1 /* 2 * ARAnyM console driver 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 9 #include <linux/module.h> 10 #include <linux/init.h> 11 #include <linux/console.h> 12 #include <linux/tty.h> 13 #include <linux/tty_driver.h> 14 #include <linux/tty_flip.h> 15 #include <linux/slab.h> 16 #include <linux/err.h> 17 #include <linux/uaccess.h> 18 #include <linux/io.h> 19 20 #include <asm/natfeat.h> 21 22 static int stderr_id; 23 static struct tty_port nfcon_tty_port; 24 static struct tty_driver *nfcon_tty_driver; 25 26 static void nfputs(const char *str, unsigned int count) 27 { 28 char buf[68]; 29 unsigned long phys = virt_to_phys(buf); 30 31 buf[64] = 0; 32 while (count > 64) { 33 memcpy(buf, str, 64); 34 nf_call(stderr_id, phys); 35 str += 64; 36 count -= 64; 37 } 38 memcpy(buf, str, count); 39 buf[count] = 0; 40 nf_call(stderr_id, phys); 41 } 42 43 static void nfcon_write(struct console *con, const char *str, 44 unsigned int count) 45 { 46 nfputs(str, count); 47 } 48 49 static struct tty_driver *nfcon_device(struct console *con, int *index) 50 { 51 *index = 0; 52 return console_is_registered(con) ? nfcon_tty_driver : NULL; 53 } 54 55 static struct console nf_console = { 56 .name = "nfcon", 57 .write = nfcon_write, 58 .device = nfcon_device, 59 .flags = CON_PRINTBUFFER, 60 .index = -1, 61 }; 62 63 64 static int nfcon_tty_open(struct tty_struct *tty, struct file *filp) 65 { 66 return 0; 67 } 68 69 static void nfcon_tty_close(struct tty_struct *tty, struct file *filp) 70 { 71 } 72 73 static int nfcon_tty_write(struct tty_struct *tty, const unsigned char *buf, 74 int count) 75 { 76 nfputs(buf, count); 77 return count; 78 } 79 80 static int nfcon_tty_put_char(struct tty_struct *tty, unsigned char ch) 81 { 82 char temp[2] = { ch, 0 }; 83 84 nf_call(stderr_id, virt_to_phys(temp)); 85 return 1; 86 } 87 88 static unsigned int nfcon_tty_write_room(struct tty_struct *tty) 89 { 90 return 64; 91 } 92 93 static const struct tty_operations nfcon_tty_ops = { 94 .open = nfcon_tty_open, 95 .close = nfcon_tty_close, 96 .write = nfcon_tty_write, 97 .put_char = nfcon_tty_put_char, 98 .write_room = nfcon_tty_write_room, 99 }; 100 101 #ifndef MODULE 102 103 static int __init nf_debug_setup(char *arg) 104 { 105 if (strcmp(arg, "nfcon")) 106 return 0; 107 108 stderr_id = nf_get_id("NF_STDERR"); 109 if (stderr_id) { 110 /* 111 * The console will be enabled when debug=nfcon is specified 112 * as a kernel parameter. Since this is a non-standard way 113 * of enabling consoles, it must be explicitly enabled. 114 */ 115 nf_console.flags |= CON_ENABLED; 116 register_console(&nf_console); 117 } 118 119 return 0; 120 } 121 122 early_param("debug", nf_debug_setup); 123 124 #endif /* !MODULE */ 125 126 static int __init nfcon_init(void) 127 { 128 struct tty_driver *driver; 129 int res; 130 131 stderr_id = nf_get_id("NF_STDERR"); 132 if (!stderr_id) 133 return -ENODEV; 134 135 driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW); 136 if (IS_ERR(driver)) 137 return PTR_ERR(driver); 138 139 tty_port_init(&nfcon_tty_port); 140 141 driver->driver_name = "nfcon"; 142 driver->name = "nfcon"; 143 driver->type = TTY_DRIVER_TYPE_SYSTEM; 144 driver->subtype = SYSTEM_TYPE_TTY; 145 driver->init_termios = tty_std_termios; 146 147 tty_set_operations(driver, &nfcon_tty_ops); 148 tty_port_link_device(&nfcon_tty_port, driver, 0); 149 res = tty_register_driver(driver); 150 if (res) { 151 pr_err("failed to register nfcon tty driver\n"); 152 tty_driver_kref_put(driver); 153 tty_port_destroy(&nfcon_tty_port); 154 return res; 155 } 156 157 nfcon_tty_driver = driver; 158 159 if (!console_is_registered(&nf_console)) 160 register_console(&nf_console); 161 162 return 0; 163 } 164 165 static void __exit nfcon_exit(void) 166 { 167 unregister_console(&nf_console); 168 tty_unregister_driver(nfcon_tty_driver); 169 tty_driver_kref_put(nfcon_tty_driver); 170 tty_port_destroy(&nfcon_tty_port); 171 } 172 173 module_init(nfcon_init); 174 module_exit(nfcon_exit); 175 176 MODULE_LICENSE("GPL"); 177