[WATCHDOG] Watchdog driver for AT32AP700X devices
Add support for the built in watchdog in AT32AP700X devices. Tested on AT32AP7000 and ATSTK1000. Hardware documentation can be found in the AT32AP7000 datasheet. Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com> Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>hifive-unleashed-5.1
Hans-Christian Egtvedt
Wim Van Sebroeck
parent
10a29304f4
commit
a9cb3959ac
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@ -187,6 +187,26 @@ config PNX4008_WATCHDOG
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Say N if you are unsure.
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# AVR32 Architecture
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config AT32AP700X_WDT
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tristate "AT32AP700x watchdog"
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depends on WATCHDOG && CPU_AT32AP7000
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help
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Watchdog timer embedded into AT32AP700x devices. This will reboot
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your system when the timeout is reached.
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config AT32AP700X_WDT_TIMEOUT
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int "Timeout value for AT32AP700x watchdog"
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depends on AT32AP700X_WDT
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default "2"
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range 1 2
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help
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Sets the timeout value for the watchdog in AT32AP700x devices.
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Limited by hardware to be 1 or 2 seconds.
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Set to 2 seconds by default.
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# X86 (i386 + ia64 + x86_64) Architecture
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config ACQUIRE_WDT
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@ -36,6 +36,9 @@ obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
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obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o
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obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
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# AVR32 Architecture
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obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
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# X86 (i386 + ia64 + x86_64) Architecture
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obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
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obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o
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@ -0,0 +1,313 @@
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/*
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* Watchdog driver for Atmel AT32AP700X devices
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*
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* Copyright (C) 2005-2006 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/miscdevice.h>
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#include <linux/fs.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#include <asm/uaccess.h>
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#include <asm/io.h>
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#define TIMEOUT_MIN 1
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#define TIMEOUT_DEFAULT CONFIG_AT32AP700X_WDT_TIMEOUT
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#define TIMEOUT_MAX 2
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/* Watchdog registers and write/read macro */
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#define WDT_CTRL 0x00
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#define WDT_CTRL_EN 0
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#define WDT_CTRL_PSEL 8
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#define WDT_CTRL_KEY 24
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#define WDT_CLR 0x04
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#define WDT_BIT(name) (1 << WDT_##name)
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#define WDT_BF(name,value) ((value) << WDT_##name)
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#define wdt_readl(dev,reg) \
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__raw_readl((dev)->regs + WDT_##reg)
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#define wdt_writel(dev,reg,value) \
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__raw_writel((value), (dev)->regs + WDT_##reg)
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struct wdt_at32ap700x {
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void __iomem *regs;
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int timeout;
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int users;
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struct miscdevice miscdev;
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};
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static struct wdt_at32ap700x *wdt;
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/*
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* Disable the watchdog.
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*/
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static void inline at32_wdt_stop(void)
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{
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unsigned long psel = wdt_readl(wdt, CTRL) & WDT_BF(CTRL_PSEL, 0x0f);
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wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0x55));
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wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0xaa));
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}
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/*
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* Enable and reset the watchdog.
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*/
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static void inline at32_wdt_start(void)
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{
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/* 0xf is 2^16 divider = 2 sec, 0xe is 2^15 divider = 1 sec */
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unsigned long psel = (wdt->timeout > 1) ? 0xf : 0xe;
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wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN)
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| WDT_BF(CTRL_PSEL, psel)
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| WDT_BF(CTRL_KEY, 0x55));
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wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN)
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| WDT_BF(CTRL_PSEL, psel)
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| WDT_BF(CTRL_KEY, 0xaa));
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}
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/*
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* Pat the watchdog timer.
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*/
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static void inline at32_wdt_pat(void)
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{
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wdt_writel(wdt, CLR, 0x42);
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}
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/*
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* Watchdog device is opened, and watchdog starts running.
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*/
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static int at32_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(1, &wdt->users))
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return -EBUSY;
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at32_wdt_start();
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return nonseekable_open(inode, file);
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}
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/*
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* Close the watchdog device. If CONFIG_WATCHDOG_NOWAYOUT is _not_ defined then
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* the watchdog is also disabled.
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*/
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static int at32_wdt_close(struct inode *inode, struct file *file)
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{
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#ifndef CONFIG_WATCHDOG_NOWAYOUT
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at32_wdt_stop();
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#endif
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clear_bit(1, &wdt->users);
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return 0;
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}
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/*
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* Change the watchdog time interval.
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*/
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static int at32_wdt_settimeout(int time)
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{
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/*
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* All counting occurs at 1 / SLOW_CLOCK (32 kHz) and max prescaler is
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* 2 ^ 16 allowing up to 2 seconds timeout.
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*/
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if ((time < TIMEOUT_MIN) || (time > TIMEOUT_MAX))
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return -EINVAL;
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/* Set new watchdog time. It will be used when at32_wdt_start() is called. */
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wdt->timeout = time;
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return 0;
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}
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static struct watchdog_info at32_wdt_info = {
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.identity = "at32ap700x watchdog",
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
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};
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/*
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* Handle commands from user-space.
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*/
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static int at32_wdt_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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int ret = -ENOTTY;
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int time;
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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switch(cmd) {
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case WDIOC_KEEPALIVE:
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at32_wdt_pat();
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ret = 0;
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break;
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case WDIOC_GETSUPPORT:
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ret = copy_to_user(argp, &at32_wdt_info,
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sizeof(at32_wdt_info)) ? -EFAULT : 0;
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break;
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case WDIOC_SETTIMEOUT:
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ret = get_user(time, p);
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if (ret)
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break;
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ret = at32_wdt_settimeout(time);
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if (ret)
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break;
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/* Enable new time value */
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at32_wdt_start();
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/* fall through */
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case WDIOC_GETTIMEOUT:
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ret = put_user(wdt->timeout, p);
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break;
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case WDIOC_GETSTATUS: /* fall through */
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case WDIOC_GETBOOTSTATUS:
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ret = put_user(0, p);
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break;
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case WDIOC_SETOPTIONS:
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ret = get_user(time, p);
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if (ret)
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break;
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if (time & WDIOS_DISABLECARD)
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at32_wdt_stop();
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if (time & WDIOS_ENABLECARD)
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at32_wdt_start();
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ret = 0;
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break;
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}
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return ret;
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}
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static ssize_t at32_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
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{
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at32_wdt_pat();
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return len;
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}
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static const struct file_operations at32_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.ioctl = at32_wdt_ioctl,
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.open = at32_wdt_open,
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.release = at32_wdt_close,
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.write = at32_wdt_write,
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};
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static int __init at32_wdt_probe(struct platform_device *pdev)
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{
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struct resource *regs;
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int ret;
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if (wdt) {
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dev_dbg(&pdev->dev, "only 1 wdt instance supported.\n");
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return -EBUSY;
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}
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regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!regs) {
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dev_dbg(&pdev->dev, "missing mmio resource\n");
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return -ENXIO;
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}
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wdt = kzalloc(sizeof(struct wdt_at32ap700x), GFP_KERNEL);
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if (!wdt) {
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dev_dbg(&pdev->dev, "no memory for wdt structure\n");
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return -ENOMEM;
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}
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wdt->regs = ioremap(regs->start, regs->end - regs->start + 1);
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wdt->users = 0;
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wdt->miscdev.minor = WATCHDOG_MINOR;
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wdt->miscdev.name = "watchdog";
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wdt->miscdev.fops = &at32_wdt_fops;
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if (at32_wdt_settimeout(TIMEOUT_DEFAULT)) {
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at32_wdt_settimeout(TIMEOUT_MAX);
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dev_dbg(&pdev->dev,
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"default timeout invalid, set to %d sec.\n",
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TIMEOUT_MAX);
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}
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ret = misc_register(&wdt->miscdev);
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if (ret) {
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dev_dbg(&pdev->dev, "failed to register wdt miscdev\n");
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goto err_register;
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}
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platform_set_drvdata(pdev, wdt);
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wdt->miscdev.parent = &pdev->dev;
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dev_info(&pdev->dev, "AT32AP700X WDT at 0x%p\n", wdt->regs);
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return 0;
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err_register:
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kfree(wdt);
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wdt = NULL;
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return ret;
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}
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static int __exit at32_wdt_remove(struct platform_device *pdev)
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{
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if (wdt && platform_get_drvdata(pdev) == wdt) {
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misc_deregister(&wdt->miscdev);
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kfree(wdt);
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wdt = NULL;
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platform_set_drvdata(pdev, NULL);
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}
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return 0;
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}
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static void at32_wdt_shutdown(struct platform_device *pdev)
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{
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at32_wdt_stop();
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}
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#ifdef CONFIG_PM
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static int at32_wdt_suspend(struct platform_device *pdev, pm_message_t message)
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{
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at32_wdt_stop();
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return 0;
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}
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static int at32_wdt_resume(struct platform_device *pdev)
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{
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if (wdt->users)
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at32_wdt_start();
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return 0;
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}
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#endif
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static struct platform_driver at32_wdt_driver = {
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.remove = __exit_p(at32_wdt_remove),
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#ifdef CONFIG_PM
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.suspend = at32_wdt_suspend,
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.resume = at32_wdt_resume,
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#endif
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.driver = {
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.name = "at32_wdt",
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.owner = THIS_MODULE,
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},
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.shutdown = at32_wdt_shutdown,
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};
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static int __init at32_wdt_init(void)
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{
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return platform_driver_probe(&at32_wdt_driver, at32_wdt_probe);
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}
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module_init(at32_wdt_init);
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static void __exit at32_wdt_exit(void)
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{
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platform_driver_unregister(&at32_wdt_driver);
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}
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module_exit(at32_wdt_exit);
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MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
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MODULE_DESCRIPTION("Watchdog driver for Atmel AT32AP700X");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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