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/seq_file.h> 22 #include <linux/serial.h> 23 #include <linux/serialP.h> 24 25 #include <asm/uaccess.h> 26 #include <asm/irq.h> 27 28 #include <platform/simcall.h> 29 30 #include <linux/tty.h> 31 #include <linux/tty_flip.h> 32 33 #ifdef SERIAL_INLINE 34 #define _INLINE_ inline 35 #endif 36 37 #define SERIAL_MAX_NUM_LINES 1 38 #define SERIAL_TIMER_VALUE (20 * HZ) 39 40 static struct tty_driver *serial_driver; 41 static struct timer_list serial_timer; 42 43 static DEFINE_SPINLOCK(timer_lock); 44 45 int errno; 46 47 static int __simc (int a, int b, int c, int d, int e, int f) __attribute__((__noinline__)); 48 static int __simc (int a, int b, int c, int d, int e, int f) 49 { 50 int ret; 51 __asm__ __volatile__ ("simcall\n" 52 "mov %0, a2\n" 53 "mov %1, a3\n" : "=a" (ret), "=a" (errno) 54 : : "a2", "a3"); 55 return ret; 56 } 57 58 static char *serial_version = "0.1"; 59 static char *serial_name = "ISS serial driver"; 60 61 /* 62 * This routine is called whenever a serial port is opened. It 63 * enables interrupts for a serial port, linking in its async structure into 64 * the IRQ chain. It also performs the serial-specific 65 * initialization for the tty structure. 66 */ 67 68 static void rs_poll(unsigned long); 69 70 static int rs_open(struct tty_struct *tty, struct file * filp) 71 { 72 int line = tty->index; 73 74 if ((line < 0) || (line >= SERIAL_MAX_NUM_LINES)) 75 return -ENODEV; 76 77 spin_lock(&timer_lock); 78 79 if (tty->count == 1) { 80 init_timer(&serial_timer); 81 serial_timer.data = (unsigned long) tty; 82 serial_timer.function = rs_poll; 83 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 84 } 85 spin_unlock(&timer_lock); 86 87 return 0; 88 } 89 90 91 /* 92 * ------------------------------------------------------------ 93 * iss_serial_close() 94 * 95 * This routine is called when the serial port gets closed. First, we 96 * wait for the last remaining data to be sent. Then, we unlink its 97 * async structure from the interrupt chain if necessary, and we free 98 * that IRQ if nothing is left in the chain. 99 * ------------------------------------------------------------ 100 */ 101 static void rs_close(struct tty_struct *tty, struct file * filp) 102 { 103 spin_lock(&timer_lock); 104 if (tty->count == 1) 105 del_timer_sync(&serial_timer); 106 spin_unlock(&timer_lock); 107 } 108 109 110 static int rs_write(struct tty_struct * tty, 111 const unsigned char *buf, int count) 112 { 113 /* see drivers/char/serialX.c to reference original version */ 114 115 __simc (SYS_write, 1, (unsigned long)buf, count, 0, 0); 116 return count; 117 } 118 119 static void rs_poll(unsigned long priv) 120 { 121 struct tty_struct* tty = (struct tty_struct*) priv; 122 123 struct timeval tv = { .tv_sec = 0, .tv_usec = 0 }; 124 int i = 0; 125 unsigned char c; 126 127 spin_lock(&timer_lock); 128 129 while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){ 130 __simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0); 131 tty_insert_flip_char(tty, c, TTY_NORMAL); 132 i++; 133 } 134 135 if (i) 136 tty_flip_buffer_push(tty); 137 138 139 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 140 spin_unlock(&timer_lock); 141 } 142 143 144 static int rs_put_char(struct tty_struct *tty, unsigned char ch) 145 { 146 char buf[2]; 147 148 buf[0] = ch; 149 buf[1] = '\0'; /* Is this NULL necessary? */ 150 __simc (SYS_write, 1, (unsigned long) buf, 1, 0, 0); 151 return 1; 152 } 153 154 static void rs_flush_chars(struct tty_struct *tty) 155 { 156 } 157 158 static int rs_write_room(struct tty_struct *tty) 159 { 160 /* Let's say iss can always accept 2K characters.. */ 161 return 2 * 1024; 162 } 163 164 static int rs_chars_in_buffer(struct tty_struct *tty) 165 { 166 /* the iss doesn't buffer characters */ 167 return 0; 168 } 169 170 static void rs_hangup(struct tty_struct *tty) 171 { 172 /* Stub, once again.. */ 173 } 174 175 static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 176 { 177 /* Stub, once again.. */ 178 } 179 180 static int rs_proc_show(struct seq_file *m, void *v) 181 { 182 seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version); 183 return 0; 184 } 185 186 static int rs_proc_open(struct inode *inode, struct file *file) 187 { 188 return single_open(file, rs_proc_show, NULL); 189 } 190 191 static const struct file_operations rs_proc_fops = { 192 .owner = THIS_MODULE, 193 .open = rs_proc_open, 194 .read = seq_read, 195 .llseek = seq_lseek, 196 .release = single_release, 197 }; 198 199 static struct tty_operations serial_ops = { 200 .open = rs_open, 201 .close = rs_close, 202 .write = rs_write, 203 .put_char = rs_put_char, 204 .flush_chars = rs_flush_chars, 205 .write_room = rs_write_room, 206 .chars_in_buffer = rs_chars_in_buffer, 207 .hangup = rs_hangup, 208 .wait_until_sent = rs_wait_until_sent, 209 .proc_fops = &rs_proc_fops, 210 }; 211 212 int __init rs_init(void) 213 { 214 serial_driver = alloc_tty_driver(1); 215 216 printk ("%s %s\n", serial_name, serial_version); 217 218 /* Initialize the tty_driver structure */ 219 220 serial_driver->owner = THIS_MODULE; 221 serial_driver->driver_name = "iss_serial"; 222 serial_driver->name = "ttyS"; 223 serial_driver->major = TTY_MAJOR; 224 serial_driver->minor_start = 64; 225 serial_driver->type = TTY_DRIVER_TYPE_SERIAL; 226 serial_driver->subtype = SERIAL_TYPE_NORMAL; 227 serial_driver->init_termios = tty_std_termios; 228 serial_driver->init_termios.c_cflag = 229 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 230 serial_driver->flags = TTY_DRIVER_REAL_RAW; 231 232 tty_set_operations(serial_driver, &serial_ops); 233 234 if (tty_register_driver(serial_driver)) 235 panic("Couldn't register serial driver\n"); 236 return 0; 237 } 238 239 240 static __exit void rs_exit(void) 241 { 242 int error; 243 244 if ((error = tty_unregister_driver(serial_driver))) 245 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n", 246 error); 247 put_tty_driver(serial_driver); 248 } 249 250 251 /* We use `late_initcall' instead of just `__initcall' as a workaround for 252 * the fact that (1) simcons_tty_init can't be called before tty_init, 253 * (2) tty_init is called via `module_init', (3) if statically linked, 254 * module_init == device_init, and (4) there's no ordering of init lists. 255 * We can do this easily because simcons is always statically linked, but 256 * other tty drivers that depend on tty_init and which must use 257 * `module_init' to declare their init routines are likely to be broken. 258 */ 259 260 late_initcall(rs_init); 261 262 263 #ifdef CONFIG_SERIAL_CONSOLE 264 265 static void iss_console_write(struct console *co, const char *s, unsigned count) 266 { 267 int len = strlen(s); 268 269 if (s != 0 && *s != 0) 270 __simc (SYS_write, 1, (unsigned long)s, 271 count < len ? count : len,0,0); 272 } 273 274 static struct tty_driver* iss_console_device(struct console *c, int *index) 275 { 276 *index = c->index; 277 return serial_driver; 278 } 279 280 281 static struct console sercons = { 282 .name = "ttyS", 283 .write = iss_console_write, 284 .device = iss_console_device, 285 .flags = CON_PRINTBUFFER, 286 .index = -1 287 }; 288 289 static int __init iss_console_init(void) 290 { 291 register_console(&sercons); 292 return 0; 293 } 294 295 console_initcall(iss_console_init); 296 297 #endif /* CONFIG_SERIAL_CONSOLE */ 298 299