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
42 struct old_serial_port {
43 unsigned int uart;
44 unsigned int baud_base;
45 unsigned int port;
46 unsigned int irq;
47 unsigned int flags;
48 unsigned char hub6;
49 unsigned char io_type;
50 unsigned char *iomem_base;
51 unsigned short iomem_reg_shift;
52 unsigned long irqflags;
53 };
54
55 /*
56 * This replaces serial_uart_config in include/linux/serial.h
57 */
58 struct serial8250_config {
59 const char *name;
60 unsigned short fifo_size;
61 unsigned short tx_loadsz;
62 unsigned char fcr;
63 unsigned int flags;
64 };
65
66 #define UART_CAP_FIFO (1 << 8) /* UART has FIFO */
67 #define UART_CAP_EFR (1 << 9) /* UART has EFR */
68 #define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */
69 #define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
70 #define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
71 #define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */
72 #define UART_CAP_HFIFO (1 << 14) /* UART has a "hidden" FIFO */
73
74 #define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
75 #define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
76 #define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
77 #define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
78
79 #define PROBE_RSA (1 << 0)
80 #define PROBE_ANY (~0)
81
82 #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
83
84 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ
85 #define SERIAL8250_SHARE_IRQS 1
86 #else
87 #define SERIAL8250_SHARE_IRQS 0
88 #endif
89
serial_in(struct uart_8250_port * up,int offset)90 static inline int serial_in(struct uart_8250_port *up, int offset)
91 {
92 return up->port.serial_in(&up->port, offset);
93 }
94
serial_out(struct uart_8250_port * up,int offset,int value)95 static inline void serial_out(struct uart_8250_port *up, int offset, int value)
96 {
97 up->port.serial_out(&up->port, offset, value);
98 }
99
100 #if defined(__alpha__) && !defined(CONFIG_PCI)
101 /*
102 * Digital did something really horribly wrong with the OUT1 and OUT2
103 * lines on at least some ALPHA's. The failure mode is that if either
104 * is cleared, the machine locks up with endless interrupts.
105 */
106 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1)
107 #elif defined(CONFIG_SBC8560)
108 /*
109 * WindRiver did something similarly broken on their SBC8560 board. The
110 * UART tristates its IRQ output while OUT2 is clear, but they pulled
111 * the interrupt line _up_ instead of down, so if we register the IRQ
112 * while the UART is in that state, we die in an IRQ storm. */
113 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2)
114 #else
115 #define ALPHA_KLUDGE_MCR 0
116 #endif
117