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9325fa36 VW |
1 | /* |
2 | * drivers/char/watchdog/pnx4008_wdt.c | |
3 | * | |
4 | * Watchdog driver for PNX4008 board | |
5 | * | |
6 | * Authors: Dmitry Chigirev <source@mvista.com>, | |
5f3b2756 | 7 | * Vitaly Wool <vitalywool@gmail.com> |
9325fa36 VW |
8 | * Based on sa1100 driver, |
9 | * Copyright (C) 2000 Oleg Drokin <green@crimea.edu> | |
10 | * | |
11 | * 2005-2006 (c) MontaVista Software, Inc. This file is licensed under | |
12 | * the terms of the GNU General Public License version 2. This program | |
13 | * is licensed "as is" without any warranty of any kind, whether express | |
14 | * or implied. | |
15 | */ | |
16 | ||
9325fa36 VW |
17 | #include <linux/module.h> |
18 | #include <linux/moduleparam.h> | |
19 | #include <linux/types.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/fs.h> | |
22 | #include <linux/miscdevice.h> | |
23 | #include <linux/watchdog.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/bitops.h> | |
26 | #include <linux/ioport.h> | |
27 | #include <linux/device.h> | |
28 | #include <linux/platform_device.h> | |
29 | #include <linux/clk.h> | |
99d2853a | 30 | #include <linux/spinlock.h> |
84ca995c AC |
31 | #include <linux/uaccess.h> |
32 | #include <linux/io.h> | |
5a0e3ad6 | 33 | #include <linux/slab.h> |
a09e64fb | 34 | #include <mach/hardware.h> |
9325fa36 VW |
35 | |
36 | #define MODULE_NAME "PNX4008-WDT: " | |
37 | ||
38 | /* WatchDog Timer - Chapter 23 Page 207 */ | |
39 | ||
40 | #define DEFAULT_HEARTBEAT 19 | |
41 | #define MAX_HEARTBEAT 60 | |
42 | ||
43 | /* Watchdog timer register set definition */ | |
44 | #define WDTIM_INT(p) ((p) + 0x0) | |
45 | #define WDTIM_CTRL(p) ((p) + 0x4) | |
46 | #define WDTIM_COUNTER(p) ((p) + 0x8) | |
47 | #define WDTIM_MCTRL(p) ((p) + 0xC) | |
48 | #define WDTIM_MATCH0(p) ((p) + 0x10) | |
49 | #define WDTIM_EMR(p) ((p) + 0x14) | |
50 | #define WDTIM_PULSE(p) ((p) + 0x18) | |
51 | #define WDTIM_RES(p) ((p) + 0x1C) | |
52 | ||
53 | /* WDTIM_INT bit definitions */ | |
54 | #define MATCH_INT 1 | |
55 | ||
56 | /* WDTIM_CTRL bit definitions */ | |
57 | #define COUNT_ENAB 1 | |
143a2e54 WVS |
58 | #define RESET_COUNT (1 << 1) |
59 | #define DEBUG_EN (1 << 2) | |
9325fa36 VW |
60 | |
61 | /* WDTIM_MCTRL bit definitions */ | |
62 | #define MR0_INT 1 | |
63 | #undef RESET_COUNT0 | |
143a2e54 WVS |
64 | #define RESET_COUNT0 (1 << 2) |
65 | #define STOP_COUNT0 (1 << 2) | |
66 | #define M_RES1 (1 << 3) | |
67 | #define M_RES2 (1 << 4) | |
68 | #define RESFRC1 (1 << 5) | |
69 | #define RESFRC2 (1 << 6) | |
9325fa36 VW |
70 | |
71 | /* WDTIM_EMR bit definitions */ | |
72 | #define EXT_MATCH0 1 | |
143a2e54 | 73 | #define MATCH_OUTPUT_HIGH (2 << 4) /*a MATCH_CTRL setting */ |
9325fa36 VW |
74 | |
75 | /* WDTIM_RES bit definitions */ | |
76 | #define WDOG_RESET 1 /* read only */ | |
77 | ||
78 | #define WDOG_COUNTER_RATE 13000000 /*the counter clock is 13 MHz fixed */ | |
79 | ||
28981727 | 80 | static int nowayout = WATCHDOG_NOWAYOUT; |
9325fa36 VW |
81 | static int heartbeat = DEFAULT_HEARTBEAT; |
82 | ||
c7dfd0cc | 83 | static DEFINE_SPINLOCK(io_lock); |
9325fa36 VW |
84 | static unsigned long wdt_status; |
85 | #define WDT_IN_USE 0 | |
86 | #define WDT_OK_TO_CLOSE 1 | |
9325fa36 VW |
87 | |
88 | static unsigned long boot_status; | |
89 | ||
9325fa36 VW |
90 | static void __iomem *wdt_base; |
91 | struct clk *wdt_clk; | |
92 | ||
93 | static void wdt_enable(void) | |
94 | { | |
99d2853a WVS |
95 | spin_lock(&io_lock); |
96 | ||
9325fa36 | 97 | /* stop counter, initiate counter reset */ |
7cbc3535 | 98 | writel(RESET_COUNT, WDTIM_CTRL(wdt_base)); |
9325fa36 | 99 | /*wait for reset to complete. 100% guarantee event */ |
7cbc3535 | 100 | while (readl(WDTIM_COUNTER(wdt_base))) |
65a64ec3 | 101 | cpu_relax(); |
9325fa36 | 102 | /* internal and external reset, stop after that */ |
7cbc3535 | 103 | writel(M_RES2 | STOP_COUNT0 | RESET_COUNT0, WDTIM_MCTRL(wdt_base)); |
9325fa36 | 104 | /* configure match output */ |
7cbc3535 | 105 | writel(MATCH_OUTPUT_HIGH, WDTIM_EMR(wdt_base)); |
9325fa36 | 106 | /* clear interrupt, just in case */ |
7cbc3535 | 107 | writel(MATCH_INT, WDTIM_INT(wdt_base)); |
9325fa36 | 108 | /* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */ |
7cbc3535 WS |
109 | writel(0xFFFF, WDTIM_PULSE(wdt_base)); |
110 | writel(heartbeat * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base)); | |
9325fa36 | 111 | /*enable counter, stop when debugger active */ |
7cbc3535 | 112 | writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base)); |
99d2853a WVS |
113 | |
114 | spin_unlock(&io_lock); | |
9325fa36 VW |
115 | } |
116 | ||
117 | static void wdt_disable(void) | |
118 | { | |
99d2853a WVS |
119 | spin_lock(&io_lock); |
120 | ||
7cbc3535 | 121 | writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */ |
99d2853a WVS |
122 | |
123 | spin_unlock(&io_lock); | |
9325fa36 VW |
124 | } |
125 | ||
126 | static int pnx4008_wdt_open(struct inode *inode, struct file *file) | |
127 | { | |
24fd1eda RK |
128 | int ret; |
129 | ||
9325fa36 VW |
130 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) |
131 | return -EBUSY; | |
132 | ||
133 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
134 | ||
24fd1eda RK |
135 | ret = clk_enable(wdt_clk); |
136 | if (ret) { | |
137 | clear_bit(WDT_IN_USE, &wdt_status); | |
138 | return ret; | |
139 | } | |
140 | ||
9325fa36 VW |
141 | wdt_enable(); |
142 | ||
143 | return nonseekable_open(inode, file); | |
144 | } | |
145 | ||
84ca995c AC |
146 | static ssize_t pnx4008_wdt_write(struct file *file, const char *data, |
147 | size_t len, loff_t *ppos) | |
9325fa36 | 148 | { |
9325fa36 VW |
149 | if (len) { |
150 | if (!nowayout) { | |
151 | size_t i; | |
152 | ||
153 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
154 | ||
155 | for (i = 0; i != len; i++) { | |
156 | char c; | |
157 | ||
158 | if (get_user(c, data + i)) | |
159 | return -EFAULT; | |
160 | if (c == 'V') | |
161 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
162 | } | |
163 | } | |
164 | wdt_enable(); | |
165 | } | |
166 | ||
167 | return len; | |
168 | } | |
169 | ||
84ca995c | 170 | static const struct watchdog_info ident = { |
9325fa36 VW |
171 | .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | |
172 | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
173 | .identity = "PNX4008 Watchdog", | |
174 | }; | |
175 | ||
7275fc8c WVS |
176 | static long pnx4008_wdt_ioctl(struct file *file, unsigned int cmd, |
177 | unsigned long arg) | |
9325fa36 | 178 | { |
f311896a | 179 | int ret = -ENOTTY; |
9325fa36 VW |
180 | int time; |
181 | ||
182 | switch (cmd) { | |
183 | case WDIOC_GETSUPPORT: | |
184 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
185 | sizeof(ident)) ? -EFAULT : 0; | |
186 | break; | |
187 | ||
188 | case WDIOC_GETSTATUS: | |
189 | ret = put_user(0, (int *)arg); | |
190 | break; | |
191 | ||
192 | case WDIOC_GETBOOTSTATUS: | |
193 | ret = put_user(boot_status, (int *)arg); | |
194 | break; | |
195 | ||
0c06090c WVS |
196 | case WDIOC_KEEPALIVE: |
197 | wdt_enable(); | |
198 | ret = 0; | |
199 | break; | |
200 | ||
9325fa36 VW |
201 | case WDIOC_SETTIMEOUT: |
202 | ret = get_user(time, (int *)arg); | |
203 | if (ret) | |
204 | break; | |
205 | ||
206 | if (time <= 0 || time > MAX_HEARTBEAT) { | |
207 | ret = -EINVAL; | |
208 | break; | |
209 | } | |
210 | ||
211 | heartbeat = time; | |
212 | wdt_enable(); | |
213 | /* Fall through */ | |
214 | ||
215 | case WDIOC_GETTIMEOUT: | |
216 | ret = put_user(heartbeat, (int *)arg); | |
217 | break; | |
9325fa36 VW |
218 | } |
219 | return ret; | |
220 | } | |
221 | ||
222 | static int pnx4008_wdt_release(struct inode *inode, struct file *file) | |
223 | { | |
224 | if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status)) | |
b1785dfd | 225 | printk(KERN_WARNING "WATCHDOG: Device closed unexpectedly\n"); |
9325fa36 VW |
226 | |
227 | wdt_disable(); | |
24fd1eda | 228 | clk_disable(wdt_clk); |
9325fa36 VW |
229 | clear_bit(WDT_IN_USE, &wdt_status); |
230 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
231 | ||
232 | return 0; | |
233 | } | |
234 | ||
2b8693c0 | 235 | static const struct file_operations pnx4008_wdt_fops = { |
9325fa36 VW |
236 | .owner = THIS_MODULE, |
237 | .llseek = no_llseek, | |
238 | .write = pnx4008_wdt_write, | |
84ca995c | 239 | .unlocked_ioctl = pnx4008_wdt_ioctl, |
9325fa36 VW |
240 | .open = pnx4008_wdt_open, |
241 | .release = pnx4008_wdt_release, | |
242 | }; | |
243 | ||
244 | static struct miscdevice pnx4008_wdt_miscdev = { | |
245 | .minor = WATCHDOG_MINOR, | |
246 | .name = "watchdog", | |
247 | .fops = &pnx4008_wdt_fops, | |
248 | }; | |
249 | ||
b6bf291f | 250 | static int __devinit pnx4008_wdt_probe(struct platform_device *pdev) |
9325fa36 | 251 | { |
19f505f0 WS |
252 | struct resource *r; |
253 | int ret = 0; | |
9325fa36 VW |
254 | |
255 | if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT) | |
256 | heartbeat = DEFAULT_HEARTBEAT; | |
257 | ||
19f505f0 WS |
258 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
259 | wdt_base = devm_request_and_ioremap(&pdev->dev, r); | |
260 | if (!wdt_base) | |
261 | return -EADDRINUSE; | |
9325fa36 | 262 | |
9bb787f4 | 263 | wdt_clk = clk_get(&pdev->dev, NULL); |
19f505f0 WS |
264 | if (IS_ERR(wdt_clk)) |
265 | return PTR_ERR(wdt_clk); | |
24fd1eda RK |
266 | |
267 | ret = clk_enable(wdt_clk); | |
19f505f0 | 268 | if (ret) |
24fd1eda | 269 | goto out; |
19f505f0 | 270 | |
7cbc3535 WS |
271 | boot_status = (readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ? |
272 | WDIOF_CARDRESET : 0; | |
19f505f0 WS |
273 | wdt_disable(); /*disable for now */ |
274 | clk_disable(wdt_clk); | |
9325fa36 VW |
275 | |
276 | ret = misc_register(&pnx4008_wdt_miscdev); | |
277 | if (ret < 0) { | |
19f505f0 WS |
278 | dev_err(&pdev->dev, "cannot register misc device\n"); |
279 | goto out; | |
9325fa36 VW |
280 | } |
281 | ||
19f505f0 WS |
282 | dev_info(&pdev->dev, "PNX4008 Watchdog Timer: heartbeat %d sec\n", |
283 | heartbeat); | |
284 | ||
285 | return 0; | |
286 | ||
9325fa36 | 287 | out: |
19f505f0 | 288 | clk_put(wdt_clk); |
9325fa36 VW |
289 | return ret; |
290 | } | |
291 | ||
b6bf291f | 292 | static int __devexit pnx4008_wdt_remove(struct platform_device *pdev) |
9325fa36 | 293 | { |
f6764497 | 294 | misc_deregister(&pnx4008_wdt_miscdev); |
24fd1eda RK |
295 | |
296 | clk_disable(wdt_clk); | |
297 | clk_put(wdt_clk); | |
298 | ||
9325fa36 VW |
299 | return 0; |
300 | } | |
301 | ||
302 | static struct platform_driver platform_wdt_driver = { | |
303 | .driver = { | |
1508c995 | 304 | .name = "pnx4008-watchdog", |
f37d193c | 305 | .owner = THIS_MODULE, |
9325fa36 VW |
306 | }, |
307 | .probe = pnx4008_wdt_probe, | |
b6bf291f | 308 | .remove = __devexit_p(pnx4008_wdt_remove), |
9325fa36 VW |
309 | }; |
310 | ||
b8ec6118 | 311 | module_platform_driver(platform_wdt_driver); |
9325fa36 VW |
312 | |
313 | MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>"); | |
314 | MODULE_DESCRIPTION("PNX4008 Watchdog Driver"); | |
315 | ||
316 | module_param(heartbeat, int, 0); | |
317 | MODULE_PARM_DESC(heartbeat, | |
318 | "Watchdog heartbeat period in seconds from 1 to " | |
319 | __MODULE_STRING(MAX_HEARTBEAT) ", default " | |
320 | __MODULE_STRING(DEFAULT_HEARTBEAT)); | |
321 | ||
322 | module_param(nowayout, int, 0); | |
323 | MODULE_PARM_DESC(nowayout, | |
324 | "Set to 1 to keep watchdog running after device release"); | |
325 | ||
326 | MODULE_LICENSE("GPL"); | |
327 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
1508c995 | 328 | MODULE_ALIAS("platform:pnx4008-watchdog"); |