1 /*
2 * Copyright (c) 2004 Cucy Systems (http://www.cucy.com)
3 * Curt Brune <curt@cucy.com>
4 *
5 * (C) Copyright 2004
6 * DAVE Srl
7 * http://www.dave-tech.it
8 * http://www.wawnet.biz
9 * mailto:info@wawnet.biz
10 *
11 * (C) Copyright 2002-2004
12 * Wolfgang Denk, DENX Software Engineering, <wd@denx.de>
13 *
14 * (C) Copyright 2002
15 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
16 * Marius Groeger <mgroeger@sysgo.de>
17 *
18 * (C) Copyright 2002
19 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
20 * Alex Zuepke <azu@sysgo.de>
21 *
22 * Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2 of the License, or
27 * (at your option) any later version.
28 *
29 * This program is distributed in the hope that it will be useful,
30 * but WITHOUT ANY WARRANTY; without even the implied warranty of
31 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
32 * GNU General Public License for more details.
33 *
34 * You should have received a copy of the GNU General Public License
35 * along with this program; if not, write to the Free Software
36 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
37 *
38 * MODULE: $Id:$
39 * Description: UART/Serial interface for Samsung S3C4510B SoC
40 * Runtime Env: ARM7TDMI
41 * Change History:
42 * 03-02-04 Create (Curt Brune) curt@cucy.com
43 *
44 */
46 #include <common.h>
48 #include <asm/hardware.h>
49 #include "s3c4510b_uart.h"
51 DECLARE_GLOBAL_DATA_PTR;
53 static UART *uart;
55 /* flush serial input queue. returns 0 on success or negative error
56 * number otherwise
57 */
58 static int serial_flush_input(void)
59 {
60 volatile u32 tmp;
62 /* keep on reading as long as the receiver is not empty */
63 while( uart->m_stat.bf.rxReady) {
64 tmp = uart->m_rx;
65 }
67 return 0;
68 }
71 /* flush output queue. returns 0 on success or negative error number
72 * otherwise
73 */
74 static int serial_flush_output(void)
75 {
76 /* wait until the transmitter is no longer busy */
77 while( !uart->m_stat.bf.txBufEmpty);
79 return 0;
80 }
83 static void s3c4510b_serial_setbrg(void)
84 {
85 UART_LINE_CTRL ulctrl;
86 UART_CTRL uctrl;
87 UART_BAUD_DIV ubd;
89 serial_flush_output();
90 serial_flush_input();
92 /* control register */
93 uctrl.ui = 0x0;
94 uctrl.bf.rxMode = 0x1;
95 uctrl.bf.rxIrq = 0x0;
96 uctrl.bf.txMode = 0x1;
97 uctrl.bf.DSR = 0x0;
98 uctrl.bf.sendBreak = 0x0;
99 uctrl.bf.loopBack = 0x0;
100 uart->m_ctrl.ui = uctrl.ui;
102 /* line control register */
103 ulctrl.ui = 0x0;
104 ulctrl.bf.wordLen = 0x3; /* 8 bit data */
105 ulctrl.bf.nStop = 0x0; /* 1 stop bit */
106 ulctrl.bf.parity = 0x0; /* no parity */
107 ulctrl.bf.clk = 0x0; /* internal clock */
108 ulctrl.bf.infra_red = 0x0; /* no infra_red */
109 uart->m_lineCtrl.ui = ulctrl.ui;
111 ubd.ui = 0x0;
113 /* see table on page 10-15 in SAMSUNG S3C4510B manual */
114 /* get correct divisor */
115 switch(gd->baudrate) {
116 case 1200: ubd.bf.cnt0 = 1301; break;
117 case 2400: ubd.bf.cnt0 = 650; break;
118 case 4800: ubd.bf.cnt0 = 324; break;
119 case 9600: ubd.bf.cnt0 = 162; break;
120 case 19200: ubd.bf.cnt0 = 80; break;
121 case 38400: ubd.bf.cnt0 = 40; break;
122 case 57600: ubd.bf.cnt0 = 26; break;
123 case 115200: ubd.bf.cnt0 = 13; break;
124 }
126 uart->m_baudDiv.ui = ubd.ui;
127 uart->m_baudCnt = 0x0;
128 uart->m_baudClk = 0x0;
130 }
133 /*
134 * Initialise the serial port with the given baudrate. The settings
135 * are always 8 data bits, no parity, 1 stop bit, no start bits.
136 *
137 */
138 static int s3c4510b_serial_init(void)
139 {
141 #if CONFIG_SERIAL1 == 1
142 uart = (UART *)UART0_BASE;
143 #elif CONFIG_SERIAL1 == 2
144 uart = (UART *)UART1_BASE;
145 #else
146 #error CONFIG_SERIAL1 not equal to 1 or 2
147 #endif
149 serial_setbrg ();
151 return (0);
152 }
155 /*
156 * Output a single byte to the serial port.
157 */
158 static void s3c4510_serial_putc(const char c)
159 {
160 /* wait for room in the transmit FIFO */
161 while( !uart->m_stat.bf.txBufEmpty);
163 uart->m_tx = c;
165 /*
166 to be polite with serial console add a line feed
167 to the carriage return character
168 */
169 if (c=='\n')
170 serial_putc('\r');
171 }
173 /*
174 * Test if an input byte is ready from the serial port. Returns non-zero on
175 * success, 0 otherwise.
176 */
177 static int s3c4510b_serial_tstc(void)
178 {
179 return uart->m_stat.bf.rxReady;
180 }
182 /*
183 * Read a single byte from the serial port. Returns 1 on success, 0
184 * otherwise. When the function is succesfull, the character read is
185 * written into its argument c.
186 */
187 static int s3c4510b_serial_getc(void)
188 {
189 int rv;
191 for(;;) {
192 rv = serial_tstc();
194 if (rv) {
195 return uart->m_rx & 0xFF;
196 }
197 }
198 }
200 static void s3c4510b_serial_puts(const char *s)
201 {
202 default_serial_puts(s);
204 /* busy wait for tx complete */
205 while (!uart->m_stat.bf.txComplete);
207 /* clear break */
208 uart->m_ctrl.bf.sendBreak = 0;
210 }
212 static struct serial_device s3c4510b_serial_drv = {
213 .name = "s3c4510b_serial",
214 .start = s3c4510b_serial_init,
215 .stop = NULL,
216 .setbrg = s3c4510b_serial_setbrg,
217 .putc = s3c4510b_serial_putc,
218 .puts = s3c4510b_serial_puts,
219 .getc = s3c4510b_serial_getc,
220 .tstc = s3c4510b_serial_tstc,
221 };
223 void s3c4510b_serial_initialize(void)
224 {
225 serial_register(&s3c4510b_serial_drv);
226 }
228 __weak struct serial_device *default_serial_console(void)
229 {
230 return &s3c4510b_serial_drv;
231 }