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