LXR linux/drivers/char/hvc

   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
  35#include <asm/hvconsole.h>
  36#include <asm/vio.h>
  37#include <asm/prom.h>
  38#include <asm/firmware.h>
  39
  40#include "hvc_console.h"
  41
  42char hvc_driver_name[] = "hvc_console";
  43
  44static struct vio_device_id hvc_driver_table[] __devinitdata = {
  45        {"serial", "hvterm1"},
  46        { "", "" }
  47};
  48MODULE_DEVICE_TABLE(vio, hvc_driver_table);
  49
  50static int filtered_get_chars(uint32_t vtermno, char *buf, int count)
  51{
  52        unsigned long got;
  53        int i;
  54
  55        /*
  56         * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion
  57         * so we play safe and avoid the situation where got > count which could
  58         * overload the flip buffer.
  59         */
  60        if (count < SIZE_VIO_GET_CHARS)
  61                return -EAGAIN;
  62
  63        got = hvc_get_chars(vtermno, buf, count);
  64
  65        /*
  66         * Work around a HV bug where it gives us a null
  67         * after every \r.  -- paulus
  68         */
  69        for (i = 1; i < got; ++i) {
  70                if (buf[i] == 0 && buf[i-1] == '\r') {
  71                        --got;
  72                        if (i < got)
  73                                memmove(&buf[i], &buf[i+1],
  74                                        got - i);
  75                }
  76        }
  77        return got;
  78}
  79
  80static struct hv_ops hvc_get_put_ops = {
  81        .get_chars = filtered_get_chars,
  82        .put_chars = hvc_put_chars,
  83        .notifier_add = notifier_add_irq,
  84        .notifier_del = notifier_del_irq,
  85        .notifier_hangup = notifier_hangup_irq,
  86};
  87
  88static int __devinit hvc_vio_probe(struct vio_dev *vdev,
  89                                const struct vio_device_id *id)
  90{
  91        struct hvc_struct *hp;
  92
  93        /* probed with invalid parameters. */
  94        if (!vdev || !id)
  95                return -EPERM;
  96
  97        hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops,
  98                        MAX_VIO_PUT_CHARS);
  99        if (IS_ERR(hp))
 100                return PTR_ERR(hp);
 101        dev_set_drvdata(&vdev->dev, hp);
 102
 103        return 0;
 104}
 105
 106static int __devexit hvc_vio_remove(struct vio_dev *vdev)
 107{
 108        struct hvc_struct *hp = dev_get_drvdata(&vdev->dev);
 109
 110        return hvc_remove(hp);
 111}
 112
 113static struct vio_driver hvc_vio_driver = {
 114        .id_table       = hvc_driver_table,
 115        .probe          = hvc_vio_probe,
 116        .remove         = __devexit_p(hvc_vio_remove),
 117        .driver         = {
 118                .name   = hvc_driver_name,
 119                .owner  = THIS_MODULE,
 120        }
 121};
 122
 123static int __init hvc_vio_init(void)
 124{
 125        int rc;
 126
 127        if (firmware_has_feature(FW_FEATURE_ISERIES))
 128                return -EIO;
 129
 130        /* Register as a vio device to receive callbacks */
 131        rc = vio_register_driver(&hvc_vio_driver);
 132
 133        return rc;
 134}
 135module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */
 136
 137static void __exit hvc_vio_exit(void)
 138{
 139        vio_unregister_driver(&hvc_vio_driver);
 140}
 141module_exit(hvc_vio_exit);
 142
 143/* the device tree order defines our numbering */
 144static int hvc_find_vtys(void)
 145{
 146        struct device_node *vty;
 147        int num_found = 0;
 148
 149        for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL;
 150                        vty = of_find_node_by_name(vty, "vty")) {
 151                const uint32_t *vtermno;
 152
 153                /* We have statically defined space for only a certain number
 154                 * of console adapters.
 155                 */
 156                if (num_found >= MAX_NR_HVC_CONSOLES) {
 157                        of_node_put(vty);
 158                        break;
 159                }
 160
 161                vtermno = of_get_property(vty, "reg", NULL);
 162                if (!vtermno)
 163                        continue;
 164
 165                if (of_device_is_compatible(vty, "hvterm1")) {
 166                        hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops);
 167                        ++num_found;
 168                }
 169        }
 170
 171        return num_found;
 172}
 173console_initcall(hvc_find_vtys);
 174