1 /* 2 * IBM RTAS driver interface to hvc_console.c 3 * 4 * (C) Copyright IBM Corporation 2001-2005 5 * (C) Copyright Red Hat, Inc. 2005 6 * 7 * Author(s): Maximino Augilar <IBM STI Design Center> 8 * : Ryan S. Arnold <rsa@us.ibm.com> 9 * : Utz Bacher <utz.bacher@de.ibm.com> 10 * : David Woodhouse <dwmw2@infradead.org> 11 * 12 * inspired by drivers/char/hvc_console.c 13 * written by Anton Blanchard and Paul Mackerras 14 * 15 * This program is free software; you can redistribute it and/or modify 16 * it under the terms of the GNU General Public License as published by 17 * the Free Software Foundation; either version 2 of the License, or 18 * (at your option) any later version. 19 * 20 * This program is distributed in the hope that it will be useful, 21 * but WITHOUT ANY WARRANTY; without even the implied warranty of 22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 23 * GNU General Public License for more details. 24 * 25 * You should have received a copy of the GNU General Public License 26 * along with this program; if not, write to the Free Software 27 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 28 */ 29 30 #include <linux/console.h> 31 #include <linux/delay.h> 32 #include <linux/err.h> 33 #include <linux/init.h> 34 #include <linux/moduleparam.h> 35 #include <linux/types.h> 36 37 #include <asm/irq.h> 38 #include <asm/rtas.h> 39 #include "hvc_console.h" 40 41 #define hvc_rtas_cookie 0x67781e15 42 struct hvc_struct *hvc_rtas_dev; 43 44 static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE; 45 static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE; 46 47 static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf, 48 int count) 49 { 50 int i; 51 52 for (i = 0; i < count; i++) { 53 if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i])) 54 break; 55 } 56 57 return i; 58 } 59 60 static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count) 61 { 62 int i, c; 63 64 for (i = 0; i < count; i++) { 65 if (rtas_call(rtascons_get_char_token, 0, 2, &c)) 66 break; 67 68 buf[i] = c; 69 } 70 71 return i; 72 } 73 74 static const struct hv_ops hvc_rtas_get_put_ops = { 75 .get_chars = hvc_rtas_read_console, 76 .put_chars = hvc_rtas_write_console, 77 }; 78 79 static int __init hvc_rtas_init(void) 80 { 81 struct hvc_struct *hp; 82 83 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) 84 rtascons_put_char_token = rtas_token("put-term-char"); 85 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) 86 return -EIO; 87 88 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) 89 rtascons_get_char_token = rtas_token("get-term-char"); 90 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) 91 return -EIO; 92 93 BUG_ON(hvc_rtas_dev); 94 95 /* Allocate an hvc_struct for the console device we instantiated 96 * earlier. Save off hp so that we can return it on exit */ 97 hp = hvc_alloc(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops, 16); 98 if (IS_ERR(hp)) 99 return PTR_ERR(hp); 100 101 hvc_rtas_dev = hp; 102 103 return 0; 104 } 105 module_init(hvc_rtas_init); 106 107 /* This will tear down the tty portion of the driver */ 108 static void __exit hvc_rtas_exit(void) 109 { 110 /* Really the fun isn't over until the worker thread breaks down and 111 * the tty cleans up */ 112 if (hvc_rtas_dev) 113 hvc_remove(hvc_rtas_dev); 114 } 115 module_exit(hvc_rtas_exit); 116 117 /* This will happen prior to module init. There is no tty at this time? */ 118 static int __init hvc_rtas_console_init(void) 119 { 120 rtascons_put_char_token = rtas_token("put-term-char"); 121 if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) 122 return -EIO; 123 124 rtascons_get_char_token = rtas_token("get-term-char"); 125 if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) 126 return -EIO; 127 128 hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops); 129 add_preferred_console("hvc", 0, NULL); 130 131 return 0; 132 } 133 console_initcall(hvc_rtas_console_init); 134