1 /* 2 * arch/xtensa/platforms/iss/console.c 3 * 4 * This file is subject to the terms and conditions of the GNU General Public 5 * License. See the file "COPYING" in the main directory of this archive 6 * for more details. 7 * 8 * Copyright (C) 2001-2005 Tensilica Inc. 9 * Authors Christian Zankel, Joe Taylor 10 */ 11 12 #include <linux/module.h> 13 #include <linux/kernel.h> 14 #include <linux/sched.h> 15 #include <linux/console.h> 16 #include <linux/init.h> 17 #include <linux/slab.h> 18 #include <linux/mm.h> 19 #include <linux/major.h> 20 #include <linux/param.h> 21 #include <linux/serial.h> 22 #include <linux/serialP.h> 23 24 #include <asm/uaccess.h> 25 #include <asm/irq.h> 26 27 #include <platform/simcall.h> 28 29 #include <linux/tty.h> 30 #include <linux/tty_flip.h> 31 32 #ifdef SERIAL_INLINE 33 #define _INLINE_ inline 34 #endif 35 36 #define SERIAL_MAX_NUM_LINES 1 37 #define SERIAL_TIMER_VALUE (20 * HZ) 38 39 static struct tty_driver *serial_driver; 40 static struct timer_list serial_timer; 41 42 static DEFINE_SPINLOCK(timer_lock); 43 44 int errno; 45 46 static int __simc (int a, int b, int c, int d, int e, int f) __attribute__((__noinline__)); 47 static int __simc (int a, int b, int c, int d, int e, int f) 48 { 49 int ret; 50 __asm__ __volatile__ ("simcall\n" 51 "mov %0, a2\n" 52 "mov %1, a3\n" : "=a" (ret), "=a" (errno) 53 : : "a2", "a3"); 54 return ret; 55 } 56 57 static char *serial_version = "0.1"; 58 static char *serial_name = "ISS serial driver"; 59 60 /* 61 * This routine is called whenever a serial port is opened. It 62 * enables interrupts for a serial port, linking in its async structure into 63 * the IRQ chain. It also performs the serial-specific 64 * initialization for the tty structure. 65 */ 66 67 static void rs_poll(unsigned long); 68 69 static int rs_open(struct tty_struct *tty, struct file * filp) 70 { 71 int line = tty->index; 72 73 if ((line < 0) || (line >= SERIAL_MAX_NUM_LINES)) 74 return -ENODEV; 75 76 spin_lock(&timer_lock); 77 78 if (tty->count == 1) { 79 init_timer(&serial_timer); 80 serial_timer.data = (unsigned long) tty; 81 serial_timer.function = rs_poll; 82 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 83 } 84 spin_unlock(&timer_lock); 85 86 return 0; 87 } 88 89 90 /* 91 * ------------------------------------------------------------ 92 * iss_serial_close() 93 * 94 * This routine is called when the serial port gets closed. First, we 95 * wait for the last remaining data to be sent. Then, we unlink its 96 * async structure from the interrupt chain if necessary, and we free 97 * that IRQ if nothing is left in the chain. 98 * ------------------------------------------------------------ 99 */ 100 static void rs_close(struct tty_struct *tty, struct file * filp) 101 { 102 spin_lock(&timer_lock); 103 if (tty->count == 1) 104 del_timer_sync(&serial_timer); 105 spin_unlock(&timer_lock); 106 } 107 108 109 static int rs_write(struct tty_struct * tty, 110 const unsigned char *buf, int count) 111 { 112 /* see drivers/char/serialX.c to reference original version */ 113 114 __simc (SYS_write, 1, (unsigned long)buf, count, 0, 0); 115 return count; 116 } 117 118 static void rs_poll(unsigned long priv) 119 { 120 struct tty_struct* tty = (struct tty_struct*) priv; 121 122 struct timeval tv = { .tv_sec = 0, .tv_usec = 0 }; 123 int i = 0; 124 unsigned char c; 125 126 spin_lock(&timer_lock); 127 128 while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){ 129 __simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0); 130 tty_insert_flip_char(tty, c, TTY_NORMAL); 131 i++; 132 } 133 134 if (i) 135 tty_flip_buffer_push(tty); 136 137 138 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 139 spin_unlock(&timer_lock); 140 } 141 142 143 static int rs_put_char(struct tty_struct *tty, unsigned char ch) 144 { 145 char buf[2]; 146 147 buf[0] = ch; 148 buf[1] = '\0'; /* Is this NULL necessary? */ 149 __simc (SYS_write, 1, (unsigned long) buf, 1, 0, 0); 150 return 1; 151 } 152 153 static void rs_flush_chars(struct tty_struct *tty) 154 { 155 } 156 157 static int rs_write_room(struct tty_struct *tty) 158 { 159 /* Let's say iss can always accept 2K characters.. */ 160 return 2 * 1024; 161 } 162 163 static int rs_chars_in_buffer(struct tty_struct *tty) 164 { 165 /* the iss doesn't buffer characters */ 166 return 0; 167 } 168 169 static void rs_hangup(struct tty_struct *tty) 170 { 171 /* Stub, once again.. */ 172 } 173 174 static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 175 { 176 /* Stub, once again.. */ 177 } 178 179 static int rs_read_proc(char *page, char **start, off_t off, int count, 180 int *eof, void *data) 181 { 182 int len = 0; 183 off_t begin = 0; 184 185 len += sprintf(page, "serinfo:1.0 driver:%s\n", serial_version); 186 *eof = 1; 187 188 if (off >= len + begin) 189 return 0; 190 191 *start = page + (off - begin); 192 return ((count < begin + len - off) ? count : begin + len - off); 193 } 194 195 196 static struct tty_operations serial_ops = { 197 .open = rs_open, 198 .close = rs_close, 199 .write = rs_write, 200 .put_char = rs_put_char, 201 .flush_chars = rs_flush_chars, 202 .write_room = rs_write_room, 203 .chars_in_buffer = rs_chars_in_buffer, 204 .hangup = rs_hangup, 205 .wait_until_sent = rs_wait_until_sent, 206 .read_proc = rs_read_proc 207 }; 208 209 int __init rs_init(void) 210 { 211 serial_driver = alloc_tty_driver(1); 212 213 printk ("%s %s\n", serial_name, serial_version); 214 215 /* Initialize the tty_driver structure */ 216 217 serial_driver->owner = THIS_MODULE; 218 serial_driver->driver_name = "iss_serial"; 219 serial_driver->name = "ttyS"; 220 serial_driver->major = TTY_MAJOR; 221 serial_driver->minor_start = 64; 222 serial_driver->type = TTY_DRIVER_TYPE_SERIAL; 223 serial_driver->subtype = SERIAL_TYPE_NORMAL; 224 serial_driver->init_termios = tty_std_termios; 225 serial_driver->init_termios.c_cflag = 226 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 227 serial_driver->flags = TTY_DRIVER_REAL_RAW; 228 229 tty_set_operations(serial_driver, &serial_ops); 230 231 if (tty_register_driver(serial_driver)) 232 panic("Couldn't register serial driver\n"); 233 return 0; 234 } 235 236 237 static __exit void rs_exit(void) 238 { 239 int error; 240 241 if ((error = tty_unregister_driver(serial_driver))) 242 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n", 243 error); 244 put_tty_driver(serial_driver); 245 } 246 247 248 /* We use `late_initcall' instead of just `__initcall' as a workaround for 249 * the fact that (1) simcons_tty_init can't be called before tty_init, 250 * (2) tty_init is called via `module_init', (3) if statically linked, 251 * module_init == device_init, and (4) there's no ordering of init lists. 252 * We can do this easily because simcons is always statically linked, but 253 * other tty drivers that depend on tty_init and which must use 254 * `module_init' to declare their init routines are likely to be broken. 255 */ 256 257 late_initcall(rs_init); 258 259 260 #ifdef CONFIG_SERIAL_CONSOLE 261 262 static void iss_console_write(struct console *co, const char *s, unsigned count) 263 { 264 int len = strlen(s); 265 266 if (s != 0 && *s != 0) 267 __simc (SYS_write, 1, (unsigned long)s, 268 count < len ? count : len,0,0); 269 } 270 271 static struct tty_driver* iss_console_device(struct console *c, int *index) 272 { 273 *index = c->index; 274 return serial_driver; 275 } 276 277 278 static struct console sercons = { 279 .name = "ttyS", 280 .write = iss_console_write, 281 .device = iss_console_device, 282 .flags = CON_PRINTBUFFER, 283 .index = -1 284 }; 285 286 static int __init iss_console_init(void) 287 { 288 register_console(&sercons); 289 return 0; 290 } 291 292 console_initcall(iss_console_init); 293 294 #endif /* CONFIG_SERIAL_CONSOLE */ 295 296