diff options
Diffstat (limited to 'drivers/watchdog/ie6xx_wdt.c')
| -rw-r--r-- | drivers/watchdog/ie6xx_wdt.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/drivers/watchdog/ie6xx_wdt.c b/drivers/watchdog/ie6xx_wdt.c new file mode 100644 index 000000000..78c2541f5 --- /dev/null +++ b/drivers/watchdog/ie6xx_wdt.c @@ -0,0 +1,346 @@ +/* + * 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/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 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 ie6xx_wdt_debugfs_exit(void) +{ + debugfs_remove(ie6xx_wdt_data.debugfs); +} + +#else +static void ie6xx_wdt_debugfs_init(void) +{ +} + +static void ie6xx_wdt_debugfs_exit(void) +{ +} +#endif + +static int 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); + ie6xx_wdt_dev.parent = &pdev->dev; + + 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 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 = ie6xx_wdt_remove, + .driver = { + .name = DRIVER_NAME, + }, +}; + +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("platform:" DRIVER_NAME); 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