aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-xtensa/xtensa/xt2000-uart.h
blob: 0154460f0ed8265dcfea62ea4d52b07fba788e38 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
#ifndef _uart_h_included_
#define _uart_h_included_

/*
 * THIS FILE IS GENERATED -- DO NOT MODIFY BY HAND
 *
 * include/asm-xtensa/xtensa/xt2000-uart.h -- NatSemi PC16552D DUART
 * definitions
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2002 Tensilica Inc.
 */


#include <xtensa/xt2000.h>


/* 16550 UART DEVICE REGISTERS
   The XT2000 board aligns each register to a 32-bit word but the UART device only uses
   one byte of the word, which is the least-significant byte regardless of the
   endianness of the core (ie. byte offset 0 for little-endian and 3 for big-endian).
   So if using word accesses then endianness doesn't matter.
   The macros provided here do that.
*/
struct uart_dev_s {
  union {
    unsigned int rxb;	/* DLAB=0: receive buffer, read-only */
    unsigned int txb;	/* DLAB=0: transmit buffer, write-only */
    unsigned int dll;	/* DLAB=1: divisor, least-significant byte latch (was write-only?) */
  } w0;
  union {
    unsigned int ier;	/* DLAB=0: interrupt-enable register (was write-only?) */
    unsigned int dlm;	/* DLAB=1: divisor, most-significant byte latch (was write-only?) */
  } w1;

  union {
    unsigned int isr;	/* DLAB=0: interrupt status register, read-only */
    unsigned int fcr;	/* DLAB=0: FIFO control register, write-only */
    unsigned int afr;	/* DLAB=1: alternate function register */
  } w2;

  unsigned int lcr;	/* line control-register, write-only */
  unsigned int mcr;	/* modem control-regsiter, write-only */
  unsigned int lsr;	/* line status register, read-only */
  unsigned int msr;	/* modem status register, read-only */
  unsigned int scr;	/* scratch regsiter, read/write */
};

#define _RXB(u) ((u)->w0.rxb)
#define _TXB(u) ((u)->w0.txb)
#define _DLL(u) ((u)->w0.dll)
#define _IER(u) ((u)->w1.ier)
#define _DLM(u) ((u)->w1.dlm)
#define _ISR(u) ((u)->w2.isr)
#define _FCR(u) ((u)->w2.fcr)
#define _AFR(u) ((u)->w2.afr)
#define _LCR(u) ((u)->lcr)
#define _MCR(u) ((u)->mcr)
#define _LSR(u) ((u)->lsr)
#define _MSR(u) ((u)->msr)
#define _SCR(u) ((u)->scr)

typedef volatile struct uart_dev_s uart_dev_t;

/* IER bits */
#define RCVR_DATA_REG_INTENABLE 0x01
#define XMIT_HOLD_REG_INTENABLE    0x02
#define RCVR_STATUS_INTENABLE   0x04
#define MODEM_STATUS_INTENABLE     0x08

/* FCR bits */
#define _FIFO_ENABLE      0x01
#define RCVR_FIFO_RESET  0x02
#define XMIT_FIFO_RESET  0x04
#define DMA_MODE_SELECT  0x08
#define RCVR_TRIGGER_LSB 0x40
#define RCVR_TRIGGER_MSB 0x80

/* AFR bits */
#define AFR_CONC_WRITE	0x01
#define AFR_BAUDOUT_SEL	0x02
#define AFR_RXRDY_SEL	0x04

/* ISR bits */
#define INT_STATUS(r)   ((r)&1)
#define INT_PRIORITY(r) (((r)>>1)&0x7)

/* LCR bits */
#define WORD_LENGTH(n)  (((n)-5)&0x3)
#define STOP_BIT_ENABLE 0x04
#define PARITY_ENABLE   0x08
#define EVEN_PARITY     0x10
#define FORCE_PARITY    0x20
#define XMIT_BREAK      0x40
#define DLAB_ENABLE     0x80

/* MCR bits */
#define _DTR 0x01
#define _RTS 0x02
#define _OP1 0x04
#define _OP2 0x08
#define LOOP_BACK 0x10

/* LSR Bits */
#define RCVR_DATA_READY 0x01
#define OVERRUN_ERROR   0x02
#define PARITY_ERROR    0x04
#define FRAMING_ERROR   0x08
#define BREAK_INTERRUPT 0x10
#define XMIT_HOLD_EMPTY 0x20
#define XMIT_EMPTY      0x40
#define FIFO_ERROR      0x80
#define RCVR_READY(u)   (_LSR(u)&RCVR_DATA_READY)
#define XMIT_READY(u)   (_LSR(u)&XMIT_HOLD_EMPTY)

/* MSR bits */
#define _RDR       0x01
#define DELTA_DSR 0x02
#define DELTA_RI  0x04
#define DELTA_CD  0x08
#define _CTS       0x10
#define _DSR       0x20
#define _RI        0x40
#define _CD        0x80

/* prototypes */
void uart_init( uart_dev_t *u, int bitrate );
void uart_out( uart_dev_t *u, char c );
void uart_puts( uart_dev_t *u, char *s );
char uart_in( uart_dev_t *u );
void uart_enable_rcvr_int( uart_dev_t *u );
void uart_disable_rcvr_int( uart_dev_t *u );

#ifdef DUART16552_1_VADDR
/*  DUART present.  */
#define DUART_1_BASE	(*(uart_dev_t*)DUART16552_1_VADDR)
#define DUART_2_BASE	(*(uart_dev_t*)DUART16552_2_VADDR)
#define UART1_PUTS(s)	uart_puts( &DUART_1_BASE, s )
#define UART2_PUTS(s)	uart_puts( &DUART_2_BASE, s )
#else
/*  DUART not configured, use dummy placeholders to allow compiles to work.  */
#define DUART_1_BASE	(*(uart_dev_t*)0)
#define DUART_2_BASE	(*(uart_dev_t*)0)
#define UART1_PUTS(s)
#define UART2_PUTS(s)
#endif

/*  Compute 16-bit divisor for baudrate generator, with rounding:  */
#define DUART_DIVISOR(crystal,speed)	(((crystal)/16 + (speed)/2)/(speed))

#endif /*_uart_h_included_*/