1 /* 2 * udbg for for NS16550 compatable serial ports 3 * 4 * Copyright (C) 2001-2005 PPC 64 Team, IBM Corp 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 #include <linux/config.h> 12 #include <linux/types.h> 13 #include <asm/udbg.h> 14 #include <asm/io.h> 15 16 extern u8 real_readb(volatile u8 __iomem *addr); 17 extern void real_writeb(u8 data, volatile u8 __iomem *addr); 18 19 struct NS16550 { 20 /* this struct must be packed */ 21 unsigned char rbr; /* 0 */ 22 unsigned char ier; /* 1 */ 23 unsigned char fcr; /* 2 */ 24 unsigned char lcr; /* 3 */ 25 unsigned char mcr; /* 4 */ 26 unsigned char lsr; /* 5 */ 27 unsigned char msr; /* 6 */ 28 unsigned char scr; /* 7 */ 29 }; 30 31 #define thr rbr 32 #define iir fcr 33 #define dll rbr 34 #define dlm ier 35 #define dlab lcr 36 37 #define LSR_DR 0x01 /* Data ready */ 38 #define LSR_OE 0x02 /* Overrun */ 39 #define LSR_PE 0x04 /* Parity error */ 40 #define LSR_FE 0x08 /* Framing error */ 41 #define LSR_BI 0x10 /* Break */ 42 #define LSR_THRE 0x20 /* Xmit holding register empty */ 43 #define LSR_TEMT 0x40 /* Xmitter empty */ 44 #define LSR_ERR 0x80 /* Error */ 45 46 static volatile struct NS16550 __iomem *udbg_comport; 47 48 static void udbg_550_putc(unsigned char c) 49 { 50 if (udbg_comport) { 51 while ((in_8(&udbg_comport->lsr) & LSR_THRE) == 0) 52 /* wait for idle */; 53 out_8(&udbg_comport->thr, c); 54 if (c == '\n') 55 udbg_550_putc('\r'); 56 } 57 } 58 59 static int udbg_550_getc_poll(void) 60 { 61 if (udbg_comport) { 62 if ((in_8(&udbg_comport->lsr) & LSR_DR) != 0) 63 return in_8(&udbg_comport->rbr); 64 else 65 return -1; 66 } 67 return -1; 68 } 69 70 static unsigned char udbg_550_getc(void) 71 { 72 if (udbg_comport) { 73 while ((in_8(&udbg_comport->lsr) & LSR_DR) == 0) 74 /* wait for char */; 75 return in_8(&udbg_comport->rbr); 76 } 77 return 0; 78 } 79 80 void udbg_init_uart(void __iomem *comport, unsigned int speed) 81 { 82 u16 dll = speed ? (115200 / speed) : 12; 83 84 if (comport) { 85 udbg_comport = (struct NS16550 __iomem *)comport; 86 out_8(&udbg_comport->lcr, 0x00); 87 out_8(&udbg_comport->ier, 0xff); 88 out_8(&udbg_comport->ier, 0x00); 89 out_8(&udbg_comport->lcr, 0x80); /* Access baud rate */ 90 out_8(&udbg_comport->dll, dll & 0xff); /* 1 = 115200, 2 = 57600, 91 3 = 38400, 12 = 9600 baud */ 92 out_8(&udbg_comport->dlm, dll >> 8); /* dll >> 8 which should be zero 93 for fast rates; */ 94 out_8(&udbg_comport->lcr, 0x03); /* 8 data, 1 stop, no parity */ 95 out_8(&udbg_comport->mcr, 0x03); /* RTS/DTR */ 96 out_8(&udbg_comport->fcr ,0x07); /* Clear & enable FIFOs */ 97 udbg_putc = udbg_550_putc; 98 udbg_getc = udbg_550_getc; 99 udbg_getc_poll = udbg_550_getc_poll; 100 } 101 } 102 103 #ifdef CONFIG_PPC_MAPLE 104 void udbg_maple_real_putc(unsigned char c) 105 { 106 if (udbg_comport) { 107 while ((real_readb(&udbg_comport->lsr) & LSR_THRE) == 0) 108 /* wait for idle */; 109 real_writeb(c, &udbg_comport->thr); eieio(); 110 if (c == '\n') 111 udbg_maple_real_putc('\r'); 112 } 113 } 114 115 void udbg_init_maple_realmode(void) 116 { 117 udbg_comport = (volatile struct NS16550 __iomem *)0xf40003f8; 118 119 udbg_putc = udbg_maple_real_putc; 120 udbg_getc = NULL; 121 udbg_getc_poll = NULL; 122 } 123 #endif /* CONFIG_PPC_MAPLE */ 124