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 (HZ / 10) 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 static char *serial_version = "0.1"; 45 static char *serial_name = "ISS serial driver"; 46 47 /* 48 * This routine is called whenever a serial port is opened. It 49 * enables interrupts for a serial port, linking in its async structure into 50 * the IRQ chain. It also performs the serial-specific 51 * initialization for the tty structure. 52 */ 53 54 static void rs_poll(unsigned long); 55 56 static int rs_open(struct tty_struct *tty, struct file * filp) 57 { 58 tty->port = &serial_port; 59 spin_lock(&timer_lock); 60 if (tty->count == 1) { 61 setup_timer(&serial_timer, rs_poll, (unsigned long)tty); 62 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 63 } 64 spin_unlock(&timer_lock); 65 66 return 0; 67 } 68 69 70 /* 71 * ------------------------------------------------------------ 72 * iss_serial_close() 73 * 74 * This routine is called when the serial port gets closed. First, we 75 * wait for the last remaining data to be sent. Then, we unlink its 76 * async structure from the interrupt chain if necessary, and we free 77 * that IRQ if nothing is left in the chain. 78 * ------------------------------------------------------------ 79 */ 80 static void rs_close(struct tty_struct *tty, struct file * filp) 81 { 82 spin_lock_bh(&timer_lock); 83 if (tty->count == 1) 84 del_timer_sync(&serial_timer); 85 spin_unlock_bh(&timer_lock); 86 } 87 88 89 static int rs_write(struct tty_struct * tty, 90 const unsigned char *buf, int count) 91 { 92 /* see drivers/char/serialX.c to reference original version */ 93 94 simc_write(1, buf, count); 95 return count; 96 } 97 98 static void rs_poll(unsigned long priv) 99 { 100 struct tty_struct* tty = (struct tty_struct*) priv; 101 102 struct timeval tv = { .tv_sec = 0, .tv_usec = 0 }; 103 int i = 0; 104 unsigned char c; 105 106 spin_lock(&timer_lock); 107 108 while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){ 109 __simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0); 110 tty_insert_flip_char(tty, c, TTY_NORMAL); 111 i++; 112 } 113 114 if (i) 115 tty_flip_buffer_push(tty); 116 117 118 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 119 spin_unlock(&timer_lock); 120 } 121 122 123 static int rs_put_char(struct tty_struct *tty, unsigned char ch) 124 { 125 return rs_write(tty, &ch, 1); 126 } 127 128 static void rs_flush_chars(struct tty_struct *tty) 129 { 130 } 131 132 static int rs_write_room(struct tty_struct *tty) 133 { 134 /* Let's say iss can always accept 2K characters.. */ 135 return 2 * 1024; 136 } 137 138 static int rs_chars_in_buffer(struct tty_struct *tty) 139 { 140 /* the iss doesn't buffer characters */ 141 return 0; 142 } 143 144 static void rs_hangup(struct tty_struct *tty) 145 { 146 /* Stub, once again.. */ 147 } 148 149 static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 150 { 151 /* Stub, once again.. */ 152 } 153 154 static int rs_proc_show(struct seq_file *m, void *v) 155 { 156 seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version); 157 return 0; 158 } 159 160 static int rs_proc_open(struct inode *inode, struct file *file) 161 { 162 return single_open(file, rs_proc_show, NULL); 163 } 164 165 static const struct file_operations rs_proc_fops = { 166 .owner = THIS_MODULE, 167 .open = rs_proc_open, 168 .read = seq_read, 169 .llseek = seq_lseek, 170 .release = single_release, 171 }; 172 173 static const struct tty_operations serial_ops = { 174 .open = rs_open, 175 .close = rs_close, 176 .write = rs_write, 177 .put_char = rs_put_char, 178 .flush_chars = rs_flush_chars, 179 .write_room = rs_write_room, 180 .chars_in_buffer = rs_chars_in_buffer, 181 .hangup = rs_hangup, 182 .wait_until_sent = rs_wait_until_sent, 183 .proc_fops = &rs_proc_fops, 184 }; 185 186 int __init rs_init(void) 187 { 188 tty_port_init(&serial_port); 189 190 serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES); 191 192 printk ("%s %s\n", serial_name, serial_version); 193 194 /* Initialize the tty_driver structure */ 195 196 serial_driver->driver_name = "iss_serial"; 197 serial_driver->name = "ttyS"; 198 serial_driver->major = TTY_MAJOR; 199 serial_driver->minor_start = 64; 200 serial_driver->type = TTY_DRIVER_TYPE_SERIAL; 201 serial_driver->subtype = SERIAL_TYPE_NORMAL; 202 serial_driver->init_termios = tty_std_termios; 203 serial_driver->init_termios.c_cflag = 204 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 205 serial_driver->flags = TTY_DRIVER_REAL_RAW; 206 207 tty_set_operations(serial_driver, &serial_ops); 208 tty_port_link_device(&serial_port, serial_driver, 0); 209 210 if (tty_register_driver(serial_driver)) 211 panic("Couldn't register serial driver\n"); 212 return 0; 213 } 214 215 216 static __exit void rs_exit(void) 217 { 218 int error; 219 220 if ((error = tty_unregister_driver(serial_driver))) 221 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n", 222 error); 223 put_tty_driver(serial_driver); 224 tty_port_destroy(&serial_port); 225 } 226 227 228 /* We use `late_initcall' instead of just `__initcall' as a workaround for 229 * the fact that (1) simcons_tty_init can't be called before tty_init, 230 * (2) tty_init is called via `module_init', (3) if statically linked, 231 * module_init == device_init, and (4) there's no ordering of init lists. 232 * We can do this easily because simcons is always statically linked, but 233 * other tty drivers that depend on tty_init and which must use 234 * `module_init' to declare their init routines are likely to be broken. 235 */ 236 237 late_initcall(rs_init); 238 239 240 #ifdef CONFIG_SERIAL_CONSOLE 241 242 static void iss_console_write(struct console *co, const char *s, unsigned count) 243 { 244 int len = strlen(s); 245 246 if (s != 0 && *s != 0) 247 __simc (SYS_write, 1, (unsigned long)s, 248 count < len ? count : len,0,0); 249 } 250 251 static struct tty_driver* iss_console_device(struct console *c, int *index) 252 { 253 *index = c->index; 254 return serial_driver; 255 } 256 257 258 static struct console sercons = { 259 .name = "ttyS", 260 .write = iss_console_write, 261 .device = iss_console_device, 262 .flags = CON_PRINTBUFFER, 263 .index = -1 264 }; 265 266 static int __init iss_console_init(void) 267 { 268 register_console(&sercons); 269 return 0; 270 } 271 272 console_initcall(iss_console_init); 273 274 #endif /* CONFIG_SERIAL_CONSOLE */ 275 276