103 lines
2.4 KiB
C
103 lines
2.4 KiB
C
/*
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* JZ4740 Watchdog driver
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*
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* Copyright (C) 2014 Antony Pavlov <antonynpavlov@gmail.com>
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*
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* Based on jz4740_wdt.c from linux-3.15.
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*
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* Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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*/
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#include <common.h>
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#include <init.h>
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#include <io.h>
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#define JZ_REG_WDT_TIMER_DATA 0x0
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#define JZ_REG_WDT_COUNTER_ENABLE 0x4
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#define JZ_REG_WDT_TIMER_COUNTER 0x8
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#define JZ_REG_WDT_TIMER_CONTROL 0xC
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#define JZ_WDT_CLOCK_PCLK 0x1
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#define JZ_WDT_CLOCK_RTC 0x2
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#define JZ_WDT_CLOCK_EXT 0x4
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#define JZ_WDT_CLOCK_DIV_SHIFT 3
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#define JZ_WDT_CLOCK_DIV_1 (0 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_4 (1 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_16 (2 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_64 (3 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_256 (4 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_WDT_CLOCK_DIV_1024 (5 << JZ_WDT_CLOCK_DIV_SHIFT)
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#define JZ_EXTAL 24000000
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struct jz4740_wdt_drvdata {
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void __iomem *base;
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};
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static struct jz4740_wdt_drvdata *reset_wd;
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void __noreturn reset_cpu(unsigned long addr)
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{
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if (reset_wd) {
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void __iomem *base = reset_wd->base;
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writew(JZ_WDT_CLOCK_DIV_4 | JZ_WDT_CLOCK_EXT,
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base + JZ_REG_WDT_TIMER_CONTROL);
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writew(0, base + JZ_REG_WDT_TIMER_COUNTER);
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/* reset after 4ms */
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writew(JZ_EXTAL / 1000, base + JZ_REG_WDT_TIMER_DATA);
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/* start wdt */
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writeb(0x1, base + JZ_REG_WDT_COUNTER_ENABLE);
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mdelay(1000);
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} else
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pr_err("%s: can't reset cpu\n", __func__);
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hang();
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}
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EXPORT_SYMBOL(reset_cpu);
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static int jz4740_wdt_probe(struct device_d *dev)
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{
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struct jz4740_wdt_drvdata *priv;
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priv = xzalloc(sizeof(struct jz4740_wdt_drvdata));
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priv->base = dev_request_mem_region(dev, 0);
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if (!priv->base) {
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dev_err(dev, "could not get memory region\n");
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return -ENODEV;
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}
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if (!reset_wd)
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reset_wd = priv;
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dev->priv = priv;
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return 0;
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}
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static __maybe_unused struct of_device_id jz4740_wdt_dt_ids[] = {
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{
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.compatible = "ingenic,jz4740-wdt",
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}, {
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/* sentinel */
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}
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};
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static struct driver_d jz4740_wdt_driver = {
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.name = "jz4740-wdt",
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.probe = jz4740_wdt_probe,
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.of_compatible = DRV_OF_COMPAT(jz4740_wdt_dt_ids),
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};
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device_platform_driver(jz4740_wdt_driver);
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