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167 lines
4.2 KiB
167 lines
4.2 KiB
/* |
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* MOXA ART SoCs watchdog driver. |
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* |
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* Copyright (C) 2013 Jonas Jensen |
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* |
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* Jonas Jensen <[email protected]> |
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* |
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* This file is licensed under the terms of the GNU General Public |
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* License version 2. This program is licensed "as is" without any |
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* warranty of any kind, whether express or implied. |
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*/ |
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#include <linux/clk.h> |
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#include <linux/io.h> |
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#include <linux/module.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/err.h> |
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#include <linux/kernel.h> |
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#include <linux/platform_device.h> |
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#include <linux/watchdog.h> |
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#include <linux/moduleparam.h> |
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#define REG_COUNT 0x4 |
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#define REG_MODE 0x8 |
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#define REG_ENABLE 0xC |
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struct moxart_wdt_dev { |
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struct watchdog_device dev; |
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void __iomem *base; |
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unsigned int clock_frequency; |
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}; |
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static int heartbeat; |
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static int moxart_wdt_restart(struct watchdog_device *wdt_dev, |
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unsigned long action, void *data) |
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{ |
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struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); |
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writel(1, moxart_wdt->base + REG_COUNT); |
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writel(0x5ab9, moxart_wdt->base + REG_MODE); |
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writel(0x03, moxart_wdt->base + REG_ENABLE); |
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return 0; |
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} |
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static int moxart_wdt_stop(struct watchdog_device *wdt_dev) |
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{ |
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struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); |
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writel(0, moxart_wdt->base + REG_ENABLE); |
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return 0; |
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} |
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static int moxart_wdt_start(struct watchdog_device *wdt_dev) |
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{ |
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struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev); |
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writel(moxart_wdt->clock_frequency * wdt_dev->timeout, |
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moxart_wdt->base + REG_COUNT); |
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writel(0x5ab9, moxart_wdt->base + REG_MODE); |
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writel(0x03, moxart_wdt->base + REG_ENABLE); |
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return 0; |
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} |
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static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev, |
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unsigned int timeout) |
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{ |
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wdt_dev->timeout = timeout; |
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return 0; |
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} |
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static const struct watchdog_info moxart_wdt_info = { |
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.identity = "moxart-wdt", |
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | |
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WDIOF_MAGICCLOSE, |
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}; |
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static const struct watchdog_ops moxart_wdt_ops = { |
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.owner = THIS_MODULE, |
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.start = moxart_wdt_start, |
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.stop = moxart_wdt_stop, |
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.set_timeout = moxart_wdt_set_timeout, |
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.restart = moxart_wdt_restart, |
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}; |
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static int moxart_wdt_probe(struct platform_device *pdev) |
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{ |
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struct moxart_wdt_dev *moxart_wdt; |
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struct device *dev = &pdev->dev; |
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struct clk *clk; |
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int err; |
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unsigned int max_timeout; |
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bool nowayout = WATCHDOG_NOWAYOUT; |
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moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL); |
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if (!moxart_wdt) |
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return -ENOMEM; |
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platform_set_drvdata(pdev, moxart_wdt); |
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moxart_wdt->base = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(moxart_wdt->base)) |
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return PTR_ERR(moxart_wdt->base); |
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clk = devm_clk_get(dev, NULL); |
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if (IS_ERR(clk)) { |
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pr_err("%s: of_clk_get failed\n", __func__); |
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return PTR_ERR(clk); |
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} |
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moxart_wdt->clock_frequency = clk_get_rate(clk); |
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if (moxart_wdt->clock_frequency == 0) { |
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pr_err("%s: incorrect clock frequency\n", __func__); |
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return -EINVAL; |
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} |
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max_timeout = UINT_MAX / moxart_wdt->clock_frequency; |
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moxart_wdt->dev.info = &moxart_wdt_info; |
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moxart_wdt->dev.ops = &moxart_wdt_ops; |
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moxart_wdt->dev.timeout = max_timeout; |
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moxart_wdt->dev.min_timeout = 1; |
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moxart_wdt->dev.max_timeout = max_timeout; |
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moxart_wdt->dev.parent = dev; |
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watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev); |
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watchdog_set_nowayout(&moxart_wdt->dev, nowayout); |
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watchdog_set_restart_priority(&moxart_wdt->dev, 128); |
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watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt); |
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watchdog_stop_on_unregister(&moxart_wdt->dev); |
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err = devm_watchdog_register_device(dev, &moxart_wdt->dev); |
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if (err) |
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return err; |
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dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n", |
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moxart_wdt->dev.timeout, nowayout); |
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return 0; |
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} |
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static const struct of_device_id moxart_watchdog_match[] = { |
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{ .compatible = "moxa,moxart-watchdog" }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, moxart_watchdog_match); |
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static struct platform_driver moxart_wdt_driver = { |
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.probe = moxart_wdt_probe, |
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.driver = { |
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.name = "moxart-watchdog", |
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.of_match_table = moxart_watchdog_match, |
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}, |
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}; |
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module_platform_driver(moxart_wdt_driver); |
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module_param(heartbeat, int, 0); |
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MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds"); |
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MODULE_DESCRIPTION("MOXART watchdog driver"); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Jonas Jensen <[email protected]>");
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