1101ce87bSAlexander Stein /* 2101ce87bSAlexander Stein * Intel Atom E6xx Watchdog driver 3101ce87bSAlexander Stein * 4101ce87bSAlexander Stein * Copyright (C) 2011 Alexander Stein 5101ce87bSAlexander Stein * <alexander.stein@systec-electronic.com> 6101ce87bSAlexander Stein * 7101ce87bSAlexander Stein * This program is free software; you can redistribute it and/or 8101ce87bSAlexander Stein * modify it under the terms of version 2 of the GNU General 9101ce87bSAlexander Stein * Public License as published by the Free Software Foundation. 10101ce87bSAlexander Stein * 11101ce87bSAlexander Stein * This program is distributed in the hope that it will be 12101ce87bSAlexander Stein * useful, but WITHOUT ANY WARRANTY; without even the implied 13101ce87bSAlexander Stein * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 14101ce87bSAlexander Stein * PURPOSE. See the GNU General Public License for more details. 15101ce87bSAlexander Stein * You should have received a copy of the GNU General Public 16101ce87bSAlexander Stein * License along with this program; if not, write to the Free 17101ce87bSAlexander Stein * Software Foundation, Inc., 59 Temple Place - Suite 330, 18101ce87bSAlexander Stein * Boston, MA 02111-1307, USA. 19101ce87bSAlexander Stein * The full GNU General Public License is included in this 20101ce87bSAlexander Stein * distribution in the file called COPYING. 21101ce87bSAlexander Stein * 22101ce87bSAlexander Stein */ 23101ce87bSAlexander Stein 24101ce87bSAlexander Stein #include <linux/module.h> 25101ce87bSAlexander Stein #include <linux/moduleparam.h> 26101ce87bSAlexander Stein #include <linux/platform_device.h> 27491d9e2aSRandy Dunlap #include <linux/io.h> 28101ce87bSAlexander Stein #include <linux/kernel.h> 29101ce87bSAlexander Stein #include <linux/types.h> 30101ce87bSAlexander Stein #include <linux/watchdog.h> 31101ce87bSAlexander Stein #include <linux/miscdevice.h> 32101ce87bSAlexander Stein #include <linux/seq_file.h> 33101ce87bSAlexander Stein #include <linux/debugfs.h> 34101ce87bSAlexander Stein #include <linux/uaccess.h> 35101ce87bSAlexander Stein #include <linux/spinlock.h> 36101ce87bSAlexander Stein 37101ce87bSAlexander Stein #define DRIVER_NAME "ie6xx_wdt" 38101ce87bSAlexander Stein 39101ce87bSAlexander Stein #define PV1 0x00 40101ce87bSAlexander Stein #define PV2 0x04 41101ce87bSAlexander Stein 42101ce87bSAlexander Stein #define RR0 0x0c 43101ce87bSAlexander Stein #define RR1 0x0d 44101ce87bSAlexander Stein #define WDT_RELOAD 0x01 45101ce87bSAlexander Stein #define WDT_TOUT 0x02 46101ce87bSAlexander Stein 47101ce87bSAlexander Stein #define WDTCR 0x10 48101ce87bSAlexander Stein #define WDT_PRE_SEL 0x04 49101ce87bSAlexander Stein #define WDT_RESET_SEL 0x08 50101ce87bSAlexander Stein #define WDT_RESET_EN 0x10 51101ce87bSAlexander Stein #define WDT_TOUT_EN 0x20 52101ce87bSAlexander Stein 53101ce87bSAlexander Stein #define DCR 0x14 54101ce87bSAlexander Stein 55101ce87bSAlexander Stein #define WDTLR 0x18 56101ce87bSAlexander Stein #define WDT_LOCK 0x01 57101ce87bSAlexander Stein #define WDT_ENABLE 0x02 58101ce87bSAlexander Stein #define WDT_TOUT_CNF 0x03 59101ce87bSAlexander Stein 60101ce87bSAlexander Stein #define MIN_TIME 1 61101ce87bSAlexander Stein #define MAX_TIME (10 * 60) /* 10 minutes */ 62101ce87bSAlexander Stein #define DEFAULT_TIME 60 63101ce87bSAlexander Stein 64101ce87bSAlexander Stein static unsigned int timeout = DEFAULT_TIME; 65101ce87bSAlexander Stein module_param(timeout, uint, 0); 66101ce87bSAlexander Stein MODULE_PARM_DESC(timeout, 67101ce87bSAlexander Stein "Default Watchdog timer setting (" 68101ce87bSAlexander Stein __MODULE_STRING(DEFAULT_TIME) "s)." 69101ce87bSAlexander Stein "The range is from 1 to 600"); 70101ce87bSAlexander Stein 71101ce87bSAlexander Stein static bool nowayout = WATCHDOG_NOWAYOUT; 72101ce87bSAlexander Stein module_param(nowayout, bool, 0); 73101ce87bSAlexander Stein MODULE_PARM_DESC(nowayout, 74101ce87bSAlexander Stein "Watchdog cannot be stopped once started (default=" 75101ce87bSAlexander Stein __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 76101ce87bSAlexander Stein 77101ce87bSAlexander Stein static u8 resetmode = 0x10; 78101ce87bSAlexander Stein module_param(resetmode, byte, 0); 79101ce87bSAlexander Stein MODULE_PARM_DESC(resetmode, 80101ce87bSAlexander Stein "Resetmode bits: 0x08 warm reset (cold reset otherwise), " 81101ce87bSAlexander Stein "0x10 reset enable, 0x20 disable toggle GPIO[4] (default=0x10)"); 82101ce87bSAlexander Stein 83101ce87bSAlexander Stein static struct { 84101ce87bSAlexander Stein unsigned short sch_wdtba; 85101ce87bSAlexander Stein struct spinlock unlock_sequence; 86101ce87bSAlexander Stein #ifdef CONFIG_DEBUG_FS 87101ce87bSAlexander Stein struct dentry *debugfs; 88101ce87bSAlexander Stein #endif 89101ce87bSAlexander Stein } ie6xx_wdt_data; 90101ce87bSAlexander Stein 91101ce87bSAlexander Stein /* 92101ce87bSAlexander Stein * This is needed to write to preload and reload registers 93101ce87bSAlexander Stein * struct ie6xx_wdt_data.unlock_sequence must be used 94101ce87bSAlexander Stein * to prevent sequence interrupts 95101ce87bSAlexander Stein */ 96101ce87bSAlexander Stein static void ie6xx_wdt_unlock_registers(void) 97101ce87bSAlexander Stein { 98101ce87bSAlexander Stein outb(0x80, ie6xx_wdt_data.sch_wdtba + RR0); 99101ce87bSAlexander Stein outb(0x86, ie6xx_wdt_data.sch_wdtba + RR0); 100101ce87bSAlexander Stein } 101101ce87bSAlexander Stein 102101ce87bSAlexander Stein static int ie6xx_wdt_ping(struct watchdog_device *wdd) 103101ce87bSAlexander Stein { 104101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 105101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 106101ce87bSAlexander Stein outb(WDT_RELOAD, ie6xx_wdt_data.sch_wdtba + RR1); 107101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 108101ce87bSAlexander Stein return 0; 109101ce87bSAlexander Stein } 110101ce87bSAlexander Stein 111101ce87bSAlexander Stein static int ie6xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) 112101ce87bSAlexander Stein { 113101ce87bSAlexander Stein u32 preload; 114101ce87bSAlexander Stein u64 clock; 115101ce87bSAlexander Stein u8 wdtcr; 116101ce87bSAlexander Stein 117101ce87bSAlexander Stein /* Watchdog clock is PCI Clock (33MHz) */ 118101ce87bSAlexander Stein clock = 33000000; 119101ce87bSAlexander Stein /* and the preload value is loaded into [34:15] of the down counter */ 120101ce87bSAlexander Stein preload = (t * clock) >> 15; 121101ce87bSAlexander Stein /* 122101ce87bSAlexander Stein * Manual states preload must be one less. 123101ce87bSAlexander Stein * Does not wrap as t is at least 1 124101ce87bSAlexander Stein */ 125101ce87bSAlexander Stein preload -= 1; 126101ce87bSAlexander Stein 127101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 128101ce87bSAlexander Stein 129101ce87bSAlexander Stein /* Set ResetMode & Enable prescaler for range 10ms to 10 min */ 130101ce87bSAlexander Stein wdtcr = resetmode & 0x38; 131101ce87bSAlexander Stein outb(wdtcr, ie6xx_wdt_data.sch_wdtba + WDTCR); 132101ce87bSAlexander Stein 133101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 134101ce87bSAlexander Stein outl(0, ie6xx_wdt_data.sch_wdtba + PV1); 135101ce87bSAlexander Stein 136101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 137101ce87bSAlexander Stein outl(preload, ie6xx_wdt_data.sch_wdtba + PV2); 138101ce87bSAlexander Stein 139101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 140101ce87bSAlexander Stein outb(WDT_RELOAD | WDT_TOUT, ie6xx_wdt_data.sch_wdtba + RR1); 141101ce87bSAlexander Stein 142101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 143101ce87bSAlexander Stein 144101ce87bSAlexander Stein wdd->timeout = t; 145101ce87bSAlexander Stein return 0; 146101ce87bSAlexander Stein } 147101ce87bSAlexander Stein 148101ce87bSAlexander Stein static int ie6xx_wdt_start(struct watchdog_device *wdd) 149101ce87bSAlexander Stein { 150101ce87bSAlexander Stein ie6xx_wdt_set_timeout(wdd, wdd->timeout); 151101ce87bSAlexander Stein 152101ce87bSAlexander Stein /* Enable the watchdog timer */ 153101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 154101ce87bSAlexander Stein outb(WDT_ENABLE, ie6xx_wdt_data.sch_wdtba + WDTLR); 155101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 156101ce87bSAlexander Stein 157101ce87bSAlexander Stein return 0; 158101ce87bSAlexander Stein } 159101ce87bSAlexander Stein 160101ce87bSAlexander Stein static int ie6xx_wdt_stop(struct watchdog_device *wdd) 161101ce87bSAlexander Stein { 162101ce87bSAlexander Stein if (inb(ie6xx_wdt_data.sch_wdtba + WDTLR) & WDT_LOCK) 163101ce87bSAlexander Stein return -1; 164101ce87bSAlexander Stein 165101ce87bSAlexander Stein /* Disable the watchdog timer */ 166101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 167101ce87bSAlexander Stein outb(0, ie6xx_wdt_data.sch_wdtba + WDTLR); 168101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 169101ce87bSAlexander Stein 170101ce87bSAlexander Stein return 0; 171101ce87bSAlexander Stein } 172101ce87bSAlexander Stein 173101ce87bSAlexander Stein static const struct watchdog_info ie6xx_wdt_info = { 174101ce87bSAlexander Stein .identity = "Intel Atom E6xx Watchdog", 175101ce87bSAlexander Stein .options = WDIOF_SETTIMEOUT | 176101ce87bSAlexander Stein WDIOF_MAGICCLOSE | 177101ce87bSAlexander Stein WDIOF_KEEPALIVEPING, 178101ce87bSAlexander Stein }; 179101ce87bSAlexander Stein 180101ce87bSAlexander Stein static const struct watchdog_ops ie6xx_wdt_ops = { 181101ce87bSAlexander Stein .owner = THIS_MODULE, 182101ce87bSAlexander Stein .start = ie6xx_wdt_start, 183101ce87bSAlexander Stein .stop = ie6xx_wdt_stop, 184101ce87bSAlexander Stein .ping = ie6xx_wdt_ping, 185101ce87bSAlexander Stein .set_timeout = ie6xx_wdt_set_timeout, 186101ce87bSAlexander Stein }; 187101ce87bSAlexander Stein 188101ce87bSAlexander Stein static struct watchdog_device ie6xx_wdt_dev = { 189101ce87bSAlexander Stein .info = &ie6xx_wdt_info, 190101ce87bSAlexander Stein .ops = &ie6xx_wdt_ops, 191101ce87bSAlexander Stein .min_timeout = MIN_TIME, 192101ce87bSAlexander Stein .max_timeout = MAX_TIME, 193101ce87bSAlexander Stein }; 194101ce87bSAlexander Stein 195101ce87bSAlexander Stein #ifdef CONFIG_DEBUG_FS 196101ce87bSAlexander Stein 197101ce87bSAlexander Stein static int ie6xx_wdt_dbg_show(struct seq_file *s, void *unused) 198101ce87bSAlexander Stein { 199101ce87bSAlexander Stein seq_printf(s, "PV1 = 0x%08x\n", 200101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + PV1)); 201101ce87bSAlexander Stein seq_printf(s, "PV2 = 0x%08x\n", 202101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + PV2)); 203101ce87bSAlexander Stein seq_printf(s, "RR = 0x%08x\n", 204101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + RR0)); 205101ce87bSAlexander Stein seq_printf(s, "WDTCR = 0x%08x\n", 206101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + WDTCR)); 207101ce87bSAlexander Stein seq_printf(s, "DCR = 0x%08x\n", 208101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + DCR)); 209101ce87bSAlexander Stein seq_printf(s, "WDTLR = 0x%08x\n", 210101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + WDTLR)); 211101ce87bSAlexander Stein 212101ce87bSAlexander Stein seq_printf(s, "\n"); 213101ce87bSAlexander Stein return 0; 214101ce87bSAlexander Stein } 215101ce87bSAlexander Stein 216101ce87bSAlexander Stein static int ie6xx_wdt_dbg_open(struct inode *inode, struct file *file) 217101ce87bSAlexander Stein { 218101ce87bSAlexander Stein return single_open(file, ie6xx_wdt_dbg_show, NULL); 219101ce87bSAlexander Stein } 220101ce87bSAlexander Stein 221101ce87bSAlexander Stein static const struct file_operations ie6xx_wdt_dbg_operations = { 222101ce87bSAlexander Stein .open = ie6xx_wdt_dbg_open, 223101ce87bSAlexander Stein .read = seq_read, 224101ce87bSAlexander Stein .llseek = seq_lseek, 225101ce87bSAlexander Stein .release = single_release, 226101ce87bSAlexander Stein }; 227101ce87bSAlexander Stein 2282d991a16SBill Pemberton static void ie6xx_wdt_debugfs_init(void) 229101ce87bSAlexander Stein { 230101ce87bSAlexander Stein /* /sys/kernel/debug/ie6xx_wdt */ 231101ce87bSAlexander Stein ie6xx_wdt_data.debugfs = debugfs_create_file("ie6xx_wdt", 232101ce87bSAlexander Stein S_IFREG | S_IRUGO, NULL, NULL, &ie6xx_wdt_dbg_operations); 233101ce87bSAlexander Stein } 234101ce87bSAlexander Stein 2350402450fSGerard Snitselaar static void ie6xx_wdt_debugfs_exit(void) 236101ce87bSAlexander Stein { 237101ce87bSAlexander Stein debugfs_remove(ie6xx_wdt_data.debugfs); 238101ce87bSAlexander Stein } 239101ce87bSAlexander Stein 240101ce87bSAlexander Stein #else 2412d991a16SBill Pemberton static void ie6xx_wdt_debugfs_init(void) 242101ce87bSAlexander Stein { 243101ce87bSAlexander Stein } 244101ce87bSAlexander Stein 2450402450fSGerard Snitselaar static void ie6xx_wdt_debugfs_exit(void) 246101ce87bSAlexander Stein { 247101ce87bSAlexander Stein } 248101ce87bSAlexander Stein #endif 249101ce87bSAlexander Stein 2502d991a16SBill Pemberton static int ie6xx_wdt_probe(struct platform_device *pdev) 251101ce87bSAlexander Stein { 252101ce87bSAlexander Stein struct resource *res; 253101ce87bSAlexander Stein u8 wdtlr; 254101ce87bSAlexander Stein int ret; 255101ce87bSAlexander Stein 256101ce87bSAlexander Stein res = platform_get_resource(pdev, IORESOURCE_IO, 0); 257101ce87bSAlexander Stein if (!res) 258101ce87bSAlexander Stein return -ENODEV; 259101ce87bSAlexander Stein 260101ce87bSAlexander Stein if (!request_region(res->start, resource_size(res), pdev->name)) { 261744f6f4dSRandy Dunlap dev_err(&pdev->dev, "Watchdog region 0x%llx already in use!\n", 262744f6f4dSRandy Dunlap (u64)res->start); 263101ce87bSAlexander Stein return -EBUSY; 264101ce87bSAlexander Stein } 265101ce87bSAlexander Stein 266101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = res->start; 267101ce87bSAlexander Stein dev_dbg(&pdev->dev, "WDT = 0x%X\n", ie6xx_wdt_data.sch_wdtba); 268101ce87bSAlexander Stein 269101ce87bSAlexander Stein ie6xx_wdt_dev.timeout = timeout; 270101ce87bSAlexander Stein watchdog_set_nowayout(&ie6xx_wdt_dev, nowayout); 271101ce87bSAlexander Stein 272101ce87bSAlexander Stein spin_lock_init(&ie6xx_wdt_data.unlock_sequence); 273101ce87bSAlexander Stein 274101ce87bSAlexander Stein wdtlr = inb(ie6xx_wdt_data.sch_wdtba + WDTLR); 275101ce87bSAlexander Stein if (wdtlr & WDT_LOCK) 276101ce87bSAlexander Stein dev_warn(&pdev->dev, 277101ce87bSAlexander Stein "Watchdog Timer is Locked (Reg=0x%x)\n", wdtlr); 278101ce87bSAlexander Stein 279101ce87bSAlexander Stein ie6xx_wdt_debugfs_init(); 280101ce87bSAlexander Stein 281101ce87bSAlexander Stein ret = watchdog_register_device(&ie6xx_wdt_dev); 282101ce87bSAlexander Stein if (ret) { 283101ce87bSAlexander Stein dev_err(&pdev->dev, 284101ce87bSAlexander Stein "Watchdog timer: cannot register device (err =%d)\n", 285101ce87bSAlexander Stein ret); 286101ce87bSAlexander Stein goto misc_register_error; 287101ce87bSAlexander Stein } 288101ce87bSAlexander Stein 289101ce87bSAlexander Stein return 0; 290101ce87bSAlexander Stein 291101ce87bSAlexander Stein misc_register_error: 292101ce87bSAlexander Stein ie6xx_wdt_debugfs_exit(); 293101ce87bSAlexander Stein release_region(res->start, resource_size(res)); 294101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = 0; 295101ce87bSAlexander Stein return ret; 296101ce87bSAlexander Stein } 297101ce87bSAlexander Stein 298101ce87bSAlexander Stein static int __devexit ie6xx_wdt_remove(struct platform_device *pdev) 299101ce87bSAlexander Stein { 300101ce87bSAlexander Stein struct resource *res; 301101ce87bSAlexander Stein 302101ce87bSAlexander Stein res = platform_get_resource(pdev, IORESOURCE_IO, 0); 303101ce87bSAlexander Stein ie6xx_wdt_stop(NULL); 304101ce87bSAlexander Stein watchdog_unregister_device(&ie6xx_wdt_dev); 305101ce87bSAlexander Stein ie6xx_wdt_debugfs_exit(); 306101ce87bSAlexander Stein release_region(res->start, resource_size(res)); 307101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = 0; 308101ce87bSAlexander Stein 309101ce87bSAlexander Stein return 0; 310101ce87bSAlexander Stein } 311101ce87bSAlexander Stein 312101ce87bSAlexander Stein static struct platform_driver ie6xx_wdt_driver = { 313101ce87bSAlexander Stein .probe = ie6xx_wdt_probe, 31482268714SBill Pemberton .remove = ie6xx_wdt_remove, 315101ce87bSAlexander Stein .driver = { 316101ce87bSAlexander Stein .name = DRIVER_NAME, 317101ce87bSAlexander Stein .owner = THIS_MODULE, 318101ce87bSAlexander Stein }, 319101ce87bSAlexander Stein }; 320101ce87bSAlexander Stein 321101ce87bSAlexander Stein static int __init ie6xx_wdt_init(void) 322101ce87bSAlexander Stein { 323101ce87bSAlexander Stein /* Check boot parameters to verify that their initial values */ 324101ce87bSAlexander Stein /* are in range. */ 325101ce87bSAlexander Stein if ((timeout < MIN_TIME) || 326101ce87bSAlexander Stein (timeout > MAX_TIME)) { 327101ce87bSAlexander Stein pr_err("Watchdog timer: value of timeout %d (dec) " 328101ce87bSAlexander Stein "is out of range from %d to %d (dec)\n", 329101ce87bSAlexander Stein timeout, MIN_TIME, MAX_TIME); 330101ce87bSAlexander Stein return -EINVAL; 331101ce87bSAlexander Stein } 332101ce87bSAlexander Stein 333101ce87bSAlexander Stein return platform_driver_register(&ie6xx_wdt_driver); 334101ce87bSAlexander Stein } 335101ce87bSAlexander Stein 336101ce87bSAlexander Stein static void __exit ie6xx_wdt_exit(void) 337101ce87bSAlexander Stein { 338101ce87bSAlexander Stein platform_driver_unregister(&ie6xx_wdt_driver); 339101ce87bSAlexander Stein } 340101ce87bSAlexander Stein 341101ce87bSAlexander Stein late_initcall(ie6xx_wdt_init); 342101ce87bSAlexander Stein module_exit(ie6xx_wdt_exit); 343101ce87bSAlexander Stein 344101ce87bSAlexander Stein MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>"); 345101ce87bSAlexander Stein MODULE_DESCRIPTION("Intel Atom E6xx Watchdog Device Driver"); 346101ce87bSAlexander Stein MODULE_LICENSE("GPL"); 347101ce87bSAlexander Stein MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 348101ce87bSAlexander Stein MODULE_ALIAS("platform:" DRIVER_NAME); 349