drivers/tty/hvc/hvc_tile.c

   1 /*
   2  * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  *
  14  * Tilera TILE Processor hypervisor console
  15  */
  16
  17 #include <linux/console.h>
  18 #include <linux/delay.h>
  19 #include <linux/err.h>
  20 #include <linux/init.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/irq.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/types.h>
  26
  27 #include <asm/setup.h>
  28 #include <arch/sim_def.h>
  29
  30 #include <hv/hypervisor.h>
  31
  32 #include "hvc_console.h"
  33
  34 static int use_sim_console;
  35 static int __init sim_console(char *str)
  36 {
  37         use_sim_console = 1;
  38         return 0;
  39 }
  40 early_param("sim_console", sim_console);
  41
  42 int tile_console_write(const char *buf, int count)
  43 {
  44         if (unlikely(use_sim_console)) {
  45                 int i;
  46                 for (i = 0; i < count; ++i)
  47                         __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PUTC |
  48                                      (buf[i] << _SIM_CONTROL_OPERATOR_BITS));
  49                 __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PUTC |
  50                              (SIM_PUTC_FLUSH_BINARY <<
  51                               _SIM_CONTROL_OPERATOR_BITS));
  52                 return 0;
  53         } else {
  54                 return hv_console_write((HV_VirtAddr)buf, count);
  55         }
  56 }
  57
  58 static int hvc_tile_put_chars(uint32_t vt, const char *buf, int count)
  59 {
  60         return tile_console_write(buf, count);
  61 }
  62
  63 static int hvc_tile_get_chars(uint32_t vt, char *buf, int count)
  64 {
  65         int i, c;
  66
  67         for (i = 0; i < count; ++i) {
  68                 c = hv_console_read_if_ready();
  69                 if (c < 0)
  70                         break;
  71                 buf[i] = c;
  72         }
  73
  74         return i;
  75 }
  76
  77 #ifdef __tilegx__
  78 /*
  79  * IRQ based callbacks.
  80  */
  81 static int hvc_tile_notifier_add_irq(struct hvc_struct *hp, int irq)
  82 {
  83         int rc;
  84         int cpu = raw_smp_processor_id();  /* Choose an arbitrary cpu */
  85         HV_Coord coord = { .x = cpu_x(cpu), .y = cpu_y(cpu) };
  86
  87         rc = notifier_add_irq(hp, irq);
  88         if (rc)
  89                 return rc;
  90
  91         /*
  92          * Request that the hypervisor start sending us interrupts.
  93          * If the hypervisor returns an error, we still return 0, so that
  94          * we can fall back to polling.
  95          */
  96         if (hv_console_set_ipi(KERNEL_PL, irq, coord) < 0)
  97                 notifier_del_irq(hp, irq);
  98
  99         return 0;
 100 }
 101
 102 static void hvc_tile_notifier_del_irq(struct hvc_struct *hp, int irq)
 103 {
 104         HV_Coord coord = { 0, 0 };
 105
 106         /* Tell the hypervisor to stop sending us interrupts. */
 107         hv_console_set_ipi(KERNEL_PL, -1, coord);
 108
 109         notifier_del_irq(hp, irq);
 110 }
 111
 112 static void hvc_tile_notifier_hangup_irq(struct hvc_struct *hp, int irq)
 113 {
 114         hvc_tile_notifier_del_irq(hp, irq);
 115 }
 116 #endif
 117
 118 static const struct hv_ops hvc_tile_get_put_ops = {
 119         .get_chars = hvc_tile_get_chars,
 120         .put_chars = hvc_tile_put_chars,
 121 #ifdef __tilegx__
 122         .notifier_add = hvc_tile_notifier_add_irq,
 123         .notifier_del = hvc_tile_notifier_del_irq,
 124         .notifier_hangup = hvc_tile_notifier_hangup_irq,
 125 #endif
 126 };
 127
 128
 129 #ifdef __tilegx__
 130 static int hvc_tile_probe(struct platform_device *pdev)
 131 {
 132         struct hvc_struct *hp;
 133         int tile_hvc_irq;
 134
 135         /* Create our IRQ and register it. */
 136         tile_hvc_irq = create_irq();
 137         if (tile_hvc_irq < 0)
 138                 return -ENXIO;
 139
 140         tile_irq_activate(tile_hvc_irq, TILE_IRQ_PERCPU);
 141         hp = hvc_alloc(0, tile_hvc_irq, &hvc_tile_get_put_ops, 128);
 142         if (IS_ERR(hp)) {
 143                 destroy_irq(tile_hvc_irq);
 144                 return PTR_ERR(hp);
 145         }
 146         dev_set_drvdata(&pdev->dev, hp);
 147
 148         return 0;
 149 }
 150
 151 static int hvc_tile_remove(struct platform_device *pdev)
 152 {
 153         int rc;
 154         struct hvc_struct *hp = dev_get_drvdata(&pdev->dev);
 155
 156         rc = hvc_remove(hp);
 157         if (rc == 0)
 158                 destroy_irq(hp->data);
 159
 160         return rc;
 161 }
 162
 163 static void hvc_tile_shutdown(struct platform_device *pdev)
 164 {
 165         struct hvc_struct *hp = dev_get_drvdata(&pdev->dev);
 166
 167         hvc_tile_notifier_del_irq(hp, hp->data);
 168 }
 169
 170 static struct platform_device hvc_tile_pdev = {
 171         .name           = "hvc-tile",
 172         .id             = 0,
 173 };
 174
 175 static struct platform_driver hvc_tile_driver = {
 176         .probe          = hvc_tile_probe,
 177         .remove         = hvc_tile_remove,
 178         .shutdown       = hvc_tile_shutdown,
 179         .driver         = {
 180                 .name   = "hvc-tile",
 181                 .owner  = THIS_MODULE,
 182         }
 183 };
 184 #endif
 185
 186 static int __init hvc_tile_console_init(void)
 187 {
 188         hvc_instantiate(0, 0, &hvc_tile_get_put_ops);
 189         add_preferred_console("hvc", 0, NULL);
 190         return 0;
 191 }
 192 console_initcall(hvc_tile_console_init);
 193
 194 static int __init hvc_tile_init(void)
 195 {
 196 #ifndef __tilegx__
 197         struct hvc_struct *hp;
 198         hp = hvc_alloc(0, 0, &hvc_tile_get_put_ops, 128);
 199         return PTR_ERR_OR_ZERO(hp);
 200 #else
 201         platform_device_register(&hvc_tile_pdev);
 202         return platform_driver_register(&hvc_tile_driver);
 203 #endif
 204 }
 205 device_initcall(hvc_tile_init);