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 void rs_poll(struct timer_list *); 35 36 static struct tty_driver *serial_driver; 37 static struct tty_port serial_port; 38 static DEFINE_TIMER(serial_timer, rs_poll); 39 40 static int rs_open(struct tty_struct *tty, struct file * filp) 41 { 42 if (tty->count == 1) 43 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 44 45 return 0; 46 } 47 48 static void rs_close(struct tty_struct *tty, struct file * filp) 49 { 50 if (tty->count == 1) 51 del_timer_sync(&serial_timer); 52 } 53 54 55 static int rs_write(struct tty_struct * tty, 56 const unsigned char *buf, int count) 57 { 58 /* see drivers/char/serialX.c to reference original version */ 59 60 simc_write(1, buf, count); 61 return count; 62 } 63 64 static void rs_poll(struct timer_list *unused) 65 { 66 struct tty_port *port = &serial_port; 67 int i = 0; 68 int rd = 1; 69 unsigned char c; 70 71 while (simc_poll(0)) { 72 rd = simc_read(0, &c, 1); 73 if (rd <= 0) 74 break; 75 tty_insert_flip_char(port, c, TTY_NORMAL); 76 i++; 77 } 78 79 if (i) 80 tty_flip_buffer_push(port); 81 if (rd) 82 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 83 } 84 85 86 static int rs_put_char(struct tty_struct *tty, unsigned char ch) 87 { 88 return rs_write(tty, &ch, 1); 89 } 90 91 static void rs_flush_chars(struct tty_struct *tty) 92 { 93 } 94 95 static unsigned int rs_write_room(struct tty_struct *tty) 96 { 97 /* Let's say iss can always accept 2K characters.. */ 98 return 2 * 1024; 99 } 100 101 static void rs_hangup(struct tty_struct *tty) 102 { 103 /* Stub, once again.. */ 104 } 105 106 static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 107 { 108 /* Stub, once again.. */ 109 } 110 111 static int rs_proc_show(struct seq_file *m, void *v) 112 { 113 seq_printf(m, "serinfo:1.0 driver:0.1\n"); 114 return 0; 115 } 116 117 static const struct tty_operations serial_ops = { 118 .open = rs_open, 119 .close = rs_close, 120 .write = rs_write, 121 .put_char = rs_put_char, 122 .flush_chars = rs_flush_chars, 123 .write_room = rs_write_room, 124 .hangup = rs_hangup, 125 .wait_until_sent = rs_wait_until_sent, 126 .proc_show = rs_proc_show, 127 }; 128 129 static int __init rs_init(void) 130 { 131 struct tty_driver *driver; 132 int ret; 133 134 driver = tty_alloc_driver(SERIAL_MAX_NUM_LINES, TTY_DRIVER_REAL_RAW); 135 if (IS_ERR(driver)) 136 return PTR_ERR(driver); 137 138 tty_port_init(&serial_port); 139 140 /* Initialize the tty_driver structure */ 141 142 driver->driver_name = "iss_serial"; 143 driver->name = "ttyS"; 144 driver->major = TTY_MAJOR; 145 driver->minor_start = 64; 146 driver->type = TTY_DRIVER_TYPE_SERIAL; 147 driver->subtype = SERIAL_TYPE_NORMAL; 148 driver->init_termios = tty_std_termios; 149 driver->init_termios.c_cflag = 150 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 151 152 tty_set_operations(driver, &serial_ops); 153 tty_port_link_device(&serial_port, driver, 0); 154 155 ret = tty_register_driver(driver); 156 if (ret) { 157 pr_err("Couldn't register serial driver\n"); 158 tty_driver_kref_put(driver); 159 tty_port_destroy(&serial_port); 160 161 return ret; 162 } 163 164 serial_driver = driver; 165 166 return 0; 167 } 168 169 170 static __exit void rs_exit(void) 171 { 172 tty_unregister_driver(serial_driver); 173 tty_driver_kref_put(serial_driver); 174 tty_port_destroy(&serial_port); 175 } 176 177 178 /* We use `late_initcall' instead of just `__initcall' as a workaround for 179 * the fact that (1) simcons_tty_init can't be called before tty_init, 180 * (2) tty_init is called via `module_init', (3) if statically linked, 181 * module_init == device_init, and (4) there's no ordering of init lists. 182 * We can do this easily because simcons is always statically linked, but 183 * other tty drivers that depend on tty_init and which must use 184 * `module_init' to declare their init routines are likely to be broken. 185 */ 186 187 late_initcall(rs_init); 188 189 190 #ifdef CONFIG_SERIAL_CONSOLE 191 192 static void iss_console_write(struct console *co, const char *s, unsigned count) 193 { 194 if (s && *s != 0) { 195 int len = strlen(s); 196 simc_write(1, s, count < len ? count : len); 197 } 198 } 199 200 static struct tty_driver* iss_console_device(struct console *c, int *index) 201 { 202 *index = c->index; 203 return serial_driver; 204 } 205 206 207 static struct console sercons = { 208 .name = "ttyS", 209 .write = iss_console_write, 210 .device = iss_console_device, 211 .flags = CON_PRINTBUFFER, 212 .index = -1 213 }; 214 215 static int __init iss_console_init(void) 216 { 217 register_console(&sercons); 218 return 0; 219 } 220 221 console_initcall(iss_console_init); 222 223 #endif /* CONFIG_SERIAL_CONSOLE */ 224 225