xref: /openbmc/linux/drivers/tty/serial/suncore.c (revision 778ec49c)
1 // SPDX-License-Identifier: GPL-2.0
2 /* suncore.c
3  *
4  * Common SUN serial routines.  Based entirely
5  * upon drivers/sbus/char/sunserial.c which is:
6  *
7  * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
8  *
9  * Adaptation to new UART layer is:
10  *
11  * Copyright (C) 2002 David S. Miller (davem@redhat.com)
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/console.h>
16 #include <linux/tty.h>
17 #include <linux/errno.h>
18 #include <linux/string.h>
19 #include <linux/serial_core.h>
20 #include <linux/sunserialcore.h>
21 #include <linux/init.h>
22 
23 #include <asm/prom.h>
24 
25 
26 static int sunserial_current_minor = 64;
27 
sunserial_register_minors(struct uart_driver * drv,int count)28 int sunserial_register_minors(struct uart_driver *drv, int count)
29 {
30 	int err = 0;
31 
32 	drv->minor = sunserial_current_minor;
33 	drv->nr += count;
34 	/* Register the driver on the first call */
35 	if (drv->nr == count)
36 		err = uart_register_driver(drv);
37 	if (err == 0) {
38 		sunserial_current_minor += count;
39 		drv->tty_driver->name_base = drv->minor - 64;
40 	}
41 	return err;
42 }
43 EXPORT_SYMBOL(sunserial_register_minors);
44 
sunserial_unregister_minors(struct uart_driver * drv,int count)45 void sunserial_unregister_minors(struct uart_driver *drv, int count)
46 {
47 	drv->nr -= count;
48 	sunserial_current_minor -= count;
49 
50 	if (drv->nr == 0)
51 		uart_unregister_driver(drv);
52 }
53 EXPORT_SYMBOL(sunserial_unregister_minors);
54 
sunserial_console_match(struct console * con,struct device_node * dp,struct uart_driver * drv,int line,bool ignore_line)55 int sunserial_console_match(struct console *con, struct device_node *dp,
56 			    struct uart_driver *drv, int line, bool ignore_line)
57 {
58 	if (!con)
59 		return 0;
60 
61 	drv->cons = con;
62 
63 	if (of_console_device != dp)
64 		return 0;
65 
66 	if (!ignore_line) {
67 		int off = 0;
68 
69 		if (of_console_options &&
70 		    *of_console_options == 'b')
71 			off = 1;
72 
73 		if ((line & 1) != off)
74 			return 0;
75 	}
76 
77 	if (!console_set_on_cmdline) {
78 		con->index = line;
79 		add_preferred_console(con->name, line, NULL);
80 	}
81 	return 1;
82 }
83 EXPORT_SYMBOL(sunserial_console_match);
84 
sunserial_console_termios(struct console * con,struct device_node * uart_dp)85 void sunserial_console_termios(struct console *con, struct device_node *uart_dp)
86 {
87 	const char *mode, *s;
88 	char mode_prop[] = "ttyX-mode";
89 	int baud, bits, stop, cflag;
90 	char parity;
91 
92 	if (of_node_name_eq(uart_dp, "rsc") ||
93 	    of_node_name_eq(uart_dp, "rsc-console") ||
94 	    of_node_name_eq(uart_dp, "rsc-control")) {
95 		mode = of_get_property(uart_dp,
96 				       "ssp-console-modes", NULL);
97 		if (!mode)
98 			mode = "115200,8,n,1,-";
99 	} else if (of_node_name_eq(uart_dp, "lom-console")) {
100 		mode = "9600,8,n,1,-";
101 	} else {
102 		struct device_node *dp;
103 		char c;
104 
105 		c = 'a';
106 		if (of_console_options)
107 			c = *of_console_options;
108 
109 		mode_prop[3] = c;
110 
111 		dp = of_find_node_by_path("/options");
112 		mode = of_get_property(dp, mode_prop, NULL);
113 		if (!mode)
114 			mode = "9600,8,n,1,-";
115 		of_node_put(dp);
116 	}
117 
118 	cflag = CREAD | HUPCL | CLOCAL;
119 
120 	s = mode;
121 	baud = simple_strtoul(s, NULL, 0);
122 	s = strchr(s, ',');
123 	bits = simple_strtoul(++s, NULL, 0);
124 	s = strchr(s, ',');
125 	parity = *(++s);
126 	s = strchr(s, ',');
127 	stop = simple_strtoul(++s, NULL, 0);
128 	s = strchr(s, ',');
129 	/* XXX handshake is not handled here. */
130 
131 	switch (baud) {
132 		case 150: cflag |= B150; break;
133 		case 300: cflag |= B300; break;
134 		case 600: cflag |= B600; break;
135 		case 1200: cflag |= B1200; break;
136 		case 2400: cflag |= B2400; break;
137 		case 4800: cflag |= B4800; break;
138 		case 9600: cflag |= B9600; break;
139 		case 19200: cflag |= B19200; break;
140 		case 38400: cflag |= B38400; break;
141 		case 57600: cflag |= B57600; break;
142 		case 115200: cflag |= B115200; break;
143 		case 230400: cflag |= B230400; break;
144 		case 460800: cflag |= B460800; break;
145 		default: baud = 9600; cflag |= B9600; break;
146 	}
147 
148 	switch (bits) {
149 		case 5: cflag |= CS5; break;
150 		case 6: cflag |= CS6; break;
151 		case 7: cflag |= CS7; break;
152 		case 8: cflag |= CS8; break;
153 		default: cflag |= CS8; break;
154 	}
155 
156 	switch (parity) {
157 		case 'o': cflag |= (PARENB | PARODD); break;
158 		case 'e': cflag |= PARENB; break;
159 		case 'n': default: break;
160 	}
161 
162 	switch (stop) {
163 		case 2: cflag |= CSTOPB; break;
164 		case 1: default: break;
165 	}
166 
167 	con->cflag = cflag;
168 }
169 
170 /* Sun serial MOUSE auto baud rate detection.  */
171 static struct mouse_baud_cflag {
172 	int baud;
173 	unsigned int cflag;
174 } mouse_baud_table[] = {
175 	{ 1200, B1200 },
176 	{ 2400, B2400 },
177 	{ 4800, B4800 },
178 	{ 9600, B9600 },
179 	{ -1, ~0 },
180 	{ -1, ~0 },
181 };
182 
suncore_mouse_baud_cflag_next(unsigned int cflag,int * new_baud)183 unsigned int suncore_mouse_baud_cflag_next(unsigned int cflag, int *new_baud)
184 {
185 	int i;
186 
187 	for (i = 0; mouse_baud_table[i].baud != -1; i++)
188 		if (mouse_baud_table[i].cflag == (cflag & CBAUD))
189 			break;
190 
191 	i += 1;
192 	if (mouse_baud_table[i].baud == -1)
193 		i = 0;
194 
195 	*new_baud = mouse_baud_table[i].baud;
196 	return mouse_baud_table[i].cflag;
197 }
198 
199 EXPORT_SYMBOL(suncore_mouse_baud_cflag_next);
200 
201 /* Basically, when the baud rate is wrong the mouse spits out
202  * breaks to us.
203  */
suncore_mouse_baud_detection(unsigned char ch,int is_break)204 int suncore_mouse_baud_detection(unsigned char ch, int is_break)
205 {
206 	static int mouse_got_break = 0;
207 	static int ctr = 0;
208 
209 	if (is_break) {
210 		/* Let a few normal bytes go by before we jump the gun
211 		 * and say we need to try another baud rate.
212 		 */
213 		if (mouse_got_break && ctr < 8)
214 			return 1;
215 
216 		/* Ok, we need to try another baud. */
217 		ctr = 0;
218 		mouse_got_break = 1;
219 		return 2;
220 	}
221 	if (mouse_got_break) {
222 		ctr++;
223 		if (ch == 0x87) {
224 			/* Correct baud rate determined. */
225 			mouse_got_break = 0;
226 		}
227 		return 1;
228 	}
229 	return 0;
230 }
231 
232 EXPORT_SYMBOL(suncore_mouse_baud_detection);
233 
suncore_init(void)234 static int __init suncore_init(void)
235 {
236 	return 0;
237 }
238 device_initcall(suncore_init);
239 
240 #if 0 /* ..def MODULE ; never supported as such */
241 MODULE_AUTHOR("Eddie C. Dost, David S. Miller");
242 MODULE_DESCRIPTION("Sun serial common layer");
243 MODULE_LICENSE("GPL");
244 #endif
245