summaryrefslogtreecommitdiffstats
path: root/arch/sparc/cpu/leon2/serial.c
blob: b41ee01818ca0dcf5aef507958ca18d7cacecdc6 (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
/* GRLIB APBUART Serial controller driver
 *
 * (C) Copyright 2008
 * 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 <serial.h>
#include <linux/compiler.h>

DECLARE_GLOBAL_DATA_PTR;

static int leon2_serial_init(void)
{
	LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
	LEON2_Uart_regs *regs;
	unsigned int tmp;

	/* Init LEON2 UART
	 *
	 * Set scaler / baud rate
	 *
	 * Receiver & transmitter enable
	 */
#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif

	regs->UART_Scaler = CONFIG_SYS_LEON2_UART1_SCALER;

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

	regs->UART_Control = ((tmp & LEON2_UART_CTRL_DBG) |
			      (LEON2_UART1_LOOPBACK_ENABLE << 7) |
			      (LEON2_UART1_FLOWCTRL_ENABLE << 6) |
			      (LEON2_UART1_PARITY_ENABLE << 5) |
			      (LEON2_UART1_ODDPAR_ENABLE << 4) |
			      LEON2_UART_CTRL_RE | LEON2_UART_CTRL_TE);

	return 0;
}

static void leon2_serial_putc_raw(const char c)
{
	LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
	LEON2_Uart_regs *regs;

#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif

	/* Wait for last character to go. */
	while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_THE)) ;

	/* Send data */
	regs->UART_Channel = c;

#ifdef LEON_DEBUG
	/* Wait for data to be sent */
	while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_TSE)) ;
#endif
}

static void leon2_serial_putc(const char c)
{
	if (c == '\n')
		leon2_serial_putc_raw('\r');

	leon2_serial_putc_raw(c);
}

static int leon2_serial_getc(void)
{
	LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
	LEON2_Uart_regs *regs;

#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif

	/* Wait for a character to arrive. */
	while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_DR)) ;

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

static int leon2_serial_tstc(void)
{
	LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
	LEON2_Uart_regs *regs;

#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif

	return (READ_WORD(regs->UART_Status) & LEON2_UART_STAT_DR);
}

/* set baud rate for uart */
static void leon2_serial_setbrg(void)
{
	/* update baud rate settings, read it from gd->baudrate */
	unsigned int scaler;
	LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
	LEON2_Uart_regs *regs;

#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
	regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif

	if (gd->baudrate > 0) {
		scaler =
		    (((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
		     5) / 10;
		regs->UART_Scaler = scaler;
	}
}

static struct serial_device leon2_serial_drv = {
	.name	= "leon2_serial",
	.start	= leon2_serial_init,
	.stop	= NULL,
	.setbrg	= leon2_serial_setbrg,
	.putc	= leon2_serial_putc,
	.puts	= default_serial_puts,
	.getc	= leon2_serial_getc,
	.tstc	= leon2_serial_tstc,
};

void leon2_serial_initialize(void)
{
	serial_register(&leon2_serial_drv);
}

__weak struct serial_device *default_serial_console(void)
{
	return &leon2_serial_drv;
}
OpenPOWER on IntegriCloud