175d67a54SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2101ce87bSAlexander Stein /* 3101ce87bSAlexander Stein * Intel Atom E6xx Watchdog driver 4101ce87bSAlexander Stein * 5101ce87bSAlexander Stein * Copyright (C) 2011 Alexander Stein 6101ce87bSAlexander Stein * <alexander.stein@systec-electronic.com> 7101ce87bSAlexander Stein */ 8101ce87bSAlexander Stein 9101ce87bSAlexander Stein #include <linux/module.h> 10101ce87bSAlexander Stein #include <linux/moduleparam.h> 11101ce87bSAlexander Stein #include <linux/platform_device.h> 12491d9e2aSRandy Dunlap #include <linux/io.h> 13101ce87bSAlexander Stein #include <linux/kernel.h> 14101ce87bSAlexander Stein #include <linux/types.h> 15101ce87bSAlexander Stein #include <linux/watchdog.h> 16101ce87bSAlexander Stein #include <linux/seq_file.h> 17101ce87bSAlexander Stein #include <linux/debugfs.h> 18101ce87bSAlexander Stein #include <linux/uaccess.h> 19101ce87bSAlexander Stein #include <linux/spinlock.h> 20101ce87bSAlexander Stein 21101ce87bSAlexander Stein #define DRIVER_NAME "ie6xx_wdt" 22101ce87bSAlexander Stein 23101ce87bSAlexander Stein #define PV1 0x00 24101ce87bSAlexander Stein #define PV2 0x04 25101ce87bSAlexander Stein 26101ce87bSAlexander Stein #define RR0 0x0c 27101ce87bSAlexander Stein #define RR1 0x0d 28101ce87bSAlexander Stein #define WDT_RELOAD 0x01 29101ce87bSAlexander Stein #define WDT_TOUT 0x02 30101ce87bSAlexander Stein 31101ce87bSAlexander Stein #define WDTCR 0x10 32101ce87bSAlexander Stein #define WDT_PRE_SEL 0x04 33101ce87bSAlexander Stein #define WDT_RESET_SEL 0x08 34101ce87bSAlexander Stein #define WDT_RESET_EN 0x10 35101ce87bSAlexander Stein #define WDT_TOUT_EN 0x20 36101ce87bSAlexander Stein 37101ce87bSAlexander Stein #define DCR 0x14 38101ce87bSAlexander Stein 39101ce87bSAlexander Stein #define WDTLR 0x18 40101ce87bSAlexander Stein #define WDT_LOCK 0x01 41101ce87bSAlexander Stein #define WDT_ENABLE 0x02 42101ce87bSAlexander Stein #define WDT_TOUT_CNF 0x03 43101ce87bSAlexander Stein 44101ce87bSAlexander Stein #define MIN_TIME 1 45101ce87bSAlexander Stein #define MAX_TIME (10 * 60) /* 10 minutes */ 46101ce87bSAlexander Stein #define DEFAULT_TIME 60 47101ce87bSAlexander Stein 48101ce87bSAlexander Stein static unsigned int timeout = DEFAULT_TIME; 49101ce87bSAlexander Stein module_param(timeout, uint, 0); 50101ce87bSAlexander Stein MODULE_PARM_DESC(timeout, 51101ce87bSAlexander Stein "Default Watchdog timer setting (" 52101ce87bSAlexander Stein __MODULE_STRING(DEFAULT_TIME) "s)." 53101ce87bSAlexander Stein "The range is from 1 to 600"); 54101ce87bSAlexander Stein 55101ce87bSAlexander Stein static bool nowayout = WATCHDOG_NOWAYOUT; 56101ce87bSAlexander Stein module_param(nowayout, bool, 0); 57101ce87bSAlexander Stein MODULE_PARM_DESC(nowayout, 58101ce87bSAlexander Stein "Watchdog cannot be stopped once started (default=" 59101ce87bSAlexander Stein __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 60101ce87bSAlexander Stein 61101ce87bSAlexander Stein static u8 resetmode = 0x10; 62101ce87bSAlexander Stein module_param(resetmode, byte, 0); 63101ce87bSAlexander Stein MODULE_PARM_DESC(resetmode, 64101ce87bSAlexander Stein "Resetmode bits: 0x08 warm reset (cold reset otherwise), " 65101ce87bSAlexander Stein "0x10 reset enable, 0x20 disable toggle GPIO[4] (default=0x10)"); 66101ce87bSAlexander Stein 67101ce87bSAlexander Stein static struct { 68101ce87bSAlexander Stein unsigned short sch_wdtba; 69101ce87bSAlexander Stein struct spinlock unlock_sequence; 70101ce87bSAlexander Stein #ifdef CONFIG_DEBUG_FS 71101ce87bSAlexander Stein struct dentry *debugfs; 72101ce87bSAlexander Stein #endif 73101ce87bSAlexander Stein } ie6xx_wdt_data; 74101ce87bSAlexander Stein 75101ce87bSAlexander Stein /* 76101ce87bSAlexander Stein * This is needed to write to preload and reload registers 77101ce87bSAlexander Stein * struct ie6xx_wdt_data.unlock_sequence must be used 78101ce87bSAlexander Stein * to prevent sequence interrupts 79101ce87bSAlexander Stein */ 80101ce87bSAlexander Stein static void ie6xx_wdt_unlock_registers(void) 81101ce87bSAlexander Stein { 82101ce87bSAlexander Stein outb(0x80, ie6xx_wdt_data.sch_wdtba + RR0); 83101ce87bSAlexander Stein outb(0x86, ie6xx_wdt_data.sch_wdtba + RR0); 84101ce87bSAlexander Stein } 85101ce87bSAlexander Stein 86101ce87bSAlexander Stein static int ie6xx_wdt_ping(struct watchdog_device *wdd) 87101ce87bSAlexander Stein { 88101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 89101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 90101ce87bSAlexander Stein outb(WDT_RELOAD, ie6xx_wdt_data.sch_wdtba + RR1); 91101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 92101ce87bSAlexander Stein return 0; 93101ce87bSAlexander Stein } 94101ce87bSAlexander Stein 95101ce87bSAlexander Stein static int ie6xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) 96101ce87bSAlexander Stein { 97101ce87bSAlexander Stein u32 preload; 98101ce87bSAlexander Stein u64 clock; 99101ce87bSAlexander Stein u8 wdtcr; 100101ce87bSAlexander Stein 101101ce87bSAlexander Stein /* Watchdog clock is PCI Clock (33MHz) */ 102101ce87bSAlexander Stein clock = 33000000; 103101ce87bSAlexander Stein /* and the preload value is loaded into [34:15] of the down counter */ 104101ce87bSAlexander Stein preload = (t * clock) >> 15; 105101ce87bSAlexander Stein /* 106101ce87bSAlexander Stein * Manual states preload must be one less. 107101ce87bSAlexander Stein * Does not wrap as t is at least 1 108101ce87bSAlexander Stein */ 109101ce87bSAlexander Stein preload -= 1; 110101ce87bSAlexander Stein 111101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 112101ce87bSAlexander Stein 113101ce87bSAlexander Stein /* Set ResetMode & Enable prescaler for range 10ms to 10 min */ 114101ce87bSAlexander Stein wdtcr = resetmode & 0x38; 115101ce87bSAlexander Stein outb(wdtcr, ie6xx_wdt_data.sch_wdtba + WDTCR); 116101ce87bSAlexander Stein 117101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 118101ce87bSAlexander Stein outl(0, ie6xx_wdt_data.sch_wdtba + PV1); 119101ce87bSAlexander Stein 120101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 121101ce87bSAlexander Stein outl(preload, ie6xx_wdt_data.sch_wdtba + PV2); 122101ce87bSAlexander Stein 123101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 124101ce87bSAlexander Stein outb(WDT_RELOAD | WDT_TOUT, ie6xx_wdt_data.sch_wdtba + RR1); 125101ce87bSAlexander Stein 126101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 127101ce87bSAlexander Stein 128101ce87bSAlexander Stein wdd->timeout = t; 129101ce87bSAlexander Stein return 0; 130101ce87bSAlexander Stein } 131101ce87bSAlexander Stein 132101ce87bSAlexander Stein static int ie6xx_wdt_start(struct watchdog_device *wdd) 133101ce87bSAlexander Stein { 134101ce87bSAlexander Stein ie6xx_wdt_set_timeout(wdd, wdd->timeout); 135101ce87bSAlexander Stein 136101ce87bSAlexander Stein /* Enable the watchdog timer */ 137101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 138101ce87bSAlexander Stein outb(WDT_ENABLE, ie6xx_wdt_data.sch_wdtba + WDTLR); 139101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 140101ce87bSAlexander Stein 141101ce87bSAlexander Stein return 0; 142101ce87bSAlexander Stein } 143101ce87bSAlexander Stein 144101ce87bSAlexander Stein static int ie6xx_wdt_stop(struct watchdog_device *wdd) 145101ce87bSAlexander Stein { 146101ce87bSAlexander Stein if (inb(ie6xx_wdt_data.sch_wdtba + WDTLR) & WDT_LOCK) 147101ce87bSAlexander Stein return -1; 148101ce87bSAlexander Stein 149101ce87bSAlexander Stein /* Disable the watchdog timer */ 150101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 151101ce87bSAlexander Stein outb(0, ie6xx_wdt_data.sch_wdtba + WDTLR); 152101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 153101ce87bSAlexander Stein 154101ce87bSAlexander Stein return 0; 155101ce87bSAlexander Stein } 156101ce87bSAlexander Stein 157101ce87bSAlexander Stein static const struct watchdog_info ie6xx_wdt_info = { 158101ce87bSAlexander Stein .identity = "Intel Atom E6xx Watchdog", 159101ce87bSAlexander Stein .options = WDIOF_SETTIMEOUT | 160101ce87bSAlexander Stein WDIOF_MAGICCLOSE | 161101ce87bSAlexander Stein WDIOF_KEEPALIVEPING, 162101ce87bSAlexander Stein }; 163101ce87bSAlexander Stein 164101ce87bSAlexander Stein static const struct watchdog_ops ie6xx_wdt_ops = { 165101ce87bSAlexander Stein .owner = THIS_MODULE, 166101ce87bSAlexander Stein .start = ie6xx_wdt_start, 167101ce87bSAlexander Stein .stop = ie6xx_wdt_stop, 168101ce87bSAlexander Stein .ping = ie6xx_wdt_ping, 169101ce87bSAlexander Stein .set_timeout = ie6xx_wdt_set_timeout, 170101ce87bSAlexander Stein }; 171101ce87bSAlexander Stein 172101ce87bSAlexander Stein static struct watchdog_device ie6xx_wdt_dev = { 173101ce87bSAlexander Stein .info = &ie6xx_wdt_info, 174101ce87bSAlexander Stein .ops = &ie6xx_wdt_ops, 175101ce87bSAlexander Stein .min_timeout = MIN_TIME, 176101ce87bSAlexander Stein .max_timeout = MAX_TIME, 177101ce87bSAlexander Stein }; 178101ce87bSAlexander Stein 179101ce87bSAlexander Stein #ifdef CONFIG_DEBUG_FS 180101ce87bSAlexander Stein 181248e655bSYangtao Li static int ie6xx_wdt_show(struct seq_file *s, void *unused) 182101ce87bSAlexander Stein { 183101ce87bSAlexander Stein seq_printf(s, "PV1 = 0x%08x\n", 184101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + PV1)); 185101ce87bSAlexander Stein seq_printf(s, "PV2 = 0x%08x\n", 186101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + PV2)); 187101ce87bSAlexander Stein seq_printf(s, "RR = 0x%08x\n", 188101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + RR0)); 189101ce87bSAlexander Stein seq_printf(s, "WDTCR = 0x%08x\n", 190101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + WDTCR)); 191101ce87bSAlexander Stein seq_printf(s, "DCR = 0x%08x\n", 192101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + DCR)); 193101ce87bSAlexander Stein seq_printf(s, "WDTLR = 0x%08x\n", 194101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + WDTLR)); 195101ce87bSAlexander Stein 196101ce87bSAlexander Stein seq_printf(s, "\n"); 197101ce87bSAlexander Stein return 0; 198101ce87bSAlexander Stein } 199101ce87bSAlexander Stein 200248e655bSYangtao Li DEFINE_SHOW_ATTRIBUTE(ie6xx_wdt); 201101ce87bSAlexander Stein 2022d991a16SBill Pemberton static void ie6xx_wdt_debugfs_init(void) 203101ce87bSAlexander Stein { 204101ce87bSAlexander Stein /* /sys/kernel/debug/ie6xx_wdt */ 205101ce87bSAlexander Stein ie6xx_wdt_data.debugfs = debugfs_create_file("ie6xx_wdt", 206248e655bSYangtao Li S_IFREG | S_IRUGO, NULL, NULL, &ie6xx_wdt_fops); 207101ce87bSAlexander Stein } 208101ce87bSAlexander Stein 2090402450fSGerard Snitselaar static void ie6xx_wdt_debugfs_exit(void) 210101ce87bSAlexander Stein { 211101ce87bSAlexander Stein debugfs_remove(ie6xx_wdt_data.debugfs); 212101ce87bSAlexander Stein } 213101ce87bSAlexander Stein 214101ce87bSAlexander Stein #else 2152d991a16SBill Pemberton static void ie6xx_wdt_debugfs_init(void) 216101ce87bSAlexander Stein { 217101ce87bSAlexander Stein } 218101ce87bSAlexander Stein 2190402450fSGerard Snitselaar static void ie6xx_wdt_debugfs_exit(void) 220101ce87bSAlexander Stein { 221101ce87bSAlexander Stein } 222101ce87bSAlexander Stein #endif 223101ce87bSAlexander Stein 2242d991a16SBill Pemberton static int ie6xx_wdt_probe(struct platform_device *pdev) 225101ce87bSAlexander Stein { 226101ce87bSAlexander Stein struct resource *res; 227101ce87bSAlexander Stein u8 wdtlr; 228101ce87bSAlexander Stein int ret; 229101ce87bSAlexander Stein 230101ce87bSAlexander Stein res = platform_get_resource(pdev, IORESOURCE_IO, 0); 231101ce87bSAlexander Stein if (!res) 232101ce87bSAlexander Stein return -ENODEV; 233101ce87bSAlexander Stein 234101ce87bSAlexander Stein if (!request_region(res->start, resource_size(res), pdev->name)) { 235744f6f4dSRandy Dunlap dev_err(&pdev->dev, "Watchdog region 0x%llx already in use!\n", 236744f6f4dSRandy Dunlap (u64)res->start); 237101ce87bSAlexander Stein return -EBUSY; 238101ce87bSAlexander Stein } 239101ce87bSAlexander Stein 240101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = res->start; 241101ce87bSAlexander Stein dev_dbg(&pdev->dev, "WDT = 0x%X\n", ie6xx_wdt_data.sch_wdtba); 242101ce87bSAlexander Stein 243101ce87bSAlexander Stein ie6xx_wdt_dev.timeout = timeout; 244101ce87bSAlexander Stein watchdog_set_nowayout(&ie6xx_wdt_dev, nowayout); 2456551881cSPratyush Anand ie6xx_wdt_dev.parent = &pdev->dev; 246101ce87bSAlexander Stein 247101ce87bSAlexander Stein spin_lock_init(&ie6xx_wdt_data.unlock_sequence); 248101ce87bSAlexander Stein 249101ce87bSAlexander Stein wdtlr = inb(ie6xx_wdt_data.sch_wdtba + WDTLR); 250101ce87bSAlexander Stein if (wdtlr & WDT_LOCK) 251101ce87bSAlexander Stein dev_warn(&pdev->dev, 252101ce87bSAlexander Stein "Watchdog Timer is Locked (Reg=0x%x)\n", wdtlr); 253101ce87bSAlexander Stein 254101ce87bSAlexander Stein ie6xx_wdt_debugfs_init(); 255101ce87bSAlexander Stein 256101ce87bSAlexander Stein ret = watchdog_register_device(&ie6xx_wdt_dev); 257101ce87bSAlexander Stein if (ret) { 258101ce87bSAlexander Stein dev_err(&pdev->dev, 259101ce87bSAlexander Stein "Watchdog timer: cannot register device (err =%d)\n", 260101ce87bSAlexander Stein ret); 261101ce87bSAlexander Stein goto misc_register_error; 262101ce87bSAlexander Stein } 263101ce87bSAlexander Stein 264101ce87bSAlexander Stein return 0; 265101ce87bSAlexander Stein 266101ce87bSAlexander Stein misc_register_error: 267101ce87bSAlexander Stein ie6xx_wdt_debugfs_exit(); 268101ce87bSAlexander Stein release_region(res->start, resource_size(res)); 269101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = 0; 270101ce87bSAlexander Stein return ret; 271101ce87bSAlexander Stein } 272101ce87bSAlexander Stein 2734b12b896SBill Pemberton static int ie6xx_wdt_remove(struct platform_device *pdev) 274101ce87bSAlexander Stein { 275101ce87bSAlexander Stein struct resource *res; 276101ce87bSAlexander Stein 277101ce87bSAlexander Stein res = platform_get_resource(pdev, IORESOURCE_IO, 0); 278101ce87bSAlexander Stein ie6xx_wdt_stop(NULL); 279101ce87bSAlexander Stein watchdog_unregister_device(&ie6xx_wdt_dev); 280101ce87bSAlexander Stein ie6xx_wdt_debugfs_exit(); 281101ce87bSAlexander Stein release_region(res->start, resource_size(res)); 282101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = 0; 283101ce87bSAlexander Stein 284101ce87bSAlexander Stein return 0; 285101ce87bSAlexander Stein } 286101ce87bSAlexander Stein 287101ce87bSAlexander Stein static struct platform_driver ie6xx_wdt_driver = { 288101ce87bSAlexander Stein .probe = ie6xx_wdt_probe, 28982268714SBill Pemberton .remove = ie6xx_wdt_remove, 290101ce87bSAlexander Stein .driver = { 291101ce87bSAlexander Stein .name = DRIVER_NAME, 292101ce87bSAlexander Stein }, 293101ce87bSAlexander Stein }; 294101ce87bSAlexander Stein 295101ce87bSAlexander Stein static int __init ie6xx_wdt_init(void) 296101ce87bSAlexander Stein { 297101ce87bSAlexander Stein /* Check boot parameters to verify that their initial values */ 298101ce87bSAlexander Stein /* are in range. */ 299101ce87bSAlexander Stein if ((timeout < MIN_TIME) || 300101ce87bSAlexander Stein (timeout > MAX_TIME)) { 301101ce87bSAlexander Stein pr_err("Watchdog timer: value of timeout %d (dec) " 302101ce87bSAlexander Stein "is out of range from %d to %d (dec)\n", 303101ce87bSAlexander Stein timeout, MIN_TIME, MAX_TIME); 304101ce87bSAlexander Stein return -EINVAL; 305101ce87bSAlexander Stein } 306101ce87bSAlexander Stein 307101ce87bSAlexander Stein return platform_driver_register(&ie6xx_wdt_driver); 308101ce87bSAlexander Stein } 309101ce87bSAlexander Stein 310101ce87bSAlexander Stein static void __exit ie6xx_wdt_exit(void) 311101ce87bSAlexander Stein { 312101ce87bSAlexander Stein platform_driver_unregister(&ie6xx_wdt_driver); 313101ce87bSAlexander Stein } 314101ce87bSAlexander Stein 315101ce87bSAlexander Stein late_initcall(ie6xx_wdt_init); 316101ce87bSAlexander Stein module_exit(ie6xx_wdt_exit); 317101ce87bSAlexander Stein 318101ce87bSAlexander Stein MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>"); 319101ce87bSAlexander Stein MODULE_DESCRIPTION("Intel Atom E6xx Watchdog Device Driver"); 320101ce87bSAlexander Stein MODULE_LICENSE("GPL"); 321101ce87bSAlexander Stein MODULE_ALIAS("platform:" DRIVER_NAME); 322