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![Wei Yongjun](/assets/img/avatar_default.png)
In case of error, the function device_node_to_regmap() returns
ERR_PTR() and never returns NULL. The NULL test in the return
value check should be replaced with IS_ERR().
Fixes: 6d532143c9
("watchdog: jz4740: Use regmap provided by TCU driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20210304045909.945799-1-weiyongjun1@huawei.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
200 lines
5.1 KiB
C
200 lines
5.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2010, Paul Cercueil <paul@crapouillou.net>
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* JZ4740 Watchdog driver
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*/
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#include <linux/mfd/ingenic-tcu.h>
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#include <linux/mfd/syscon.h>
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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/kernel.h>
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#include <linux/watchdog.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/device.h>
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#include <linux/clk.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/of.h>
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#include <linux/regmap.h>
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#define DEFAULT_HEARTBEAT 5
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#define MAX_HEARTBEAT 2048
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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 (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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static unsigned int heartbeat = DEFAULT_HEARTBEAT;
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module_param(heartbeat, uint, 0);
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MODULE_PARM_DESC(heartbeat,
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"Watchdog heartbeat period in seconds from 1 to "
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__MODULE_STRING(MAX_HEARTBEAT) ", default "
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__MODULE_STRING(DEFAULT_HEARTBEAT));
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struct jz4740_wdt_drvdata {
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struct watchdog_device wdt;
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struct regmap *map;
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struct clk *clk;
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unsigned long clk_rate;
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};
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static int jz4740_wdt_ping(struct watchdog_device *wdt_dev)
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{
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struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
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return 0;
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}
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static int jz4740_wdt_set_timeout(struct watchdog_device *wdt_dev,
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unsigned int new_timeout)
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{
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struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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u16 timeout_value = (u16)(drvdata->clk_rate * new_timeout);
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unsigned int tcer;
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regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);
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regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
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regmap_write(drvdata->map, TCU_REG_WDT_TDR, timeout_value);
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regmap_write(drvdata->map, TCU_REG_WDT_TCNT, 0);
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if (tcer & TCU_WDT_TCER_TCEN)
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regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
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wdt_dev->timeout = new_timeout;
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return 0;
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}
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static int jz4740_wdt_start(struct watchdog_device *wdt_dev)
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{
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struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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unsigned int tcer;
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int ret;
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ret = clk_prepare_enable(drvdata->clk);
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if (ret)
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return ret;
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regmap_read(drvdata->map, TCU_REG_WDT_TCER, &tcer);
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jz4740_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
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/* Start watchdog if it wasn't started already */
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if (!(tcer & TCU_WDT_TCER_TCEN))
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regmap_write(drvdata->map, TCU_REG_WDT_TCER, TCU_WDT_TCER_TCEN);
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return 0;
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}
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static int jz4740_wdt_stop(struct watchdog_device *wdt_dev)
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{
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struct jz4740_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
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regmap_write(drvdata->map, TCU_REG_WDT_TCER, 0);
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clk_disable_unprepare(drvdata->clk);
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return 0;
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}
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static int jz4740_wdt_restart(struct watchdog_device *wdt_dev,
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unsigned long action, void *data)
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{
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wdt_dev->timeout = 0;
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jz4740_wdt_start(wdt_dev);
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return 0;
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}
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static const struct watchdog_info jz4740_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "jz4740 Watchdog",
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};
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static const struct watchdog_ops jz4740_wdt_ops = {
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.owner = THIS_MODULE,
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.start = jz4740_wdt_start,
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.stop = jz4740_wdt_stop,
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.ping = jz4740_wdt_ping,
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.set_timeout = jz4740_wdt_set_timeout,
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.restart = jz4740_wdt_restart,
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};
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#ifdef CONFIG_OF
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static const struct of_device_id jz4740_wdt_of_matches[] = {
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{ .compatible = "ingenic,jz4740-watchdog", },
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{ .compatible = "ingenic,jz4780-watchdog", },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, jz4740_wdt_of_matches);
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#endif
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static int jz4740_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct jz4740_wdt_drvdata *drvdata;
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struct watchdog_device *jz4740_wdt;
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long rate;
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int ret;
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drvdata = devm_kzalloc(dev, sizeof(struct jz4740_wdt_drvdata),
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GFP_KERNEL);
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if (!drvdata)
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return -ENOMEM;
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drvdata->clk = devm_clk_get(&pdev->dev, "wdt");
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if (IS_ERR(drvdata->clk)) {
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dev_err(&pdev->dev, "cannot find WDT clock\n");
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return PTR_ERR(drvdata->clk);
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}
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/* Set smallest clock possible */
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rate = clk_round_rate(drvdata->clk, 1);
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if (rate < 0)
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return rate;
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ret = clk_set_rate(drvdata->clk, rate);
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if (ret)
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return ret;
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drvdata->clk_rate = rate;
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jz4740_wdt = &drvdata->wdt;
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jz4740_wdt->info = &jz4740_wdt_info;
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jz4740_wdt->ops = &jz4740_wdt_ops;
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jz4740_wdt->min_timeout = 1;
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jz4740_wdt->max_timeout = 0xffff / rate;
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jz4740_wdt->timeout = clamp(heartbeat,
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jz4740_wdt->min_timeout,
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jz4740_wdt->max_timeout);
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jz4740_wdt->parent = dev;
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watchdog_set_nowayout(jz4740_wdt, nowayout);
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watchdog_set_drvdata(jz4740_wdt, drvdata);
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drvdata->map = device_node_to_regmap(dev->parent->of_node);
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if (IS_ERR(drvdata->map)) {
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dev_err(dev, "regmap not found\n");
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return PTR_ERR(drvdata->map);
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}
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return devm_watchdog_register_device(dev, &drvdata->wdt);
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}
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static struct platform_driver jz4740_wdt_driver = {
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.probe = jz4740_wdt_probe,
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.driver = {
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.name = "jz4740-wdt",
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.of_match_table = of_match_ptr(jz4740_wdt_of_matches),
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},
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};
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module_platform_driver(jz4740_wdt_driver);
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MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
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MODULE_DESCRIPTION("jz4740 Watchdog Driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:jz4740-wdt");
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