summaryrefslogtreecommitdiffstats
path: root/arch/sparc/cpu/leon3/serial.c
blob: 66b377302700f39a93755ecebd186ab93012cd3f (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
/* GRLIB APBUART Serial controller driver
 *
 * (C) Copyright 2007, 2015
 * Daniel Hellstrom, Cobham Gaisler, daniel@gaisler.com.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <asm/io.h>
#include <ambapp.h>
#include <grlib/apbuart.h>
#include <serial.h>
#include <watchdog.h>

DECLARE_GLOBAL_DATA_PTR;

/* Select which UART that will become u-boot console */
#ifndef CONFIG_SYS_GRLIB_APBUART_INDEX
#define CONFIG_SYS_GRLIB_APBUART_INDEX 0
#endif

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

	/* find UART */
	if (ambapp_apb_find(&ambapp_plb, VENDOR_GAISLER, GAISLER_APBUART,
		CONFIG_SYS_GRLIB_APBUART_INDEX, &apbdev) != 1) {
		panic("%s: apbuart not found!\n", __func__);
		return -1; /* didn't find hardware */
	}

	/* found apbuart, let's init .. */
	uart = (ambapp_dev_apbuart *) apbdev.address;

	/* Set scaler / baud rate */
	tmp = (((CONFIG_SYS_CLK_FREQ*10) / (CONFIG_BAUDRATE*8)) - 5)/10;
	writel(tmp, &uart->scaler);

	/* Let bit 11 be unchanged (debug bit for GRMON) */
	tmp = readl(&uart->ctrl) & APBUART_CTRL_DBG;
	/* Receiver & transmitter enable */
	tmp |= APBUART_CTRL_RE | APBUART_CTRL_TE;
	writel(tmp, &uart->ctrl);

	gd->arch.uart = uart;
	return 0;
}

static inline ambapp_dev_apbuart *leon3_get_uart_regs(void)
{
	ambapp_dev_apbuart *uart = gd->arch.uart;
	return uart;
}

static void leon3_serial_putc_raw(const char c)
{
	ambapp_dev_apbuart * const uart = leon3_get_uart_regs();

	if (!uart)
		return;

	/* Wait for last character to go. */
	while (!(readl(&uart->status) & APBUART_STATUS_THE))
		WATCHDOG_RESET();

	/* Send data */
	writel(c, &uart->data);

#ifdef LEON_DEBUG
	/* Wait for data to be sent */
	while (!(readl(&uart->status) & APBUART_STATUS_TSE))
		WATCHDOG_RESET();
#endif
}

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

	leon3_serial_putc_raw(c);
}

static int leon3_serial_getc(void)
{
	ambapp_dev_apbuart * const uart = leon3_get_uart_regs();

	if (!uart)
		return 0;

	/* Wait for a character to arrive. */
	while (!(readl(&uart->status) & APBUART_STATUS_DR))
		WATCHDOG_RESET();

	/* Read character data */
	return readl(&uart->data);
}

static int leon3_serial_tstc(void)
{
	ambapp_dev_apbuart * const uart = leon3_get_uart_regs();

	if (!uart)
		return 0;

	return readl(&uart->status) & APBUART_STATUS_DR;
}

/* set baud rate for uart */
static void leon3_serial_setbrg(void)
{
	ambapp_dev_apbuart * const uart = leon3_get_uart_regs();
	unsigned int scaler;

	if (!uart)
		return;

	if (!gd->baudrate)
		gd->baudrate = CONFIG_BAUDRATE;

	scaler = (((CONFIG_SYS_CLK_FREQ*10) / (gd->baudrate*8)) - 5)/10;

	writel(scaler, &uart->scaler);
}

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	= default_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;
}

#ifdef CONFIG_DEBUG_UART_APBUART

#include <debug_uart.h>

static inline void _debug_uart_init(void)
{
	ambapp_dev_apbuart *uart = (ambapp_dev_apbuart *)CONFIG_DEBUG_UART_BASE;
	uart->scaler = (((CONFIG_DEBUG_UART_CLOCK*10) / (CONFIG_BAUDRATE*8)) - 5)/10;
	uart->ctrl = APBUART_CTRL_RE | APBUART_CTRL_TE;
}

static inline void _debug_uart_putc(int ch)
{
	ambapp_dev_apbuart *uart = (ambapp_dev_apbuart *)CONFIG_DEBUG_UART_BASE;
	while (!(readl(&uart->status) & APBUART_STATUS_THE))
		WATCHDOG_RESET();
	writel(ch, &uart->data);
}

DEBUG_UART_FUNCS

#endif
OpenPOWER on IntegriCloud