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216 lines
4.9 KiB
216 lines
4.9 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Watchdog driver for the SA11x0/PXA2xx |
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* |
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* (c) Copyright 2000 Oleg Drokin <[email protected]> |
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* Based on SoftDog driver by Alan Cox <[email protected]> |
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* |
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* Neither Oleg Drokin nor iXcelerator.com admit liability nor provide |
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* warranty for any of this software. This material is provided |
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* "AS-IS" and at no charge. |
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* |
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* (c) Copyright 2000 Oleg Drokin <[email protected]> |
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* |
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* 27/11/2000 Initial release |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/clk.h> |
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#include <linux/types.h> |
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#include <linux/kernel.h> |
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#include <linux/fs.h> |
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#include <linux/miscdevice.h> |
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#include <linux/watchdog.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/bitops.h> |
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#include <linux/uaccess.h> |
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#include <linux/timex.h> |
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#ifdef CONFIG_ARCH_PXA |
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#include <mach/regs-ost.h> |
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#endif |
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#include <mach/reset.h> |
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#include <mach/hardware.h> |
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static unsigned long oscr_freq; |
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static unsigned long sa1100wdt_users; |
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static unsigned int pre_margin; |
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static int boot_status; |
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/* |
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* Allow only one person to hold it open |
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*/ |
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static int sa1100dog_open(struct inode *inode, struct file *file) |
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{ |
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if (test_and_set_bit(1, &sa1100wdt_users)) |
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return -EBUSY; |
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/* Activate SA1100 Watchdog timer */ |
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writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); |
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writel_relaxed(OSSR_M3, OSSR); |
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writel_relaxed(OWER_WME, OWER); |
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writel_relaxed(readl_relaxed(OIER) | OIER_E3, OIER); |
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return stream_open(inode, file); |
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} |
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/* |
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* The watchdog cannot be disabled. |
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* |
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* Previous comments suggested that turning off the interrupt by |
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* clearing OIER[E3] would prevent the watchdog timing out but this |
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* does not appear to be true (at least on the PXA255). |
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*/ |
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static int sa1100dog_release(struct inode *inode, struct file *file) |
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{ |
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pr_crit("Device closed - timer will not stop\n"); |
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clear_bit(1, &sa1100wdt_users); |
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return 0; |
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} |
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static ssize_t sa1100dog_write(struct file *file, const char __user *data, |
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size_t len, loff_t *ppos) |
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{ |
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if (len) |
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/* Refresh OSMR3 timer. */ |
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writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); |
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return len; |
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} |
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static const struct watchdog_info ident = { |
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.options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT |
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| WDIOF_KEEPALIVEPING, |
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.identity = "SA1100/PXA255 Watchdog", |
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.firmware_version = 1, |
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}; |
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static long sa1100dog_ioctl(struct file *file, unsigned int cmd, |
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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_GETSUPPORT: |
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ret = copy_to_user(argp, &ident, |
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sizeof(ident)) ? -EFAULT : 0; |
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break; |
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case WDIOC_GETSTATUS: |
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ret = put_user(0, p); |
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break; |
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case WDIOC_GETBOOTSTATUS: |
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ret = put_user(boot_status, p); |
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break; |
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case WDIOC_KEEPALIVE: |
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writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); |
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ret = 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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if (time <= 0 || (oscr_freq * (long long)time >= 0xffffffff)) { |
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ret = -EINVAL; |
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break; |
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} |
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pre_margin = oscr_freq * time; |
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writel_relaxed(readl_relaxed(OSCR) + pre_margin, OSMR3); |
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fallthrough; |
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case WDIOC_GETTIMEOUT: |
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ret = put_user(pre_margin / oscr_freq, p); |
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break; |
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} |
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return ret; |
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} |
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static const struct file_operations sa1100dog_fops = { |
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.owner = THIS_MODULE, |
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.llseek = no_llseek, |
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.write = sa1100dog_write, |
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.unlocked_ioctl = sa1100dog_ioctl, |
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.compat_ioctl = compat_ptr_ioctl, |
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.open = sa1100dog_open, |
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.release = sa1100dog_release, |
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}; |
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static struct miscdevice sa1100dog_miscdev = { |
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.minor = WATCHDOG_MINOR, |
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.name = "watchdog", |
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.fops = &sa1100dog_fops, |
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}; |
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static int margin __initdata = 60; /* (secs) Default is 1 minute */ |
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static struct clk *clk; |
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static int __init sa1100dog_init(void) |
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{ |
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int ret; |
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clk = clk_get(NULL, "OSTIMER0"); |
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if (IS_ERR(clk)) { |
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pr_err("SA1100/PXA2xx Watchdog Timer: clock not found: %d\n", |
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(int) PTR_ERR(clk)); |
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return PTR_ERR(clk); |
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} |
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ret = clk_prepare_enable(clk); |
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if (ret) { |
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pr_err("SA1100/PXA2xx Watchdog Timer: clock failed to prepare+enable: %d\n", |
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ret); |
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goto err; |
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} |
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oscr_freq = clk_get_rate(clk); |
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/* |
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* Read the reset status, and save it for later. If |
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* we suspend, RCSR will be cleared, and the watchdog |
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* reset reason will be lost. |
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*/ |
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boot_status = (reset_status & RESET_STATUS_WATCHDOG) ? |
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WDIOF_CARDRESET : 0; |
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pre_margin = oscr_freq * margin; |
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ret = misc_register(&sa1100dog_miscdev); |
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if (ret == 0) { |
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pr_info("SA1100/PXA2xx Watchdog Timer: timer margin %d sec\n", |
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margin); |
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return 0; |
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} |
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clk_disable_unprepare(clk); |
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err: |
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clk_put(clk); |
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return ret; |
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} |
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static void __exit sa1100dog_exit(void) |
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{ |
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misc_deregister(&sa1100dog_miscdev); |
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clk_disable_unprepare(clk); |
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clk_put(clk); |
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} |
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module_init(sa1100dog_init); |
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module_exit(sa1100dog_exit); |
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MODULE_AUTHOR("Oleg Drokin <[email protected]>"); |
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MODULE_DESCRIPTION("SA1100/PXA2xx Watchdog"); |
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module_param(margin, int, 0); |
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MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)"); |
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MODULE_LICENSE("GPL");
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