hvc_rtas.c 3.6 KB

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  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. #include <linux/console.h>
  30. #include <linux/delay.h>
  31. #include <linux/err.h>
  32. #include <linux/init.h>
  33. #include <linux/moduleparam.h>
  34. #include <linux/types.h>
  35. #include <asm/irq.h>
  36. #include <asm/rtas.h>
  37. #include "hvc_console.h"
  38. #define hvc_rtas_cookie 0x67781e15
  39. struct hvc_struct *hvc_rtas_dev;
  40. static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE;
  41. static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE;
  42. static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf,
  43. int count)
  44. {
  45. int i;
  46. for (i = 0; i < count; i++) {
  47. if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i]))
  48. break;
  49. }
  50. return i;
  51. }
  52. static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count)
  53. {
  54. int i, c;
  55. for (i = 0; i < count; i++) {
  56. if (rtas_call(rtascons_get_char_token, 0, 2, &c))
  57. break;
  58. buf[i] = c;
  59. }
  60. return i;
  61. }
  62. static struct hv_ops hvc_rtas_get_put_ops = {
  63. .get_chars = hvc_rtas_read_console,
  64. .put_chars = hvc_rtas_write_console,
  65. };
  66. static int hvc_rtas_init(void)
  67. {
  68. struct hvc_struct *hp;
  69. if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
  70. rtascons_put_char_token = rtas_token("put-term-char");
  71. if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
  72. return -EIO;
  73. if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
  74. rtascons_get_char_token = rtas_token("get-term-char");
  75. if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
  76. return -EIO;
  77. BUG_ON(hvc_rtas_dev);
  78. /* Allocate an hvc_struct for the console device we instantiated
  79. * earlier. Save off hp so that we can return it on exit */
  80. hp = hvc_alloc(hvc_rtas_cookie, NO_IRQ, &hvc_rtas_get_put_ops, 16);
  81. if (IS_ERR(hp))
  82. return PTR_ERR(hp);
  83. hvc_rtas_dev = hp;
  84. return 0;
  85. }
  86. module_init(hvc_rtas_init);
  87. /* This will tear down the tty portion of the driver */
  88. static void __exit hvc_rtas_exit(void)
  89. {
  90. /* Really the fun isn't over until the worker thread breaks down and
  91. * the tty cleans up */
  92. if (hvc_rtas_dev)
  93. hvc_remove(hvc_rtas_dev);
  94. }
  95. module_exit(hvc_rtas_exit);
  96. /* This will happen prior to module init. There is no tty at this time? */
  97. static int hvc_rtas_console_init(void)
  98. {
  99. rtascons_put_char_token = rtas_token("put-term-char");
  100. if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
  101. return -EIO;
  102. rtascons_get_char_token = rtas_token("get-term-char");
  103. if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
  104. return -EIO;
  105. hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops);
  106. add_preferred_console("hvc", 0, NULL);
  107. return 0;
  108. }
  109. console_initcall(hvc_rtas_console_init);