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 ssize_t rs_write(struct tty_struct * tty, const u8 *buf, size_t count) 56 { 57 /* see drivers/char/serialX.c to reference original version */ 58 59 simc_write(1, buf, count); 60 return count; 61 } 62 63 static void rs_poll(struct timer_list *unused) 64 { 65 struct tty_port *port = &serial_port; 66 int i = 0; 67 int rd = 1; 68 u8 c; 69 70 while (simc_poll(0)) { 71 rd = simc_read(0, &c, 1); 72 if (rd <= 0) 73 break; 74 tty_insert_flip_char(port, c, TTY_NORMAL); 75 i++; 76 } 77 78 if (i) 79 tty_flip_buffer_push(port); 80 if (rd) 81 mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE); 82 } 83 84 static unsigned int rs_write_room(struct tty_struct *tty) 85 { 86 /* Let's say iss can always accept 2K characters.. */ 87 return 2 * 1024; 88 } 89 90 static int rs_proc_show(struct seq_file *m, void *v) 91 { 92 seq_printf(m, "serinfo:1.0 driver:0.1\n"); 93 return 0; 94 } 95 96 static const struct tty_operations serial_ops = { 97 .open = rs_open, 98 .close = rs_close, 99 .write = rs_write, 100 .write_room = rs_write_room, 101 .proc_show = rs_proc_show, 102 }; 103 104 static int __init rs_init(void) 105 { 106 struct tty_driver *driver; 107 int ret; 108 109 driver = tty_alloc_driver(SERIAL_MAX_NUM_LINES, TTY_DRIVER_REAL_RAW); 110 if (IS_ERR(driver)) 111 return PTR_ERR(driver); 112 113 tty_port_init(&serial_port); 114 115 /* Initialize the tty_driver structure */ 116 117 driver->driver_name = "iss_serial"; 118 driver->name = "ttyS"; 119 driver->major = TTY_MAJOR; 120 driver->minor_start = 64; 121 driver->type = TTY_DRIVER_TYPE_SERIAL; 122 driver->subtype = SERIAL_TYPE_NORMAL; 123 driver->init_termios = tty_std_termios; 124 driver->init_termios.c_cflag = 125 B9600 | CS8 | CREAD | HUPCL | CLOCAL; 126 127 tty_set_operations(driver, &serial_ops); 128 tty_port_link_device(&serial_port, driver, 0); 129 130 ret = tty_register_driver(driver); 131 if (ret) { 132 pr_err("Couldn't register serial driver\n"); 133 tty_driver_kref_put(driver); 134 tty_port_destroy(&serial_port); 135 136 return ret; 137 } 138 139 serial_driver = driver; 140 141 return 0; 142 } 143 144 145 static __exit void rs_exit(void) 146 { 147 tty_unregister_driver(serial_driver); 148 tty_driver_kref_put(serial_driver); 149 tty_port_destroy(&serial_port); 150 } 151 152 153 /* We use `late_initcall' instead of just `__initcall' as a workaround for 154 * the fact that (1) simcons_tty_init can't be called before tty_init, 155 * (2) tty_init is called via `module_init', (3) if statically linked, 156 * module_init == device_init, and (4) there's no ordering of init lists. 157 * We can do this easily because simcons is always statically linked, but 158 * other tty drivers that depend on tty_init and which must use 159 * `module_init' to declare their init routines are likely to be broken. 160 */ 161 162 late_initcall(rs_init); 163 164 165 #ifdef CONFIG_SERIAL_CONSOLE 166 167 static void iss_console_write(struct console *co, const char *s, unsigned count) 168 { 169 if (s && *s != 0) 170 simc_write(1, s, min(count, strlen(s))); 171 } 172 173 static struct tty_driver* iss_console_device(struct console *c, int *index) 174 { 175 *index = c->index; 176 return serial_driver; 177 } 178 179 180 static struct console sercons = { 181 .name = "ttyS", 182 .write = iss_console_write, 183 .device = iss_console_device, 184 .flags = CON_PRINTBUFFER, 185 .index = -1 186 }; 187 188 static int __init iss_console_init(void) 189 { 190 register_console(&sercons); 191 return 0; 192 } 193 194 console_initcall(iss_console_init); 195 196 #endif /* CONFIG_SERIAL_CONSOLE */ 197 198