| /* |
| * Intel Atom E6xx Watchdog driver |
| * |
| * Copyright (C) 2011 Alexander Stein |
| * <alexander.stein@systec-electronic.com> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of version 2 of the GNU General |
| * Public License as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be |
| * useful, but WITHOUT ANY WARRANTY; without even the implied |
| * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR |
| * PURPOSE. See the GNU General Public License for more details. |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the Free |
| * Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 02111-1307, USA. |
| * The full GNU General Public License is included in this |
| * distribution in the file called COPYING. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/platform_device.h> |
| #include <linux/io.h> |
| #include <linux/kernel.h> |
| #include <linux/types.h> |
| #include <linux/watchdog.h> |
| #include <linux/miscdevice.h> |
| #include <linux/seq_file.h> |
| #include <linux/debugfs.h> |
| #include <linux/uaccess.h> |
| #include <linux/spinlock.h> |
| |
| #define DRIVER_NAME "ie6xx_wdt" |
| |
| #define PV1 0x00 |
| #define PV2 0x04 |
| |
| #define RR0 0x0c |
| #define RR1 0x0d |
| #define WDT_RELOAD 0x01 |
| #define WDT_TOUT 0x02 |
| |
| #define WDTCR 0x10 |
| #define WDT_PRE_SEL 0x04 |
| #define WDT_RESET_SEL 0x08 |
| #define WDT_RESET_EN 0x10 |
| #define WDT_TOUT_EN 0x20 |
| |
| #define DCR 0x14 |
| |
| #define WDTLR 0x18 |
| #define WDT_LOCK 0x01 |
| #define WDT_ENABLE 0x02 |
| #define WDT_TOUT_CNF 0x03 |
| |
| #define MIN_TIME 1 |
| #define MAX_TIME (10 * 60) /* 10 minutes */ |
| #define DEFAULT_TIME 60 |
| |
| static unsigned int timeout = DEFAULT_TIME; |
| module_param(timeout, uint, 0); |
| MODULE_PARM_DESC(timeout, |
| "Default Watchdog timer setting (" |
| __MODULE_STRING(DEFAULT_TIME) "s)." |
| "The range is from 1 to 600"); |
| |
| static bool nowayout = WATCHDOG_NOWAYOUT; |
| module_param(nowayout, bool, 0); |
| MODULE_PARM_DESC(nowayout, |
| "Watchdog cannot be stopped once started (default=" |
| __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| |
| static u8 resetmode = 0x10; |
| module_param(resetmode, byte, 0); |
| MODULE_PARM_DESC(resetmode, |
| "Resetmode bits: 0x08 warm reset (cold reset otherwise), " |
| "0x10 reset enable, 0x20 disable toggle GPIO[4] (default=0x10)"); |
| |
| static struct { |
| unsigned short sch_wdtba; |
| struct spinlock unlock_sequence; |
| #ifdef CONFIG_DEBUG_FS |
| struct dentry *debugfs; |
| #endif |
| } ie6xx_wdt_data; |
| |
| /* |
| * This is needed to write to preload and reload registers |
| * struct ie6xx_wdt_data.unlock_sequence must be used |
| * to prevent sequence interrupts |
| */ |
| static void ie6xx_wdt_unlock_registers(void) |
| { |
| outb(0x80, ie6xx_wdt_data.sch_wdtba + RR0); |
| outb(0x86, ie6xx_wdt_data.sch_wdtba + RR0); |
| } |
| |
| static int ie6xx_wdt_ping(struct watchdog_device *wdd) |
| { |
| spin_lock(&ie6xx_wdt_data.unlock_sequence); |
| ie6xx_wdt_unlock_registers(); |
| outb(WDT_RELOAD, ie6xx_wdt_data.sch_wdtba + RR1); |
| spin_unlock(&ie6xx_wdt_data.unlock_sequence); |
| return 0; |
| } |
| |
| static int ie6xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t) |
| { |
| u32 preload; |
| u64 clock; |
| u8 wdtcr; |
| |
| /* Watchdog clock is PCI Clock (33MHz) */ |
| clock = 33000000; |
| /* and the preload value is loaded into [34:15] of the down counter */ |
| preload = (t * clock) >> 15; |
| /* |
| * Manual states preload must be one less. |
| * Does not wrap as t is at least 1 |
| */ |
| preload -= 1; |
| |
| spin_lock(&ie6xx_wdt_data.unlock_sequence); |
| |
| /* Set ResetMode & Enable prescaler for range 10ms to 10 min */ |
| wdtcr = resetmode & 0x38; |
| outb(wdtcr, ie6xx_wdt_data.sch_wdtba + WDTCR); |
| |
| ie6xx_wdt_unlock_registers(); |
| outl(0, ie6xx_wdt_data.sch_wdtba + PV1); |
| |
| ie6xx_wdt_unlock_registers(); |
| outl(preload, ie6xx_wdt_data.sch_wdtba + PV2); |
| |
| ie6xx_wdt_unlock_registers(); |
| outb(WDT_RELOAD | WDT_TOUT, ie6xx_wdt_data.sch_wdtba + RR1); |
| |
| spin_unlock(&ie6xx_wdt_data.unlock_sequence); |
| |
| wdd->timeout = t; |
| return 0; |
| } |
| |
| static int ie6xx_wdt_start(struct watchdog_device *wdd) |
| { |
| ie6xx_wdt_set_timeout(wdd, wdd->timeout); |
| |
| /* Enable the watchdog timer */ |
| spin_lock(&ie6xx_wdt_data.unlock_sequence); |
| outb(WDT_ENABLE, ie6xx_wdt_data.sch_wdtba + WDTLR); |
| spin_unlock(&ie6xx_wdt_data.unlock_sequence); |
| |
| return 0; |
| } |
| |
| static int ie6xx_wdt_stop(struct watchdog_device *wdd) |
| { |
| if (inb(ie6xx_wdt_data.sch_wdtba + WDTLR) & WDT_LOCK) |
| return -1; |
| |
| /* Disable the watchdog timer */ |
| spin_lock(&ie6xx_wdt_data.unlock_sequence); |
| outb(0, ie6xx_wdt_data.sch_wdtba + WDTLR); |
| spin_unlock(&ie6xx_wdt_data.unlock_sequence); |
| |
| return 0; |
| } |
| |
| static const struct watchdog_info ie6xx_wdt_info = { |
| .identity = "Intel Atom E6xx Watchdog", |
| .options = WDIOF_SETTIMEOUT | |
| WDIOF_MAGICCLOSE | |
| WDIOF_KEEPALIVEPING, |
| }; |
| |
| static const struct watchdog_ops ie6xx_wdt_ops = { |
| .owner = THIS_MODULE, |
| .start = ie6xx_wdt_start, |
| .stop = ie6xx_wdt_stop, |
| .ping = ie6xx_wdt_ping, |
| .set_timeout = ie6xx_wdt_set_timeout, |
| }; |
| |
| static struct watchdog_device ie6xx_wdt_dev = { |
| .info = &ie6xx_wdt_info, |
| .ops = &ie6xx_wdt_ops, |
| .min_timeout = MIN_TIME, |
| .max_timeout = MAX_TIME, |
| }; |
| |
| #ifdef CONFIG_DEBUG_FS |
| |
| static int ie6xx_wdt_dbg_show(struct seq_file *s, void *unused) |
| { |
| seq_printf(s, "PV1 = 0x%08x\n", |
| inl(ie6xx_wdt_data.sch_wdtba + PV1)); |
| seq_printf(s, "PV2 = 0x%08x\n", |
| inl(ie6xx_wdt_data.sch_wdtba + PV2)); |
| seq_printf(s, "RR = 0x%08x\n", |
| inw(ie6xx_wdt_data.sch_wdtba + RR0)); |
| seq_printf(s, "WDTCR = 0x%08x\n", |
| inw(ie6xx_wdt_data.sch_wdtba + WDTCR)); |
| seq_printf(s, "DCR = 0x%08x\n", |
| inl(ie6xx_wdt_data.sch_wdtba + DCR)); |
| seq_printf(s, "WDTLR = 0x%08x\n", |
| inw(ie6xx_wdt_data.sch_wdtba + WDTLR)); |
| |
| seq_printf(s, "\n"); |
| return 0; |
| } |
| |
| static int ie6xx_wdt_dbg_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, ie6xx_wdt_dbg_show, NULL); |
| } |
| |
| static const struct file_operations ie6xx_wdt_dbg_operations = { |
| .open = ie6xx_wdt_dbg_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| }; |
| |
| static void __devinit ie6xx_wdt_debugfs_init(void) |
| { |
| /* /sys/kernel/debug/ie6xx_wdt */ |
| ie6xx_wdt_data.debugfs = debugfs_create_file("ie6xx_wdt", |
| S_IFREG | S_IRUGO, NULL, NULL, &ie6xx_wdt_dbg_operations); |
| } |
| |
| static void __devexit ie6xx_wdt_debugfs_exit(void) |
| { |
| debugfs_remove(ie6xx_wdt_data.debugfs); |
| } |
| |
| #else |
| static void __devinit ie6xx_wdt_debugfs_init(void) |
| { |
| } |
| |
| static void __devexit ie6xx_wdt_debugfs_exit(void) |
| { |
| } |
| #endif |
| |
| static int __devinit ie6xx_wdt_probe(struct platform_device *pdev) |
| { |
| struct resource *res; |
| u8 wdtlr; |
| int ret; |
| |
| res = platform_get_resource(pdev, IORESOURCE_IO, 0); |
| if (!res) |
| return -ENODEV; |
| |
| if (!request_region(res->start, resource_size(res), pdev->name)) { |
| dev_err(&pdev->dev, "Watchdog region 0x%llx already in use!\n", |
| (u64)res->start); |
| return -EBUSY; |
| } |
| |
| ie6xx_wdt_data.sch_wdtba = res->start; |
| dev_dbg(&pdev->dev, "WDT = 0x%X\n", ie6xx_wdt_data.sch_wdtba); |
| |
| ie6xx_wdt_dev.timeout = timeout; |
| watchdog_set_nowayout(&ie6xx_wdt_dev, nowayout); |
| |
| spin_lock_init(&ie6xx_wdt_data.unlock_sequence); |
| |
| wdtlr = inb(ie6xx_wdt_data.sch_wdtba + WDTLR); |
| if (wdtlr & WDT_LOCK) |
| dev_warn(&pdev->dev, |
| "Watchdog Timer is Locked (Reg=0x%x)\n", wdtlr); |
| |
| ie6xx_wdt_debugfs_init(); |
| |
| ret = watchdog_register_device(&ie6xx_wdt_dev); |
| if (ret) { |
| dev_err(&pdev->dev, |
| "Watchdog timer: cannot register device (err =%d)\n", |
| ret); |
| goto misc_register_error; |
| } |
| |
| return 0; |
| |
| misc_register_error: |
| ie6xx_wdt_debugfs_exit(); |
| release_region(res->start, resource_size(res)); |
| ie6xx_wdt_data.sch_wdtba = 0; |
| return ret; |
| } |
| |
| static int __devexit ie6xx_wdt_remove(struct platform_device *pdev) |
| { |
| struct resource *res; |
| |
| res = platform_get_resource(pdev, IORESOURCE_IO, 0); |
| ie6xx_wdt_stop(NULL); |
| watchdog_unregister_device(&ie6xx_wdt_dev); |
| ie6xx_wdt_debugfs_exit(); |
| release_region(res->start, resource_size(res)); |
| ie6xx_wdt_data.sch_wdtba = 0; |
| |
| return 0; |
| } |
| |
| static struct platform_driver ie6xx_wdt_driver = { |
| .probe = ie6xx_wdt_probe, |
| .remove = __devexit_p(ie6xx_wdt_remove), |
| .driver = { |
| .name = DRIVER_NAME, |
| .owner = THIS_MODULE, |
| }, |
| }; |
| |
| static int __init ie6xx_wdt_init(void) |
| { |
| /* Check boot parameters to verify that their initial values */ |
| /* are in range. */ |
| if ((timeout < MIN_TIME) || |
| (timeout > MAX_TIME)) { |
| pr_err("Watchdog timer: value of timeout %d (dec) " |
| "is out of range from %d to %d (dec)\n", |
| timeout, MIN_TIME, MAX_TIME); |
| return -EINVAL; |
| } |
| |
| return platform_driver_register(&ie6xx_wdt_driver); |
| } |
| |
| static void __exit ie6xx_wdt_exit(void) |
| { |
| platform_driver_unregister(&ie6xx_wdt_driver); |
| } |
| |
| late_initcall(ie6xx_wdt_init); |
| module_exit(ie6xx_wdt_exit); |
| |
| MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>"); |
| MODULE_DESCRIPTION("Intel Atom E6xx Watchdog Device Driver"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
| MODULE_ALIAS("platform:" DRIVER_NAME); |