1 /* 2 * Driver for 8250/16550-type serial ports 3 * 4 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. 5 * 6 * Copyright (C) 2001 Russell King. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 */ 13 14 #include <linux/serial_8250.h> 15 16 struct uart_8250_port { 17 struct uart_port port; 18 struct timer_list timer; /* "no irq" timer */ 19 struct list_head list; /* ports on this IRQ */ 20 unsigned short capabilities; /* port capabilities */ 21 unsigned short bugs; /* port bugs */ 22 unsigned int tx_loadsz; /* transmit fifo load size */ 23 unsigned char acr; 24 unsigned char ier; 25 unsigned char lcr; 26 unsigned char mcr; 27 unsigned char mcr_mask; /* mask of user bits */ 28 unsigned char mcr_force; /* mask of forced bits */ 29 unsigned char cur_iotype; /* Running I/O type */ 30 31 /* 32 * Some bits in registers are cleared on a read, so they must 33 * be saved whenever the register is read but the bits will not 34 * be immediately processed. 35 */ 36 #define LSR_SAVE_FLAGS UART_LSR_BRK_ERROR_BITS 37 unsigned char lsr_saved_flags; 38 #define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA 39 unsigned char msr_saved_flags; 40 41 /* 8250 specific callbacks */ 42 int (*dl_read)(struct uart_8250_port *); 43 void (*dl_write)(struct uart_8250_port *, int); 44 }; 45 46 struct old_serial_port { 47 unsigned int uart; 48 unsigned int baud_base; 49 unsigned int port; 50 unsigned int irq; 51 unsigned int flags; 52 unsigned char hub6; 53 unsigned char io_type; 54 unsigned char *iomem_base; 55 unsigned short iomem_reg_shift; 56 unsigned long irqflags; 57 }; 58 59 /* 60 * This replaces serial_uart_config in include/linux/serial.h 61 */ 62 struct serial8250_config { 63 const char *name; 64 unsigned short fifo_size; 65 unsigned short tx_loadsz; 66 unsigned char fcr; 67 unsigned int flags; 68 }; 69 70 #define UART_CAP_FIFO (1 << 8) /* UART has FIFO */ 71 #define UART_CAP_EFR (1 << 9) /* UART has EFR */ 72 #define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */ 73 #define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */ 74 #define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */ 75 #define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */ 76 77 #define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */ 78 #define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */ 79 #define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */ 80 #define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */ 81 82 #define PROBE_RSA (1 << 0) 83 #define PROBE_ANY (~0) 84 85 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) 86 87 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ 88 #define SERIAL8250_SHARE_IRQS 1 89 #else 90 #define SERIAL8250_SHARE_IRQS 0 91 #endif 92 93 static inline int serial_in(struct uart_8250_port *up, int offset) 94 { 95 return up->port.serial_in(&up->port, offset); 96 } 97 98 static inline void serial_out(struct uart_8250_port *up, int offset, int value) 99 { 100 up->port.serial_out(&up->port, offset, value); 101 } 102 103 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p); 104 105 static inline int serial_dl_read(struct uart_8250_port *up) 106 { 107 return up->dl_read(up); 108 } 109 110 static inline void serial_dl_write(struct uart_8250_port *up, int value) 111 { 112 up->dl_write(up, value); 113 } 114 115 #if defined(__alpha__) && !defined(CONFIG_PCI) 116 /* 117 * Digital did something really horribly wrong with the OUT1 and OUT2 118 * lines on at least some ALPHA's. The failure mode is that if either 119 * is cleared, the machine locks up with endless interrupts. 120 */ 121 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1) 122 #elif defined(CONFIG_SBC8560) 123 /* 124 * WindRiver did something similarly broken on their SBC8560 board. The 125 * UART tristates its IRQ output while OUT2 is clear, but they pulled 126 * the interrupt line _up_ instead of down, so if we register the IRQ 127 * while the UART is in that state, we die in an IRQ storm. */ 128 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2) 129 #else 130 #define ALPHA_KLUDGE_MCR 0 131 #endif 132