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
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
/*
* Copyright (C) 1999 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd
* Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
* Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <asm/proc-fns.h>
#include <asm/system.h>
#include <mach/mxs.h>
#include <mach/common.h>
#define MX23_CLKCTRL_RESET_OFFSET 0x120
#define MX28_CLKCTRL_RESET_OFFSET 0x1e0
#define MXS_CLKCTRL_RESET_CHIP (1 << 1)
#define MXS_MODULE_CLKGATE (1 << 30)
#define MXS_MODULE_SFTRST (1 << 31)
static void __iomem *mxs_clkctrl_reset_addr;
/*
* Reset the system. It is called by machine_restart().
*/
void arch_reset(char mode, const char *cmd)
{
/* reset the chip */
__mxs_setl(MXS_CLKCTRL_RESET_CHIP, mxs_clkctrl_reset_addr);
pr_err("Failed to assert the chip reset\n");
/* Delay to allow the serial port to show the message */
mdelay(50);
/* We'll take a jump through zero as a poor second */
cpu_reset(0);
}
static int __init mxs_arch_reset_init(void)
{
struct clk *clk;
mxs_clkctrl_reset_addr = MXS_IO_ADDRESS(MXS_CLKCTRL_BASE_ADDR) +
(cpu_is_mx23() ? MX23_CLKCTRL_RESET_OFFSET :
MX28_CLKCTRL_RESET_OFFSET);
clk = clk_get_sys("rtc", NULL);
if (!IS_ERR(clk))
clk_enable(clk);
return 0;
}
core_initcall(mxs_arch_reset_init);
/*
* Clear the bit and poll it cleared. This is usually called with
* a reset address and mask being either SFTRST(bit 31) or CLKGATE
* (bit 30).
*/
static int clear_poll_bit(void __iomem *addr, u32 mask)
{
int timeout = 0x400;
/* clear the bit */
__mxs_clrl(mask, addr);
/*
* SFTRST needs 3 GPMI clocks to settle, the reference manual
* recommends to wait 1us.
*/
udelay(1);
/* poll the bit becoming clear */
while ((__raw_readl(addr) & mask) && --timeout)
/* nothing */;
return !timeout;
}
int mxs_reset_block(void __iomem *reset_addr)
{
int ret;
int timeout = 0x400;
/* clear and poll SFTRST */
ret = clear_poll_bit(reset_addr, MXS_MODULE_SFTRST);
if (unlikely(ret))
goto error;
/* clear CLKGATE */
__mxs_clrl(MXS_MODULE_CLKGATE, reset_addr);
/* set SFTRST to reset the block */
__mxs_setl(MXS_MODULE_SFTRST, reset_addr);
udelay(1);
/* poll CLKGATE becoming set */
while ((!(__raw_readl(reset_addr) & MXS_MODULE_CLKGATE)) && --timeout)
/* nothing */;
if (unlikely(!timeout))
goto error;
/* clear and poll SFTRST */
ret = clear_poll_bit(reset_addr, MXS_MODULE_SFTRST);
if (unlikely(ret))
goto error;
/* clear and poll CLKGATE */
ret = clear_poll_bit(reset_addr, MXS_MODULE_CLKGATE);
if (unlikely(ret))
goto error;
return 0;
error:
pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
return -ETIMEDOUT;
}
|
