2 +++ b/drivers/watchdog/gemini_wdt.c
5 + * Watchdog driver for Cortina Systems Gemini SoC
7 + * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
9 + * This program is free software; you can redistribute it and/or modify
10 + * it under the terms of the GNU General Public License version 2 as
11 + * published by the Free Software Foundation.
14 +#include <linux/kernel.h>
15 +#include <linux/init.h>
16 +#include <linux/module.h>
17 +#include <linux/io.h>
18 +#include <linux/fs.h>
19 +#include <linux/uaccess.h>
20 +#include <linux/miscdevice.h>
21 +#include <linux/platform_device.h>
22 +#include <linux/watchdog.h>
23 +#include <linux/slab.h>
25 +#define GEMINI_WDCOUNTER 0x0
26 +#define GEMINI_WDLOAD 0x4
27 +#define GEMINI_WDRESTART 0x8
29 +#define WDRESTART_MAGIC 0x5AB9
31 +#define GEMINI_WDCR 0xC
33 +#define WDCR_CLOCK_5MHZ (1 << 4)
34 +#define WDCR_SYS_RST (1 << 1)
35 +#define WDCR_ENABLE (1 << 0)
37 +#define WDT_CLOCK 5000000 /* 5 MHz */
38 +#define WDT_DEFAULT_TIMEOUT 13
39 +#define WDT_MAX_TIMEOUT (0xFFFFFFFF / WDT_CLOCK)
43 +#define WDT_OK_TO_CLOSE 1
45 +static unsigned int timeout = WDT_DEFAULT_TIMEOUT;
46 +static int nowayout = WATCHDOG_NOWAYOUT;
48 +static DEFINE_SPINLOCK(gemini_wdt_lock);
50 +static struct platform_device *gemini_wdt_dev;
52 +struct gemini_wdt_struct {
53 + struct resource *res;
56 + unsigned long status;
59 +static struct watchdog_info gemini_wdt_info = {
60 + .identity = "Gemini watchdog",
61 + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
65 +/* Disable the watchdog. */
66 +static void gemini_wdt_stop(struct gemini_wdt_struct *gemini_wdt)
68 + spin_lock(&gemini_wdt_lock);
70 + __raw_writel(0, gemini_wdt->base + GEMINI_WDCR);
72 + clear_bit(WDT_ACTIVE, &gemini_wdt->status);
74 + spin_unlock(&gemini_wdt_lock);
77 +/* Service the watchdog */
78 +static void gemini_wdt_service(struct gemini_wdt_struct *gemini_wdt)
80 + __raw_writel(WDRESTART_MAGIC, gemini_wdt->base + GEMINI_WDRESTART);
83 +/* Enable and reset the watchdog. */
84 +static void gemini_wdt_start(struct gemini_wdt_struct *gemini_wdt)
86 + spin_lock(&gemini_wdt_lock);
88 + __raw_writel(timeout * WDT_CLOCK, gemini_wdt->base + GEMINI_WDLOAD);
90 + gemini_wdt_service(gemini_wdt);
92 + /* set clock before enabling */
93 + __raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST,
94 + gemini_wdt->base + GEMINI_WDCR);
96 + __raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST | WDCR_ENABLE,
97 + gemini_wdt->base + GEMINI_WDCR);
99 + set_bit(WDT_ACTIVE, &gemini_wdt->status);
101 + spin_unlock(&gemini_wdt_lock);
104 +/* Watchdog device is opened, and watchdog starts running. */
105 +static int gemini_wdt_open(struct inode *inode, struct file *file)
107 + struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(gemini_wdt_dev);
109 + if (test_bit(WDT_ACTIVE, &gemini_wdt->status))
112 + file->private_data = gemini_wdt;
114 + gemini_wdt_start(gemini_wdt);
116 + return nonseekable_open(inode, file);
119 +/* Close the watchdog device. */
120 +static int gemini_wdt_close(struct inode *inode, struct file *file)
122 + struct gemini_wdt_struct *gemini_wdt = file->private_data;
124 + /* Disable the watchdog if possible */
125 + if (test_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status))
126 + gemini_wdt_stop(gemini_wdt);
128 + dev_warn(gemini_wdt->dev, "Device closed unexpectedly - timer will not stop\n");
133 +/* Handle commands from user-space. */
134 +static long gemini_wdt_ioctl(struct file *file, unsigned int cmd,
137 + struct gemini_wdt_struct *gemini_wdt = file->private_data;
142 + case WDIOC_KEEPALIVE:
143 + gemini_wdt_service(gemini_wdt);
146 + case WDIOC_GETSUPPORT:
147 + return copy_to_user((struct watchdog_info *)arg, &gemini_wdt_info,
148 + sizeof(gemini_wdt_info)) ? -EFAULT : 0;
150 + case WDIOC_SETTIMEOUT:
151 + if (get_user(value, (int *)arg))
154 + if ((value < 1) || (value > WDT_MAX_TIMEOUT))
159 + /* restart wdt to use new timeout */
160 + gemini_wdt_stop(gemini_wdt);
161 + gemini_wdt_start(gemini_wdt);
164 + case WDIOC_GETTIMEOUT:
165 + return put_user(timeout, (int *)arg);
167 + case WDIOC_GETTIMELEFT:
168 + value = __raw_readl(gemini_wdt->base + GEMINI_WDCOUNTER);
169 + return put_user(value / WDT_CLOCK, (int *)arg);
176 +/* Refresh the watchdog whenever device is written to. */
177 +static ssize_t gemini_wdt_write(struct file *file, const char *data,
178 + size_t len, loff_t *ppos)
180 + struct gemini_wdt_struct *gemini_wdt = file->private_data;
186 + clear_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status);
187 + for (i = 0; i != len; i++) {
190 + if (get_user(c, data + i))
193 + set_bit(WDT_OK_TO_CLOSE,
194 + &gemini_wdt->status);
197 + gemini_wdt_service(gemini_wdt);
203 +static const struct file_operations gemini_wdt_fops = {
204 + .owner = THIS_MODULE,
205 + .llseek = no_llseek,
206 + .unlocked_ioctl = gemini_wdt_ioctl,
207 + .open = gemini_wdt_open,
208 + .release = gemini_wdt_close,
209 + .write = gemini_wdt_write,
212 +static struct miscdevice gemini_wdt_miscdev = {
213 + .minor = WATCHDOG_MINOR,
214 + .name = "watchdog",
215 + .fops = &gemini_wdt_fops,
218 +static void gemini_wdt_shutdown(struct platform_device *pdev)
220 + struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
222 + gemini_wdt_stop(gemini_wdt);
225 +static int gemini_wdt_probe(struct platform_device *pdev)
229 + struct resource *res;
230 + void __iomem *base;
231 + struct gemini_wdt_struct *gemini_wdt;
234 + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
236 + dev_err(&pdev->dev, "can't get device resources\n");
240 + res_size = resource_size(res);
241 + if (!request_mem_region(res->start, res_size, res->name)) {
242 + dev_err(&pdev->dev, "can't allocate %d bytes at %d address\n",
243 + res_size, res->start);
247 + base = ioremap(res->start, res_size);
249 + dev_err(&pdev->dev, "ioremap failed\n");
254 + gemini_wdt = kzalloc(sizeof(struct gemini_wdt_struct), GFP_KERNEL);
256 + dev_err(&pdev->dev, "can't allocate interface\n");
261 + /* Setup gemini_wdt driver structure */
262 + gemini_wdt->base = base;
263 + gemini_wdt->res = res;
265 + /* Set up platform driver data */
266 + platform_set_drvdata(pdev, gemini_wdt);
267 + gemini_wdt_dev = pdev;
269 + if (gemini_wdt_miscdev.parent) {
274 + gemini_wdt_miscdev.parent = &pdev->dev;
276 + reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
277 + if (reg & WDCR_ENABLE) {
278 + /* Watchdog was enabled by the bootloader, disable it. */
279 + reg &= ~(WDCR_ENABLE);
280 + __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
283 + ret = misc_register(&gemini_wdt_miscdev);
290 + platform_set_drvdata(pdev, NULL);
295 + release_mem_region(res->start, res_size);
300 +static int gemini_wdt_remove(struct platform_device *pdev)
302 + struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
304 + platform_set_drvdata(pdev, NULL);
305 + misc_deregister(&gemini_wdt_miscdev);
306 + gemini_wdt_dev = NULL;
307 + iounmap(gemini_wdt->base);
308 + release_mem_region(gemini_wdt->res->start, resource_size(gemini_wdt->res));
316 +static int gemini_wdt_suspend(struct platform_device *pdev, pm_message_t message)
318 + struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
321 + reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
322 + reg &= ~(WDCR_WDENABLE);
323 + __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
328 +static int gemini_wdt_resume(struct platform_device *pdev)
330 + struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
333 + if (gemini_wdt->status) {
334 + reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
335 + reg |= WDCR_WDENABLE;
336 + __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
342 +#define gemini_wdt_suspend NULL
343 +#define gemini_wdt_resume NULL
346 +static struct platform_driver gemini_wdt_driver = {
347 + .probe = gemini_wdt_probe,
348 + .remove = gemini_wdt_remove,
349 + .shutdown = gemini_wdt_shutdown,
350 + .suspend = gemini_wdt_suspend,
351 + .resume = gemini_wdt_resume,
353 + .name = "gemini-wdt",
354 + .owner = THIS_MODULE,
358 +static int __init gemini_wdt_init(void)
360 + return platform_driver_probe(&gemini_wdt_driver, gemini_wdt_probe);
363 +static void __exit gemini_wdt_exit(void)
365 + platform_driver_unregister(&gemini_wdt_driver);
368 +module_init(gemini_wdt_init);
369 +module_exit(gemini_wdt_exit);
371 +module_param(timeout, uint, 0);
372 +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
374 +module_param(nowayout, int, 0);
375 +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
377 +MODULE_AUTHOR("Paulius Zaleckas");
378 +MODULE_DESCRIPTION("Watchdog driver for Gemini");
379 +MODULE_LICENSE("GPL");
380 +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
381 +MODULE_ALIAS("platform:gemini-wdt");
382 --- a/drivers/watchdog/Kconfig
383 +++ b/drivers/watchdog/Kconfig
384 @@ -154,6 +154,16 @@ config 977_WATCHDOG
386 Not sure? It's safe to say N.
388 +config GEMINI_WATCHDOG
389 + tristate "Gemini watchdog"
390 + depends on ARCH_GEMINI
392 + Say Y here if to include support for the watchdog timer
393 + embedded in the Cortina Systems Gemini family of devices.
395 + To compile this driver as a module, choose M here: the
396 + module will be called gemini_wdt.
398 config IXP4XX_WATCHDOG
399 tristate "IXP4xx Watchdog"
400 depends on ARCH_IXP4XX
401 --- a/drivers/watchdog/Makefile
402 +++ b/drivers/watchdog/Makefile
403 @@ -36,6 +36,7 @@ obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.
404 obj-$(CONFIG_TWL4030_WATCHDOG) += twl4030_wdt.o
405 obj-$(CONFIG_21285_WATCHDOG) += wdt285.o
406 obj-$(CONFIG_977_WATCHDOG) += wdt977.o
407 +obj-$(CONFIG_GEMINI_WATCHDOG) += gemini_wdt.o
408 obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
409 obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o
410 obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o