1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) Nokia Corporation 4 * 5 * Written by Timo Kokkonen <timo.t.kokkonen at nokia.com> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/types.h> 10 #include <linux/slab.h> 11 #include <linux/kernel.h> 12 #include <linux/watchdog.h> 13 #include <linux/platform_device.h> 14 #include <linux/mfd/twl.h> 15 16 #define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3 17 18 static bool nowayout = WATCHDOG_NOWAYOUT; 19 module_param(nowayout, bool, 0); 20 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " 21 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 22 23 static int twl4030_wdt_write(unsigned char val) 24 { 25 return twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, val, 26 TWL4030_WATCHDOG_CFG_REG_OFFS); 27 } 28 29 static int twl4030_wdt_start(struct watchdog_device *wdt) 30 { 31 return twl4030_wdt_write(wdt->timeout + 1); 32 } 33 34 static int twl4030_wdt_stop(struct watchdog_device *wdt) 35 { 36 return twl4030_wdt_write(0); 37 } 38 39 static int twl4030_wdt_set_timeout(struct watchdog_device *wdt, 40 unsigned int timeout) 41 { 42 wdt->timeout = timeout; 43 return 0; 44 } 45 46 static const struct watchdog_info twl4030_wdt_info = { 47 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, 48 .identity = "TWL4030 Watchdog", 49 }; 50 51 static const struct watchdog_ops twl4030_wdt_ops = { 52 .owner = THIS_MODULE, 53 .start = twl4030_wdt_start, 54 .stop = twl4030_wdt_stop, 55 .set_timeout = twl4030_wdt_set_timeout, 56 }; 57 58 static int twl4030_wdt_probe(struct platform_device *pdev) 59 { 60 struct device *dev = &pdev->dev; 61 struct watchdog_device *wdt; 62 63 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); 64 if (!wdt) 65 return -ENOMEM; 66 67 wdt->info = &twl4030_wdt_info; 68 wdt->ops = &twl4030_wdt_ops; 69 wdt->status = 0; 70 wdt->timeout = 30; 71 wdt->min_timeout = 1; 72 wdt->max_timeout = 30; 73 wdt->parent = dev; 74 75 watchdog_set_nowayout(wdt, nowayout); 76 platform_set_drvdata(pdev, wdt); 77 78 twl4030_wdt_stop(wdt); 79 80 return devm_watchdog_register_device(dev, wdt); 81 } 82 83 #ifdef CONFIG_PM 84 static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state) 85 { 86 struct watchdog_device *wdt = platform_get_drvdata(pdev); 87 if (watchdog_active(wdt)) 88 return twl4030_wdt_stop(wdt); 89 90 return 0; 91 } 92 93 static int twl4030_wdt_resume(struct platform_device *pdev) 94 { 95 struct watchdog_device *wdt = platform_get_drvdata(pdev); 96 if (watchdog_active(wdt)) 97 return twl4030_wdt_start(wdt); 98 99 return 0; 100 } 101 #else 102 #define twl4030_wdt_suspend NULL 103 #define twl4030_wdt_resume NULL 104 #endif 105 106 static const struct of_device_id twl_wdt_of_match[] = { 107 { .compatible = "ti,twl4030-wdt", }, 108 { }, 109 }; 110 MODULE_DEVICE_TABLE(of, twl_wdt_of_match); 111 112 static struct platform_driver twl4030_wdt_driver = { 113 .probe = twl4030_wdt_probe, 114 .suspend = twl4030_wdt_suspend, 115 .resume = twl4030_wdt_resume, 116 .driver = { 117 .name = "twl4030_wdt", 118 .of_match_table = twl_wdt_of_match, 119 }, 120 }; 121 122 module_platform_driver(twl4030_wdt_driver); 123 124 MODULE_AUTHOR("Nokia Corporation"); 125 MODULE_LICENSE("GPL"); 126 MODULE_ALIAS("platform:twl4030_wdt"); 127 128