Root/target/linux/gemini/patches-3.3/110-watchdog-add-gemini_wdt-driver.patch

1--- /dev/null
2+++ b/drivers/watchdog/gemini_wdt.c
3@@ -0,0 +1,378 @@
4+/*
5+ * Watchdog driver for Cortina Systems Gemini SoC
6+ *
7+ * Copyright (C) 2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
8+ *
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.
12+ */
13+
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>
24+
25+#define GEMINI_WDCOUNTER 0x0
26+#define GEMINI_WDLOAD 0x4
27+#define GEMINI_WDRESTART 0x8
28+
29+#define WDRESTART_MAGIC 0x5AB9
30+
31+#define GEMINI_WDCR 0xC
32+
33+#define WDCR_CLOCK_5MHZ (1 << 4)
34+#define WDCR_SYS_RST (1 << 1)
35+#define WDCR_ENABLE (1 << 0)
36+
37+#define WDT_CLOCK 5000000 /* 5 MHz */
38+#define WDT_DEFAULT_TIMEOUT 13
39+#define WDT_MAX_TIMEOUT (0xFFFFFFFF / WDT_CLOCK)
40+
41+/* status bits */
42+#define WDT_ACTIVE 0
43+#define WDT_OK_TO_CLOSE 1
44+
45+static unsigned int timeout = WDT_DEFAULT_TIMEOUT;
46+static int nowayout = WATCHDOG_NOWAYOUT;
47+
48+static DEFINE_SPINLOCK(gemini_wdt_lock);
49+
50+static struct platform_device *gemini_wdt_dev;
51+
52+struct gemini_wdt_struct {
53+ struct resource *res;
54+ struct device *dev;
55+ void __iomem *base;
56+ unsigned long status;
57+};
58+
59+static struct watchdog_info gemini_wdt_info = {
60+ .identity = "Gemini watchdog",
61+ .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
62+ WDIOF_SETTIMEOUT,
63+};
64+
65+/* Disable the watchdog. */
66+static void gemini_wdt_stop(struct gemini_wdt_struct *gemini_wdt)
67+{
68+ spin_lock(&gemini_wdt_lock);
69+
70+ __raw_writel(0, gemini_wdt->base + GEMINI_WDCR);
71+
72+ clear_bit(WDT_ACTIVE, &gemini_wdt->status);
73+
74+ spin_unlock(&gemini_wdt_lock);
75+}
76+
77+/* Service the watchdog */
78+static void gemini_wdt_service(struct gemini_wdt_struct *gemini_wdt)
79+{
80+ __raw_writel(WDRESTART_MAGIC, gemini_wdt->base + GEMINI_WDRESTART);
81+}
82+
83+/* Enable and reset the watchdog. */
84+static void gemini_wdt_start(struct gemini_wdt_struct *gemini_wdt)
85+{
86+ spin_lock(&gemini_wdt_lock);
87+
88+ __raw_writel(timeout * WDT_CLOCK, gemini_wdt->base + GEMINI_WDLOAD);
89+
90+ gemini_wdt_service(gemini_wdt);
91+
92+ /* set clock before enabling */
93+ __raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST,
94+ gemini_wdt->base + GEMINI_WDCR);
95+
96+ __raw_writel(WDCR_CLOCK_5MHZ | WDCR_SYS_RST | WDCR_ENABLE,
97+ gemini_wdt->base + GEMINI_WDCR);
98+
99+ set_bit(WDT_ACTIVE, &gemini_wdt->status);
100+
101+ spin_unlock(&gemini_wdt_lock);
102+}
103+
104+/* Watchdog device is opened, and watchdog starts running. */
105+static int gemini_wdt_open(struct inode *inode, struct file *file)
106+{
107+ struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(gemini_wdt_dev);
108+
109+ if (test_bit(WDT_ACTIVE, &gemini_wdt->status))
110+ return -EBUSY;
111+
112+ file->private_data = gemini_wdt;
113+
114+ gemini_wdt_start(gemini_wdt);
115+
116+ return nonseekable_open(inode, file);
117+}
118+
119+/* Close the watchdog device. */
120+static int gemini_wdt_close(struct inode *inode, struct file *file)
121+{
122+ struct gemini_wdt_struct *gemini_wdt = file->private_data;
123+
124+ /* Disable the watchdog if possible */
125+ if (test_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status))
126+ gemini_wdt_stop(gemini_wdt);
127+ else
128+ dev_warn(gemini_wdt->dev, "Device closed unexpectedly - timer will not stop\n");
129+
130+ return 0;
131+}
132+
133+/* Handle commands from user-space. */
134+static long gemini_wdt_ioctl(struct file *file, unsigned int cmd,
135+ unsigned long arg)
136+{
137+ struct gemini_wdt_struct *gemini_wdt = file->private_data;
138+
139+ int value;
140+
141+ switch (cmd) {
142+ case WDIOC_KEEPALIVE:
143+ gemini_wdt_service(gemini_wdt);
144+ return 0;
145+
146+ case WDIOC_GETSUPPORT:
147+ return copy_to_user((struct watchdog_info *)arg, &gemini_wdt_info,
148+ sizeof(gemini_wdt_info)) ? -EFAULT : 0;
149+
150+ case WDIOC_SETTIMEOUT:
151+ if (get_user(value, (int *)arg))
152+ return -EFAULT;
153+
154+ if ((value < 1) || (value > WDT_MAX_TIMEOUT))
155+ return -EINVAL;
156+
157+ timeout = value;
158+
159+ /* restart wdt to use new timeout */
160+ gemini_wdt_stop(gemini_wdt);
161+ gemini_wdt_start(gemini_wdt);
162+
163+ /* Fall through */
164+ case WDIOC_GETTIMEOUT:
165+ return put_user(timeout, (int *)arg);
166+
167+ case WDIOC_GETTIMELEFT:
168+ value = __raw_readl(gemini_wdt->base + GEMINI_WDCOUNTER);
169+ return put_user(value / WDT_CLOCK, (int *)arg);
170+
171+ default:
172+ return -ENOTTY;
173+ }
174+}
175+
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)
179+{
180+ struct gemini_wdt_struct *gemini_wdt = file->private_data;
181+
182+ if (len) {
183+ if (!nowayout) {
184+ size_t i;
185+
186+ clear_bit(WDT_OK_TO_CLOSE, &gemini_wdt->status);
187+ for (i = 0; i != len; i++) {
188+ char c;
189+
190+ if (get_user(c, data + i))
191+ return -EFAULT;
192+ if (c == 'V')
193+ set_bit(WDT_OK_TO_CLOSE,
194+ &gemini_wdt->status);
195+ }
196+ }
197+ gemini_wdt_service(gemini_wdt);
198+ }
199+
200+ return len;
201+}
202+
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,
210+};
211+
212+static struct miscdevice gemini_wdt_miscdev = {
213+ .minor = WATCHDOG_MINOR,
214+ .name = "watchdog",
215+ .fops = &gemini_wdt_fops,
216+};
217+
218+static void gemini_wdt_shutdown(struct platform_device *pdev)
219+{
220+ struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
221+
222+ gemini_wdt_stop(gemini_wdt);
223+}
224+
225+static int __devinit gemini_wdt_probe(struct platform_device *pdev)
226+{
227+ int ret;
228+ int res_size;
229+ struct resource *res;
230+ void __iomem *base;
231+ struct gemini_wdt_struct *gemini_wdt;
232+ unsigned int reg;
233+
234+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
235+ if (!res) {
236+ dev_err(&pdev->dev, "can't get device resources\n");
237+ return -ENODEV;
238+ }
239+
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);
244+ return -ENOMEM;
245+ }
246+
247+ base = ioremap(res->start, res_size);
248+ if (!base) {
249+ dev_err(&pdev->dev, "ioremap failed\n");
250+ ret = -EIO;
251+ goto fail0;
252+ }
253+
254+ gemini_wdt = kzalloc(sizeof(struct gemini_wdt_struct), GFP_KERNEL);
255+ if (!gemini_wdt) {
256+ dev_err(&pdev->dev, "can't allocate interface\n");
257+ ret = -ENOMEM;
258+ goto fail1;
259+ }
260+
261+ /* Setup gemini_wdt driver structure */
262+ gemini_wdt->base = base;
263+ gemini_wdt->res = res;
264+
265+ /* Set up platform driver data */
266+ platform_set_drvdata(pdev, gemini_wdt);
267+ gemini_wdt_dev = pdev;
268+
269+ if (gemini_wdt_miscdev.parent) {
270+ ret = -EBUSY;
271+ goto fail2;
272+ }
273+
274+ gemini_wdt_miscdev.parent = &pdev->dev;
275+
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);
281+ }
282+
283+ ret = misc_register(&gemini_wdt_miscdev);
284+ if (ret)
285+ goto fail2;
286+
287+ return 0;
288+
289+fail2:
290+ platform_set_drvdata(pdev, NULL);
291+ kfree(gemini_wdt);
292+fail1:
293+ iounmap(base);
294+fail0:
295+ release_mem_region(res->start, res_size);
296+
297+ return ret;
298+}
299+
300+static int __devexit gemini_wdt_remove(struct platform_device *pdev)
301+{
302+ struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
303+
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));
309+
310+ kfree(gemini_wdt);
311+
312+ return 0;
313+}
314+
315+#ifdef CONFIG_PM
316+static int gemini_wdt_suspend(struct platform_device *pdev, pm_message_t message)
317+{
318+ struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
319+ unsigned int reg;
320+
321+ reg = __raw_readw(gemini_wdt->base + GEMINI_WDCR);
322+ reg &= ~(WDCR_WDENABLE);
323+ __raw_writel(reg, gemini_wdt->base + GEMINI_WDCR);
324+
325+ return 0;
326+}
327+
328+static int gemini_wdt_resume(struct platform_device *pdev)
329+{
330+ struct gemini_wdt_struct *gemini_wdt = platform_get_drvdata(pdev);
331+ unsigned int reg;
332+
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);
337+ }
338+
339+ return 0;
340+}
341+#else
342+#define gemini_wdt_suspend NULL
343+#define gemini_wdt_resume NULL
344+#endif
345+
346+static struct platform_driver gemini_wdt_driver = {
347+ .probe = gemini_wdt_probe,
348+ .remove = __devexit_p(gemini_wdt_remove),
349+ .shutdown = gemini_wdt_shutdown,
350+ .suspend = gemini_wdt_suspend,
351+ .resume = gemini_wdt_resume,
352+ .driver = {
353+ .name = "gemini-wdt",
354+ .owner = THIS_MODULE,
355+ },
356+};
357+
358+static int __init gemini_wdt_init(void)
359+{
360+ return platform_driver_probe(&gemini_wdt_driver, gemini_wdt_probe);
361+}
362+
363+static void __exit gemini_wdt_exit(void)
364+{
365+ platform_driver_unregister(&gemini_wdt_driver);
366+}
367+
368+module_init(gemini_wdt_init);
369+module_exit(gemini_wdt_exit);
370+
371+module_param(timeout, uint, 0);
372+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds");
373+
374+module_param(nowayout, int, 0);
375+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
376+
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@@ -127,6 +127,16 @@ config 977_WATCHDOG
385 
386       Not sure? It's safe to say N.
387 
388+config GEMINI_WATCHDOG
389+ tristate "Gemini watchdog"
390+ depends on ARCH_GEMINI
391+ help
392+ Say Y here if to include support for the watchdog timer
393+ embedded in the Cortina Systems Gemini family of devices.
394+
395+ To compile this driver as a module, choose M here: the
396+ module will be called gemini_wdt.
397+
398 config IXP2000_WATCHDOG
399     tristate "IXP2000 Watchdog"
400     depends on ARCH_IXP2000
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_IXP2000_WATCHDOG) += ixp2000_wdt.o
409 obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
410 obj-$(CONFIG_KS8695_WATCHDOG) += ks8695_wdt.o
411

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