source: rtems/c/src/lib/libcpu/arm/at91rm9200/dbgu/dbgu.c @ 1c4890b

4.115
Last change on this file since 1c4890b was 1c4890b, checked in by Joel Sherrill <joel.sherrill@…>, on 10/20/14 at 14:13:06

libcpu/arm/at91rm9200/dbgu/dbgu.c: Fix warning

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File size: 5.5 KB
Line 
1/*
2 *  Console driver for AT91RM9200 DBGU port
3 *
4 *  This driver uses the shared console driver in
5 *  ...../libbsp/shared/console.c
6 *
7 *  Copyright (c) 2003 by Cogent Computer Systems
8 *  Written by Mike Kelly <mike@cogcomp.com>
9 *        and Jay Monkman <jtm@lopingdog.com>
10 *
11 *  The license and distribution terms for this file may be
12 *  found in the file LICENSE in this distribution or at
13 *  http://www.rtems.org/license/LICENSE.
14 */
15#include <bsp.h>
16#include <rtems/libio.h>
17#include <termios.h>
18
19#include <at91rm9200.h>
20#include <at91rm9200_dbgu.h>
21#include <at91rm9200_pmc.h>
22#include <rtems/bspIo.h>
23#include <libchip/serial.h>
24#include <libchip/sersupp.h>
25
26volatile int dbg_dly;
27
28/* static function prototypes */
29static int     dbgu_first_open(int major, int minor, void *arg);
30static int     dbgu_last_close(int major, int minor, void *arg);
31static int     dbgu_read(int minor);
32static ssize_t dbgu_write(int minor, const char *buf, size_t len);
33static void    dbgu_init(int minor);
34static void    dbgu_write_polled(int minor, char c);
35static int     dbgu_set_attributes(int minor, const struct termios *t);
36
37/* Pointers to functions for handling the UART. */
38const console_fns dbgu_fns =
39{
40    libchip_serial_default_probe,
41    dbgu_first_open,
42    dbgu_last_close,
43    dbgu_read,
44    dbgu_write,
45    dbgu_init,
46    dbgu_write_polled,   /* not used in this driver */
47    dbgu_set_attributes,
48    FALSE      /* TRUE if interrupt driven, FALSE if not. */
49};
50/*********************************************************************/
51/* Functions called via callbacks (i.e. the ones in uart_fns */
52/*********************************************************************/
53
54/*
55 * This is called the first time each device is opened. Since
56 * the driver is polled, we don't have to do anything. If the driver
57 * were interrupt driven, we'd enable interrupts here.
58 */
59static int dbgu_first_open(int major, int minor, void *arg)
60{
61    return 0;
62}
63
64
65/*
66 * This is called the last time each device is closed.  Since
67 * the driver is polled, we don't have to do anything. If the driver
68 * were interrupt driven, we'd disable interrupts here.
69 */
70static int dbgu_last_close(int major, int minor, void *arg)
71{
72    return 0;
73}
74
75
76/*
77 * Read one character from UART.
78 *
79 * return -1 if there's no data, otherwise return
80 * the character in lowest 8 bits of returned int.
81 */
82static int dbgu_read(int minor)
83{
84    char c;
85    console_tbl *console_entry;
86    at91rm9200_dbgu_regs_t *dbgu;
87
88    console_entry = BSP_get_uart_from_minor(minor);
89
90    if (console_entry == NULL) {
91        return -1;
92    }
93
94    dbgu = (at91rm9200_dbgu_regs_t *)console_entry->ulCtrlPort1;
95
96    if (!(dbgu->sr & DBGU_INT_RXRDY)) {
97        return -1;
98    }
99
100    c  = dbgu->rhr & 0xff;
101
102    return c;
103}
104
105
106/*
107 * Write buffer to UART
108 *
109 * return 1 on success, -1 on error
110 */
111static ssize_t dbgu_write(int minor, const char *buf, size_t len)
112{
113    int i, x;
114    char c;
115    console_tbl *console_entry;
116    at91rm9200_dbgu_regs_t *dbgu;
117
118    console_entry = BSP_get_uart_from_minor(minor);
119
120    if (console_entry == NULL) {
121        return -1;
122    }
123
124    dbgu = (at91rm9200_dbgu_regs_t *)console_entry->ulCtrlPort1;
125
126    for (i = 0; i < len; i++) {
127        /* Wait for fifo to have room */
128        while(1) {
129            if (dbgu->sr & DBGU_INT_TXRDY) {
130                break;
131            }
132        }
133
134        c = (char) buf[i];
135        dbgu->thr = c;
136
137        /* the TXRDY flag does not seem to update right away (is this true?) */
138        /* so we wait a bit before continuing */
139        for (x = 0; x < 100; x++) {
140            dbg_dly++; /* using a global so this doesn't get optimized out */
141        }
142    }
143
144    return 1;
145}
146
147
148/* Set up the UART. */
149static void dbgu_init(int minor)
150{
151    console_tbl *console_entry;
152    at91rm9200_dbgu_regs_t *dbgu;
153
154    console_entry = BSP_get_uart_from_minor(minor);
155
156    if (console_entry == NULL) {
157        return;
158    }
159
160    dbgu = (at91rm9200_dbgu_regs_t *)console_entry->ulCtrlPort1;
161
162    /* Clear error bits, and reset */
163    dbgu->cr = (DBGU_CR_RSTSTA | DBGU_CR_RSTTX | DBGU_CR_RSTRX);
164
165    /* Clear pending interrupts */
166    dbgu->idr = DBGU_INT_ALL;
167    dbgu->imr = 0;
168
169    /* Set port to no parity, no loopback */
170    dbgu->mr = DBGU_MR_PAR_NONE | DBGU_MR_CHMODE_NORM;
171
172    /* Set the baud rate */
173    dbgu->brgr = (at91rm9200_get_mck() / 16) / BSP_get_baud();
174
175    /* Enable the DBGU */
176    dbgu->cr = (DBGU_CR_TXEN | DBGU_CR_RXEN);
177}
178
179/* This is used for getchark support */
180static void dbgu_write_polled(int minor, char c)
181{
182    dbgu_write(minor, &c, 1);
183}
184
185/* This is for setting baud rate, bits, etc. */
186static int dbgu_set_attributes(int minor, const struct termios *t)
187{
188    return 0;
189}
190
191/***********************************************************************/
192/*
193 * The following functions are not used by TERMIOS, but other RTEMS
194 * functions use them instead.
195 */
196/***********************************************************************/
197/*
198 * Read from UART. This is used in the exit code, and can't
199 * rely on interrupts.
200 */
201static int dbgu_poll_read(int minor)
202{
203    return dbgu_read(minor);
204}
205
206
207/*
208 * Write a character to the console. This is used by printk() and
209 * maybe other low level functions. It should not use interrupts or any
210 * RTEMS system calls. It needs to be very simple
211 */
212static void _BSP_put_char( char c ) {
213  dbgu_write_polled(0, c);
214  if ( c == '\n' )
215    dbgu_write_polled(0, '\r');
216}
217
218BSP_output_char_function_type     BSP_output_char = _BSP_put_char;
219
220static int _BSP_poll_char(void)
221{
222  return dbgu_poll_read(0);
223}
224
225BSP_polling_getchar_function_type BSP_poll_char = _BSP_poll_char;
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