diff options
Diffstat (limited to 'drivers/char/watchdog/at32ap700x_wdt.c')
| -rw-r--r-- | drivers/char/watchdog/at32ap700x_wdt.c | 386 |
1 files changed, 0 insertions, 386 deletions
diff --git a/drivers/char/watchdog/at32ap700x_wdt.c b/drivers/char/watchdog/at32ap700x_wdt.c deleted file mode 100644 index 54a516169d0..00000000000 --- a/drivers/char/watchdog/at32ap700x_wdt.c +++ /dev/null @@ -1,386 +0,0 @@ -/* - * Watchdog driver for Atmel AT32AP700X devices - * - * Copyright (C) 2005-2006 Atmel Corporation - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include <linux/init.h> -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/moduleparam.h> -#include <linux/miscdevice.h> -#include <linux/fs.h> -#include <linux/platform_device.h> -#include <linux/watchdog.h> -#include <linux/uaccess.h> -#include <linux/io.h> -#include <linux/spinlock.h> - -#define TIMEOUT_MIN 1 -#define TIMEOUT_MAX 2 -#define TIMEOUT_DEFAULT TIMEOUT_MAX - -/* module parameters */ -static int timeout = TIMEOUT_DEFAULT; -module_param(timeout, int, 0); -MODULE_PARM_DESC(timeout, - "Timeout value. Limited to be 1 or 2 seconds. (default=" - __MODULE_STRING(TIMEOUT_DEFAULT) ")"); - -static int nowayout = WATCHDOG_NOWAYOUT; -module_param(nowayout, int, 0); -MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" - __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); - -/* Watchdog registers and write/read macro */ -#define WDT_CTRL 0x00 -#define WDT_CTRL_EN 0 -#define WDT_CTRL_PSEL 8 -#define WDT_CTRL_KEY 24 - -#define WDT_CLR 0x04 - -#define WDT_BIT(name) (1 << WDT_##name) -#define WDT_BF(name, value) ((value) << WDT_##name) - -#define wdt_readl(dev, reg) \ - __raw_readl((dev)->regs + WDT_##reg) -#define wdt_writel(dev, reg, value) \ - __raw_writel((value), (dev)->regs + WDT_##reg) - -struct wdt_at32ap700x { - void __iomem *regs; - spinlock_t io_lock; - int timeout; - unsigned long users; - struct miscdevice miscdev; -}; - -static struct wdt_at32ap700x *wdt; -static char expect_release; - -/* - * Disable the watchdog. - */ -static inline void at32_wdt_stop(void) -{ - unsigned long psel; - - spin_lock(&wdt->io_lock); - psel = wdt_readl(wdt, CTRL) & WDT_BF(CTRL_PSEL, 0x0f); - wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0x55)); - wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0xaa)); - spin_unlock(&wdt->io_lock); -} - -/* - * Enable and reset the watchdog. - */ -static inline void at32_wdt_start(void) -{ - /* 0xf is 2^16 divider = 2 sec, 0xe is 2^15 divider = 1 sec */ - unsigned long psel = (wdt->timeout > 1) ? 0xf : 0xe; - - spin_lock(&wdt->io_lock); - wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN) - | WDT_BF(CTRL_PSEL, psel) - | WDT_BF(CTRL_KEY, 0x55)); - wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN) - | WDT_BF(CTRL_PSEL, psel) - | WDT_BF(CTRL_KEY, 0xaa)); - spin_unlock(&wdt->io_lock); -} - -/* - * Pat the watchdog timer. - */ -static inline void at32_wdt_pat(void) -{ - spin_lock(&wdt->io_lock); - wdt_writel(wdt, CLR, 0x42); - spin_unlock(&wdt->io_lock); -} - -/* - * Watchdog device is opened, and watchdog starts running. - */ -static int at32_wdt_open(struct inode *inode, struct file *file) -{ - if (test_and_set_bit(1, &wdt->users)) - return -EBUSY; - - at32_wdt_start(); - return nonseekable_open(inode, file); -} - -/* - * Close the watchdog device. - */ -static int at32_wdt_close(struct inode *inode, struct file *file) -{ - if (expect_release == 42) { - at32_wdt_stop(); - } else { - dev_dbg(wdt->miscdev.parent, - "Unexpected close, not stopping watchdog!\n"); - at32_wdt_pat(); - } - clear_bit(1, &wdt->users); - expect_release = 0; - return 0; -} - -/* - * Change the watchdog time interval. - */ -static int at32_wdt_settimeout(int time) -{ - /* - * All counting occurs at 1 / SLOW_CLOCK (32 kHz) and max prescaler is - * 2 ^ 16 allowing up to 2 seconds timeout. - */ - if ((time < TIMEOUT_MIN) || (time > TIMEOUT_MAX)) - return -EINVAL; - - /* - * Set new watchdog time. It will be used when at32_wdt_start() is - * called. - */ - wdt->timeout = time; - return 0; -} - -static struct watchdog_info at32_wdt_info = { - .identity = "at32ap700x watchdog", - .options = WDIOF_SETTIMEOUT | - WDIOF_KEEPALIVEPING | - WDIOF_MAGICCLOSE, -}; - -/* - * Handle commands from user-space. - */ -static int at32_wdt_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) -{ - int ret = -ENOTTY; - int time; - void __user *argp = (void __user *)arg; - int __user *p = argp; - - switch (cmd) { - case WDIOC_KEEPALIVE: - at32_wdt_pat(); - ret = 0; - break; - case WDIOC_GETSUPPORT: - ret = copy_to_user(argp, &at32_wdt_info, - sizeof(at32_wdt_info)) ? -EFAULT : 0; - break; - case WDIOC_SETTIMEOUT: - ret = get_user(time, p); - if (ret) - break; - ret = at32_wdt_settimeout(time); - if (ret) - break; - /* Enable new time value */ - at32_wdt_start(); - /* fall through */ - case WDIOC_GETTIMEOUT: - ret = put_user(wdt->timeout, p); - break; - case WDIOC_GETSTATUS: /* fall through */ - case WDIOC_GETBOOTSTATUS: - ret = put_user(0, p); - break; - case WDIOC_SETOPTIONS: - ret = get_user(time, p); - if (ret) - break; - if (time & WDIOS_DISABLECARD) - at32_wdt_stop(); - if (time & WDIOS_ENABLECARD) - at32_wdt_start(); - ret = 0; - break; - } - - return ret; -} - -static ssize_t at32_wdt_write(struct file *file, const char __user *data, - size_t len, loff_t *ppos) -{ - /* See if we got the magic character 'V' and reload the timer */ - if (len) { - if (!nowayout) { - size_t i; - - /* - * note: just in case someone wrote the magic - * character five months ago... - */ - expect_release = 0; - - /* - * scan to see whether or not we got the magic - * character - */ - for (i = 0; i != len; i++) { - char c; - if (get_user(c, data+i)) - return -EFAULT; - if (c == 'V') - expect_release = 42; - } - } - /* someone wrote to us, we should pat the watchdog */ - at32_wdt_pat(); - } - return len; -} - -static const struct file_operations at32_wdt_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .ioctl = at32_wdt_ioctl, - .open = at32_wdt_open, - .release = at32_wdt_close, - .write = at32_wdt_write, -}; - -static int __init at32_wdt_probe(struct platform_device *pdev) -{ - struct resource *regs; - int ret; - - if (wdt) { - dev_dbg(&pdev->dev, "only 1 wdt instance supported.\n"); - return -EBUSY; - } - - regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!regs) { - dev_dbg(&pdev->dev, "missing mmio resource\n"); - return -ENXIO; - } - - wdt = kzalloc(sizeof(struct wdt_at32ap700x), GFP_KERNEL); - if (!wdt) { - dev_dbg(&pdev->dev, "no memory for wdt structure\n"); - return -ENOMEM; - } - - wdt->regs = ioremap(regs->start, regs->end - regs->start + 1); - if (!wdt->regs) { - ret = -ENOMEM; - dev_dbg(&pdev->dev, "could not map I/O memory\n"); - goto err_free; - } - spin_lock_init(&wdt->io_lock); - wdt->users = 0; - wdt->miscdev.minor = WATCHDOG_MINOR; - wdt->miscdev.name = "watchdog"; - wdt->miscdev.fops = &at32_wdt_fops; - - if (at32_wdt_settimeout(timeout)) { - at32_wdt_settimeout(TIMEOUT_DEFAULT); - dev_dbg(&pdev->dev, - "default timeout invalid, set to %d sec.\n", - TIMEOUT_DEFAULT); - } - - ret = misc_register(&wdt->miscdev); - if (ret) { - dev_dbg(&pdev->dev, "failed to register wdt miscdev\n"); - goto err_iounmap; - } - - platform_set_drvdata(pdev, wdt); - wdt->miscdev.parent = &pdev->dev; - dev_info(&pdev->dev, - "AT32AP700X WDT at 0x%p, timeout %d sec (nowayout=%d)\n", - wdt->regs, wdt->timeout, nowayout); - - return 0; - -err_iounmap: - iounmap(wdt->regs); -err_free: - kfree(wdt); - wdt = NULL; - return ret; -} - -static int __exit at32_wdt_remove(struct platform_device *pdev) -{ - if (wdt && platform_get_drvdata(pdev) == wdt) { - /* Stop the timer before we leave */ - if (!nowayout) - at32_wdt_stop(); - - misc_deregister(&wdt->miscdev); - iounmap(wdt->regs); - kfree(wdt); - wdt = NULL; - platform_set_drvdata(pdev, NULL); - } - - return 0; -} - -static void at32_wdt_shutdown(struct platform_device *pdev) -{ - at32_wdt_stop(); -} - -#ifdef CONFIG_PM -static int at32_wdt_suspend(struct platform_device *pdev, pm_message_t message) -{ - at32_wdt_stop(); - return 0; -} - -static int at32_wdt_resume(struct platform_device *pdev) -{ - if (wdt->users) - at32_wdt_start(); - return 0; -} -#else -#define at32_wdt_suspend NULL -#define at32_wdt_resume NULL -#endif - -static struct platform_driver at32_wdt_driver = { - .remove = __exit_p(at32_wdt_remove), - .suspend = at32_wdt_suspend, - .resume = at32_wdt_resume, - .driver = { - .name = "at32_wdt", - .owner = THIS_MODULE, - }, - .shutdown = at32_wdt_shutdown, -}; - -static int __init at32_wdt_init(void) -{ - return platform_driver_probe(&at32_wdt_driver, at32_wdt_probe); -} -module_init(at32_wdt_init); - -static void __exit at32_wdt_exit(void) -{ - platform_driver_unregister(&at32_wdt_driver); -} -module_exit(at32_wdt_exit); - -MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>"); -MODULE_DESCRIPTION("Watchdog driver for Atmel AT32AP700X"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |