mirror of https://gitee.com/openkylin/linux.git
180 lines
4.4 KiB
C
180 lines
4.4 KiB
C
/*
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* A library of polled 16550 serial routines. These are intended to
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* be used to support progress messages, xmon, kgdb, etc. on a
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* variety of platforms.
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*
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* Adapted from lots of code ripped from the arch/ppc/boot/ polled
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* 16550 support.
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*
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* Author: Matt Porter <mporter@mvista.com>
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*
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* 2002-2003 (c) MontaVista Software, Inc. This file is licensed under
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* the terms of the GNU General Public License version 2. This program
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* is licensed "as is" without any warranty of any kind, whether express
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* or implied.
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*/
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#include <linux/types.h>
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#include <linux/serial.h>
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#include <linux/tty.h> /* For linux/serial_core.h */
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#include <linux/serial_core.h>
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#include <linux/serialP.h>
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#include <linux/serial_reg.h>
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#include <asm/machdep.h>
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#include <asm/serial.h>
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#include <asm/io.h>
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#define SERIAL_BAUD 9600
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/* SERIAL_PORT_DFNS is defined in <asm/serial.h> */
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#ifndef SERIAL_PORT_DFNS
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#define SERIAL_PORT_DFNS
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#endif
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static struct serial_state rs_table[RS_TABLE_SIZE] = {
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SERIAL_PORT_DFNS /* defined in <asm/serial.h> */
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};
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static void (*serial_outb)(unsigned long, unsigned char);
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static unsigned long (*serial_inb)(unsigned long);
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static int shift;
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unsigned long direct_inb(unsigned long addr)
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{
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return readb((void __iomem *)addr);
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}
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void direct_outb(unsigned long addr, unsigned char val)
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{
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writeb(val, (void __iomem *)addr);
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}
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unsigned long io_inb(unsigned long port)
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{
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return inb(port);
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}
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void io_outb(unsigned long port, unsigned char val)
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{
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outb(val, port);
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}
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unsigned long serial_init(int chan, void *ignored)
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{
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unsigned long com_port;
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unsigned char lcr, dlm;
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/* We need to find out which type io we're expecting. If it's
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* 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
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* If it's 'SERIAL_IO_MEM', we can the exact location. -- Tom */
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switch (rs_table[chan].io_type) {
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case SERIAL_IO_PORT:
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com_port = rs_table[chan].port;
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serial_outb = io_outb;
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serial_inb = io_inb;
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break;
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case SERIAL_IO_MEM:
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com_port = (unsigned long)rs_table[chan].iomem_base;
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serial_outb = direct_outb;
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serial_inb = direct_inb;
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break;
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default:
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/* We can't deal with it. */
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return -1;
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}
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/* How far apart the registers are. */
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shift = rs_table[chan].iomem_reg_shift;
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/* save the LCR */
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lcr = serial_inb(com_port + (UART_LCR << shift));
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/* Access baud rate */
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serial_outb(com_port + (UART_LCR << shift), UART_LCR_DLAB);
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dlm = serial_inb(com_port + (UART_DLM << shift));
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/*
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* Test if serial port is unconfigured
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* We assume that no-one uses less than 110 baud or
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* less than 7 bits per character these days.
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* -- paulus.
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*/
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if ((dlm <= 4) && (lcr & 2)) {
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/* port is configured, put the old LCR back */
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serial_outb(com_port + (UART_LCR << shift), lcr);
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}
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else {
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/* Input clock. */
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serial_outb(com_port + (UART_DLL << shift),
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(rs_table[chan].baud_base / SERIAL_BAUD) & 0xFF);
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serial_outb(com_port + (UART_DLM << shift),
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(rs_table[chan].baud_base / SERIAL_BAUD) >> 8);
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/* 8 data, 1 stop, no parity */
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serial_outb(com_port + (UART_LCR << shift), 0x03);
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/* RTS/DTR */
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serial_outb(com_port + (UART_MCR << shift), 0x03);
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/* Clear & enable FIFOs */
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serial_outb(com_port + (UART_FCR << shift), 0x07);
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}
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return (com_port);
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}
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void
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serial_putc(unsigned long com_port, unsigned char c)
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{
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while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
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;
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serial_outb(com_port, c);
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}
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unsigned char
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serial_getc(unsigned long com_port)
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{
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while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
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;
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return serial_inb(com_port);
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}
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int
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serial_tstc(unsigned long com_port)
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{
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return ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
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}
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void
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serial_close(unsigned long com_port)
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{
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}
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void
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gen550_init(int i, struct uart_port *serial_req)
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{
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rs_table[i].io_type = serial_req->iotype;
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rs_table[i].port = serial_req->iobase;
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rs_table[i].iomem_base = serial_req->membase;
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rs_table[i].iomem_reg_shift = serial_req->regshift;
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rs_table[i].baud_base = serial_req->uartclk ? serial_req->uartclk / 16 : BASE_BAUD;
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}
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#ifdef CONFIG_SERIAL_TEXT_DEBUG
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void
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gen550_progress(char *s, unsigned short hex)
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{
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volatile unsigned int progress_debugport;
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volatile char c;
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progress_debugport = serial_init(0, NULL);
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serial_putc(progress_debugport, '\r');
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while ((c = *s++) != 0)
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serial_putc(progress_debugport, c);
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serial_putc(progress_debugport, '\n');
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serial_putc(progress_debugport, '\r');
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}
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#endif /* CONFIG_SERIAL_TEXT_DEBUG */
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