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#include <linux/serialP.h> 23 24#include <asm/uaccess.h> 25#include <asm/irq.h> 26 27#include <platform/simcall.h> 28 29#include <linux/tty.h> 30#include <linux/tty_flip.h> 31 32#ifdef SERIAL_INLINE 33#define _INLINE_ inline 34#endif 35 36#define SERIAL_MAX_NUM_LINES 1 37#define SERIAL_TIMER_VALUE (20 * HZ) 38 39static struct tty_driver *serial_driver; 40static struct timer_list serial_timer; 41 42static DEFINE_SPINLOCK(timer_lock); 43 44int errno; 45 46static int __simc (int a, int b, int c, int d, int e, int f) __attribute__((__noinline__)); 47static 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 57static char *serial_version = "0.1"; 58static 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 67static void rs_poll(unsigned long); 68 69static int rs_open(struct tty_struct *tty, struct file * filp) 70{ 71 int line = tty->index; 72 73 if ((line < 0) || (line >= SERIAL_MAX_NUM_LINES)) 74 return -ENODEV; 75 76 spin_lock(&timer_lock); 77 78 if (tty->count == 1) { 79 init_timer(&serial_timer); 80 serial_timer.data = (unsigned long) tty; 81 serial_timer.function = rs_poll; 82 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 83 } 84 spin_unlock(&timer_lock); 85 86 return 0; 87} 88 89 90/* 91 * ------------------------------------------------------------ 92 * iss_serial_close() 93 * 94 * This routine is called when the serial port gets closed. First, we 95 * wait for the last remaining data to be sent. Then, we unlink its 96 * async structure from the interrupt chain if necessary, and we free 97 * that IRQ if nothing is left in the chain. 98 * ------------------------------------------------------------ 99 */ 100static void rs_close(struct tty_struct *tty, struct file * filp) 101{ 102 spin_lock(&timer_lock); 103 if (tty->count == 1) 104 del_timer_sync(&serial_timer); 105 spin_unlock(&timer_lock); 106} 107 108 109static int rs_write(struct tty_struct * tty, 110 const unsigned char *buf, int count) 111{ 112 /* see drivers/char/serialX.c to reference original version */ 113 114 __simc (SYS_write, 1, (unsigned long)buf, count, 0, 0); 115 return count; 116} 117 118static void rs_poll(unsigned long priv) 119{ 120 struct tty_struct* tty = (struct tty_struct*) priv; 121 122 struct timeval tv = { .tv_sec = 0, .tv_usec = 0 }; 123 int i = 0; 124 unsigned char c; 125 126 spin_lock(&timer_lock); 127 128 while (__simc(SYS_select_one, 0, XTISS_SELECT_ONE_READ, (int)&tv,0,0)){ 129 __simc (SYS_read, 0, (unsigned long)&c, 1, 0, 0); 130 tty_insert_flip_char(tty, c, TTY_NORMAL); 131 i++; 132 } 133 134 if (i) 135 tty_flip_buffer_push(tty); 136 137 138 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 139 spin_unlock(&timer_lock); 140} 141 142 143static int rs_put_char(struct tty_struct *tty, unsigned char ch) 144{ 145 char buf[2]; 146 147 buf[0] = ch; 148 buf[1] = '\0'; /* Is this NULL necessary? */ 149 __simc (SYS_write, 1, (unsigned long) buf, 1, 0, 0); 150 return 1; 151} 152 153static void rs_flush_chars(struct tty_struct *tty) 154{ 155} 156 157static int rs_write_room(struct tty_struct *tty) 158{ 159 /* Let's say iss can always accept 2K characters.. */ 160 return 2 * 1024; 161} 162 163static int rs_chars_in_buffer(struct tty_struct *tty) 164{ 165 /* the iss doesn't buffer characters */ 166 return 0; 167} 168 169static void rs_hangup(struct tty_struct *tty) 170{ 171 /* Stub, once again.. */ 172} 173 174static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 175{ 176 /* Stub, once again.. */ 177} 178 179static int rs_proc_show(struct seq_file *m, void *v) 180{ 181 seq_printf(m, "serinfo:1.0 driver:%s\n", serial_version); 182 return 0; 183} 184 185static int rs_proc_open(struct inode *inode, struct file *file) 186{ 187 return single_open(file, rs_proc_show, NULL); 188} 189 190static const struct file_operations rs_proc_fops = { 191 .owner = THIS_MODULE, 192 .open = rs_proc_open, 193 .read = seq_read, 194 .llseek = seq_lseek, 195 .release = single_release, 196}; 197 198static const struct tty_operations serial_ops = { 199 .open = rs_open, 200 .close = rs_close, 201 .write = rs_write, 202 .put_char = rs_put_char, 203 .flush_chars = rs_flush_chars, 204 .write_room = rs_write_room, 205 .chars_in_buffer = rs_chars_in_buffer, 206 .hangup = rs_hangup, 207 .wait_until_sent = rs_wait_until_sent, 208 .proc_fops = &rs_proc_fops, 209}; 210 211int __init rs_init(void) 212{ 213 serial_driver = alloc_tty_driver(1); 214 215 printk ("%s %s\n", serial_name, serial_version); 216 217 /* Initialize the tty_driver structure */ 218 219 serial_driver->owner = THIS_MODULE; 220 serial_driver->driver_name = "iss_serial"; 221 serial_driver->name = "ttyS"; 222 serial_driver->major = TTY_MAJOR; 223 serial_driver->minor_start = 64; 224 serial_driver->type = TTY_DRIVER_TYPE_SERIAL; 225 serial_driver->subtype = SERIAL_TYPE_NORMAL; 226 serial_driver->init_termios = tty_std_termios; 227 serial_driver->init_termios.c_cflag = 228 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 229 serial_driver->flags = TTY_DRIVER_REAL_RAW; 230 231 tty_set_operations(serial_driver, &serial_ops); 232 233 if (tty_register_driver(serial_driver)) 234 panic("Couldn't register serial driver\n"); 235 return 0; 236} 237 238 239static __exit void rs_exit(void) 240{ 241 int error; 242 243 if ((error = tty_unregister_driver(serial_driver))) 244 printk("ISS_SERIAL: failed to unregister serial driver (%d)\n", 245 error); 246 put_tty_driver(serial_driver); 247} 248 249 250 251late_initcall(rs_init); 252 253 254#ifdef CONFIG_SERIAL_CONSOLE 255 256static void iss_console_write(struct console *co, const char *s, unsigned count) 257{ 258 int len = strlen(s); 259 260 if (s != 0 && *s != 0) 261 __simc (SYS_write, 1, (unsigned long)s, 262 count < len ? count : len,0,0); 263} 264 265static struct tty_driver* iss_console_device(struct console *c, int *index) 266{ 267 *index = c->index; 268 return serial_driver; 269} 270 271 272static struct console sercons = { 273 .name = "ttyS", 274 .write = iss_console_write, 275 .device = iss_console_device, 276 .flags = CON_PRINTBUFFER, 277 .index = -1 278}; 279 280static int __init iss_console_init(void) 281{ 282 register_console(&sercons); 283 return 0; 284} 285 286console_initcall(iss_console_init); 287 288#endif /* CONFIG_SERIAL_CONSOLE */ 289