182 lines
4.1 KiB
C
182 lines
4.1 KiB
C
/*
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* Watchdog driver for the wm8350
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*
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* Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.com>
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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
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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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/platform_device.h>
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#include <linux/watchdog.h>
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#include <linux/uaccess.h>
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#include <linux/mfd/wm8350/core.h>
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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 DEFINE_MUTEX(wdt_mutex);
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static struct {
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unsigned int time; /* Seconds */
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u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */
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} wm8350_wdt_cfgs[] = {
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{ 1, 0x02 },
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{ 2, 0x04 },
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{ 4, 0x05 },
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};
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static int wm8350_wdt_set_timeout(struct watchdog_device *wdt_dev,
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unsigned int timeout)
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{
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struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
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int ret, i;
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u16 reg;
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for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++)
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if (wm8350_wdt_cfgs[i].time == timeout)
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break;
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if (i == ARRAY_SIZE(wm8350_wdt_cfgs))
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return -EINVAL;
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mutex_lock(&wdt_mutex);
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wm8350_reg_unlock(wm8350);
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reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
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reg &= ~WM8350_WDOG_TO_MASK;
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reg |= wm8350_wdt_cfgs[i].val;
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ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
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wm8350_reg_lock(wm8350);
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mutex_unlock(&wdt_mutex);
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wdt_dev->timeout = timeout;
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return ret;
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}
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static int wm8350_wdt_start(struct watchdog_device *wdt_dev)
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{
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struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
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int ret;
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u16 reg;
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mutex_lock(&wdt_mutex);
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wm8350_reg_unlock(wm8350);
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reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
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reg &= ~WM8350_WDOG_MODE_MASK;
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reg |= 0x20;
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ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
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wm8350_reg_lock(wm8350);
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mutex_unlock(&wdt_mutex);
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return ret;
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}
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static int wm8350_wdt_stop(struct watchdog_device *wdt_dev)
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{
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struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
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int ret;
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u16 reg;
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mutex_lock(&wdt_mutex);
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wm8350_reg_unlock(wm8350);
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reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
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reg &= ~WM8350_WDOG_MODE_MASK;
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ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
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wm8350_reg_lock(wm8350);
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mutex_unlock(&wdt_mutex);
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return ret;
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}
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static int wm8350_wdt_ping(struct watchdog_device *wdt_dev)
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{
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struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
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int ret;
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u16 reg;
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mutex_lock(&wdt_mutex);
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reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
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ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
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mutex_unlock(&wdt_mutex);
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return ret;
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}
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static const struct watchdog_info wm8350_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "WM8350 Watchdog",
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};
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static const struct watchdog_ops wm8350_wdt_ops = {
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.owner = THIS_MODULE,
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.start = wm8350_wdt_start,
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.stop = wm8350_wdt_stop,
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.ping = wm8350_wdt_ping,
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.set_timeout = wm8350_wdt_set_timeout,
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};
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static struct watchdog_device wm8350_wdt = {
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.info = &wm8350_wdt_info,
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.ops = &wm8350_wdt_ops,
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.timeout = 4,
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.min_timeout = 1,
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.max_timeout = 4,
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};
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static int wm8350_wdt_probe(struct platform_device *pdev)
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{
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struct wm8350 *wm8350 = platform_get_drvdata(pdev);
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if (!wm8350) {
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pr_err("No driver data supplied\n");
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return -ENODEV;
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}
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watchdog_set_nowayout(&wm8350_wdt, nowayout);
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watchdog_set_drvdata(&wm8350_wdt, wm8350);
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wm8350_wdt.parent = &pdev->dev;
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/* Default to 4s timeout */
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wm8350_wdt_set_timeout(&wm8350_wdt, 4);
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return watchdog_register_device(&wm8350_wdt);
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}
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static int wm8350_wdt_remove(struct platform_device *pdev)
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{
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watchdog_unregister_device(&wm8350_wdt);
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return 0;
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}
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static struct platform_driver wm8350_wdt_driver = {
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.probe = wm8350_wdt_probe,
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.remove = wm8350_wdt_remove,
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.driver = {
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.name = "wm8350-wdt",
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},
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};
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module_platform_driver(wm8350_wdt_driver);
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MODULE_AUTHOR("Mark Brown");
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MODULE_DESCRIPTION("WM8350 Watchdog");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:wm8350-wdt");
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