4_MCR_DCDLP +#define UA4_MCR_LOOPBACK_ENABLE UA4_MCR_LOOP + +/* +** Line Status Register +*/ +#define UA4_LSR (UA4_PORT+5) +# define UA4_LINE_STATUS UA4_LSR + +#define UA4_LSR_RXDA 0x01 // Receiver Data Available +#define UA4_LSR_OE 0x02 // Overrun Error +#define UA4_LSR_PE 0x04 // Parity Error +#define UA4_LSR_FE 0x08 // Framing Error +#define UA4_LSR_BRK 0x10 // Break Event Detected +#define UA4_LSR_TXRDY 0x20 // Transmitter Ready +#define UA4_LSR_TXEMP 0x40 // Transmitter Empty +#define UA4_LSR_ER_INF 0x80 // Error in RX_FIFO + +// aliases +#define UA4_LSR_RX_DATA_AVAILABLE UA4_LSR_RXDA +#define UA4_LSR_OVERRUN_ERROR UA4_LSR_OE +#define UA4_LSR_PARITY_ERROR UA4_LSR_PE +#define UA4_LSR_FRAMING_ERROR UA4_LSR_FE +#define UA4_LSR_BREAK_DETECTED UA4_LSR_BRK +#define UA4_LSR_TX_READY UA4_LSR_TXRDY +#define UA4_LSR_TX_EMPTY UA4_LSR_TXEMP +#define UA4_LSR_RX_FIFO_ERROR UA4_LSR_ER_INF + +/* +** Modem Status Register +*/ +#define UA4_MSR (UA4_PORT+6) +# define UA4_MODEM_STATUS UA4_MSR + +#define UA4_MSR_DCTS 0x01 // Delta Clear to Send +#define UA4_MSR_DDSR 0x02 // Delta Data Set Ready +#define UA4_MSR_TERI 0x04 // Trailing Edge Ring Indicate +#define UA4_MSR_DDCD 0x08 // Delta Data Carrier Detect +#define UA4_MSR_CTS 0x10 // Clear to Send +#define UA4_MSR_DSR 0x20 // Data Set Ready +#define UA4_MSR_RI 0x40 // Ring Indicate +#define UA4_MSR_DCD 0x80 // Data Carrier Detect + +// aliases +#define UA4_MSR_DELTA_CLEAR_TO_SEND UA4_MSR_DCTS +#define UA4_MSR_DELTA_DATA_SET_READY UA4_MSR_DDSR +#define UA4_MSR_TRAILING_EDGE_RING UA4_MSR_TERI +#define UA4_MSR_DELTA_DATA_CARRIER_DETECT UA4_MSR_DDCD +#define UA4_MSR_CLEAR_TO_SEND UA4_MSR_CTS +#define UA4_MSR_DATA_SET_READY UA4_MSR_DSR +#define UA4_MSR_RING_INDICATE UA4_MSR_RI +#define UA4_MSR_DATA_CARRIER_DETECT UA4_MSR_DCD + +/* +** Scratch Register +** +** Not used by the UART; usable as a "scratchpad" register for +** temporary storage. +*/ +#define UA4_SCR (UA4_PORT+7) +# define UA4_SCRATCH UA4_UA5_SCR + +#endif /* uart.h */ |