Guenter Roeck | d017327 | 2019-06-20 09:28:46 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 2 | /* |
| 3 | * Retu watchdog driver |
| 4 | * |
| 5 | * Copyright (C) 2004, 2005 Nokia Corporation |
| 6 | * |
| 7 | * Based on code written by Amit Kucheria and Michael Buesch. |
| 8 | * Rewritten by Aaro Koskinen. |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 9 | */ |
| 10 | |
Matti Vaittinen | a7d30f3 | 2021-03-23 15:58:28 +0200 | [diff] [blame] | 11 | #include <linux/devm-helpers.h> |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 12 | #include <linux/slab.h> |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/device.h> |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/mfd/retu.h> |
| 18 | #include <linux/watchdog.h> |
| 19 | #include <linux/platform_device.h> |
| 20 | |
| 21 | /* Watchdog timer values in seconds */ |
| 22 | #define RETU_WDT_MAX_TIMER 63 |
| 23 | |
| 24 | struct retu_wdt_dev { |
| 25 | struct retu_dev *rdev; |
| 26 | struct device *dev; |
| 27 | struct delayed_work ping_work; |
| 28 | }; |
| 29 | |
| 30 | /* |
| 31 | * Since Retu watchdog cannot be disabled in hardware, we must kick it |
| 32 | * with a timer until userspace watchdog software takes over. If |
| 33 | * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding. |
| 34 | */ |
| 35 | static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev) |
| 36 | { |
| 37 | retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER); |
| 38 | schedule_delayed_work(&wdev->ping_work, |
| 39 | round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2)); |
| 40 | } |
| 41 | |
| 42 | static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev) |
| 43 | { |
| 44 | retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER); |
| 45 | cancel_delayed_work_sync(&wdev->ping_work); |
| 46 | } |
| 47 | |
| 48 | static void retu_wdt_ping_work(struct work_struct *work) |
| 49 | { |
| 50 | struct retu_wdt_dev *wdev = container_of(to_delayed_work(work), |
| 51 | struct retu_wdt_dev, ping_work); |
| 52 | retu_wdt_ping_enable(wdev); |
| 53 | } |
| 54 | |
| 55 | static int retu_wdt_start(struct watchdog_device *wdog) |
| 56 | { |
| 57 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); |
| 58 | |
| 59 | retu_wdt_ping_disable(wdev); |
| 60 | |
| 61 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); |
| 62 | } |
| 63 | |
| 64 | static int retu_wdt_stop(struct watchdog_device *wdog) |
| 65 | { |
| 66 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); |
| 67 | |
| 68 | retu_wdt_ping_enable(wdev); |
| 69 | |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | static int retu_wdt_ping(struct watchdog_device *wdog) |
| 74 | { |
| 75 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); |
| 76 | |
| 77 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); |
| 78 | } |
| 79 | |
| 80 | static int retu_wdt_set_timeout(struct watchdog_device *wdog, |
| 81 | unsigned int timeout) |
| 82 | { |
| 83 | struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog); |
| 84 | |
| 85 | wdog->timeout = timeout; |
| 86 | return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout); |
| 87 | } |
| 88 | |
| 89 | static const struct watchdog_info retu_wdt_info = { |
Tony Lindgren | fb1cbea | 2014-10-14 12:25:19 -0700 | [diff] [blame] | 90 | .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 91 | .identity = "Retu watchdog", |
| 92 | }; |
| 93 | |
| 94 | static const struct watchdog_ops retu_wdt_ops = { |
| 95 | .owner = THIS_MODULE, |
| 96 | .start = retu_wdt_start, |
| 97 | .stop = retu_wdt_stop, |
| 98 | .ping = retu_wdt_ping, |
| 99 | .set_timeout = retu_wdt_set_timeout, |
| 100 | }; |
| 101 | |
| 102 | static int retu_wdt_probe(struct platform_device *pdev) |
| 103 | { |
| 104 | struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent); |
| 105 | bool nowayout = WATCHDOG_NOWAYOUT; |
| 106 | struct watchdog_device *retu_wdt; |
| 107 | struct retu_wdt_dev *wdev; |
| 108 | int ret; |
| 109 | |
| 110 | retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL); |
| 111 | if (!retu_wdt) |
| 112 | return -ENOMEM; |
| 113 | |
| 114 | wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL); |
| 115 | if (!wdev) |
| 116 | return -ENOMEM; |
| 117 | |
| 118 | retu_wdt->info = &retu_wdt_info; |
| 119 | retu_wdt->ops = &retu_wdt_ops; |
| 120 | retu_wdt->timeout = RETU_WDT_MAX_TIMER; |
| 121 | retu_wdt->min_timeout = 0; |
| 122 | retu_wdt->max_timeout = RETU_WDT_MAX_TIMER; |
Pratyush Anand | 6551881 | 2015-08-20 14:05:01 +0530 | [diff] [blame] | 123 | retu_wdt->parent = &pdev->dev; |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 124 | |
| 125 | watchdog_set_drvdata(retu_wdt, wdev); |
| 126 | watchdog_set_nowayout(retu_wdt, nowayout); |
| 127 | |
| 128 | wdev->rdev = rdev; |
| 129 | wdev->dev = &pdev->dev; |
| 130 | |
Matti Vaittinen | a7d30f3 | 2021-03-23 15:58:28 +0200 | [diff] [blame] | 131 | ret = devm_delayed_work_autocancel(&pdev->dev, &wdev->ping_work, |
| 132 | retu_wdt_ping_work); |
| 133 | if (ret) |
| 134 | return ret; |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 135 | |
Matti Vaittinen | a7d30f3 | 2021-03-23 15:58:28 +0200 | [diff] [blame] | 136 | ret = devm_watchdog_register_device(&pdev->dev, retu_wdt); |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 137 | if (ret < 0) |
| 138 | return ret; |
| 139 | |
| 140 | if (nowayout) |
| 141 | retu_wdt_ping(retu_wdt); |
| 142 | else |
| 143 | retu_wdt_ping_enable(wdev); |
| 144 | |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 145 | return 0; |
| 146 | } |
| 147 | |
| 148 | static struct platform_driver retu_wdt_driver = { |
| 149 | .probe = retu_wdt_probe, |
Aaro Koskinen | 3d3a6d1 | 2012-12-27 22:58:29 +0200 | [diff] [blame] | 150 | .driver = { |
| 151 | .name = "retu-wdt", |
| 152 | }, |
| 153 | }; |
| 154 | module_platform_driver(retu_wdt_driver); |
| 155 | |
| 156 | MODULE_ALIAS("platform:retu-wdt"); |
| 157 | MODULE_DESCRIPTION("Retu watchdog"); |
| 158 | MODULE_AUTHOR("Amit Kucheria"); |
| 159 | MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>"); |
| 160 | MODULE_LICENSE("GPL"); |