Blame view

kernel/linux-imx6_3.14.28/arch/arm/mach-zynq/slcr.c 3.02 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
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
  /*
   * Xilinx SLCR driver
   *
   * Copyright (c) 2011-2013 Xilinx Inc.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   *
   * You should have received a copy of the GNU General Public
   * License along with this program; if not, write to the Free
   * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA
   * 02139, USA.
   */
  
  #include <linux/io.h>
  #include <linux/of_address.h>
  #include <linux/clk/zynq.h>
  #include "common.h"
  
  /* register offsets */
  #define SLCR_UNLOCK_OFFSET		0x8   /* SCLR unlock register */
  #define SLCR_PS_RST_CTRL_OFFSET		0x200 /* PS Software Reset Control */
  #define SLCR_A9_CPU_RST_CTRL_OFFSET	0x244 /* CPU Software Reset Control */
  #define SLCR_REBOOT_STATUS_OFFSET	0x258 /* PS Reboot Status */
  
  #define SLCR_UNLOCK_MAGIC		0xDF0D
  #define SLCR_A9_CPU_CLKSTOP		0x10
  #define SLCR_A9_CPU_RST			0x1
  
  void __iomem *zynq_slcr_base;
  
  /**
   * zynq_slcr_system_reset - Reset the entire system.
   */
  void zynq_slcr_system_reset(void)
  {
  	u32 reboot;
  
  	/*
  	 * Unlock the SLCR then reset the system.
  	 * Note that this seems to require raw i/o
  	 * functions or there's a lockup?
  	 */
  	writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + SLCR_UNLOCK_OFFSET);
  
  	/*
  	 * Clear 0x0F000000 bits of reboot status register to workaround
  	 * the FSBL not loading the bitstream after soft-reboot
  	 * This is a temporary solution until we know more.
  	 */
  	reboot = readl(zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
  	writel(reboot & 0xF0FFFFFF, zynq_slcr_base + SLCR_REBOOT_STATUS_OFFSET);
  	writel(1, zynq_slcr_base + SLCR_PS_RST_CTRL_OFFSET);
  }
  
  /**
   * zynq_slcr_cpu_start - Start cpu
   * @cpu:	cpu number
   */
  void zynq_slcr_cpu_start(int cpu)
  {
  	u32 reg = readl(zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
  	reg &= ~(SLCR_A9_CPU_RST << cpu);
  	writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
  	reg &= ~(SLCR_A9_CPU_CLKSTOP << cpu);
  	writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
  }
  
  /**
   * zynq_slcr_cpu_stop - Stop cpu
   * @cpu:	cpu number
   */
  void zynq_slcr_cpu_stop(int cpu)
  {
  	u32 reg = readl(zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
  	reg |= (SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu;
  	writel(reg, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL_OFFSET);
  }
  
  /**
   * zynq_slcr_init
   * Returns 0 on success, negative errno otherwise.
   *
   * Called early during boot from platform code to remap SLCR area.
   */
  int __init zynq_slcr_init(void)
  {
  	struct device_node *np;
  
  	np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-slcr");
  	if (!np) {
  		pr_err("%s: no slcr node found
  ", __func__);
  		BUG();
  	}
  
  	zynq_slcr_base = of_iomap(np, 0);
  	if (!zynq_slcr_base) {
  		pr_err("%s: Unable to map I/O memory
  ", __func__);
  		BUG();
  	}
  
  	/* unlock the SLCR so that registers can be changed */
  	writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + SLCR_UNLOCK_OFFSET);
  
  	pr_info("%s mapped to %p
  ", np->name, zynq_slcr_base);
  
  	zynq_clock_init(zynq_slcr_base);
  
  	of_node_put(np);
  
  	return 0;
  }