| 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(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 | |