1/*
2 * BRIEF MODULE DESCRIPTION
3 *	Low level uart routines to directly access a TX[34]927 SIO.
4 *
5 * Copyright 2001 MontaVista Software Inc.
6 * Author: MontaVista Software, Inc.
7 *         	ahennessy@mvista.com or source@mvista.com
8 *
9 * Based on arch/mips/ddb5xxx/ddb5477/kgdb_io.c
10 *
11 * Copyright (C) 2000-2001 Toshiba Corporation
12 *
13 *  This program is free software; you can redistribute  it and/or modify it
14 *  under  the terms of  the GNU General  Public License as published by the
15 *  Free Software Foundation;  either version 2 of the  License, or (at your
16 *  option) any later version.
17 *
18 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
19 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
20 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
21 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
22 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
24 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
25 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
26 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 *  You should have received a copy of the  GNU General Public License along
30 *  with this program; if not, write  to the Free Software Foundation, Inc.,
31 *  675 Mass Ave, Cambridge, MA 02139, USA.
32 */
33
34#include <linux/types.h>
35#include <asm/jmr3927/txx927.h>
36#include <asm/jmr3927/tx3927.h>
37#include <asm/jmr3927/jmr3927.h>
38
39#define TIMEOUT       0xffffff
40#define SLOW_DOWN
41
42static const char digits[16] = "0123456789abcdef";
43
44#ifdef SLOW_DOWN
45#define slow_down() { int k; for (k=0; k<10000; k++); }
46#else
47#define slow_down()
48#endif
49
50static int remoteDebugInitialized = 0;
51
52int putDebugChar(unsigned char c)
53{
54        int i = 0;
55
56	if (!remoteDebugInitialized) {
57		remoteDebugInitialized = 1;
58		debugInit(38400);
59	}
60
61        do {
62            slow_down();
63            i++;
64            if (i>TIMEOUT) {
65                break;
66            }
67        } while (!(tx3927_sioptr(0)->cisr & TXx927_SICISR_TXALS));
68	tx3927_sioptr(0)->tfifo = c;
69
70	return 1;
71}
72
73unsigned char getDebugChar(void)
74{
75        int i = 0;
76	int dicr;
77	char c;
78
79	if (!remoteDebugInitialized) {
80		remoteDebugInitialized = 1;
81		debugInit(38400);
82	}
83
84	/* diable RX int. */
85	dicr = tx3927_sioptr(0)->dicr;
86	tx3927_sioptr(0)->dicr = 0;
87
88        do {
89            slow_down();
90            i++;
91            if (i>TIMEOUT) {
92                break;
93            }
94        } while (tx3927_sioptr(0)->disr & TXx927_SIDISR_UVALID)
95		;
96	c = tx3927_sioptr(0)->rfifo;
97
98	/* clear RX int. status */
99	tx3927_sioptr(0)->disr &= ~TXx927_SIDISR_RDIS;
100	/* enable RX int. */
101	tx3927_sioptr(0)->dicr = dicr;
102
103	return c;
104}
105
106void debugInit(int baud)
107{
108	/*
109	volatile unsigned long lcr;
110	volatile unsigned long dicr;
111	volatile unsigned long disr;
112	volatile unsigned long cisr;
113	volatile unsigned long fcr;
114	volatile unsigned long flcr;
115	volatile unsigned long bgr;
116	volatile unsigned long tfifo;
117	volatile unsigned long rfifo;
118	*/
119
120	tx3927_sioptr(0)->lcr = 0x020;
121	tx3927_sioptr(0)->dicr = 0;
122	tx3927_sioptr(0)->disr = 0x4100;
123	tx3927_sioptr(0)->cisr = 0x014;
124	tx3927_sioptr(0)->fcr = 0;
125	tx3927_sioptr(0)->flcr = 0x02;
126	tx3927_sioptr(0)->bgr = ((JMR3927_BASE_BAUD + baud / 2) / baud) |
127		TXx927_SIBGR_BCLK_T0;
128}
129