drivers/char/hvc_vio.c

   1 /*
   2  * vio driver interface to hvc_console.c
   3  *
   4  * This code was moved here to allow the remaing code to be reused as a
   5  * generic polling mode with semi-reliable transport driver core to the
   6  * console and tty subsystems.
   7  *
   8  *
   9  * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
  10  * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
  11  * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
  12  * Copyright (C) 2004 IBM Corporation
  13  *
  14  * Additional Author(s):
  15  *  Ryan S. Arnold <rsa@us.ibm.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 2 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  30  */
  31
  32 #include <linux/types.h>
  33 #include <linux/init.h>
  34 #include <asm/hvconsole.h>
  35 #include <asm/vio.h>
  36 #include <asm/prom.h>
  37
  38 char hvc_driver_name[] = "hvc_console";
  39
  40 static struct vio_device_id hvc_driver_table[] __devinitdata = {
  41         {"serial", "hvterm1"},
  42         { "", "" }
  43 };
  44 MODULE_DEVICE_TABLE(vio, hvc_driver_table);
  45
  46 static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
  47 {
  48         unsigned long got;
  49         int i;
  50
  51         got = hvc_get_chars(vtermno, buf, count);
  52
  53         /*
  54          * Work around a HV bug where it gives us a null
  55          * after every \r.  -- paulus
  56          */
  57         for (i = 1; i < got; ++i) {
  58                 if (buf[i] == 0 && buf[i-1] == '\r') {
  59                         --got;
  60                         if (i < got)
  61                                 memmove(&buf[i], &buf[i+1],
  62                                         got - i);
  63                 }
  64         }
  65         return got;
  66 }
  67
  68 static struct hv_ops hvc_get_put_ops = {
  69         .get_chars = filtered_get_chars,
  70         .put_chars = hvc_put_chars,
  71 };
  72
  73 static int __devinit hvc_vio_probe(struct vio_dev *vdev,
  74                                 const struct vio_device_id *id)
  75 {
  76         struct hvc_struct *hp;
  77
  78         /* probed with invalid parameters. */
  79         if (!vdev || !id)
  80                 return -EPERM;
  81
  82         hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops);
  83         if (IS_ERR(hp))
  84                 return PTR_ERR(hp);
  85         dev_set_drvdata(&vdev->dev, hp);
  86
  87         return 0;
  88 }
  89
  90 static int __devexit hvc_vio_remove(struct vio_dev *vdev)
  91 {
  92         struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
  93
  94         return hvc_remove(hp);
  95 }
  96
  97 static struct vio_driver hvc_vio_driver = {
  98         .name           = hvc_driver_name,
  99         .id_table       = hvc_driver_table,
 100         .probe          = hvc_vio_probe,
 101         .remove         = hvc_vio_remove,
 102         .driver         = {
 103                 .owner  = THIS_MODULE,
 104         }
 105 };
 106
 107 static int hvc_vio_init(void)
 108 {
 109         int rc;
 110
 111         /* Register as a vio device to receive callbacks */
 112         rc = vio_register_driver(&hvc_vio_driver);
 113
 114         return rc;
 115 }
 116 module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
 117
 118 static void hvc_vio_exit(void)
 119 {
 120         vio_unregister_driver(&hvc_vio_driver);
 121 }
 122 module_exit(hvc_vio_exit);
 123
 124 /* the device tree order defines our numbering */
 125 static int hvc_find_vtys(void)
 126 {
 127         struct device_node *vty;
 128         int num_found = 0;
 129
 130         for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
 131                         vty = of_find_node_by_name(vty, "vty")) {
 132                 uint32_t *vtermno;
 133
 134                 /* We have statically defined space for only a certain number
 135                  * of console adapters.
 136                  */
 137                 if (num_found >= MAX_NR_HVC_CONSOLES)
 138                         break;
 139
 140                 vtermno = (uint32_t *)get_property(vty, "reg", NULL);
 141                 if (!vtermno)
 142                         continue;
 143
 144                 if (device_is_compatible(vty, "hvterm1")) {
 145                         hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
 146                         ++num_found;
 147                 }
 148         }
 149
 150         return num_found;
 151 }
 152 console_initcall(hvc_find_vtys);