249 lines
6.2 KiB
C
249 lines
6.2 KiB
C
/*
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* Watchdog device driver for DA9062 and DA9061 PMICs
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* Copyright (C) 2015 Dialog Semiconductor Ltd.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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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/jiffies.h>
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#include <linux/mfd/da9062/registers.h>
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#include <linux/mfd/da9062/core.h>
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#include <linux/regmap.h>
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#include <linux/of.h>
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static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
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#define DA9062_TWDSCALE_DISABLE 0
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#define DA9062_TWDSCALE_MIN 1
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#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
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#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN]
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#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX]
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#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1]
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#define DA9062_RESET_PROTECTION_MS 300
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struct da9062_watchdog {
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struct da9062 *hw;
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struct watchdog_device wdtdev;
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unsigned long j_time_stamp;
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};
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static void da9062_set_window_start(struct da9062_watchdog *wdt)
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{
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wdt->j_time_stamp = jiffies;
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}
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static void da9062_apply_window_protection(struct da9062_watchdog *wdt)
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{
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unsigned long delay = msecs_to_jiffies(DA9062_RESET_PROTECTION_MS);
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unsigned long timeout = wdt->j_time_stamp + delay;
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unsigned long now = jiffies;
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unsigned int diff_ms;
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/* if time-limit has not elapsed then wait for remainder */
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if (time_before(now, timeout)) {
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diff_ms = jiffies_to_msecs(timeout-now);
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dev_dbg(wdt->hw->dev,
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"Kicked too quickly. Delaying %u msecs\n", diff_ms);
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msleep(diff_ms);
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}
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}
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static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
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{
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unsigned int i;
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for (i = DA9062_TWDSCALE_MIN; i <= DA9062_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 DA9062_TWDSCALE_MAX;
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}
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static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
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{
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int ret;
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da9062_apply_window_protection(wdt);
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ret = regmap_update_bits(wdt->hw->regmap,
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DA9062AA_CONTROL_F,
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DA9062AA_WATCHDOG_MASK,
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DA9062AA_WATCHDOG_MASK);
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da9062_set_window_start(wdt);
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return ret;
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}
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static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
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unsigned int regval)
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{
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struct da9062 *chip = wdt->hw;
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int ret;
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ret = da9062_reset_watchdog_timer(wdt);
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if (ret)
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return ret;
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return regmap_update_bits(chip->regmap,
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DA9062AA_CONTROL_D,
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DA9062AA_TWDSCALE_MASK,
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regval);
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}
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static int da9062_wdt_start(struct watchdog_device *wdd)
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{
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struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
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unsigned int selector;
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int ret;
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selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
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ret = da9062_wdt_update_timeout_register(wdt, selector);
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if (ret)
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dev_err(wdt->hw->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 da9062_wdt_stop(struct watchdog_device *wdd)
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{
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struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
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int ret;
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ret = da9062_reset_watchdog_timer(wdt);
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if (ret) {
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dev_err(wdt->hw->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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ret = regmap_update_bits(wdt->hw->regmap,
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DA9062AA_CONTROL_D,
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DA9062AA_TWDSCALE_MASK,
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DA9062_TWDSCALE_DISABLE);
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if (ret)
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dev_err(wdt->hw->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 da9062_wdt_ping(struct watchdog_device *wdd)
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{
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struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
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int ret;
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ret = da9062_reset_watchdog_timer(wdt);
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if (ret)
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dev_err(wdt->hw->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 da9062_wdt_set_timeout(struct watchdog_device *wdd,
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unsigned int timeout)
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{
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struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
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unsigned int selector;
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int ret;
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selector = da9062_wdt_timeout_to_sel(timeout);
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ret = da9062_wdt_update_timeout_register(wdt, selector);
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if (ret)
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dev_err(wdt->hw->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[selector];
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return ret;
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}
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static const struct watchdog_info da9062_watchdog_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
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.identity = "DA9062 WDT",
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};
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static const struct watchdog_ops da9062_watchdog_ops = {
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.owner = THIS_MODULE,
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.start = da9062_wdt_start,
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.stop = da9062_wdt_stop,
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.ping = da9062_wdt_ping,
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.set_timeout = da9062_wdt_set_timeout,
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};
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static const struct of_device_id da9062_compatible_id_table[] = {
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{ .compatible = "dlg,da9062-watchdog", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
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static int da9062_wdt_probe(struct platform_device *pdev)
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{
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int ret;
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struct da9062 *chip;
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struct da9062_watchdog *wdt;
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chip = dev_get_drvdata(pdev->dev.parent);
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if (!chip)
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return -EINVAL;
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wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
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if (!wdt)
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return -ENOMEM;
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wdt->hw = chip;
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wdt->wdtdev.info = &da9062_watchdog_info;
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wdt->wdtdev.ops = &da9062_watchdog_ops;
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wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
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wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
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wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
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wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
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wdt->wdtdev.parent = &pdev->dev;
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watchdog_set_drvdata(&wdt->wdtdev, wdt);
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ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev);
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if (ret < 0) {
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dev_err(wdt->hw->dev,
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"watchdog registration failed (%d)\n", ret);
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return ret;
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}
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da9062_set_window_start(wdt);
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return da9062_wdt_ping(&wdt->wdtdev);
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}
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static struct platform_driver da9062_wdt_driver = {
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.probe = da9062_wdt_probe,
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.driver = {
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.name = "da9062-watchdog",
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.of_match_table = da9062_compatible_id_table,
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},
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};
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module_platform_driver(da9062_wdt_driver);
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MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
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MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:da9062-watchdog");
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