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254 lines
6.3 KiB
254 lines
6.3 KiB
/* |
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* da9062_wdt.c - WDT device driver for DA9062 |
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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 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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dev_set_drvdata(&pdev->dev, wdt); |
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ret = watchdog_register_device(&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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ret = da9062_wdt_ping(&wdt->wdtdev); |
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if (ret < 0) |
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watchdog_unregister_device(&wdt->wdtdev); |
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return ret; |
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} |
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static int da9062_wdt_remove(struct platform_device *pdev) |
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{ |
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struct da9062_watchdog *wdt = dev_get_drvdata(&pdev->dev); |
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watchdog_unregister_device(&wdt->wdtdev); |
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return 0; |
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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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.remove = da9062_wdt_remove, |
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.driver = { |
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.name = "da9062-watchdog", |
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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"); |
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MODULE_LICENSE("GPL"); |
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MODULE_ALIAS("platform:da9062-watchdog");
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