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