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> 27101ce87bSAlexander Stein #include <linux/kernel.h> 28101ce87bSAlexander Stein #include <linux/types.h> 29101ce87bSAlexander Stein #include <linux/watchdog.h> 30101ce87bSAlexander Stein #include <linux/miscdevice.h> 31101ce87bSAlexander Stein #include <linux/seq_file.h> 32101ce87bSAlexander Stein #include <linux/debugfs.h> 33101ce87bSAlexander Stein #include <linux/uaccess.h> 34101ce87bSAlexander Stein #include <linux/spinlock.h> 35101ce87bSAlexander Stein 36101ce87bSAlexander Stein #define DRIVER_NAME "ie6xx_wdt" 37101ce87bSAlexander Stein 38101ce87bSAlexander Stein #define PV1 0x00 39101ce87bSAlexander Stein #define PV2 0x04 40101ce87bSAlexander Stein 41101ce87bSAlexander Stein #define RR0 0x0c 42101ce87bSAlexander Stein #define RR1 0x0d 43101ce87bSAlexander Stein #define WDT_RELOAD 0x01 44101ce87bSAlexander Stein #define WDT_TOUT 0x02 45101ce87bSAlexander Stein 46101ce87bSAlexander Stein #define WDTCR 0x10 47101ce87bSAlexander Stein #define WDT_PRE_SEL 0x04 48101ce87bSAlexander Stein #define WDT_RESET_SEL 0x08 49101ce87bSAlexander Stein #define WDT_RESET_EN 0x10 50101ce87bSAlexander Stein #define WDT_TOUT_EN 0x20 51101ce87bSAlexander Stein 52101ce87bSAlexander Stein #define DCR 0x14 53101ce87bSAlexander Stein 54101ce87bSAlexander Stein #define WDTLR 0x18 55101ce87bSAlexander Stein #define WDT_LOCK 0x01 56101ce87bSAlexander Stein #define WDT_ENABLE 0x02 57101ce87bSAlexander Stein #define WDT_TOUT_CNF 0x03 58101ce87bSAlexander Stein 59101ce87bSAlexander Stein #define MIN_TIME 1 60101ce87bSAlexander Stein #define MAX_TIME (10 * 60) /* 10 minutes */ 61101ce87bSAlexander Stein #define DEFAULT_TIME 60 62101ce87bSAlexander Stein 63101ce87bSAlexander Stein static unsigned int timeout = DEFAULT_TIME; 64101ce87bSAlexander Stein module_param(timeout, uint, 0); 65101ce87bSAlexander Stein MODULE_PARM_DESC(timeout, 66101ce87bSAlexander Stein "Default Watchdog timer setting (" 67101ce87bSAlexander Stein __MODULE_STRING(DEFAULT_TIME) "s)." 68101ce87bSAlexander Stein "The range is from 1 to 600"); 69101ce87bSAlexander Stein 70101ce87bSAlexander Stein static bool nowayout = WATCHDOG_NOWAYOUT; 71101ce87bSAlexander Stein module_param(nowayout, bool, 0); 72101ce87bSAlexander Stein MODULE_PARM_DESC(nowayout, 73101ce87bSAlexander Stein "Watchdog cannot be stopped once started (default=" 74101ce87bSAlexander Stein __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 75101ce87bSAlexander Stein 76101ce87bSAlexander Stein static u8 resetmode = 0x10; 77101ce87bSAlexander Stein module_param(resetmode, byte, 0); 78101ce87bSAlexander Stein MODULE_PARM_DESC(resetmode, 79101ce87bSAlexander Stein "Resetmode bits: 0x08 warm reset (cold reset otherwise), " 80101ce87bSAlexander Stein "0x10 reset enable, 0x20 disable toggle GPIO[4] (default=0x10)"); 81101ce87bSAlexander Stein 82101ce87bSAlexander Stein static struct { 83101ce87bSAlexander Stein unsigned short sch_wdtba; 84101ce87bSAlexander Stein struct spinlock unlock_sequence; 85101ce87bSAlexander Stein #ifdef CONFIG_DEBUG_FS 86101ce87bSAlexander Stein struct dentry *debugfs; 87101ce87bSAlexander Stein #endif 88101ce87bSAlexander Stein } ie6xx_wdt_data; 89101ce87bSAlexander Stein 90101ce87bSAlexander Stein /* 91101ce87bSAlexander Stein * This is needed to write to preload and reload registers 92101ce87bSAlexander Stein * struct ie6xx_wdt_data.unlock_sequence must be used 93101ce87bSAlexander Stein * to prevent sequence interrupts 94101ce87bSAlexander Stein */ 95101ce87bSAlexander Stein static void ie6xx_wdt_unlock_registers(void) 96101ce87bSAlexander Stein { 97101ce87bSAlexander Stein outb(0x80, ie6xx_wdt_data.sch_wdtba + RR0); 98101ce87bSAlexander Stein outb(0x86, ie6xx_wdt_data.sch_wdtba + RR0); 99101ce87bSAlexander Stein } 100101ce87bSAlexander Stein 101101ce87bSAlexander Stein static int ie6xx_wdt_ping(struct watchdog_device *wdd) 102101ce87bSAlexander Stein { 103101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 104101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 105101ce87bSAlexander Stein outb(WDT_RELOAD, ie6xx_wdt_data.sch_wdtba + RR1); 106101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 107101ce87bSAlexander Stein return 0; 108101ce87bSAlexander Stein } 109101ce87bSAlexander Stein 110101ce87bSAlexander Stein static int ie6xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) 111101ce87bSAlexander Stein { 112101ce87bSAlexander Stein u32 preload; 113101ce87bSAlexander Stein u64 clock; 114101ce87bSAlexander Stein u8 wdtcr; 115101ce87bSAlexander Stein 116101ce87bSAlexander Stein /* Watchdog clock is PCI Clock (33MHz) */ 117101ce87bSAlexander Stein clock = 33000000; 118101ce87bSAlexander Stein /* and the preload value is loaded into [34:15] of the down counter */ 119101ce87bSAlexander Stein preload = (t * clock) >> 15; 120101ce87bSAlexander Stein /* 121101ce87bSAlexander Stein * Manual states preload must be one less. 122101ce87bSAlexander Stein * Does not wrap as t is at least 1 123101ce87bSAlexander Stein */ 124101ce87bSAlexander Stein preload -= 1; 125101ce87bSAlexander Stein 126101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 127101ce87bSAlexander Stein 128101ce87bSAlexander Stein /* Set ResetMode & Enable prescaler for range 10ms to 10 min */ 129101ce87bSAlexander Stein wdtcr = resetmode & 0x38; 130101ce87bSAlexander Stein outb(wdtcr, ie6xx_wdt_data.sch_wdtba + WDTCR); 131101ce87bSAlexander Stein 132101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 133101ce87bSAlexander Stein outl(0, ie6xx_wdt_data.sch_wdtba + PV1); 134101ce87bSAlexander Stein 135101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 136101ce87bSAlexander Stein outl(preload, ie6xx_wdt_data.sch_wdtba + PV2); 137101ce87bSAlexander Stein 138101ce87bSAlexander Stein ie6xx_wdt_unlock_registers(); 139101ce87bSAlexander Stein outb(WDT_RELOAD | WDT_TOUT, ie6xx_wdt_data.sch_wdtba + RR1); 140101ce87bSAlexander Stein 141101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 142101ce87bSAlexander Stein 143101ce87bSAlexander Stein wdd->timeout = t; 144101ce87bSAlexander Stein return 0; 145101ce87bSAlexander Stein } 146101ce87bSAlexander Stein 147101ce87bSAlexander Stein static int ie6xx_wdt_start(struct watchdog_device *wdd) 148101ce87bSAlexander Stein { 149101ce87bSAlexander Stein ie6xx_wdt_set_timeout(wdd, wdd->timeout); 150101ce87bSAlexander Stein 151101ce87bSAlexander Stein /* Enable the watchdog timer */ 152101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 153101ce87bSAlexander Stein outb(WDT_ENABLE, ie6xx_wdt_data.sch_wdtba + WDTLR); 154101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 155101ce87bSAlexander Stein 156101ce87bSAlexander Stein return 0; 157101ce87bSAlexander Stein } 158101ce87bSAlexander Stein 159101ce87bSAlexander Stein static int ie6xx_wdt_stop(struct watchdog_device *wdd) 160101ce87bSAlexander Stein { 161101ce87bSAlexander Stein if (inb(ie6xx_wdt_data.sch_wdtba + WDTLR) & WDT_LOCK) 162101ce87bSAlexander Stein return -1; 163101ce87bSAlexander Stein 164101ce87bSAlexander Stein /* Disable the watchdog timer */ 165101ce87bSAlexander Stein spin_lock(&ie6xx_wdt_data.unlock_sequence); 166101ce87bSAlexander Stein outb(0, ie6xx_wdt_data.sch_wdtba + WDTLR); 167101ce87bSAlexander Stein spin_unlock(&ie6xx_wdt_data.unlock_sequence); 168101ce87bSAlexander Stein 169101ce87bSAlexander Stein return 0; 170101ce87bSAlexander Stein } 171101ce87bSAlexander Stein 172101ce87bSAlexander Stein static const struct watchdog_info ie6xx_wdt_info = { 173101ce87bSAlexander Stein .identity = "Intel Atom E6xx Watchdog", 174101ce87bSAlexander Stein .options = WDIOF_SETTIMEOUT | 175101ce87bSAlexander Stein WDIOF_MAGICCLOSE | 176101ce87bSAlexander Stein WDIOF_KEEPALIVEPING, 177101ce87bSAlexander Stein }; 178101ce87bSAlexander Stein 179101ce87bSAlexander Stein static const struct watchdog_ops ie6xx_wdt_ops = { 180101ce87bSAlexander Stein .owner = THIS_MODULE, 181101ce87bSAlexander Stein .start = ie6xx_wdt_start, 182101ce87bSAlexander Stein .stop = ie6xx_wdt_stop, 183101ce87bSAlexander Stein .ping = ie6xx_wdt_ping, 184101ce87bSAlexander Stein .set_timeout = ie6xx_wdt_set_timeout, 185101ce87bSAlexander Stein }; 186101ce87bSAlexander Stein 187101ce87bSAlexander Stein static struct watchdog_device ie6xx_wdt_dev = { 188101ce87bSAlexander Stein .info = &ie6xx_wdt_info, 189101ce87bSAlexander Stein .ops = &ie6xx_wdt_ops, 190101ce87bSAlexander Stein .min_timeout = MIN_TIME, 191101ce87bSAlexander Stein .max_timeout = MAX_TIME, 192101ce87bSAlexander Stein }; 193101ce87bSAlexander Stein 194101ce87bSAlexander Stein #ifdef CONFIG_DEBUG_FS 195101ce87bSAlexander Stein 196101ce87bSAlexander Stein static int ie6xx_wdt_dbg_show(struct seq_file *s, void *unused) 197101ce87bSAlexander Stein { 198101ce87bSAlexander Stein seq_printf(s, "PV1 = 0x%08x\n", 199101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + PV1)); 200101ce87bSAlexander Stein seq_printf(s, "PV2 = 0x%08x\n", 201101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + PV2)); 202101ce87bSAlexander Stein seq_printf(s, "RR = 0x%08x\n", 203101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + RR0)); 204101ce87bSAlexander Stein seq_printf(s, "WDTCR = 0x%08x\n", 205101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + WDTCR)); 206101ce87bSAlexander Stein seq_printf(s, "DCR = 0x%08x\n", 207101ce87bSAlexander Stein inl(ie6xx_wdt_data.sch_wdtba + DCR)); 208101ce87bSAlexander Stein seq_printf(s, "WDTLR = 0x%08x\n", 209101ce87bSAlexander Stein inw(ie6xx_wdt_data.sch_wdtba + WDTLR)); 210101ce87bSAlexander Stein 211101ce87bSAlexander Stein seq_printf(s, "\n"); 212101ce87bSAlexander Stein return 0; 213101ce87bSAlexander Stein } 214101ce87bSAlexander Stein 215101ce87bSAlexander Stein static int ie6xx_wdt_dbg_open(struct inode *inode, struct file *file) 216101ce87bSAlexander Stein { 217101ce87bSAlexander Stein return single_open(file, ie6xx_wdt_dbg_show, NULL); 218101ce87bSAlexander Stein } 219101ce87bSAlexander Stein 220101ce87bSAlexander Stein static const struct file_operations ie6xx_wdt_dbg_operations = { 221101ce87bSAlexander Stein .open = ie6xx_wdt_dbg_open, 222101ce87bSAlexander Stein .read = seq_read, 223101ce87bSAlexander Stein .llseek = seq_lseek, 224101ce87bSAlexander Stein .release = single_release, 225101ce87bSAlexander Stein }; 226101ce87bSAlexander Stein 227101ce87bSAlexander Stein static void __devinit ie6xx_wdt_debugfs_init(void) 228101ce87bSAlexander Stein { 229101ce87bSAlexander Stein /* /sys/kernel/debug/ie6xx_wdt */ 230101ce87bSAlexander Stein ie6xx_wdt_data.debugfs = debugfs_create_file("ie6xx_wdt", 231101ce87bSAlexander Stein S_IFREG | S_IRUGO, NULL, NULL, &ie6xx_wdt_dbg_operations); 232101ce87bSAlexander Stein } 233101ce87bSAlexander Stein 234101ce87bSAlexander Stein static void __devexit ie6xx_wdt_debugfs_exit(void) 235101ce87bSAlexander Stein { 236101ce87bSAlexander Stein debugfs_remove(ie6xx_wdt_data.debugfs); 237101ce87bSAlexander Stein } 238101ce87bSAlexander Stein 239101ce87bSAlexander Stein #else 240101ce87bSAlexander Stein static void __devinit ie6xx_wdt_debugfs_init(void) 241101ce87bSAlexander Stein { 242101ce87bSAlexander Stein } 243101ce87bSAlexander Stein 244101ce87bSAlexander Stein static void __devexit ie6xx_wdt_debugfs_exit(void) 245101ce87bSAlexander Stein { 246101ce87bSAlexander Stein } 247101ce87bSAlexander Stein #endif 248101ce87bSAlexander Stein 249101ce87bSAlexander Stein static int __devinit ie6xx_wdt_probe(struct platform_device *pdev) 250101ce87bSAlexander Stein { 251101ce87bSAlexander Stein struct resource *res; 252101ce87bSAlexander Stein u8 wdtlr; 253101ce87bSAlexander Stein int ret; 254101ce87bSAlexander Stein 255101ce87bSAlexander Stein res = platform_get_resource(pdev, IORESOURCE_IO, 0); 256101ce87bSAlexander Stein if (!res) 257101ce87bSAlexander Stein return -ENODEV; 258101ce87bSAlexander Stein 259101ce87bSAlexander Stein if (!request_region(res->start, resource_size(res), pdev->name)) { 260101ce87bSAlexander Stein dev_err(&pdev->dev, "Watchdog region 0x%x already in use!\n", 261101ce87bSAlexander Stein res->start); 262101ce87bSAlexander Stein return -EBUSY; 263101ce87bSAlexander Stein } 264101ce87bSAlexander Stein 265101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = res->start; 266101ce87bSAlexander Stein dev_dbg(&pdev->dev, "WDT = 0x%X\n", ie6xx_wdt_data.sch_wdtba); 267101ce87bSAlexander Stein 268101ce87bSAlexander Stein ie6xx_wdt_dev.timeout = timeout; 269101ce87bSAlexander Stein watchdog_set_nowayout(&ie6xx_wdt_dev, nowayout); 270101ce87bSAlexander Stein 271101ce87bSAlexander Stein spin_lock_init(&ie6xx_wdt_data.unlock_sequence); 272101ce87bSAlexander Stein 273101ce87bSAlexander Stein wdtlr = inb(ie6xx_wdt_data.sch_wdtba + WDTLR); 274101ce87bSAlexander Stein if (wdtlr & WDT_LOCK) 275101ce87bSAlexander Stein dev_warn(&pdev->dev, 276101ce87bSAlexander Stein "Watchdog Timer is Locked (Reg=0x%x)\n", wdtlr); 277101ce87bSAlexander Stein 278101ce87bSAlexander Stein ie6xx_wdt_debugfs_init(); 279101ce87bSAlexander Stein 280101ce87bSAlexander Stein ret = watchdog_register_device(&ie6xx_wdt_dev); 281101ce87bSAlexander Stein if (ret) { 282101ce87bSAlexander Stein dev_err(&pdev->dev, 283101ce87bSAlexander Stein "Watchdog timer: cannot register device (err =%d)\n", 284101ce87bSAlexander Stein ret); 285101ce87bSAlexander Stein goto misc_register_error; 286101ce87bSAlexander Stein } 287101ce87bSAlexander Stein 288101ce87bSAlexander Stein return 0; 289101ce87bSAlexander Stein 290101ce87bSAlexander Stein misc_register_error: 291101ce87bSAlexander Stein ie6xx_wdt_debugfs_exit(); 292101ce87bSAlexander Stein release_region(res->start, resource_size(res)); 293101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = 0; 294101ce87bSAlexander Stein return ret; 295101ce87bSAlexander Stein } 296101ce87bSAlexander Stein 297101ce87bSAlexander Stein static int __devexit ie6xx_wdt_remove(struct platform_device *pdev) 298101ce87bSAlexander Stein { 299101ce87bSAlexander Stein struct resource *res; 300101ce87bSAlexander Stein 301101ce87bSAlexander Stein res = platform_get_resource(pdev, IORESOURCE_IO, 0); 302101ce87bSAlexander Stein ie6xx_wdt_stop(NULL); 303101ce87bSAlexander Stein watchdog_unregister_device(&ie6xx_wdt_dev); 304101ce87bSAlexander Stein ie6xx_wdt_debugfs_exit(); 305101ce87bSAlexander Stein release_region(res->start, resource_size(res)); 306101ce87bSAlexander Stein ie6xx_wdt_data.sch_wdtba = 0; 307101ce87bSAlexander Stein 308101ce87bSAlexander Stein return 0; 309101ce87bSAlexander Stein } 310101ce87bSAlexander Stein 311101ce87bSAlexander Stein static struct platform_driver ie6xx_wdt_driver = { 312101ce87bSAlexander Stein .probe = ie6xx_wdt_probe, 313101ce87bSAlexander Stein .remove = __devexit_p(ie6xx_wdt_remove), 314101ce87bSAlexander Stein .driver = { 315101ce87bSAlexander Stein .name = DRIVER_NAME, 316101ce87bSAlexander Stein .owner = THIS_MODULE, 317101ce87bSAlexander Stein }, 318101ce87bSAlexander Stein }; 319101ce87bSAlexander Stein 320101ce87bSAlexander Stein static int __init ie6xx_wdt_init(void) 321101ce87bSAlexander Stein { 322101ce87bSAlexander Stein /* Check boot parameters to verify that their initial values */ 323101ce87bSAlexander Stein /* are in range. */ 324101ce87bSAlexander Stein if ((timeout < MIN_TIME) || 325101ce87bSAlexander Stein (timeout > MAX_TIME)) { 326101ce87bSAlexander Stein pr_err("Watchdog timer: value of timeout %d (dec) " 327101ce87bSAlexander Stein "is out of range from %d to %d (dec)\n", 328101ce87bSAlexander Stein timeout, MIN_TIME, MAX_TIME); 329101ce87bSAlexander Stein return -EINVAL; 330101ce87bSAlexander Stein } 331101ce87bSAlexander Stein 332101ce87bSAlexander Stein return platform_driver_register(&ie6xx_wdt_driver); 333101ce87bSAlexander Stein } 334101ce87bSAlexander Stein 335101ce87bSAlexander Stein static void __exit ie6xx_wdt_exit(void) 336101ce87bSAlexander Stein { 337101ce87bSAlexander Stein platform_driver_unregister(&ie6xx_wdt_driver); 338101ce87bSAlexander Stein } 339101ce87bSAlexander Stein 340101ce87bSAlexander Stein late_initcall(ie6xx_wdt_init); 341101ce87bSAlexander Stein module_exit(ie6xx_wdt_exit); 342101ce87bSAlexander Stein 343101ce87bSAlexander Stein MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>"); 344101ce87bSAlexander Stein MODULE_DESCRIPTION("Intel Atom E6xx Watchdog Device Driver"); 345101ce87bSAlexander Stein MODULE_LICENSE("GPL"); 346101ce87bSAlexander Stein MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 347101ce87bSAlexander Stein MODULE_ALIAS("platform:" DRIVER_NAME); 348