forked from Minki/linux
bfb1f46f69
While the custom minimal TXx9 clock implementation doesn't need or use clock (un)prepare calls (they are dummies if !CONFIG_HAVE_CLK_PREPARE), they are mandatory when using the Common Clock Framework. Hence add them, to prepare for the advent of CCF. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
179 lines
4.6 KiB
C
179 lines
4.6 KiB
C
/*
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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 <anemo@mba.ocn.ne.jp>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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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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struct resource *res;
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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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res = platform_get_resource(dev, IORESOURCE_MEM, 0);
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txx9wdt_reg = devm_ioremap_resource(&dev->dev, res);
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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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