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173 lines
4.4 KiB
173 lines
4.4 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* txx9wdt: A Hardware Watchdog Driver for TXx9 SoCs |
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* |
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* Copyright (C) 2007 Atsushi Nemoto <[email protected]> |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/types.h> |
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#include <linux/watchdog.h> |
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#include <linux/init.h> |
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#include <linux/platform_device.h> |
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#include <linux/clk.h> |
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#include <linux/err.h> |
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#include <linux/io.h> |
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#include <asm/txx9tmr.h> |
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#define WD_TIMER_CCD 7 /* 1/256 */ |
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#define WD_TIMER_CLK (clk_get_rate(txx9_imclk) / (2 << WD_TIMER_CCD)) |
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#define WD_MAX_TIMEOUT ((0xffffffff >> (32 - TXX9_TIMER_BITS)) / WD_TIMER_CLK) |
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#define TIMER_MARGIN 60 /* Default is 60 seconds */ |
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static unsigned int timeout = TIMER_MARGIN; /* in seconds */ |
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module_param(timeout, uint, 0); |
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MODULE_PARM_DESC(timeout, |
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"Watchdog timeout in seconds. " |
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"(0<timeout<((2^" __MODULE_STRING(TXX9_TIMER_BITS) ")/(IMCLK/256)), " |
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"default=" __MODULE_STRING(TIMER_MARGIN) ")"); |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(nowayout, |
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"Watchdog cannot be stopped once started " |
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"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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static struct txx9_tmr_reg __iomem *txx9wdt_reg; |
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static struct clk *txx9_imclk; |
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static DEFINE_SPINLOCK(txx9_lock); |
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static int txx9wdt_ping(struct watchdog_device *wdt_dev) |
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{ |
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spin_lock(&txx9_lock); |
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__raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr); |
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spin_unlock(&txx9_lock); |
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return 0; |
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} |
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static int txx9wdt_start(struct watchdog_device *wdt_dev) |
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{ |
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spin_lock(&txx9_lock); |
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__raw_writel(WD_TIMER_CLK * wdt_dev->timeout, &txx9wdt_reg->cpra); |
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__raw_writel(WD_TIMER_CCD, &txx9wdt_reg->ccdr); |
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__raw_writel(0, &txx9wdt_reg->tisr); /* clear pending interrupt */ |
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__raw_writel(TXx9_TMTCR_TCE | TXx9_TMTCR_CCDE | TXx9_TMTCR_TMODE_WDOG, |
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&txx9wdt_reg->tcr); |
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__raw_writel(TXx9_TMWTMR_TWIE | TXx9_TMWTMR_TWC, &txx9wdt_reg->wtmr); |
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spin_unlock(&txx9_lock); |
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return 0; |
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} |
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static int txx9wdt_stop(struct watchdog_device *wdt_dev) |
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{ |
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spin_lock(&txx9_lock); |
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__raw_writel(TXx9_TMWTMR_WDIS, &txx9wdt_reg->wtmr); |
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__raw_writel(__raw_readl(&txx9wdt_reg->tcr) & ~TXx9_TMTCR_TCE, |
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&txx9wdt_reg->tcr); |
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spin_unlock(&txx9_lock); |
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return 0; |
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} |
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static int txx9wdt_set_timeout(struct watchdog_device *wdt_dev, |
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unsigned int new_timeout) |
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{ |
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wdt_dev->timeout = new_timeout; |
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txx9wdt_stop(wdt_dev); |
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txx9wdt_start(wdt_dev); |
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return 0; |
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} |
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static const struct watchdog_info txx9wdt_info = { |
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
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.identity = "Hardware Watchdog for TXx9", |
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}; |
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static const struct watchdog_ops txx9wdt_ops = { |
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.owner = THIS_MODULE, |
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.start = txx9wdt_start, |
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.stop = txx9wdt_stop, |
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.ping = txx9wdt_ping, |
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.set_timeout = txx9wdt_set_timeout, |
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}; |
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static struct watchdog_device txx9wdt = { |
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.info = &txx9wdt_info, |
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.ops = &txx9wdt_ops, |
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}; |
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static int __init txx9wdt_probe(struct platform_device *dev) |
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{ |
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int ret; |
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txx9_imclk = clk_get(NULL, "imbus_clk"); |
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if (IS_ERR(txx9_imclk)) { |
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ret = PTR_ERR(txx9_imclk); |
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txx9_imclk = NULL; |
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goto exit; |
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} |
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ret = clk_prepare_enable(txx9_imclk); |
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if (ret) { |
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clk_put(txx9_imclk); |
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txx9_imclk = NULL; |
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goto exit; |
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} |
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txx9wdt_reg = devm_platform_ioremap_resource(dev, 0); |
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if (IS_ERR(txx9wdt_reg)) { |
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ret = PTR_ERR(txx9wdt_reg); |
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goto exit; |
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} |
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if (timeout < 1 || timeout > WD_MAX_TIMEOUT) |
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timeout = TIMER_MARGIN; |
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txx9wdt.timeout = timeout; |
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txx9wdt.min_timeout = 1; |
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txx9wdt.max_timeout = WD_MAX_TIMEOUT; |
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txx9wdt.parent = &dev->dev; |
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watchdog_set_nowayout(&txx9wdt, nowayout); |
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ret = watchdog_register_device(&txx9wdt); |
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if (ret) |
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goto exit; |
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pr_info("Hardware Watchdog Timer: timeout=%d sec (max %ld) (nowayout= %d)\n", |
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timeout, WD_MAX_TIMEOUT, nowayout); |
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return 0; |
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exit: |
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if (txx9_imclk) { |
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clk_disable_unprepare(txx9_imclk); |
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clk_put(txx9_imclk); |
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} |
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return ret; |
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} |
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static int __exit txx9wdt_remove(struct platform_device *dev) |
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{ |
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watchdog_unregister_device(&txx9wdt); |
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clk_disable_unprepare(txx9_imclk); |
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clk_put(txx9_imclk); |
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return 0; |
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} |
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static void txx9wdt_shutdown(struct platform_device *dev) |
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{ |
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txx9wdt_stop(&txx9wdt); |
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} |
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static struct platform_driver txx9wdt_driver = { |
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.remove = __exit_p(txx9wdt_remove), |
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.shutdown = txx9wdt_shutdown, |
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.driver = { |
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.name = "txx9wdt", |
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}, |
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}; |
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module_platform_driver_probe(txx9wdt_driver, txx9wdt_probe); |
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MODULE_DESCRIPTION("TXx9 Watchdog Driver"); |
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MODULE_LICENSE("GPL"); |
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MODULE_ALIAS("platform:txx9wdt");
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