summaryrefslogtreecommitdiffstats
path: root/drivers/serial/mcfuart.c
blob: 407354fc4cdf2acac18fee8d014e4d92f63078f3 (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
/*
 * (C) Copyright 2004-2007 Freescale Semiconductor, Inc.
 * TsiChung Liew, Tsi-Chung.Liew@freescale.com.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/*
 * Minimal serial functions needed to use one of the uart ports
 * as serial console interface.
 */

#include <common.h>
#include <serial.h>
#include <linux/compiler.h>

#include <asm/immap.h>
#include <asm/uart.h>

DECLARE_GLOBAL_DATA_PTR;

extern void uart_port_conf(int port);

static int mcf_serial_init(void)
{
	volatile uart_t *uart;
	u32 counter;

	uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);

	uart_port_conf(CONFIG_SYS_UART_PORT);

	/* write to SICR: SIM2 = uart mode,dcd does not affect rx */
	uart->ucr = UART_UCR_RESET_RX;
	uart->ucr = UART_UCR_RESET_TX;
	uart->ucr = UART_UCR_RESET_ERROR;
	uart->ucr = UART_UCR_RESET_MR;
	__asm__("nop");

	uart->uimr = 0;

	/* write to CSR: RX/TX baud rate from timers */
	uart->ucsr = (UART_UCSR_RCS_SYS_CLK | UART_UCSR_TCS_SYS_CLK);

	uart->umr = (UART_UMR_BC_8 | UART_UMR_PM_NONE);
	uart->umr = UART_UMR_SB_STOP_BITS_1;

	/* Setting up BaudRate */
	counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
	counter = counter / gd->baudrate;

	/* write to CTUR: divide counter upper byte */
	uart->ubg1 = (u8) ((counter & 0xff00) >> 8);
	/* write to CTLR: divide counter lower byte */
	uart->ubg2 = (u8) (counter & 0x00ff);

	uart->ucr = (UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED);

	return (0);
}

static void mcf_serial_putc(const char c)
{
	volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);

	if (c == '\n')
		serial_putc('\r');

	/* Wait for last character to go. */
	while (!(uart->usr & UART_USR_TXRDY)) ;

	uart->utb = c;
}

static int mcf_serial_getc(void)
{
	volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);

	/* Wait for a character to arrive. */
	while (!(uart->usr & UART_USR_RXRDY)) ;
	return uart->urb;
}

static int mcf_serial_tstc(void)
{
	volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);

	return (uart->usr & UART_USR_RXRDY);
}

static void mcf_serial_setbrg(void)
{
	volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
	u32 counter;

	/* Setting up BaudRate */
	counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
	counter = counter / gd->baudrate;

	/* write to CTUR: divide counter upper byte */
	uart->ubg1 = ((counter & 0xff00) >> 8);
	/* write to CTLR: divide counter lower byte */
	uart->ubg2 = (counter & 0x00ff);

	uart->ucr = UART_UCR_RESET_RX;
	uart->ucr = UART_UCR_RESET_TX;

	uart->ucr = UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED;
}

static struct serial_device mcf_serial_drv = {
	.name	= "mcf_serial",
	.start	= mcf_serial_init,
	.stop	= NULL,
	.setbrg	= mcf_serial_setbrg,
	.putc	= mcf_serial_putc,
	.puts	= default_serial_puts,
	.getc	= mcf_serial_getc,
	.tstc	= mcf_serial_tstc,
};

void mcf_serial_initialize(void)
{
	serial_register(&mcf_serial_drv);
}

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