pl011.c File Reference

The driver for ARM's PrimeCell UART (PL011), the serial port of QEMU's virt machine: /dev/ttyS0, and /dev/console when there are no virtual terminals. More...

#include <core/system.h>
#include <core/module.h>
#include <cpu/io.h>
#include <dev/tty.h>
#include <dev/uart.h>
#include <dev/irq.h>
#include <dev/platform.h>

Go to the source code of this file.

Macros
#define	UART_DR   0x00
#define	UART_FR   0x18
#define	UART_LCR_H   0x2C
#define	UART_IMSC   0x38
#define	UART_ICR   0x44
#define	FR_RXFE   (1 << 4)
#define	FR_TXFF   (1 << 5)
#define	INT_RX   (1 << 4)
#define	INT_RT   (1 << 6)
#define	LCR_H_FEN   (1 << 4)
#define	LCR_H_WLEN8   (3 << 5)

Functions
static ssize_t	pl011_transmit (struct uart *u, char c)
	Sends one character, once the transmit FIFO has room.
static char	pl011_receive (struct uart *u)
	Takes one received character from the receive FIFO.
static void	pl011_irq (void *arg)
	Handles the UART's interrupt: every received character goes to the terminal, or is dropped if no one has opened it.
static void	pl011_comm_init (struct uart *u)
	Sets the UART up when it is first opened: 8-bit characters, the FIFOs, and the receive interrupts.
static int	pl011_init (void)
	Finds the platform's PL011, installs its interrupt handler, and registers it as the first UART.

Variables
static struct ioaddr	io
struct uart	uart_pl011

Detailed Description

The driver for ARM's PrimeCell UART (PL011), the serial port of QEMU's virt machine: /dev/ttyS0, and /dev/console when there are no virtual terminals.

Output is written one character at a time, waiting while the transmit FIFO is full. Input comes with the UART's interrupt, which drains the receive FIFO into the terminal. The UART's address and interrupt are the platform's (dev/platform.h); the driver drives one UART, the first the platform has.

References: [1] - ARM PrimeCell UART (PL011) Technical Reference Manual (DDI 0183): UARTDR, UARTFR, UARTIMSC, UARTICR

Definition in file pl011.c.

Macro Definition Documentation

FR_RXFE

#define FR_RXFE   (1 << 4)

Definition at line 31 of file pl011.c.

Referenced by pl011_irq().

FR_TXFF

#define FR_TXFF   (1 << 5)

Definition at line 32 of file pl011.c.

Referenced by pl011_transmit().

INT_RT

#define INT_RT   (1 << 6)

Definition at line 34 of file pl011.c.

Referenced by pl011_comm_init(), and pl011_irq().

INT_RX

#define INT_RX   (1 << 4)

Definition at line 33 of file pl011.c.

Referenced by pl011_comm_init(), and pl011_irq().

LCR_H_FEN

#define LCR_H_FEN   (1 << 4)

Definition at line 35 of file pl011.c.

Referenced by pl011_comm_init().

LCR_H_WLEN8

#define LCR_H_WLEN8   (3 << 5)

Definition at line 36 of file pl011.c.

Referenced by pl011_comm_init().

UART_DR

#define UART_DR   0x00

Definition at line 25 of file pl011.c.

UART_FR

#define UART_FR   0x18

Definition at line 26 of file pl011.c.

UART_ICR

#define UART_ICR   0x44

Definition at line 29 of file pl011.c.

Referenced by pl011_irq().

UART_IMSC

#define UART_IMSC   0x38

Definition at line 28 of file pl011.c.

Referenced by pl011_comm_init().

UART_LCR_H

#define UART_LCR_H   0x2C

Definition at line 27 of file pl011.c.

Referenced by pl011_comm_init().

Function Documentation

pl011_comm_init()

void pl011_comm_init ( struct uart * u )

static

Sets the UART up when it is first opened: 8-bit characters, the FIFOs, and the receive interrupts.

QEMU's UART needs no speed set.

Definition at line 80 of file pl011.c.

References INT_RT, INT_RX, io, io_out32(), LCR_H_FEN, LCR_H_WLEN8, pl011_comm_init(), UART_IMSC, and UART_LCR_H.

Referenced by pl011_comm_init().

pl011_init()

int pl011_init ( void )

static

Finds the platform's PL011, installs its interrupt handler, and registers it as the first UART.

Definition at line 88 of file pl011.c.

References io, platform_device::irq, irq_install(), platform_device::nirq, NULL, pl011_init(), pl011_irq(), platform_device_get(), platform_device_io(), uart_pl011, and uart_register().

Referenced by pl011_init().

pl011_irq()

void pl011_irq ( void * arg )

static

Handles the UART's interrupt: every received character goes to the terminal, or is dropped if no one has opened it.

Definition at line 62 of file pl011.c.

References FR_RXFE, INT_RT, INT_RX, io, io_in32(), io_out32(), pl011_irq(), pl011_receive(), uart::tty, UART_FR, UART_ICR, uart_pl011, and uart_receive_handler().

Referenced by pl011_init(), and pl011_irq().

pl011_receive()

char pl011_receive ( struct uart * u )

static

Takes one received character from the receive FIFO.

Definition at line 55 of file pl011.c.

References io, io_in32(), pl011_receive(), and UART_DR.

Referenced by pl011_irq(), and pl011_receive().

pl011_transmit()

ssize_t pl011_transmit ( struct uart * u, char c )

static

Sends one character, once the transmit FIFO has room.

Definition at line 43 of file pl011.c.

References FR_TXFF, io, io_in32(), io_out32(), pl011_transmit(), UART_DR, and UART_FR.

Referenced by pl011_transmit().

Variable Documentation

io

struct ioaddr io

static

Definition at line 38 of file pl011.c.

Referenced by pl011_comm_init(), pl011_init(), pl011_irq(), pl011_receive(), and pl011_transmit().

uart_pl011

struct uart uart_pl011

Initial value:

          = {
    .name     = "pl011",
    .init     = pl011_comm_init,
    .transmit = pl011_transmit,
    .receive  = pl011_receive,
}

Definition at line 40 of file pl011.c.

Referenced by pl011_init(), and pl011_irq().