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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 */
13
Russell Kingbc49a662005-09-01 15:56:26 +010014#include <linux/serial_8250.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
Paul Gortmaker850624c2011-12-04 18:42:18 -050016struct 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070042struct 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;
Vikram Pandita1c2f0492009-09-19 13:13:19 -070052 unsigned long irqflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053};
54
55/*
56 * This replaces serial_uart_config in include/linux/serial.h
57 */
58struct 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) */
Stephen Warren4539c242011-05-17 16:12:36 -060071#define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
Russell King4ba5e352005-06-23 10:43:04 +010073#define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
Russell King55d3b282005-06-23 15:05:41 +010074#define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
Pantelis Antoniou21c614a2005-11-06 09:07:03 +000075#define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
Will Newton363f66f2008-09-02 14:35:44 -070076#define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
Russell King4ba5e352005-06-23 10:43:04 +010077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#define PROBE_RSA (1 << 0)
79#define PROBE_ANY (~0)
80
81#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
82
83#ifdef CONFIG_SERIAL_8250_SHARE_IRQ
84#define SERIAL8250_SHARE_IRQS 1
85#else
86#define SERIAL8250_SHARE_IRQS 0
87#endif
88
Paul Gortmaker3f0ab322012-03-08 19:12:09 -050089static inline int serial_in(struct uart_8250_port *up, int offset)
90{
91 return up->port.serial_in(&up->port, offset);
92}
93
94static inline void serial_out(struct uart_8250_port *up, int offset, int value)
95{
96 up->port.serial_out(&up->port, offset, value);
97}
98
Linus Torvalds1da177e2005-04-16 15:20:36 -070099#if defined(__alpha__) && !defined(CONFIG_PCI)
100/*
101 * Digital did something really horribly wrong with the OUT1 and OUT2
102 * lines on at least some ALPHA's. The failure mode is that if either
103 * is cleared, the machine locks up with endless interrupts.
104 */
105#define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1)
106#elif defined(CONFIG_SBC8560)
107/*
108 * WindRiver did something similarly broken on their SBC8560 board. The
109 * UART tristates its IRQ output while OUT2 is clear, but they pulled
110 * the interrupt line _up_ instead of down, so if we register the IRQ
111 * while the UART is in that state, we die in an IRQ storm. */
112#define ALPHA_KLUDGE_MCR (UART_MCR_OUT2)
113#else
114#define ALPHA_KLUDGE_MCR 0
115#endif