251 lines
6.4 KiB
C
251 lines
6.4 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Watchdog driver for DA9063 PMICs.
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*
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* Copyright(c) 2012 Dialog Semiconductor Ltd.
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*
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* Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/watchdog.h>
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#include <linux/platform_device.h>
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#include <linux/uaccess.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/mfd/da9063/registers.h>
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#include <linux/mfd/da9063/core.h>
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#include <linux/regmap.h>
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/*
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* Watchdog selector to timeout in seconds.
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* 0: WDT disabled;
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* others: timeout = 2048 ms * 2^(TWDSCALE-1).
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*/
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static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
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#define DA9063_TWDSCALE_DISABLE 0
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#define DA9063_TWDSCALE_MIN 1
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#define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
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#define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN]
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#define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX]
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#define DA9063_WDG_TIMEOUT wdt_timeout[3]
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#define DA9063_RESET_PROTECTION_MS 256
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static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
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{
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unsigned int i;
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for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
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if (wdt_timeout[i] >= secs)
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return i;
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}
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return DA9063_TWDSCALE_MAX;
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}
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/*
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* Read the currently active timeout.
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* Zero means the watchdog is disabled.
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*/
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static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063)
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{
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unsigned int val;
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regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
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return wdt_timeout[val & DA9063_TWDSCALE_MASK];
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}
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static int da9063_wdt_disable_timer(struct da9063 *da9063)
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{
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return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
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DA9063_TWDSCALE_MASK,
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DA9063_TWDSCALE_DISABLE);
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}
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static int
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da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout)
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{
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unsigned int regval;
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int ret;
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/*
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* The watchdog triggers a reboot if a timeout value is already
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* programmed because the timeout value combines two functions
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* in one: indicating the counter limit and starting the watchdog.
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* The watchdog must be disabled to be able to change the timeout
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* value if the watchdog is already running. Then we can set the
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* new timeout value which enables the watchdog again.
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*/
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ret = da9063_wdt_disable_timer(da9063);
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if (ret)
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return ret;
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usleep_range(150, 300);
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regval = da9063_wdt_timeout_to_sel(timeout);
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return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
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DA9063_TWDSCALE_MASK, regval);
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}
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static int da9063_wdt_start(struct watchdog_device *wdd)
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{
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struct da9063 *da9063 = watchdog_get_drvdata(wdd);
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int ret;
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ret = da9063_wdt_update_timeout(da9063, wdd->timeout);
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if (ret)
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dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
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ret);
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return ret;
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}
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static int da9063_wdt_stop(struct watchdog_device *wdd)
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{
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struct da9063 *da9063 = watchdog_get_drvdata(wdd);
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int ret;
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ret = da9063_wdt_disable_timer(da9063);
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if (ret)
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dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
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ret);
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return ret;
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}
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static int da9063_wdt_ping(struct watchdog_device *wdd)
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{
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struct da9063 *da9063 = watchdog_get_drvdata(wdd);
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int ret;
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ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
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DA9063_WATCHDOG);
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if (ret)
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dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
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ret);
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return ret;
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}
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static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
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unsigned int timeout)
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{
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struct da9063 *da9063 = watchdog_get_drvdata(wdd);
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int ret = 0;
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/*
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* There are two cases when a set_timeout() will be called:
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* 1. The watchdog is off and someone wants to set the timeout for the
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* further use.
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* 2. The watchdog is already running and a new timeout value should be
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* set.
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*
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* The watchdog can't store a timeout value not equal zero without
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* enabling the watchdog, so the timeout must be buffered by the driver.
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*/
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if (watchdog_active(wdd))
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ret = da9063_wdt_update_timeout(da9063, timeout);
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if (ret)
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dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
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ret);
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else
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wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)];
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return ret;
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}
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static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
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void *data)
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{
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struct da9063 *da9063 = watchdog_get_drvdata(wdd);
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int ret;
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ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
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DA9063_SHUTDOWN);
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if (ret)
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dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
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ret);
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return ret;
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}
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static const struct watchdog_info da9063_watchdog_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
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.identity = "DA9063 Watchdog",
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};
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static const struct watchdog_ops da9063_watchdog_ops = {
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.owner = THIS_MODULE,
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.start = da9063_wdt_start,
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.stop = da9063_wdt_stop,
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.ping = da9063_wdt_ping,
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.set_timeout = da9063_wdt_set_timeout,
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.restart = da9063_wdt_restart,
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};
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static int da9063_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct da9063 *da9063;
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struct watchdog_device *wdd;
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unsigned int timeout;
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if (!dev->parent)
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return -EINVAL;
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da9063 = dev_get_drvdata(dev->parent);
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if (!da9063)
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return -EINVAL;
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wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL);
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if (!wdd)
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return -ENOMEM;
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wdd->info = &da9063_watchdog_info;
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wdd->ops = &da9063_watchdog_ops;
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wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
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wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
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wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
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wdd->parent = dev;
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wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;
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watchdog_set_restart_priority(wdd, 128);
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watchdog_set_drvdata(wdd, da9063);
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wdd->timeout = DA9063_WDG_TIMEOUT;
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/* Use pre-configured timeout if watchdog is already running. */
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timeout = da9063_wdt_read_timeout(da9063);
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if (timeout)
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wdd->timeout = timeout;
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/* Set timeout, maybe override it with DT value, scale it */
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watchdog_init_timeout(wdd, 0, dev);
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da9063_wdt_set_timeout(wdd, wdd->timeout);
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/* Update timeout if the watchdog is already running. */
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if (timeout) {
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da9063_wdt_update_timeout(da9063, wdd->timeout);
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set_bit(WDOG_HW_RUNNING, &wdd->status);
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}
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return devm_watchdog_register_device(dev, wdd);
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}
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static struct platform_driver da9063_wdt_driver = {
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.probe = da9063_wdt_probe,
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.driver = {
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.name = DA9063_DRVNAME_WATCHDOG,
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},
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};
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module_platform_driver(da9063_wdt_driver);
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MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
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MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);
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