drivers/tty/serial/suncore.c

   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
  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
  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
  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
  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
 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  */
 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
 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