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wdenk993cad92003-06-26 22:04:09 +00001/*
2 * (C) Copyright 2003
3 *
4 * Pantelis Antoniou <panto@intracom.gr>
5 * Intracom S.A.
6 *
7 * See file CREDITS for list of people who contributed to this
8 * project.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23 * MA 02111-1307 USA
24 */
25
26#include <common.h>
27#include <watchdog.h>
28
29#ifdef CONFIG_MAX3100_SERIAL
30
31/**************************************************************/
32
33/* convienient macros */
34#define MAX3100_SPI_RXD() (MAX3100_SPI_RXD_PORT & MAX3100_SPI_RXD_BIT)
35
36#define MAX3100_SPI_TXD(x) \
37 do { \
38 if (x) \
39 MAX3100_SPI_TXD_PORT |= MAX3100_SPI_TXD_BIT; \
40 else \
41 MAX3100_SPI_TXD_PORT &= ~MAX3100_SPI_TXD_BIT; \
42 } while(0)
43
44#define MAX3100_SPI_CLK(x) \
45 do { \
46 if (x) \
47 MAX3100_SPI_CLK_PORT |= MAX3100_SPI_CLK_BIT; \
48 else \
49 MAX3100_SPI_CLK_PORT &= ~MAX3100_SPI_CLK_BIT; \
50 } while(0)
51
52#define MAX3100_SPI_CLK_TOGGLE() (MAX3100_SPI_CLK_PORT ^= MAX3100_SPI_CLK_BIT)
53
54#define MAX3100_CS(x) \
55 do { \
56 if (x) \
57 MAX3100_CS_PORT |= MAX3100_CS_BIT; \
58 else \
59 MAX3100_CS_PORT &= ~MAX3100_CS_BIT; \
60 } while(0)
61
62/**************************************************************/
63
64/* MAX3100 definitions */
65
66#define MAX3100_WC (3 << 14) /* write configuration */
67#define MAX3100_RC (1 << 14) /* read configuration */
68#define MAX3100_WD (2 << 14) /* write data */
69#define MAX3100_RD (0 << 14) /* read data */
70
71/* configuration register bits */
72#define MAX3100_FEN (1 << 13) /* FIFO enable */
73#define MAX3100_SHDN (1 << 12) /* shutdown bit */
74#define MAX3100_TM (1 << 11) /* T bit irq mask */
75#define MAX3100_RM (1 << 10) /* R bit irq mask */
76#define MAX3100_PM (1 << 9) /* P bit irq mask */
77#define MAX3100_RAM (1 << 8) /* mask for RA/FE bit */
78#define MAX3100_IR (1 << 7) /* IRDA timing mode */
79#define MAX3100_ST (1 << 6) /* transmit stop bit */
80#define MAX3100_PE (1 << 5) /* parity enable bit */
81#define MAX3100_L (1 << 4) /* Length bit */
82#define MAX3100_B_MASK (0x000F) /* baud rate bits mask */
83#define MAX3100_B(x) ((x) & 0x000F) /* baud rate select bits */
84
85/* data register bits (write) */
86#define MAX3100_TE (1 << 10) /* transmit enable bit (active low) */
87#define MAX3100_RTS (1 << 9) /* request-to-send bit (inverted ~RTS pin) */
88
89/* data register bits (read) */
90#define MAX3100_RA (1 << 10) /* receiver activity when in shutdown mode */
91#define MAX3100_FE (1 << 10) /* framing error when in normal mode */
92#define MAX3100_CTS (1 << 9) /* clear-to-send bit (inverted ~CTS pin) */
93
94/* data register bits (both directions) */
95#define MAX3100_R (1 << 15) /* receive bit */
96#define MAX3100_T (1 << 14) /* transmit bit */
97#define MAX3100_P (1 << 8) /* parity bit */
98#define MAX3100_D_MASK 0x00FF /* data bits mask */
99#define MAX3100_D(x) ((x) & 0x00FF) /* data bits */
100
101/* these definitions are valid only for fOSC = 3.6864MHz */
102#define MAX3100_B_230400 MAX3100_B(0)
103#define MAX3100_B_115200 MAX3100_B(1)
104#define MAX3100_B_57600 MAX3100_B(2)
105#define MAX3100_B_38400 MAX3100_B(9)
106#define MAX3100_B_19200 MAX3100_B(10)
107#define MAX3100_B_9600 MAX3100_B(11)
108#define MAX3100_B_4800 MAX3100_B(12)
109#define MAX3100_B_2400 MAX3100_B(13)
110#define MAX3100_B_1200 MAX3100_B(14)
111#define MAX3100_B_600 MAX3100_B(15)
112
113/**************************************************************/
114
115static inline unsigned int max3100_transfer(unsigned int val)
116{
117 unsigned int rx;
118 int b;
119
120 MAX3100_SPI_CLK(0);
121 MAX3100_CS(0);
122
123 rx = 0; b = 16;
124 while (--b >= 0) {
125 MAX3100_SPI_TXD(val & 0x8000);
126 val <<= 1;
127 MAX3100_SPI_CLK_TOGGLE();
128 udelay(1);
129 rx <<= 1;
130 if (MAX3100_SPI_RXD())
131 rx |= 1;
132 MAX3100_SPI_CLK_TOGGLE();
133 udelay(1);
134 }
135
136 MAX3100_SPI_CLK(1);
137 MAX3100_CS(1);
138
139 return rx;
140}
141
142/**************************************************************/
143
144/* must be power of 2 */
145#define RXFIFO_SZ 16
146
147static int rxfifo_cnt;
148static int rxfifo_in;
149static int rxfifo_out;
150static unsigned char rxfifo_buf[16];
151
152static void max3100_putc(int c)
153{
154 unsigned int rx;
155
156 while (((rx = max3100_transfer(MAX3100_RC)) & MAX3100_T) == 0)
157 WATCHDOG_RESET();
158
159 rx = max3100_transfer(MAX3100_WD | (c & 0xff));
160 if ((rx & MAX3100_RD) != 0 && rxfifo_cnt < RXFIFO_SZ) {
161 rxfifo_cnt++;
162 rxfifo_buf[rxfifo_in++] = rx & 0xff;
163 rxfifo_in &= RXFIFO_SZ - 1;
164 }
165}
166
167static int max3100_getc(void)
168{
169 int c;
170 unsigned int rx;
171
172 while (rxfifo_cnt == 0) {
173 rx = max3100_transfer(MAX3100_RD);
174 if ((rx & MAX3100_R) != 0) {
175 do {
176 rxfifo_cnt++;
177 rxfifo_buf[rxfifo_in++] = rx & 0xff;
178 rxfifo_in &= RXFIFO_SZ - 1;
179
180 if (rxfifo_cnt >= RXFIFO_SZ)
181 break;
182 } while (((rx = max3100_transfer(MAX3100_RD)) & MAX3100_R) != 0);
183 }
184 WATCHDOG_RESET();
185 }
186
187 rxfifo_cnt--;
188 c = rxfifo_buf[rxfifo_out++];
189 rxfifo_out &= RXFIFO_SZ - 1;
190 return c;
191}
192
193static int max3100_tstc(void)
194{
195 unsigned int rx;
196
197 if (rxfifo_cnt > 0)
198 return 1;
199
200 rx = max3100_transfer(MAX3100_RD);
201 if ((rx & MAX3100_R) == 0)
202 return 0;
203
204 do {
205 rxfifo_cnt++;
206 rxfifo_buf[rxfifo_in++] = rx & 0xff;
207 rxfifo_in &= RXFIFO_SZ - 1;
208
209 if (rxfifo_cnt >= RXFIFO_SZ)
210 break;
211 } while (((rx = max3100_transfer(MAX3100_RD)) & MAX3100_R) != 0);
212
213 return 1;
214}
215
216int serial_init(void)
217{
218 unsigned int wconf, rconf;
219 int i;
220 DECLARE_GLOBAL_DATA_PTR;
221
222 wconf = 0;
223
224 /* Set baud rate */
225 switch (gd->baudrate) {
226 case 1200:
227 wconf = MAX3100_B_1200;
228 break;
229 case 2400:
230 wconf = MAX3100_B_2400;
231 break;
232 case 4800:
233 wconf = MAX3100_B_4800;
234 break;
235 case 9600:
236 wconf = MAX3100_B_9600;
237 break;
238 case 19200:
239 wconf = MAX3100_B_19200;
240 break;
241 case 38400:
242 wconf = MAX3100_B_38400;
243 break;
244 case 57600:
245 wconf = MAX3100_B_57600;
246 break;
247 default:
248 case 115200:
249 wconf = MAX3100_B_115200;
250 break;
251 case 230400:
252 wconf = MAX3100_B_230400;
253 break;
254 }
255
256 /* try for 10ms, with a 100us gap */
257 for (i = 0; i < 10000; i += 100) {
258
259 max3100_transfer(MAX3100_WC | wconf);
260 rconf = max3100_transfer(MAX3100_RC) & 0x3fff;
261
262 if (rconf == wconf)
263 break;
264 udelay(100);
265 }
266
267 rxfifo_in = rxfifo_out = rxfifo_cnt = 0;
268
269 return (0);
270}
271
272void serial_putc(const char c)
273{
274 if (c == '\n')
275 max3100_putc('\r');
276
277 max3100_putc(c);
278}
279
280void serial_puts(const char *s)
281{
282 while (*s)
283 serial_putc (*s++);
284}
285
286int serial_getc(void)
287{
288 return max3100_getc();
289}
290
291int serial_tstc(void)
292{
293 return max3100_tstc();
294}
295
296/* XXX WTF? */
297void serial_setbrg(void)
298{
299}
300
301#endif