Eric Lee / smarc-fsl-linux-kernel

Blame view

drivers/acpi/acpi_cmos_rtc.c 2.13 KB
edit raw normal view history
2fa97feb4   Lan Tianyu   ACPI: Add CMOS RT... 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
 
  /*
   * ACPI support for CMOS RTC Address Space access
   *
   * Copyright (C) 2013, Intel Corporation
   * Authors: Lan Tianyu <tianyu.lan@intel.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  #include <linux/acpi.h>
  #include <linux/device.h>
  #include <linux/err.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <asm-generic/rtc.h>
  
  #include "internal.h"
2fa97feb4   Lan Tianyu   ACPI: Add CMOS RT... 
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
 
  ACPI_MODULE_NAME("cmos rtc");
  
  static const struct acpi_device_id acpi_cmos_rtc_ids[] = {
  	{ "PNP0B00" },
  	{ "PNP0B01" },
  	{ "PNP0B02" },
  	{}
  };
  
  static acpi_status
  acpi_cmos_rtc_space_handler(u32 function, acpi_physical_address address,
  		      u32 bits, u64 *value64,
  		      void *handler_context, void *region_context)
  {
  	int i;
9389f46e9   Lee, Chun-Yi   ACPI / RTC: Fix C... 
35
 
  	u8 *value = (u8 *)value64;
2fa97feb4   Lan Tianyu   ACPI: Add CMOS RT... 
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
 
  
  	if (address > 0xff || !value64)
  		return AE_BAD_PARAMETER;
  
  	if (function != ACPI_WRITE && function != ACPI_READ)
  		return AE_BAD_PARAMETER;
  
  	spin_lock_irq(&rtc_lock);
  
  	for (i = 0; i < DIV_ROUND_UP(bits, 8); ++i, ++address, ++value)
  		if (function == ACPI_READ)
  			*value = CMOS_READ(address);
  		else
  			CMOS_WRITE(*value, address);
  
  	spin_unlock_irq(&rtc_lock);
  
  	return AE_OK;
  }
  
  static int acpi_install_cmos_rtc_space_handler(struct acpi_device *adev,
  		const struct acpi_device_id *id)
  {
  	acpi_status status;
  
  	status = acpi_install_address_space_handler(adev->handle,
  			ACPI_ADR_SPACE_CMOS,
  			&acpi_cmos_rtc_space_handler,
  			NULL, NULL);
  	if (ACPI_FAILURE(status)) {
  		pr_err(PREFIX "Error installing CMOS-RTC region handler
  ");
  		return -ENODEV;
  	}
eec15edbb   Zhang Rui   ACPI / PNP: use d... 
70
 
  	return 1;
2fa97feb4   Lan Tianyu   ACPI: Add CMOS RT... 
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
 
  }
  
  static void acpi_remove_cmos_rtc_space_handler(struct acpi_device *adev)
  {
  	if (ACPI_FAILURE(acpi_remove_address_space_handler(adev->handle,
  			ACPI_ADR_SPACE_CMOS, &acpi_cmos_rtc_space_handler)))
  		pr_err(PREFIX "Error removing CMOS-RTC region handler
  ");
  }
  
  static struct acpi_scan_handler cmos_rtc_handler = {
  	.ids = acpi_cmos_rtc_ids,
  	.attach = acpi_install_cmos_rtc_space_handler,
  	.detach = acpi_remove_cmos_rtc_space_handler,
  };
  
  void __init acpi_cmos_rtc_init(void)
  {
  	acpi_scan_add_handler(&cmos_rtc_handler);
  }