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 u8 *buf, int count) 74 { 75 nfputs(buf, count); 76 return count; 77 } 78 79 static int nfcon_tty_put_char(struct tty_struct *tty, unsigned char ch) 80 { 81 char temp[2] = { ch, 0 }; 82 83 nf_call(stderr_id, virt_to_phys(temp)); 84 return 1; 85 } 86 87 static unsigned int nfcon_tty_write_room(struct tty_struct *tty) 88 { 89 return 64; 90 } 91 92 static const struct tty_operations nfcon_tty_ops = { 93 .open = nfcon_tty_open, 94 .close = nfcon_tty_close, 95 .write = nfcon_tty_write, 96 .put_char = nfcon_tty_put_char, 97 .write_room = nfcon_tty_write_room, 98 }; 99 100 #ifndef MODULE 101 102 static int __init nf_debug_setup(char *arg) 103 { 104 if (strcmp(arg, "nfcon")) 105 return 0; 106 107 stderr_id = nf_get_id("NF_STDERR"); 108 if (stderr_id) { 109 /* 110 * The console will be enabled when debug=nfcon is specified 111 * as a kernel parameter. Since this is a non-standard way 112 * of enabling consoles, it must be explicitly enabled. 113 */ 114 nf_console.flags |= CON_ENABLED; 115 register_console(&nf_console); 116 } 117 118 return 0; 119 } 120 121 early_param("debug", nf_debug_setup); 122 123 #endif /* !MODULE */ 124 125 static int __init nfcon_init(void) 126 { 127 struct tty_driver *driver; 128 int res; 129 130 stderr_id = nf_get_id("NF_STDERR"); 131 if (!stderr_id) 132 return -ENODEV; 133 134 driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW); 135 if (IS_ERR(driver)) 136 return PTR_ERR(driver); 137 138 tty_port_init(&nfcon_tty_port); 139 140 driver->driver_name = "nfcon"; 141 driver->name = "nfcon"; 142 driver->type = TTY_DRIVER_TYPE_SYSTEM; 143 driver->subtype = SYSTEM_TYPE_TTY; 144 driver->init_termios = tty_std_termios; 145 146 tty_set_operations(driver, &nfcon_tty_ops); 147 tty_port_link_device(&nfcon_tty_port, driver, 0); 148 res = tty_register_driver(driver); 149 if (res) { 150 pr_err("failed to register nfcon tty driver\n"); 151 tty_driver_kref_put(driver); 152 tty_port_destroy(&nfcon_tty_port); 153 return res; 154 } 155 156 nfcon_tty_driver = driver; 157 158 if (!console_is_registered(&nf_console)) 159 register_console(&nf_console); 160 161 return 0; 162 } 163 164 static void __exit nfcon_exit(void) 165 { 166 unregister_console(&nf_console); 167 tty_unregister_driver(nfcon_tty_driver); 168 tty_driver_kref_put(nfcon_tty_driver); 169 tty_port_destroy(&nfcon_tty_port); 170 } 171 172 module_init(nfcon_init); 173 module_exit(nfcon_exit); 174 175 MODULE_LICENSE("GPL"); 176