+++ /dev/null
-/*
- * Watchdog driver for Cortina Systems Gemini SoC
- *
- * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
- *
- * 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/kernel.h>
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/io.h>
-#include <linux/fs.h>
-#include <linux/uaccess.h>
-#include <linux/miscdevice.h>
-#include <linux/platform_device.h>
-#include <linux/watchdog.h>
-#include <linux/slab.h>
-
-#define GEMINI_WDCOUNTER 0x0
-#define GEMINI_WDLOAD 0x4
-#define GEMINI_WDRESTART 0x8
-
-#define WDRESTART_MAGIC 0x5AB9
-
-#define GEMINI_WDCR 0xC
-
-#define WDCR_CLOCK_5MHZ (1 << 4)
-#define WDCR_SYS_RST (1 << 1)
-#define WDCR_ENABLE (1 << 0)
-
-#define WDT_CLOCK 5000000 /* 5 MHz */
-#define WDT_DEFAULT_TIMEOUT 13
-#define WDT_MAX_TIMEOUT (0xFFFFFFFF / WDT_CLOCK)
-
-/* status bits */
-#define WDT_ACTIVE 0
-#define WDT_OK_TO_CLOSE 1
-
-static unsigned int timeout = WDT_DEFAULT_TIMEOUT;
-static int nowayout = WATCHDOG_NOWAYOUT;
-
-static DEFINE_SPINLOCK(gemini_wdt_lock);
-
-static struct platform_device *gemini_wdt_dev;
-
-struct gemini_wdt_struct {
- struct resource *res;
- struct device *dev;
- void __iomem *base;
- unsigned long status;
-};
-
-static struct watchdog_info gemini_wdt_info = {
- .identity = "Gemini watchdog",
- .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
- WDIOF_SETTIMEOUT,
-};
-
-/* Disable the watchdog. */
-static void gemini_wdt_stop(struct gemini_wdt_struct *gemini_wdt)
-{
- spin_lock(&gemini_wdt_lock);
-
- __raw_writel(0, gemini_wdt->base + GEMINI_WDCR);
-
- clear_bit(WDT_ACTIVE, &gemini_wdt->status);
-
- spin_unlock(&gemini_wdt_lock);
-}
-
-/* Service the watchdog */
-static void gemini_wdt_service(struct gemini_wdt_struct *gemini_wdt)
-{
- __raw_writel(WDRESTART_MAGIC, gemini_wdt->base + GEMINI_WDRESTART);
-}
-
-/* Enable and reset the watchdog. */
-static void gemini_wdt_start(struct gemini_wdt_struct *gemini_wdt)
-{
- spin_lock(&gemini_wdt_lock);
-
- __raw_writel(timeout * WDT_CLOCK, gemini_wdt->base + GEMINI_WDLOAD);
-
- gemini_wdt_service(gemini_wdt);
-
- /* set clock before enabling */
- __raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST,
- gemini_wdt->base + GEMINI_WDCR);
-
- __raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST | WDCR_ENABLE,
- gemini_wdt->base + GEMINI_WDCR);
-
- set_bit(WDT_ACTIVE, &gemini_wdt->status);
-
- spin_unlock(&gemini_wdt_lock);
-}
-
-/* Watchdog device is opened, and watchdog starts running. */
-static int gemini_wdt_open(struct inode *inode, struct file *file)
-{
- struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(gemini_wdt_dev);
-
- if (test_bit(WDT_ACTIVE, &gemini_wdt->status))
- return -EBUSY;
-
- file->private_data = gemini_wdt;
-
- gemini_wdt_start(gemini_wdt);
-
- return nonseekable_open(inode, file);
-}
-
-/* Close the watchdog device. */
-static int gemini_wdt_close(struct inode *inode, struct file *file)
-{
- struct gemini_wdt_struct *gemini_wdt = file->private_data;
-
- /* Disable the watchdog if possible */
- if (test_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status))
- gemini_wdt_stop(gemini_wdt);
- else
- dev_warn(gemini_wdt->dev, "Device closed unexpectedly - timer will not stop\n");
-
- return 0;
-}
-
-/* Handle commands from user-space. */
-static long gemini_wdt_ioctl(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- struct gemini_wdt_struct *gemini_wdt = file->private_data;
-
- int value;
-
- switch (cmd) {
- case WDIOC_KEEPALIVE:
- gemini_wdt_service(gemini_wdt);
- return 0;
-
- case WDIOC_GETSUPPORT:
- return copy_to_user((struct watchdog_info *)arg, &gemini_wdt_info,
- sizeof(gemini_wdt_info)) ? -EFAULT : 0;
-
- case WDIOC_SETTIMEOUT:
- if (get_user(value, (int *)arg))
- return -EFAULT;
-
- if ((value < 1) || (value > WDT_MAX_TIMEOUT))
- return -EINVAL;
-
- timeout = value;
-
- /* restart wdt to use new timeout */
- gemini_wdt_stop(gemini_wdt);
- gemini_wdt_start(gemini_wdt);
-
- /* Fall through */
- case WDIOC_GETTIMEOUT:
- return put_user(timeout, (int *)arg);
-
- case WDIOC_GETTIMELEFT:
- value = __raw_readl(gemini_wdt->base + GEMINI_WDCOUNTER);
- return put_user(value / WDT_CLOCK, (int *)arg);
-
- default:
- return -ENOTTY;
- }
-}
-
-/* Refresh the watchdog whenever device is written to. */
-static ssize_t gemini_wdt_write(struct file *file, const char *data,
- size_t len, loff_t *ppos)
-{
- struct gemini_wdt_struct *gemini_wdt = file->private_data;
-
- if (len) {
- if (!nowayout) {
- size_t i;
-
- clear_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status);
- for (i = 0; i != len; i++) {
- char c;
-
- if (get_user(c, data + i))
- return -EFAULT;
- if (c == 'V')
- set_bit(WDT_OK_TO_CLOSE,
- &gemini_wdt->status);
- }
- }
- gemini_wdt_service(gemini_wdt);
- }
-
- return len;
-}
-
-static const struct file_operations gemini_wdt_fops = {
- .owner = THIS_MODULE,
- .llseek = no_llseek,
- .unlocked_ioctl = gemini_wdt_ioctl,
- .open = gemini_wdt_open,
- .release = gemini_wdt_close,
- .write = gemini_wdt_write,
-};
-
-static struct miscdevice gemini_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &gemini_wdt_fops,
-};
-
-static void gemini_wdt_shutdown(struct platform_device *pdev)
-{
- struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
-
- gemini_wdt_stop(gemini_wdt);
-}
-
-static int gemini_wdt_probe(struct platform_device *pdev)
-{
- int ret;
- int res_size;
- struct resource *res;
- void __iomem *base;
- struct gemini_wdt_struct *gemini_wdt;
- unsigned int reg;
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev, "can't get device resources\n");
- return -ENODEV;
- }
-
- res_size = resource_size(res);
- if (!request_mem_region(res->start, res_size, res->name)) {
- dev_err(&pdev->dev, "can't allocate %d bytes at %d address\n",
- res_size, res->start);
- return -ENOMEM;
- }
-
- base = ioremap(res->start, res_size);
- if (!base) {
- dev_err(&pdev->dev, "ioremap failed\n");
- ret = -EIO;
- goto fail0;
- }
-
- gemini_wdt = kzalloc(sizeof(struct gemini_wdt_struct), GFP_KERNEL);
- if (!gemini_wdt) {
- dev_err(&pdev->dev, "can't allocate interface\n");
- ret = -ENOMEM;
- goto fail1;
- }
-
- /* Setup gemini_wdt driver structure */
- gemini_wdt->base = base;
- gemini_wdt->res = res;
-
- /* Set up platform driver data */
- platform_set_drvdata(pdev, gemini_wdt);
- gemini_wdt_dev = pdev;
-
- if (gemini_wdt_miscdev.parent) {
- ret = -EBUSY;
- goto fail2;
- }
-
- gemini_wdt_miscdev.parent = &pdev->dev;
-
- reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
- if (reg & WDCR_ENABLE) {
- /* Watchdog was enabled by the bootloader, disable it. */
- reg &= ~(WDCR_ENABLE);
- __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
- }
-
- ret = misc_register(&gemini_wdt_miscdev);
- if (ret)
- goto fail2;
-
- return 0;
-
-fail2:
- platform_set_drvdata(pdev, NULL);
- kfree(gemini_wdt);
-fail1:
- iounmap(base);
-fail0:
- release_mem_region(res->start, res_size);
-
- return ret;
-}
-
-static int gemini_wdt_remove(struct platform_device *pdev)
-{
- struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
-
- platform_set_drvdata(pdev, NULL);
- misc_deregister(&gemini_wdt_miscdev);
- gemini_wdt_dev = NULL;
- iounmap(gemini_wdt->base);
- release_mem_region(gemini_wdt->res->start, resource_size(gemini_wdt->res));
-
- kfree(gemini_wdt);
-
- return 0;
-}
-
-#ifdef CONFIG_PM
-static int gemini_wdt_suspend(struct platform_device *pdev, pm_message_t message)
-{
- struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
- unsigned int reg;
-
- reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
- reg &= ~(WDCR_WDENABLE);
- __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
-
- return 0;
-}
-
-static int gemini_wdt_resume(struct platform_device *pdev)
-{
- struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
- unsigned int reg;
-
- if (gemini_wdt->status) {
- reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
- reg |= WDCR_WDENABLE;
- __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
- }
-
- return 0;
-}
-#else
-#define gemini_wdt_suspend NULL
-#define gemini_wdt_resume NULL
-#endif
-
-static struct platform_driver gemini_wdt_driver = {
- .probe = gemini_wdt_probe,
- .remove = gemini_wdt_remove,
- .shutdown = gemini_wdt_shutdown,
- .suspend = gemini_wdt_suspend,
- .resume = gemini_wdt_resume,
- .driver = {
- .name = "gemini-wdt",
- .owner = THIS_MODULE,
- },
-};
-
-static int __init gemini_wdt_init(void)
-{
- return platform_driver_probe(&gemini_wdt_driver, gemini_wdt_probe);
-}
-
-static void __exit gemini_wdt_exit(void)
-{
- platform_driver_unregister(&gemini_wdt_driver);
-}
-
-module_init(gemini_wdt_init);
-module_exit(gemini_wdt_exit);
-
-module_param(timeout, uint, 0);
-MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
-
-module_param(nowayout, int, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
-
-MODULE_AUTHOR("Paulius Zaleckas");
-MODULE_DESCRIPTION("Watchdog driver for Gemini");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
-MODULE_ALIAS("platform:gemini-wdt");
projects / openwrt / staging / yousong.git / blobdiff