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/mod_devicetable.h> 13 #include <linux/watchdog.h> 14 #include <linux/platform_device.h> 15 #include <linux/mfd/twl.h> 16 17 #define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3 18 19 static bool nowayout = WATCHDOG_NOWAYOUT; 20 module_param(nowayout, bool, 0); 21 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " 22 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 23 24 static int twl4030_wdt_write(unsigned char val) 25 { 26 return twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, val, 27 TWL4030_WATCHDOG_CFG_REG_OFFS); 28 } 29 30 static int twl4030_wdt_start(struct watchdog_device *wdt) 31 { 32 return twl4030_wdt_write(wdt->timeout + 1); 33 } 34 35 static int twl4030_wdt_stop(struct watchdog_device *wdt) 36 { 37 return twl4030_wdt_write(0); 38 } 39 40 static int twl4030_wdt_set_timeout(struct watchdog_device *wdt, 41 unsigned int timeout) 42 { 43 wdt->timeout = timeout; 44 return 0; 45 } 46 47 static const struct watchdog_info twl4030_wdt_info = { 48 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, 49 .identity = "TWL4030 Watchdog", 50 }; 51 52 static const struct watchdog_ops twl4030_wdt_ops = { 53 .owner = THIS_MODULE, 54 .start = twl4030_wdt_start, 55 .stop = twl4030_wdt_stop, 56 .set_timeout = twl4030_wdt_set_timeout, 57 }; 58 59 static int twl4030_wdt_probe(struct platform_device *pdev) 60 { 61 struct device *dev = &pdev->dev; 62 struct watchdog_device *wdt; 63 64 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); 65 if (!wdt) 66 return -ENOMEM; 67 68 wdt->info = &twl4030_wdt_info; 69 wdt->ops = &twl4030_wdt_ops; 70 wdt->status = 0; 71 wdt->timeout = 30; 72 wdt->min_timeout = 1; 73 wdt->max_timeout = 30; 74 wdt->parent = dev; 75 76 watchdog_set_nowayout(wdt, nowayout); 77 platform_set_drvdata(pdev, wdt); 78 79 twl4030_wdt_stop(wdt); 80 81 return devm_watchdog_register_device(dev, wdt); 82 } 83 84 #ifdef CONFIG_PM 85 static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state) 86 { 87 struct watchdog_device *wdt = platform_get_drvdata(pdev); 88 if (watchdog_active(wdt)) 89 return twl4030_wdt_stop(wdt); 90 91 return 0; 92 } 93 94 static int twl4030_wdt_resume(struct platform_device *pdev) 95 { 96 struct watchdog_device *wdt = platform_get_drvdata(pdev); 97 if (watchdog_active(wdt)) 98 return twl4030_wdt_start(wdt); 99 100 return 0; 101 } 102 #else 103 #define twl4030_wdt_suspend NULL 104 #define twl4030_wdt_resume NULL 105 #endif 106 107 static const struct of_device_id twl_wdt_of_match[] = { 108 { .compatible = "ti,twl4030-wdt", }, 109 { }, 110 }; 111 MODULE_DEVICE_TABLE(of, twl_wdt_of_match); 112 113 static struct platform_driver twl4030_wdt_driver = { 114 .probe = twl4030_wdt_probe, 115 .suspend = twl4030_wdt_suspend, 116 .resume = twl4030_wdt_resume, 117 .driver = { 118 .name = "twl4030_wdt", 119 .of_match_table = twl_wdt_of_match, 120 }, 121 }; 122 123 module_platform_driver(twl4030_wdt_driver); 124 125 MODULE_AUTHOR("Nokia Corporation"); 126 MODULE_LICENSE("GPL"); 127 MODULE_ALIAS("platform:twl4030_wdt"); 128 129