aboutsummaryrefslogtreecommitdiff
path: root/arch/sparc/cpu/leon3/serial.c
blob: a110244c9ef76ebbff89128cf553e5ba843d89dc (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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/* GRLIB APBUART Serial controller driver
 *
 * (C) Copyright 2007
 * Daniel Hellstrom, Gaisler Research, daniel@gaisler.com.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 *
 */

#include <common.h>
#include <asm/processor.h>
#include <asm/leon.h>
#include <ambapp.h>
#include <serial.h>
#include <linux/compiler.h>

DECLARE_GLOBAL_DATA_PTR;

/* Force cache miss each time a serial controller reg is read */
#define CACHE_BYPASS 1

#ifdef CACHE_BYPASS
#define READ_BYTE(var)  SPARC_NOCACHE_READ_BYTE((unsigned int)&(var))
#define READ_HWORD(var) SPARC_NOCACHE_READ_HWORD((unsigned int)&(var))
#define READ_WORD(var)  SPARC_NOCACHE_READ((unsigned int)&(var))
#define READ_DWORD(var) SPARC_NOCACHE_READ_DWORD((unsigned int)&(var))
#endif

ambapp_dev_apbuart *leon3_apbuart = NULL;

static int leon3_serial_init(void)
{
	ambapp_apbdev apbdev;
	unsigned int tmp;

	/* find UART */
	if (ambapp_apb_first(VENDOR_GAISLER, GAISLER_APBUART, &apbdev) == 1) {

		leon3_apbuart = (ambapp_dev_apbuart *) apbdev.address;

		/* found apbuart, let's init...
		 *
		 * Set scaler / baud rate
		 *
		 * Receiver & transmitter enable
		 */
		leon3_apbuart->scaler = CONFIG_SYS_GRLIB_APBUART_SCALER;

		/* Let bit 11 be unchanged (debug bit for GRMON) */
		tmp = READ_WORD(leon3_apbuart->ctrl);

		leon3_apbuart->ctrl = ((tmp & LEON_REG_UART_CTRL_DBG) |
				       LEON_REG_UART_CTRL_RE |
				       LEON_REG_UART_CTRL_TE);

		return 0;
	}
	return -1;		/* didn't find hardware */
}

static void leon3_serial_putc_raw(const char c)
{
	if (!leon3_apbuart)
		return;

	/* Wait for last character to go. */
	while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_THE)) ;

	/* Send data */
	leon3_apbuart->data = c;

#ifdef LEON_DEBUG
	/* Wait for data to be sent */
	while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_TSE)) ;
#endif
}

static void leon3_serial_putc(const char c)
{
	if (c == '\n')
		leon3_serial_putc_raw('\r');

	leon3_serial_putc_raw(c);
}

static void leon3_serial_puts(const char *s)
{
	while (*s) {
		serial_putc(*s++);
	}
}

static int leon3_serial_getc(void)
{
	if (!leon3_apbuart)
		return 0;

	/* Wait for a character to arrive. */
	while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_DR)) ;

	/* read data */
	return READ_WORD(leon3_apbuart->data);
}

static int leon3_serial_tstc(void)
{
	if (leon3_apbuart)
		return (READ_WORD(leon3_apbuart->status) &
			LEON_REG_UART_STATUS_DR);
	return 0;
}

/* set baud rate for uart */
static void leon3_serial_setbrg(void)
{
	/* update baud rate settings, read it from gd->baudrate */
	unsigned int scaler;
	if (leon3_apbuart && (gd->baudrate > 0)) {
		scaler =
		    (((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
		     5) / 10;
		leon3_apbuart->scaler = scaler;
	}
	return;
}

#ifdef CONFIG_SERIAL_MULTI
static struct serial_device leon3_serial_drv = {
	.name	= "leon3_serial",
	.start	= leon3_serial_init,
	.stop	= NULL,
	.setbrg	= leon3_serial_setbrg,
	.putc	= leon3_serial_putc,
	.puts	= leon3_serial_puts,
	.getc	= leon3_serial_getc,
	.tstc	= leon3_serial_tstc,
};

void leon3_serial_initialize(void)
{
	serial_register(&leon3_serial_drv);
}

__weak struct serial_device *default_serial_console(void)
{
	return &leon3_serial_drv;
}
#else
int serial_init(void)
{
	return leon3_serial_init();
}

void serial_setbrg(void)
{
	leon3_serial_setbrg();
}

void serial_putc(const char c)
{
	leon3_serial_putc(c);
}

void serial_puts(const char *s)
{
	leon3_serial_puts(s);
}

int serial_getc(void)
{
	return leon3_serial_getc();
}

int serial_tstc(void)
{
	return leon3_serial_tstc();
}
#endif