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 static DEFINE_SPINLOCK(timer_lock); 40 41 static int rs_open(struct tty_struct *tty, struct file * filp) 42 { 43 spin_lock_bh(&timer_lock); 44 if (tty->count == 1) 45 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 46 spin_unlock_bh(&timer_lock); 47 48 return 0; 49 } 50 51 static void rs_close(struct tty_struct *tty, struct file * filp) 52 { 53 spin_lock_bh(&timer_lock); 54 if (tty->count == 1) 55 del_timer_sync(&serial_timer); 56 spin_unlock_bh(&timer_lock); 57 } 58 59 60 static int rs_write(struct tty_struct * tty, 61 const unsigned char *buf, int count) 62 { 63 /* see drivers/char/serialX.c to reference original version */ 64 65 simc_write(1, buf, count); 66 return count; 67 } 68 69 static void rs_poll(struct timer_list *unused) 70 { 71 struct tty_port *port = &serial_port; 72 int i = 0; 73 int rd = 1; 74 unsigned char c; 75 76 spin_lock(&timer_lock); 77 78 while (simc_poll(0)) { 79 rd = simc_read(0, &c, 1); 80 if (rd <= 0) 81 break; 82 tty_insert_flip_char(port, c, TTY_NORMAL); 83 i++; 84 } 85 86 if (i) 87 tty_flip_buffer_push(port); 88 if (rd) 89 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 90 spin_unlock(&timer_lock); 91 } 92 93 94 static int rs_put_char(struct tty_struct *tty, unsigned char ch) 95 { 96 return rs_write(tty, &ch, 1); 97 } 98 99 static void rs_flush_chars(struct tty_struct *tty) 100 { 101 } 102 103 static unsigned int rs_write_room(struct tty_struct *tty) 104 { 105 /* Let's say iss can always accept 2K characters.. */ 106 return 2 * 1024; 107 } 108 109 static void rs_hangup(struct tty_struct *tty) 110 { 111 /* Stub, once again.. */ 112 } 113 114 static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 115 { 116 /* Stub, once again.. */ 117 } 118 119 static int rs_proc_show(struct seq_file *m, void *v) 120 { 121 seq_printf(m, "serinfo:1.0 driver:0.1\n"); 122 return 0; 123 } 124 125 static const struct tty_operations serial_ops = { 126 .open = rs_open, 127 .close = rs_close, 128 .write = rs_write, 129 .put_char = rs_put_char, 130 .flush_chars = rs_flush_chars, 131 .write_room = rs_write_room, 132 .hangup = rs_hangup, 133 .wait_until_sent = rs_wait_until_sent, 134 .proc_show = rs_proc_show, 135 }; 136 137 static int __init rs_init(void) 138 { 139 struct tty_driver *driver; 140 int ret; 141 142 driver = tty_alloc_driver(SERIAL_MAX_NUM_LINES, TTY_DRIVER_REAL_RAW); 143 if (IS_ERR(driver)) 144 return PTR_ERR(driver); 145 146 tty_port_init(&serial_port); 147 148 /* Initialize the tty_driver structure */ 149 150 driver->driver_name = "iss_serial"; 151 driver->name = "ttyS"; 152 driver->major = TTY_MAJOR; 153 driver->minor_start = 64; 154 driver->type = TTY_DRIVER_TYPE_SERIAL; 155 driver->subtype = SERIAL_TYPE_NORMAL; 156 driver->init_termios = tty_std_termios; 157 driver->init_termios.c_cflag = 158 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 159 160 tty_set_operations(driver, &serial_ops); 161 tty_port_link_device(&serial_port, driver, 0); 162 163 ret = tty_register_driver(driver); 164 if (ret) { 165 pr_err("Couldn't register serial driver\n"); 166 tty_driver_kref_put(driver); 167 tty_port_destroy(&serial_port); 168 169 return ret; 170 } 171 172 serial_driver = driver; 173 174 return 0; 175 } 176 177 178 static __exit void rs_exit(void) 179 { 180 tty_unregister_driver(serial_driver); 181 tty_driver_kref_put(serial_driver); 182 tty_port_destroy(&serial_port); 183 } 184 185 186 /* We use `late_initcall' instead of just `__initcall' as a workaround for 187 * the fact that (1) simcons_tty_init can't be called before tty_init, 188 * (2) tty_init is called via `module_init', (3) if statically linked, 189 * module_init == device_init, and (4) there's no ordering of init lists. 190 * We can do this easily because simcons is always statically linked, but 191 * other tty drivers that depend on tty_init and which must use 192 * `module_init' to declare their init routines are likely to be broken. 193 */ 194 195 late_initcall(rs_init); 196 197 198 #ifdef CONFIG_SERIAL_CONSOLE 199 200 static void iss_console_write(struct console *co, const char *s, unsigned count) 201 { 202 if (s && *s != 0) { 203 int len = strlen(s); 204 simc_write(1, s, count < len ? count : len); 205 } 206 } 207 208 static struct tty_driver* iss_console_device(struct console *c, int *index) 209 { 210 *index = c->index; 211 return serial_driver; 212 } 213 214 215 static struct console sercons = { 216 .name = "ttyS", 217 .write = iss_console_write, 218 .device = iss_console_device, 219 .flags = CON_PRINTBUFFER, 220 .index = -1 221 }; 222 223 static int __init iss_console_init(void) 224 { 225 register_console(&sercons); 226 return 0; 227 } 228 229 console_initcall(iss_console_init); 230 231 #endif /* CONFIG_SERIAL_CONSOLE */ 232 233