Blame view

kernel/linux-imx6_3.14.28/arch/arm/mach-prima2/rstc.c 2.32 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
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
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
  /*
   * reset controller for CSR SiRFprimaII
   *
   * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
   *
   * Licensed under GPLv2 or later.
   */
  
  #include <linux/kernel.h>
  #include <linux/mutex.h>
  #include <linux/io.h>
  #include <linux/delay.h>
  #include <linux/device.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  #include <linux/reboot.h>
  
  void __iomem *sirfsoc_rstc_base;
  static DEFINE_MUTEX(rstc_lock);
  
  static struct of_device_id rstc_ids[]  = {
  	{ .compatible = "sirf,prima2-rstc" },
  	{ .compatible = "sirf,marco-rstc" },
  	{},
  };
  
  static int __init sirfsoc_of_rstc_init(void)
  {
  	struct device_node *np;
  
  	np = of_find_matching_node(NULL, rstc_ids);
  	if (!np) {
  		pr_err("unable to find compatible sirf rstc node in dtb
  ");
  		return -ENOENT;
  	}
  
  	sirfsoc_rstc_base = of_iomap(np, 0);
  	if (!sirfsoc_rstc_base)
  		panic("unable to map rstc cpu registers
  ");
  
  	of_node_put(np);
  
  	return 0;
  }
  early_initcall(sirfsoc_of_rstc_init);
  
  int sirfsoc_reset_device(struct device *dev)
  {
  	u32 reset_bit;
  
  	if (of_property_read_u32(dev->of_node, "reset-bit", &reset_bit))
  		return -EINVAL;
  
  	mutex_lock(&rstc_lock);
  
  	if (of_device_is_compatible(dev->of_node, "sirf,prima2-rstc")) {
  		/*
  		 * Writing 1 to this bit resets corresponding block. Writing 0 to this
  		 * bit de-asserts reset signal of the corresponding block.
  		 * datasheet doesn't require explicit delay between the set and clear
  		 * of reset bit. it could be shorter if tests pass.
  		 */
  		writel(readl(sirfsoc_rstc_base + (reset_bit / 32) * 4) | reset_bit,
  			sirfsoc_rstc_base + (reset_bit / 32) * 4);
  		msleep(10);
  		writel(readl(sirfsoc_rstc_base + (reset_bit / 32) * 4) & ~reset_bit,
  			sirfsoc_rstc_base + (reset_bit / 32) * 4);
  	} else {
  		/*
  		 * For MARCO and POLO
  		 * Writing 1 to SET register resets corresponding block. Writing 1 to CLEAR
  		 * register de-asserts reset signal of the corresponding block.
  		 * datasheet doesn't require explicit delay between the set and clear
  		 * of reset bit. it could be shorter if tests pass.
  		 */
  		writel(reset_bit, sirfsoc_rstc_base + (reset_bit / 32) * 8);
  		msleep(10);
  		writel(reset_bit, sirfsoc_rstc_base + (reset_bit / 32) * 8 + 4);
  	}
  
  	mutex_unlock(&rstc_lock);
  
  	return 0;
  }
  
  #define SIRFSOC_SYS_RST_BIT  BIT(31)
  
  void sirfsoc_restart(enum reboot_mode mode, const char *cmd)
  {
  	writel(SIRFSOC_SYS_RST_BIT, sirfsoc_rstc_base);
  }