diff options
Diffstat (limited to 'drivers/char/watchdog/s3c2410_wdt.c')
| -rw-r--r-- | drivers/char/watchdog/s3c2410_wdt.c | 563 |
1 files changed, 0 insertions, 563 deletions
diff --git a/drivers/char/watchdog/s3c2410_wdt.c b/drivers/char/watchdog/s3c2410_wdt.c deleted file mode 100644 index 5d1c15f83d23..000000000000 --- a/drivers/char/watchdog/s3c2410_wdt.c +++ /dev/null @@ -1,563 +0,0 @@ -/* linux/drivers/char/watchdog/s3c2410_wdt.c - * - * Copyright (c) 2004 Simtec Electronics - * Ben Dooks <ben@simtec.co.uk> - * - * S3C2410 Watchdog Timer Support - * - * Based on, softdog.c by Alan Cox, - * (c) Copyright 1996 Alan Cox <alan@redhat.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * 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 - * - * Changelog: - * 05-Oct-2004 BJD Added semaphore init to stop crashes on open - * Fixed tmr_count / wdt_count confusion - * Added configurable debug - * - * 11-Jan-2005 BJD Fixed divide-by-2 in timeout code - * - * 25-Jan-2005 DA Added suspend/resume support - * Replaced reboot notifier with .shutdown method - * - * 10-Mar-2005 LCVR Changed S3C2410_VA to S3C24XX_VA -*/ - -#include <linux/module.h> -#include <linux/moduleparam.h> -#include <linux/types.h> -#include <linux/timer.h> -#include <linux/miscdevice.h> -#include <linux/watchdog.h> -#include <linux/fs.h> -#include <linux/init.h> -#include <linux/platform_device.h> -#include <linux/interrupt.h> -#include <linux/clk.h> - -#include <asm/uaccess.h> -#include <asm/io.h> - -#include <asm/arch/map.h> - -#undef S3C_VA_WATCHDOG -#define S3C_VA_WATCHDOG (0) - -#include <asm/plat-s3c/regs-watchdog.h> - -#define PFX "s3c2410-wdt: " - -#define CONFIG_S3C2410_WATCHDOG_ATBOOT (0) -#define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME (15) - -static int nowayout = WATCHDOG_NOWAYOUT; -static int tmr_margin = CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME; -static int tmr_atboot = CONFIG_S3C2410_WATCHDOG_ATBOOT; -static int soft_noboot = 0; -static int debug = 0; - -module_param(tmr_margin, int, 0); -module_param(tmr_atboot, int, 0); -module_param(nowayout, int, 0); -module_param(soft_noboot, int, 0); -module_param(debug, int, 0); - -MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. default=" __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME) ")"); - -MODULE_PARM_DESC(tmr_atboot, "Watchdog is started at boot time if set to 1, default=" __MODULE_STRING(CONFIG_S3C2410_WATCHDOG_ATBOOT)); - -MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); - -MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, 0 to reboot (default depends on ONLY_TESTING)"); - -MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug, (default 0)"); - - -typedef enum close_state { - CLOSE_STATE_NOT, - CLOSE_STATE_ALLOW=0x4021 -} close_state_t; - -static DECLARE_MUTEX(open_lock); - -static struct device *wdt_dev; /* platform device attached to */ -static struct resource *wdt_mem; -static struct resource *wdt_irq; -static struct clk *wdt_clock; -static void __iomem *wdt_base; -static unsigned int wdt_count; -static close_state_t allow_close; - -/* watchdog control routines */ - -#define DBG(msg...) do { \ - if (debug) \ - printk(KERN_INFO msg); \ - } while(0) - -/* functions */ - -static int s3c2410wdt_keepalive(void) -{ - writel(wdt_count, wdt_base + S3C2410_WTCNT); - return 0; -} - -static int s3c2410wdt_stop(void) -{ - unsigned long wtcon; - - wtcon = readl(wdt_base + S3C2410_WTCON); - wtcon &= ~(S3C2410_WTCON_ENABLE | S3C2410_WTCON_RSTEN); - writel(wtcon, wdt_base + S3C2410_WTCON); - - return 0; -} - -static int s3c2410wdt_start(void) -{ - unsigned long wtcon; - - s3c2410wdt_stop(); - - wtcon = readl(wdt_base + S3C2410_WTCON); - wtcon |= S3C2410_WTCON_ENABLE | S3C2410_WTCON_DIV128; - - if (soft_noboot) { - wtcon |= S3C2410_WTCON_INTEN; - wtcon &= ~S3C2410_WTCON_RSTEN; - } else { - wtcon &= ~S3C2410_WTCON_INTEN; - wtcon |= S3C2410_WTCON_RSTEN; - } - - DBG("%s: wdt_count=0x%08x, wtcon=%08lx\n", - __FUNCTION__, wdt_count, wtcon); - - writel(wdt_count, wdt_base + S3C2410_WTDAT); - writel(wdt_count, wdt_base + S3C2410_WTCNT); - writel(wtcon, wdt_base + S3C2410_WTCON); - - return 0; -} - -static int s3c2410wdt_set_heartbeat(int timeout) -{ - unsigned int freq = clk_get_rate(wdt_clock); - unsigned int count; - unsigned int divisor = 1; - unsigned long wtcon; - - if (timeout < 1) - return -EINVAL; - - freq /= 128; - count = timeout * freq; - - DBG("%s: count=%d, timeout=%d, freq=%d\n", - __FUNCTION__, count, timeout, freq); - - /* if the count is bigger than the watchdog register, - then work out what we need to do (and if) we can - actually make this value - */ - - if (count >= 0x10000) { - for (divisor = 1; divisor <= 0x100; divisor++) { - if ((count / divisor) < 0x10000) - break; - } - - if ((count / divisor) >= 0x10000) { - dev_err(wdt_dev, "timeout %d too big\n", timeout); - return -EINVAL; - } - } - - tmr_margin = timeout; - - DBG("%s: timeout=%d, divisor=%d, count=%d (%08x)\n", - __FUNCTION__, timeout, divisor, count, count/divisor); - - count /= divisor; - wdt_count = count; - - /* update the pre-scaler */ - wtcon = readl(wdt_base + S3C2410_WTCON); - wtcon &= ~S3C2410_WTCON_PRESCALE_MASK; - wtcon |= S3C2410_WTCON_PRESCALE(divisor-1); - - writel(count, wdt_base + S3C2410_WTDAT); - writel(wtcon, wdt_base + S3C2410_WTCON); - - return 0; -} - -/* - * /dev/watchdog handling - */ - -static int s3c2410wdt_open(struct inode *inode, struct file *file) -{ - if(down_trylock(&open_lock)) - return -EBUSY; - - if (nowayout) - __module_get(THIS_MODULE); - - allow_close = CLOSE_STATE_NOT; - - /* start the timer */ - s3c2410wdt_start(); - return nonseekable_open(inode, file); -} - -static int s3c2410wdt_release(struct inode *inode, struct file *file) -{ - /* - * Shut off the timer. - * Lock it in if it's a module and we set nowayout - */ - - if (allow_close == CLOSE_STATE_ALLOW) { - s3c2410wdt_stop(); - } else { - dev_err(wdt_dev, "Unexpected close, not stopping watchdog\n"); - s3c2410wdt_keepalive(); - } - - allow_close = CLOSE_STATE_NOT; - up(&open_lock); - return 0; -} - -static ssize_t s3c2410wdt_write(struct file *file, const char __user *data, - size_t len, loff_t *ppos) -{ - /* - * Refresh the timer. - */ - if(len) { - if (!nowayout) { - size_t i; - - /* In case it was set long ago */ - allow_close = CLOSE_STATE_NOT; - - for (i = 0; i != len; i++) { - char c; - - if (get_user(c, data + i)) - return -EFAULT; - if (c == 'V') - allow_close = CLOSE_STATE_ALLOW; - } - } - - s3c2410wdt_keepalive(); - } - return len; -} - -#define OPTIONS WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE - -static struct watchdog_info s3c2410_wdt_ident = { - .options = OPTIONS, - .firmware_version = 0, - .identity = "S3C2410 Watchdog", -}; - - -static int s3c2410wdt_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) -{ - void __user *argp = (void __user *)arg; - int __user *p = argp; - int new_margin; - - switch (cmd) { - default: - return -ENOTTY; - - case WDIOC_GETSUPPORT: - return copy_to_user(argp, &s3c2410_wdt_ident, - sizeof(s3c2410_wdt_ident)) ? -EFAULT : 0; - - case WDIOC_GETSTATUS: - case WDIOC_GETBOOTSTATUS: - return put_user(0, p); - - case WDIOC_KEEPALIVE: - s3c2410wdt_keepalive(); - return 0; - - case WDIOC_SETTIMEOUT: - if (get_user(new_margin, p)) - return -EFAULT; - - if (s3c2410wdt_set_heartbeat(new_margin)) - return -EINVAL; - - s3c2410wdt_keepalive(); - return put_user(tmr_margin, p); - - case WDIOC_GETTIMEOUT: - return put_user(tmr_margin, p); - } -} - -/* kernel interface */ - -static const struct file_operations s3c2410wdt_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .write = s3c2410wdt_write, - .ioctl = s3c2410wdt_ioctl, - .open = s3c2410wdt_open, - .release = s3c2410wdt_release, -}; - -static struct miscdevice s3c2410wdt_miscdev = { - .minor = WATCHDOG_MINOR, - .name = "watchdog", - .fops = &s3c2410wdt_fops, -}; - -/* interrupt handler code */ - -static irqreturn_t s3c2410wdt_irq(int irqno, void *param) -{ - dev_info(wdt_dev, "watchdog timer expired (irq)\n"); - - s3c2410wdt_keepalive(); - return IRQ_HANDLED; -} -/* device interface */ - -static int s3c2410wdt_probe(struct platform_device *pdev) -{ - struct resource *res; - struct device *dev; - unsigned int wtcon; - int started = 0; - int ret; - int size; - - DBG("%s: probe=%p\n", __FUNCTION__, pdev); - - dev = &pdev->dev; - wdt_dev = &pdev->dev; - - /* get the memory region for the watchdog timer */ - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (res == NULL) { - dev_err(dev, "no memory resource specified\n"); - return -ENOENT; - } - - size = (res->end-res->start)+1; - wdt_mem = request_mem_region(res->start, size, pdev->name); - if (wdt_mem == NULL) { - dev_err(dev, "failed to get memory region\n"); - ret = -ENOENT; - goto err_req; - } - - wdt_base = ioremap(res->start, size); - if (wdt_base == 0) { - dev_err(dev, "failed to ioremap() region\n"); - ret = -EINVAL; - goto err_req; - } - - DBG("probe: mapped wdt_base=%p\n", wdt_base); - - wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); - if (wdt_irq == NULL) { - dev_err(dev, "no irq resource specified\n"); - ret = -ENOENT; - goto err_map; - } - - ret = request_irq(wdt_irq->start, s3c2410wdt_irq, 0, pdev->name, pdev); - if (ret != 0) { - dev_err(dev, "failed to install irq (%d)\n", ret); - goto err_map; - } - - wdt_clock = clk_get(&pdev->dev, "watchdog"); - if (IS_ERR(wdt_clock)) { - dev_err(dev, "failed to find watchdog clock source\n"); - ret = PTR_ERR(wdt_clock); - goto err_irq; - } - - clk_enable(wdt_clock); - - /* see if we can actually set the requested timer margin, and if - * not, try the default value */ - - if (s3c2410wdt_set_heartbeat(tmr_margin)) { - started = s3c2410wdt_set_heartbeat(CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME); - - if (started == 0) { - dev_info(dev,"tmr_margin value out of range, default %d used\n", - CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME); - } else { - dev_info(dev, "default timer value is out of range, cannot start\n"); - } - } - - ret = misc_register(&s3c2410wdt_miscdev); - if (ret) { - dev_err(dev, "cannot register miscdev on minor=%d (%d)\n", - WATCHDOG_MINOR, ret); - goto err_clk; - } - - if (tmr_atboot && started == 0) { - dev_info(dev, "starting watchdog timer\n"); - s3c2410wdt_start(); - } else if (!tmr_atboot) { - /* if we're not enabling the watchdog, then ensure it is - * disabled if it has been left running from the bootloader - * or other source */ - - s3c2410wdt_stop(); - } - - /* print out a statement of readiness */ - - wtcon = readl(wdt_base + S3C2410_WTCON); - - dev_info(dev, "watchdog %sactive, reset %sabled, irq %sabled\n", - (wtcon & S3C2410_WTCON_ENABLE) ? "" : "in", - (wtcon & S3C2410_WTCON_RSTEN) ? "" : "dis", - (wtcon & S3C2410_WTCON_INTEN) ? "" : "en"); - - return 0; - - err_clk: - clk_disable(wdt_clock); - clk_put(wdt_clock); - - err_irq: - free_irq(wdt_irq->start, pdev); - - err_map: - iounmap(wdt_base); - - err_req: - release_resource(wdt_mem); - kfree(wdt_mem); - - return ret; -} - -static int s3c2410wdt_remove(struct platform_device *dev) -{ - release_resource(wdt_mem); - kfree(wdt_mem); - wdt_mem = NULL; - - free_irq(wdt_irq->start, dev); - wdt_irq = NULL; - - clk_disable(wdt_clock); - clk_put(wdt_clock); - wdt_clock = NULL; - - iounmap(wdt_base); - misc_deregister(&s3c2410wdt_miscdev); - return 0; -} - -static void s3c2410wdt_shutdown(struct platform_device *dev) -{ - s3c2410wdt_stop(); -} - -#ifdef CONFIG_PM - -static unsigned long wtcon_save; -static unsigned long wtdat_save; - -static int s3c2410wdt_suspend(struct platform_device *dev, pm_message_t state) -{ - /* Save watchdog state, and turn it off. */ - wtcon_save = readl(wdt_base + S3C2410_WTCON); - wtdat_save = readl(wdt_base + S3C2410_WTDAT); - - /* Note that WTCNT doesn't need to be saved. */ - s3c2410wdt_stop(); - - return 0; -} - -static int s3c2410wdt_resume(struct platform_device *dev) -{ - /* Restore watchdog state. */ - - writel(wtdat_save, wdt_base + S3C2410_WTDAT); - writel(wtdat_save, wdt_base + S3C2410_WTCNT); /* Reset count */ - writel(wtcon_save, wdt_base + S3C2410_WTCON); - - printk(KERN_INFO PFX "watchdog %sabled\n", - (wtcon_save & S3C2410_WTCON_ENABLE) ? "en" : "dis"); - - return 0; -} - -#else -#define s3c2410wdt_suspend NULL -#define s3c2410wdt_resume NULL -#endif /* CONFIG_PM */ - - -static struct platform_driver s3c2410wdt_driver = { - .probe = s3c2410wdt_probe, - .remove = s3c2410wdt_remove, - .shutdown = s3c2410wdt_shutdown, - .suspend = s3c2410wdt_suspend, - .resume = s3c2410wdt_resume, - .driver = { - .owner = THIS_MODULE, - .name = "s3c2410-wdt", - }, -}; - - -static char banner[] __initdata = KERN_INFO "S3C2410 Watchdog Timer, (c) 2004 Simtec Electronics\n"; - -static int __init watchdog_init(void) -{ - printk(banner); - return platform_driver_register(&s3c2410wdt_driver); -} - -static void __exit watchdog_exit(void) -{ - platform_driver_unregister(&s3c2410wdt_driver); -} - -module_init(watchdog_init); -module_exit(watchdog_exit); - -MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>, " - "Dimitry Andric <dimitry.andric@tomtom.com>"); -MODULE_DESCRIPTION("S3C2410 Watchdog Device Driver"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |