Root/arch/mips/jz4740/reset.c

Source at commit ba6ccf453ba29606ccc3eae70b28021cd2be0b7d created 9 years 4 months ago.
By Maarten ter Huurne, MIPS: JZ4740: reset: Initialize hibernate wakeup counters.
1/*
2 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the
6 * Free Software Foundation; either version 2 of the License, or (at your
7 * option) any later version.
8 *
9 * You should have received a copy of the GNU General Public License along
10 * with this program; if not, write to the Free Software Foundation, Inc.,
11 * 675 Mass Ave, Cambridge, MA 02139, USA.
12 *
13 */
14
15#include <linux/io.h>
16#include <linux/kernel.h>
17#include <linux/pm.h>
18
19#include <asm/reboot.h>
20
21#include <asm/mach-jz4740/base.h>
22#include <asm/mach-jz4740/timer.h>
23
24#include "reset.h"
25#include "clock.h"
26
27static void jz4740_halt(void)
28{
29    while (1) {
30        __asm__(".set push;\n"
31            ".set mips3;\n"
32            "wait;\n"
33            ".set pop;\n"
34        );
35    }
36}
37
38#define JZ_REG_WDT_DATA 0x00
39#define JZ_REG_WDT_COUNTER_ENABLE 0x04
40#define JZ_REG_WDT_COUNTER 0x08
41#define JZ_REG_WDT_CTRL 0x0c
42
43static void jz4740_restart(char *command)
44{
45    void __iomem *wdt_base = ioremap(JZ4740_WDT_BASE_ADDR, 0x0f);
46
47    jz4740_timer_enable_watchdog();
48
49    writeb(0, wdt_base + JZ_REG_WDT_COUNTER_ENABLE);
50
51    writew(0, wdt_base + JZ_REG_WDT_COUNTER);
52    writew(0, wdt_base + JZ_REG_WDT_DATA);
53    writew(BIT(2), wdt_base + JZ_REG_WDT_CTRL);
54
55    writeb(1, wdt_base + JZ_REG_WDT_COUNTER_ENABLE);
56    jz4740_halt();
57}
58
59#define JZ_REG_RTC_CTRL 0x00
60#define JZ_REG_RTC_HIBERNATE 0x20
61#define JZ_REG_RTC_WAKEUP_FILTER 0x24
62#define JZ_REG_RTC_RESET_COUNTER 0x28
63
64#define JZ_RTC_CTRL_WRDY BIT(7)
65#define JZ_RTC_WAKEUP_FILTER_MASK 0x0000FFE0
66#define JZ_RTC_RESET_COUNTER_MASK 0x00000FE0
67
68static inline void jz4740_rtc_wait_ready(void __iomem *rtc_base)
69{
70    uint32_t ctrl;
71
72    do {
73        ctrl = readl(rtc_base + JZ_REG_RTC_CTRL);
74    } while (!(ctrl & JZ_RTC_CTRL_WRDY));
75}
76
77static void jz4740_power_off(void)
78{
79    void __iomem *rtc_base = ioremap(JZ4740_RTC_BASE_ADDR, 0x38);
80    unsigned long wakeup_filter_ticks;
81    unsigned long reset_counter_ticks;
82
83    /*
84     * Set minimum wakeup pin assertion time: 100 ms.
85     * Range is 0 to 2 sec if RTC is clocked at 32 kHz.
86     */
87    wakeup_filter_ticks = (100 * jz4740_clock_bdata.rtc_rate) / 1000;
88    if (wakeup_filter_ticks < JZ_RTC_WAKEUP_FILTER_MASK)
89        wakeup_filter_ticks &= JZ_RTC_WAKEUP_FILTER_MASK;
90    else
91        wakeup_filter_ticks = JZ_RTC_WAKEUP_FILTER_MASK;
92    jz4740_rtc_wait_ready(rtc_base);
93    writel(wakeup_filter_ticks, rtc_base + JZ_REG_RTC_WAKEUP_FILTER);
94
95    /*
96     * Set reset pin low-level assertion time after wakeup: 60 ms.
97     * Range is 0 to 125 ms if RTC is clocked at 32 kHz.
98     */
99    reset_counter_ticks = (60 * jz4740_clock_bdata.rtc_rate) / 1000;
100    if (reset_counter_ticks < JZ_RTC_RESET_COUNTER_MASK)
101        reset_counter_ticks &= JZ_RTC_RESET_COUNTER_MASK;
102    else
103        reset_counter_ticks = JZ_RTC_RESET_COUNTER_MASK;
104    jz4740_rtc_wait_ready(rtc_base);
105    writel(reset_counter_ticks, rtc_base + JZ_REG_RTC_RESET_COUNTER);
106
107    jz4740_rtc_wait_ready(rtc_base);
108    writel(1, rtc_base + JZ_REG_RTC_HIBERNATE);
109
110    jz4740_halt();
111}
112
113void jz4740_reset_init(void)
114{
115    _machine_restart = jz4740_restart;
116    _machine_halt = jz4740_halt;
117    pm_power_off = jz4740_power_off;
118}
119

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