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/mm.h> 18 #include <linux/major.h> 19 #include <linux/param.h> 20 #include <linux/seq_file.h> 21 #include <linux/serial.h> 22 23 #include <asm/uaccess.h> 24 #include <asm/irq.h> 25 26 #include <platform/simcall.h> 27 28 #include <linux/tty.h> 29 #include <linux/tty_flip.h> 30 31 #ifdef SERIAL_INLINE 32 #define _INLINE_ inline 33 #endif 34 35 #define SERIAL_MAX_NUM_LINES 1 36 #define SERIAL_TIMER_VALUE (20 * HZ) 37 38 static struct tty_driver *serial_driver; 39 static struct tty_port serial_port; 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 tty->port = &serial_port; 72 spin_lock(&timer_lock); 73 if (tty->count == 1) { 74 setup_timer(&serial_timer, rs_poll, (unsigned long)tty); 75 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 76 } 77 spin_unlock(&timer_lock); 78 79 return 0; 80 } 81 82 83 /* 84 * ------------------------------------------------------------ 85 * iss_serial_close() 86 * 87 * This routine is called when the serial port gets closed. First, we 88 * wait for the last remaining data to be sent. Then, we unlink its 89 * async structure from the interrupt chain if necessary, and we free 90 * that IRQ if nothing is left in the chain. 91 * ------------------------------------------------------------ 92 */ 93 static void rs_close(struct tty_struct *tty, struct file * filp) 94 { 95 spin_lock_bh(&timer_lock); 96 if (tty->count == 1) 97 del_timer_sync(&serial_timer); 98 spin_unlock_bh(&timer_lock); 99 } 100 101 102 static int rs_write(struct tty_struct * tty, 103 const unsigned char *buf, int count) 104 { 105 /* see drivers/char/serialX.c to reference original version */ 106 107 __simc (SYS_write, 1, (unsigned long)buf, count, 0, 0); 108 return count; 109 } 110 111 static void rs_poll(unsigned long priv) 112 { 113 struct tty_struct* tty = (struct tty_struct*) priv; 114 115 struct timeval tv = { .tv_sec = 0, .tv_usec = 0 }; 116 int i = 0; 117 unsigned char c; 118 119 spin_lock(&timer_lock); 120 121 while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){ 122 __simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0); 123 tty_insert_flip_char(tty, c, TTY_NORMAL); 124 i++; 125 } 126 127 if (i) 128 tty_flip_buffer_push(tty); 129 130 131 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 132 spin_unlock(&timer_lock); 133 } 134 135 136 static int rs_put_char(struct tty_struct *tty, unsigned char ch) 137 { 138 char buf[2]; 139 140 buf[0] = ch; 141 buf[1] = '\0'; /* Is this NULL necessary? */ 142 __simc (SYS_write, 1, (unsigned long) buf, 1, 0, 0); 143 return 1; 144 } 145 146 static void rs_flush_chars(struct tty_struct *tty) 147 { 148 } 149 150 static int rs_write_room(struct tty_struct *tty) 151 { 152 /* Let's say iss can always accept 2K characters.. */ 153 return 2 * 1024; 154 } 155 156 static int rs_chars_in_buffer(struct tty_struct *tty) 157 { 158 /* the iss doesn't buffer characters */ 159 return 0; 160 } 161 162 static void rs_hangup(struct tty_struct *tty) 163 { 164 /* Stub, once again.. */ 165 } 166 167 static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 168 { 169 /* Stub, once again.. */ 170 } 171 172 static int rs_proc_show(struct seq_file *m, void *v) 173 { 174 seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version); 175 return 0; 176 } 177 178 static int rs_proc_open(struct inode *inode, struct file *file) 179 { 180 return single_open(file, rs_proc_show, NULL); 181 } 182 183 static const struct file_operations rs_proc_fops = { 184 .owner = THIS_MODULE, 185 .open = rs_proc_open, 186 .read = seq_read, 187 .llseek = seq_lseek, 188 .release = single_release, 189 }; 190 191 static const struct tty_operations serial_ops = { 192 .open = rs_open, 193 .close = rs_close, 194 .write = rs_write, 195 .put_char = rs_put_char, 196 .flush_chars = rs_flush_chars, 197 .write_room = rs_write_room, 198 .chars_in_buffer = rs_chars_in_buffer, 199 .hangup = rs_hangup, 200 .wait_until_sent = rs_wait_until_sent, 201 .proc_fops = &rs_proc_fops, 202 }; 203 204 int __init rs_init(void) 205 { 206 tty_port_init(&serial_port); 207 208 serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES); 209 210 printk ("%s %s\n", serial_name, serial_version); 211 212 /* Initialize the tty_driver structure */ 213 214 serial_driver->driver_name = "iss_serial"; 215 serial_driver->name = "ttyS"; 216 serial_driver->major = TTY_MAJOR; 217 serial_driver->minor_start = 64; 218 serial_driver->type = TTY_DRIVER_TYPE_SERIAL; 219 serial_driver->subtype = SERIAL_TYPE_NORMAL; 220 serial_driver->init_termios = tty_std_termios; 221 serial_driver->init_termios.c_cflag = 222 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 223 serial_driver->flags = TTY_DRIVER_REAL_RAW; 224 225 tty_set_operations(serial_driver, &serial_ops); 226 227 if (tty_register_driver(serial_driver)) 228 panic("Couldn't register serial driver\n"); 229 return 0; 230 } 231 232 233 static __exit void rs_exit(void) 234 { 235 int error; 236 237 if ((error = tty_unregister_driver(serial_driver))) 238 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n", 239 error); 240 put_tty_driver(serial_driver); 241 } 242 243 244 /* We use `late_initcall' instead of just `__initcall' as a workaround for 245 * the fact that (1) simcons_tty_init can't be called before tty_init, 246 * (2) tty_init is called via `module_init', (3) if statically linked, 247 * module_init == device_init, and (4) there's no ordering of init lists. 248 * We can do this easily because simcons is always statically linked, but 249 * other tty drivers that depend on tty_init and which must use 250 * `module_init' to declare their init routines are likely to be broken. 251 */ 252 253 late_initcall(rs_init); 254 255 256 #ifdef CONFIG_SERIAL_CONSOLE 257 258 static void iss_console_write(struct console *co, const char *s, unsigned count) 259 { 260 int len = strlen(s); 261 262 if (s != 0 && *s != 0) 263 __simc (SYS_write, 1, (unsigned long)s, 264 count < len ? count : len,0,0); 265 } 266 267 static struct tty_driver* iss_console_device(struct console *c, int *index) 268 { 269 *index = c->index; 270 return serial_driver; 271 } 272 273 274 static struct console sercons = { 275 .name = "ttyS", 276 .write = iss_console_write, 277 .device = iss_console_device, 278 .flags = CON_PRINTBUFFER, 279 .index = -1 280 }; 281 282 static int __init iss_console_init(void) 283 { 284 register_console(&sercons); 285 return 0; 286 } 287 288 console_initcall(iss_console_init); 289 290 #endif /* CONFIG_SERIAL_CONSOLE */ 291 292