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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>
Marek Vasut7cd851a2012-09-14 22:37:17 +020028#include <serial.h>
29#include <linux/compiler.h>
wdenk993cad92003-06-26 22:04:09 +000030
Wolfgang Denkd87080b2006-03-31 18:32:53 +020031DECLARE_GLOBAL_DATA_PTR;
32
wdenk993cad92003-06-26 22:04:09 +000033/**************************************************************/
34
35/* convienient macros */
36#define MAX3100_SPI_RXD() (MAX3100_SPI_RXD_PORT & MAX3100_SPI_RXD_BIT)
37
38#define MAX3100_SPI_TXD(x) \
39 do { \
40 if (x) \
41 MAX3100_SPI_TXD_PORT |= MAX3100_SPI_TXD_BIT; \
42 else \
43 MAX3100_SPI_TXD_PORT &= ~MAX3100_SPI_TXD_BIT; \
44 } while(0)
45
46#define MAX3100_SPI_CLK(x) \
47 do { \
48 if (x) \
49 MAX3100_SPI_CLK_PORT |= MAX3100_SPI_CLK_BIT; \
50 else \
51 MAX3100_SPI_CLK_PORT &= ~MAX3100_SPI_CLK_BIT; \
52 } while(0)
53
54#define MAX3100_SPI_CLK_TOGGLE() (MAX3100_SPI_CLK_PORT ^= MAX3100_SPI_CLK_BIT)
55
56#define MAX3100_CS(x) \
57 do { \
58 if (x) \
59 MAX3100_CS_PORT |= MAX3100_CS_BIT; \
60 else \
61 MAX3100_CS_PORT &= ~MAX3100_CS_BIT; \
62 } while(0)
63
64/**************************************************************/
65
66/* MAX3100 definitions */
67
68#define MAX3100_WC (3 << 14) /* write configuration */
69#define MAX3100_RC (1 << 14) /* read configuration */
70#define MAX3100_WD (2 << 14) /* write data */
71#define MAX3100_RD (0 << 14) /* read data */
72
73/* configuration register bits */
74#define MAX3100_FEN (1 << 13) /* FIFO enable */
75#define MAX3100_SHDN (1 << 12) /* shutdown bit */
76#define MAX3100_TM (1 << 11) /* T bit irq mask */
77#define MAX3100_RM (1 << 10) /* R bit irq mask */
78#define MAX3100_PM (1 << 9) /* P bit irq mask */
79#define MAX3100_RAM (1 << 8) /* mask for RA/FE bit */
80#define MAX3100_IR (1 << 7) /* IRDA timing mode */
81#define MAX3100_ST (1 << 6) /* transmit stop bit */
82#define MAX3100_PE (1 << 5) /* parity enable bit */
83#define MAX3100_L (1 << 4) /* Length bit */
84#define MAX3100_B_MASK (0x000F) /* baud rate bits mask */
85#define MAX3100_B(x) ((x) & 0x000F) /* baud rate select bits */
86
87/* data register bits (write) */
88#define MAX3100_TE (1 << 10) /* transmit enable bit (active low) */
89#define MAX3100_RTS (1 << 9) /* request-to-send bit (inverted ~RTS pin) */
90
91/* data register bits (read) */
92#define MAX3100_RA (1 << 10) /* receiver activity when in shutdown mode */
93#define MAX3100_FE (1 << 10) /* framing error when in normal mode */
94#define MAX3100_CTS (1 << 9) /* clear-to-send bit (inverted ~CTS pin) */
95
96/* data register bits (both directions) */
Wolfgang Denk53677ef2008-05-20 16:00:29 +020097#define MAX3100_R (1 << 15) /* receive bit */
wdenk993cad92003-06-26 22:04:09 +000098#define MAX3100_T (1 << 14) /* transmit bit */
99#define MAX3100_P (1 << 8) /* parity bit */
100#define MAX3100_D_MASK 0x00FF /* data bits mask */
101#define MAX3100_D(x) ((x) & 0x00FF) /* data bits */
102
103/* these definitions are valid only for fOSC = 3.6864MHz */
104#define MAX3100_B_230400 MAX3100_B(0)
105#define MAX3100_B_115200 MAX3100_B(1)
106#define MAX3100_B_57600 MAX3100_B(2)
107#define MAX3100_B_38400 MAX3100_B(9)
108#define MAX3100_B_19200 MAX3100_B(10)
109#define MAX3100_B_9600 MAX3100_B(11)
110#define MAX3100_B_4800 MAX3100_B(12)
111#define MAX3100_B_2400 MAX3100_B(13)
112#define MAX3100_B_1200 MAX3100_B(14)
113#define MAX3100_B_600 MAX3100_B(15)
114
115/**************************************************************/
116
117static inline unsigned int max3100_transfer(unsigned int val)
118{
119 unsigned int rx;
120 int b;
121
122 MAX3100_SPI_CLK(0);
123 MAX3100_CS(0);
124
125 rx = 0; b = 16;
126 while (--b >= 0) {
127 MAX3100_SPI_TXD(val & 0x8000);
128 val <<= 1;
129 MAX3100_SPI_CLK_TOGGLE();
130 udelay(1);
131 rx <<= 1;
132 if (MAX3100_SPI_RXD())
133 rx |= 1;
134 MAX3100_SPI_CLK_TOGGLE();
135 udelay(1);
136 }
137
138 MAX3100_SPI_CLK(1);
139 MAX3100_CS(1);
140
141 return rx;
142}
143
144/**************************************************************/
145
146/* must be power of 2 */
147#define RXFIFO_SZ 16
148
149static int rxfifo_cnt;
150static int rxfifo_in;
151static int rxfifo_out;
152static unsigned char rxfifo_buf[16];
153
Marek Vasut7cd851a2012-09-14 22:37:17 +0200154static void max3100_serial_putc_raw(int c)
wdenk993cad92003-06-26 22:04:09 +0000155{
156 unsigned int rx;
157
158 while (((rx = max3100_transfer(MAX3100_RC)) & MAX3100_T) == 0)
159 WATCHDOG_RESET();
160
161 rx = max3100_transfer(MAX3100_WD | (c & 0xff));
162 if ((rx & MAX3100_RD) != 0 && rxfifo_cnt < RXFIFO_SZ) {
163 rxfifo_cnt++;
164 rxfifo_buf[rxfifo_in++] = rx & 0xff;
165 rxfifo_in &= RXFIFO_SZ - 1;
166 }
167}
168
Marek Vasut7cd851a2012-09-14 22:37:17 +0200169static int max3100_serial_getc(void)
wdenk993cad92003-06-26 22:04:09 +0000170{
171 int c;
172 unsigned int rx;
173
174 while (rxfifo_cnt == 0) {
175 rx = max3100_transfer(MAX3100_RD);
176 if ((rx & MAX3100_R) != 0) {
177 do {
178 rxfifo_cnt++;
179 rxfifo_buf[rxfifo_in++] = rx & 0xff;
180 rxfifo_in &= RXFIFO_SZ - 1;
181
182 if (rxfifo_cnt >= RXFIFO_SZ)
183 break;
184 } while (((rx = max3100_transfer(MAX3100_RD)) & MAX3100_R) != 0);
185 }
186 WATCHDOG_RESET();
187 }
188
189 rxfifo_cnt--;
190 c = rxfifo_buf[rxfifo_out++];
191 rxfifo_out &= RXFIFO_SZ - 1;
192 return c;
193}
194
Marek Vasut7cd851a2012-09-14 22:37:17 +0200195static int max3100_serial_tstc(void)
wdenk993cad92003-06-26 22:04:09 +0000196{
197 unsigned int rx;
198
199 if (rxfifo_cnt > 0)
200 return 1;
201
202 rx = max3100_transfer(MAX3100_RD);
203 if ((rx & MAX3100_R) == 0)
204 return 0;
205
206 do {
207 rxfifo_cnt++;
208 rxfifo_buf[rxfifo_in++] = rx & 0xff;
209 rxfifo_in &= RXFIFO_SZ - 1;
210
211 if (rxfifo_cnt >= RXFIFO_SZ)
212 break;
213 } while (((rx = max3100_transfer(MAX3100_RD)) & MAX3100_R) != 0);
214
215 return 1;
216}
217
Marek Vasut7cd851a2012-09-14 22:37:17 +0200218static int max3100_serial_init(void)
wdenk993cad92003-06-26 22:04:09 +0000219{
220 unsigned int wconf, rconf;
221 int i;
wdenk993cad92003-06-26 22:04:09 +0000222
223 wconf = 0;
224
225 /* Set baud rate */
226 switch (gd->baudrate) {
227 case 1200:
228 wconf = MAX3100_B_1200;
229 break;
230 case 2400:
231 wconf = MAX3100_B_2400;
232 break;
233 case 4800:
234 wconf = MAX3100_B_4800;
235 break;
236 case 9600:
237 wconf = MAX3100_B_9600;
238 break;
239 case 19200:
240 wconf = MAX3100_B_19200;
241 break;
242 case 38400:
243 wconf = MAX3100_B_38400;
244 break;
245 case 57600:
246 wconf = MAX3100_B_57600;
247 break;
248 default:
249 case 115200:
250 wconf = MAX3100_B_115200;
251 break;
252 case 230400:
253 wconf = MAX3100_B_230400;
254 break;
255 }
256
257 /* try for 10ms, with a 100us gap */
258 for (i = 0; i < 10000; i += 100) {
259
260 max3100_transfer(MAX3100_WC | wconf);
261 rconf = max3100_transfer(MAX3100_RC) & 0x3fff;
262
263 if (rconf == wconf)
264 break;
265 udelay(100);
266 }
267
268 rxfifo_in = rxfifo_out = rxfifo_cnt = 0;
269
270 return (0);
271}
272
Marek Vasut7cd851a2012-09-14 22:37:17 +0200273static void max3100_serial_putc(const char c)
wdenk993cad92003-06-26 22:04:09 +0000274{
275 if (c == '\n')
Marek Vasut7cd851a2012-09-14 22:37:17 +0200276 max3100_serial_putc_raw('\r');
wdenk993cad92003-06-26 22:04:09 +0000277
Marek Vasut7cd851a2012-09-14 22:37:17 +0200278 max3100_serial_putc_raw(c);
279}
280
281static void max3100_serial_puts(const char *s)
282{
283 while (*s)
284 max3100_serial_putc_raw(*s++);
285}
286
287static void max3100_serial_setbrg(void)
288{
289}
290
Marek Vasut7cd851a2012-09-14 22:37:17 +0200291static struct serial_device max3100_serial_drv = {
292 .name = "max3100_serial",
293 .start = max3100_serial_init,
294 .stop = NULL,
295 .setbrg = max3100_serial_setbrg,
296 .putc = max3100_serial_putc,
297 .puts = max3100_serial_puts,
298 .getc = max3100_serial_getc,
299 .tstc = max3100_serial_tstc,
300};
301
302void max3100_serial_initialize(void)
303{
304 serial_register(&max3100_serial_drv);
305}
306
307__weak struct serial_device *default_serial_console(void)
308{
309 return &max3100_serial_drv;
310}