1/* 2 * A library of polled 16550 serial routines. These are intended to 3 * be used to support progress messages, xmon, kgdb, etc. on a 4 * variety of platforms. 5 * 6 * Adapted from lots of code ripped from the arch/ppc/boot/ polled 7 * 16550 support. 8 * 9 * Author: Matt Porter <mporter@mvista.com> 10 * 11 * 2002-2003 (c) MontaVista Software, Inc. This file is licensed under 12 * the terms of the GNU General Public License version 2. This program 13 * is licensed "as is" without any warranty of any kind, whether express 14 * or implied. 15 */ 16 17#include <linux/types.h> 18#include <linux/serial.h> 19#include <linux/tty.h> /* For linux/serial_core.h */ 20#include <linux/serial_core.h> 21#include <linux/serialP.h> 22#include <linux/serial_reg.h> 23#include <asm/machdep.h> 24#include <asm/serial.h> 25#include <asm/io.h> 26 27#define SERIAL_BAUD 9600 28 29/* SERIAL_PORT_DFNS is defined in <asm/serial.h> */ 30#ifndef SERIAL_PORT_DFNS 31#define SERIAL_PORT_DFNS 32#endif 33 34static struct serial_state rs_table[RS_TABLE_SIZE] = { 35 SERIAL_PORT_DFNS /* defined in <asm/serial.h> */ 36}; 37 38static void (*serial_outb)(unsigned long, unsigned char); 39static unsigned long (*serial_inb)(unsigned long); 40 41static int shift; 42 43unsigned long direct_inb(unsigned long addr) 44{ 45 return readb((void __iomem *)addr); 46} 47 48void direct_outb(unsigned long addr, unsigned char val) 49{ 50 writeb(val, (void __iomem *)addr); 51} 52 53unsigned long io_inb(unsigned long port) 54{ 55 return inb(port); 56} 57 58void io_outb(unsigned long port, unsigned char val) 59{ 60 outb(val, port); 61} 62 63unsigned long serial_init(int chan, void *ignored) 64{ 65 unsigned long com_port; 66 unsigned char lcr, dlm; 67 68 /* We need to find out which type io we're expecting. If it's 69 * 'SERIAL_IO_PORT', we get an offset from the isa_io_base. 70 * If it's 'SERIAL_IO_MEM', we can the exact location. -- Tom */ 71 switch (rs_table[chan].io_type) { 72 case SERIAL_IO_PORT: 73 com_port = rs_table[chan].port; 74 serial_outb = io_outb; 75 serial_inb = io_inb; 76 break; 77 case SERIAL_IO_MEM: 78 com_port = (unsigned long)rs_table[chan].iomem_base; 79 serial_outb = direct_outb; 80 serial_inb = direct_inb; 81 break; 82 default: 83 /* We can't deal with it. */ 84 return -1; 85 } 86 87 /* How far apart the registers are. */ 88 shift = rs_table[chan].iomem_reg_shift; 89 90 /* save the LCR */ 91 lcr = serial_inb(com_port + (UART_LCR << shift)); 92 93 /* Access baud rate */ 94 serial_outb(com_port + (UART_LCR << shift), UART_LCR_DLAB); 95 dlm = serial_inb(com_port + (UART_DLM << shift)); 96 97 /* 98 * Test if serial port is unconfigured 99 * We assume that no-one uses less than 110 baud or 100 * less than 7 bits per character these days. 101 * -- paulus. 102 */ 103 if ((dlm <= 4) && (lcr & 2)) { 104 /* port is configured, put the old LCR back */ 105 serial_outb(com_port + (UART_LCR << shift), lcr); 106 } 107 else { 108 /* Input clock. */ 109 serial_outb(com_port + (UART_DLL << shift), 110 (rs_table[chan].baud_base / SERIAL_BAUD) & 0xFF); 111 serial_outb(com_port + (UART_DLM << shift), 112 (rs_table[chan].baud_base / SERIAL_BAUD) >> 8); 113 /* 8 data, 1 stop, no parity */ 114 serial_outb(com_port + (UART_LCR << shift), 0x03); 115 /* RTS/DTR */ 116 serial_outb(com_port + (UART_MCR << shift), 0x03); 117 118 /* Clear & enable FIFOs */ 119 serial_outb(com_port + (UART_FCR << shift), 0x07); 120 } 121 122 return (com_port); 123} 124 125void 126serial_putc(unsigned long com_port, unsigned char c) 127{ 128 while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0) 129 ; 130 serial_outb(com_port, c); 131} 132 133unsigned char 134serial_getc(unsigned long com_port) 135{ 136 while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0) 137 ; 138 return serial_inb(com_port); 139} 140 141int 142serial_tstc(unsigned long com_port) 143{ 144 return ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0); 145} 146 147void 148serial_close(unsigned long com_port) 149{ 150} 151 152void 153gen550_init(int i, struct uart_port *serial_req) 154{ 155 rs_table[i].io_type = serial_req->iotype; 156 rs_table[i].port = serial_req->iobase; 157 rs_table[i].iomem_base = serial_req->membase; 158 rs_table[i].iomem_reg_shift = serial_req->regshift; 159 rs_table[i].baud_base = serial_req->uartclk ? serial_req->uartclk / 16 : BASE_BAUD; 160} 161 162#ifdef CONFIG_SERIAL_TEXT_DEBUG 163void 164gen550_progress(char *s, unsigned short hex) 165{ 166 volatile unsigned int progress_debugport; 167 volatile char c; 168 169 progress_debugport = serial_init(0, NULL); 170 171 serial_putc(progress_debugport, '\r'); 172 173 while ((c = *s++) != 0) 174 serial_putc(progress_debugport, c); 175 176 serial_putc(progress_debugport, '\n'); 177 serial_putc(progress_debugport, '\r'); 178} 179#endif /* CONFIG_SERIAL_TEXT_DEBUG */ 180