power.c 4.1 KB

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  1. /* $Id: power.c,v 1.10 2001/12/11 01:57:16 davem Exp $
  2. * power.c: Power management driver.
  3. *
  4. * Copyright (C) 1999 David S. Miller (davem@redhat.com)
  5. */
  6. #define __KERNEL_SYSCALLS__
  7. #include <linux/config.h>
  8. #include <linux/kernel.h>
  9. #include <linux/module.h>
  10. #include <linux/init.h>
  11. #include <linux/sched.h>
  12. #include <linux/signal.h>
  13. #include <linux/delay.h>
  14. #include <linux/interrupt.h>
  15. #include <asm/system.h>
  16. #include <asm/ebus.h>
  17. #include <asm/isa.h>
  18. #include <asm/auxio.h>
  19. #include <linux/unistd.h>
  20. /*
  21. * sysctl - toggle power-off restriction for serial console
  22. * systems in machine_power_off()
  23. */
  24. int scons_pwroff = 1;
  25. #ifdef CONFIG_PCI
  26. static void __iomem *power_reg;
  27. static DECLARE_WAIT_QUEUE_HEAD(powerd_wait);
  28. static int button_pressed;
  29. static irqreturn_t power_handler(int irq, void *dev_id, struct pt_regs *regs)
  30. {
  31. if (button_pressed == 0) {
  32. button_pressed = 1;
  33. wake_up(&powerd_wait);
  34. }
  35. /* FIXME: Check registers for status... */
  36. return IRQ_HANDLED;
  37. }
  38. #endif /* CONFIG_PCI */
  39. extern void machine_halt(void);
  40. extern void machine_alt_power_off(void);
  41. static void (*poweroff_method)(void) = machine_alt_power_off;
  42. void machine_power_off(void)
  43. {
  44. if (!serial_console || scons_pwroff) {
  45. #ifdef CONFIG_PCI
  46. if (power_reg) {
  47. /* Both register bits seem to have the
  48. * same effect, so until I figure out
  49. * what the difference is...
  50. */
  51. writel(AUXIO_PCIO_CPWR_OFF | AUXIO_PCIO_SPWR_OFF, power_reg);
  52. } else
  53. #endif /* CONFIG_PCI */
  54. if (poweroff_method != NULL) {
  55. poweroff_method();
  56. /* not reached */
  57. }
  58. }
  59. machine_halt();
  60. }
  61. #ifdef CONFIG_PCI
  62. static int powerd(void *__unused)
  63. {
  64. static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
  65. char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
  66. DECLARE_WAITQUEUE(wait, current);
  67. daemonize("powerd");
  68. add_wait_queue(&powerd_wait, &wait);
  69. again:
  70. for (;;) {
  71. set_task_state(current, TASK_INTERRUPTIBLE);
  72. if (button_pressed)
  73. break;
  74. flush_signals(current);
  75. schedule();
  76. }
  77. __set_current_state(TASK_RUNNING);
  78. remove_wait_queue(&powerd_wait, &wait);
  79. /* Ok, down we go... */
  80. button_pressed = 0;
  81. if (execve("/sbin/shutdown", argv, envp) < 0) {
  82. printk("powerd: shutdown execution failed\n");
  83. add_wait_queue(&powerd_wait, &wait);
  84. goto again;
  85. }
  86. return 0;
  87. }
  88. static int __init has_button_interrupt(unsigned int irq, int prom_node)
  89. {
  90. if (irq == PCI_IRQ_NONE)
  91. return 0;
  92. if (!prom_node_has_property(prom_node, "button"))
  93. return 0;
  94. return 1;
  95. }
  96. static int __init power_probe_ebus(struct resource **resp, unsigned int *irq_p, int *prom_node_p)
  97. {
  98. struct linux_ebus *ebus;
  99. struct linux_ebus_device *edev;
  100. for_each_ebus(ebus) {
  101. for_each_ebusdev(edev, ebus) {
  102. if (!strcmp(edev->prom_name, "power")) {
  103. *resp = &edev->resource[0];
  104. *irq_p = edev->irqs[0];
  105. *prom_node_p = edev->prom_node;
  106. return 0;
  107. }
  108. }
  109. }
  110. return -ENODEV;
  111. }
  112. static int __init power_probe_isa(struct resource **resp, unsigned int *irq_p, int *prom_node_p)
  113. {
  114. struct sparc_isa_bridge *isa_bus;
  115. struct sparc_isa_device *isa_dev;
  116. for_each_isa(isa_bus) {
  117. for_each_isadev(isa_dev, isa_bus) {
  118. if (!strcmp(isa_dev->prom_name, "power")) {
  119. *resp = &isa_dev->resource;
  120. *irq_p = isa_dev->irq;
  121. *prom_node_p = isa_dev->prom_node;
  122. return 0;
  123. }
  124. }
  125. }
  126. return -ENODEV;
  127. }
  128. void __init power_init(void)
  129. {
  130. struct resource *res = NULL;
  131. unsigned int irq;
  132. int prom_node;
  133. static int invoked;
  134. if (invoked)
  135. return;
  136. invoked = 1;
  137. if (!power_probe_ebus(&res, &irq, &prom_node))
  138. goto found;
  139. if (!power_probe_isa(&res, &irq, &prom_node))
  140. goto found;
  141. return;
  142. found:
  143. power_reg = ioremap(res->start, 0x4);
  144. printk("power: Control reg at %p ... ", power_reg);
  145. poweroff_method = machine_halt; /* able to use the standard halt */
  146. if (has_button_interrupt(irq, prom_node)) {
  147. if (kernel_thread(powerd, NULL, CLONE_FS) < 0) {
  148. printk("Failed to start power daemon.\n");
  149. return;
  150. }
  151. printk("powerd running.\n");
  152. if (request_irq(irq,
  153. power_handler, SA_SHIRQ, "power", NULL) < 0)
  154. printk("power: Error, cannot register IRQ handler.\n");
  155. } else {
  156. printk("not using powerd.\n");
  157. }
  158. }
  159. #endif /* CONFIG_PCI */