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200 lines
5.1 KiB
200 lines
5.1 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Copyright (C) 2010, Paul Cercueil <[email protected]> |
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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 <[email protected]>"); |
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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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