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 #define SERIAL_MAX_NUM_LINES 1 32 #define SERIAL_TIMER_VALUE (HZ / 10) 33 34 static struct tty_driver *serial_driver; 35 static struct tty_port serial_port; 36 static struct timer_list serial_timer; 37 38 static DEFINE_SPINLOCK(timer_lock); 39 40 static char *serial_version = "0.1"; 41 static char *serial_name = "ISS serial driver"; 42 43 /* 44 * This routine is called whenever a serial port is opened. It 45 * enables interrupts for a serial port, linking in its async structure into 46 * the IRQ chain. It also performs the serial-specific 47 * initialization for the tty structure. 48 */ 49 50 static void rs_poll(unsigned long); 51 52 static int rs_open(struct tty_struct *tty, struct file * filp) 53 { 54 tty->port = &serial_port; 55 spin_lock_bh(&timer_lock); 56 if (tty->count == 1) { 57 setup_timer(&serial_timer, rs_poll, 58 (unsigned long)&serial_port); 59 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 60 } 61 spin_unlock_bh(&timer_lock); 62 63 return 0; 64 } 65 66 67 /* 68 * ------------------------------------------------------------ 69 * iss_serial_close() 70 * 71 * This routine is called when the serial port gets closed. First, we 72 * wait for the last remaining data to be sent. Then, we unlink its 73 * async structure from the interrupt chain if necessary, and we free 74 * that IRQ if nothing is left in the chain. 75 * ------------------------------------------------------------ 76 */ 77 static void rs_close(struct tty_struct *tty, struct file * filp) 78 { 79 spin_lock_bh(&timer_lock); 80 if (tty->count == 1) 81 del_timer_sync(&serial_timer); 82 spin_unlock_bh(&timer_lock); 83 } 84 85 86 static int rs_write(struct tty_struct * tty, 87 const unsigned char *buf, int count) 88 { 89 /* see drivers/char/serialX.c to reference original version */ 90 91 simc_write(1, buf, count); 92 return count; 93 } 94 95 static void rs_poll(unsigned long priv) 96 { 97 struct tty_port *port = (struct tty_port *)priv; 98 int i = 0; 99 int rd = 1; 100 unsigned char c; 101 102 spin_lock(&timer_lock); 103 104 while (simc_poll(0)) { 105 rd = simc_read(0, &c, 1); 106 if (rd <= 0) 107 break; 108 tty_insert_flip_char(port, c, TTY_NORMAL); 109 i++; 110 } 111 112 if (i) 113 tty_flip_buffer_push(port); 114 if (rd) 115 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 116 spin_unlock(&timer_lock); 117 } 118 119 120 static int rs_put_char(struct tty_struct *tty, unsigned char ch) 121 { 122 return rs_write(tty, &ch, 1); 123 } 124 125 static void rs_flush_chars(struct tty_struct *tty) 126 { 127 } 128 129 static int rs_write_room(struct tty_struct *tty) 130 { 131 /* Let's say iss can always accept 2K characters.. */ 132 return 2 * 1024; 133 } 134 135 static int rs_chars_in_buffer(struct tty_struct *tty) 136 { 137 /* the iss doesn't buffer characters */ 138 return 0; 139 } 140 141 static void rs_hangup(struct tty_struct *tty) 142 { 143 /* Stub, once again.. */ 144 } 145 146 static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 147 { 148 /* Stub, once again.. */ 149 } 150 151 static int rs_proc_show(struct seq_file *m, void *v) 152 { 153 seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version); 154 return 0; 155 } 156 157 static int rs_proc_open(struct inode *inode, struct file *file) 158 { 159 return single_open(file, rs_proc_show, NULL); 160 } 161 162 static const struct file_operations rs_proc_fops = { 163 .owner = THIS_MODULE, 164 .open = rs_proc_open, 165 .read = seq_read, 166 .llseek = seq_lseek, 167 .release = single_release, 168 }; 169 170 static const struct tty_operations serial_ops = { 171 .open = rs_open, 172 .close = rs_close, 173 .write = rs_write, 174 .put_char = rs_put_char, 175 .flush_chars = rs_flush_chars, 176 .write_room = rs_write_room, 177 .chars_in_buffer = rs_chars_in_buffer, 178 .hangup = rs_hangup, 179 .wait_until_sent = rs_wait_until_sent, 180 .proc_fops = &rs_proc_fops, 181 }; 182 183 int __init rs_init(void) 184 { 185 tty_port_init(&serial_port); 186 187 serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES); 188 189 printk ("%s %s\n", serial_name, serial_version); 190 191 /* Initialize the tty_driver structure */ 192 193 serial_driver->driver_name = "iss_serial"; 194 serial_driver->name = "ttyS"; 195 serial_driver->major = TTY_MAJOR; 196 serial_driver->minor_start = 64; 197 serial_driver->type = TTY_DRIVER_TYPE_SERIAL; 198 serial_driver->subtype = SERIAL_TYPE_NORMAL; 199 serial_driver->init_termios = tty_std_termios; 200 serial_driver->init_termios.c_cflag = 201 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 202 serial_driver->flags = TTY_DRIVER_REAL_RAW; 203 204 tty_set_operations(serial_driver, &serial_ops); 205 tty_port_link_device(&serial_port, serial_driver, 0); 206 207 if (tty_register_driver(serial_driver)) 208 panic("Couldn't register serial driver\n"); 209 return 0; 210 } 211 212 213 static __exit void rs_exit(void) 214 { 215 int error; 216 217 if ((error = tty_unregister_driver(serial_driver))) 218 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n", 219 error); 220 put_tty_driver(serial_driver); 221 tty_port_destroy(&serial_port); 222 } 223 224 225 /* We use `late_initcall' instead of just `__initcall' as a workaround for 226 * the fact that (1) simcons_tty_init can't be called before tty_init, 227 * (2) tty_init is called via `module_init', (3) if statically linked, 228 * module_init == device_init, and (4) there's no ordering of init lists. 229 * We can do this easily because simcons is always statically linked, but 230 * other tty drivers that depend on tty_init and which must use 231 * `module_init' to declare their init routines are likely to be broken. 232 */ 233 234 late_initcall(rs_init); 235 236 237 #ifdef CONFIG_SERIAL_CONSOLE 238 239 static void iss_console_write(struct console *co, const char *s, unsigned count) 240 { 241 int len = strlen(s); 242 243 if (s != 0 && *s != 0) 244 simc_write(1, s, count < len ? count : len); 245 } 246 247 static struct tty_driver* iss_console_device(struct console *c, int *index) 248 { 249 *index = c->index; 250 return serial_driver; 251 } 252 253 254 static struct console sercons = { 255 .name = "ttyS", 256 .write = iss_console_write, 257 .device = iss_console_device, 258 .flags = CON_PRINTBUFFER, 259 .index = -1 260 }; 261 262 static int __init iss_console_init(void) 263 { 264 register_console(&sercons); 265 return 0; 266 } 267 268 console_initcall(iss_console_init); 269 270 #endif /* CONFIG_SERIAL_CONSOLE */ 271 272