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David S. Miller8ab0dc32008-08-29 17:07:01 -07001/* cpwd.c - driver implementation for hardware watchdog
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * timers found on Sun Microsystems CP1400 and CP1500 boards.
3 *
Wim Van Sebroeck927d6962009-03-18 08:05:24 +00004 * This device supports both the generic Linux watchdog
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 * interface and Solaris-compatible ioctls as best it is
6 * able.
7 *
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +00008 * NOTE: CP1400 systems appear to have a defective intr_mask
9 * register on the PLD, preventing the disabling of
10 * timer interrupts. We use a timer to periodically
11 * reset 'stopped' watchdogs on affected platforms.
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
David S. Millerc5f85562008-08-29 17:05:51 -070014 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 */
16
Joe Perches27c766a2012-02-15 15:06:19 -080017#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/fs.h>
22#include <linux/errno.h>
23#include <linux/major.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/miscdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/interrupt.h>
26#include <linux/ioport.h>
27#include <linux/timer.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090028#include <linux/slab.h>
Arnd Bergmann613655f2010-06-02 14:28:52 +020029#include <linux/mutex.h>
Andrew Morton347e03d2007-07-15 23:42:03 -070030#include <linux/io.h>
David S. Millerc5f85562008-08-29 17:05:51 -070031#include <linux/of.h>
32#include <linux/of_device.h>
Wim Van Sebroeck278aefc2009-03-18 09:09:26 +000033#include <linux/uaccess.h>
David S. Millerc5f85562008-08-29 17:05:51 -070034
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <asm/irq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <asm/watchdog.h>
37
David S. Millerc5f85562008-08-29 17:05:51 -070038#define DRIVER_NAME "cpwd"
David S. Millerc5f85562008-08-29 17:05:51 -070039
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#define WD_OBPNAME "watchdog"
David S. Millerc5f85562008-08-29 17:05:51 -070041#define WD_BADMODEL "SUNW,501-5336"
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#define WD_BTIMEOUT (jiffies + (HZ * 1000))
43#define WD_BLIMIT 0xFFFF
44
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#define WD0_MINOR 212
Wim Van Sebroeck927d6962009-03-18 08:05:24 +000046#define WD1_MINOR 213
47#define WD2_MINOR 214
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
David S. Millerc5f85562008-08-29 17:05:51 -070049/* Internal driver definitions. */
50#define WD0_ID 0
51#define WD1_ID 1
52#define WD2_ID 2
53#define WD_NUMDEVS 3
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
David S. Millerc5f85562008-08-29 17:05:51 -070055#define WD_INTR_OFF 0
56#define WD_INTR_ON 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58#define WD_STAT_INIT 0x01 /* Watchdog timer is initialized */
59#define WD_STAT_BSTOP 0x02 /* Watchdog timer is brokenstopped */
60#define WD_STAT_SVCD 0x04 /* Watchdog interrupt occurred */
61
62/* Register value definitions
63 */
64#define WD0_INTR_MASK 0x01 /* Watchdog device interrupt masks */
65#define WD1_INTR_MASK 0x02
66#define WD2_INTR_MASK 0x04
67
68#define WD_S_RUNNING 0x01 /* Watchdog device status running */
69#define WD_S_EXPIRED 0x02 /* Watchdog device status expired */
70
David S. Millerc5f85562008-08-29 17:05:51 -070071struct cpwd {
72 void __iomem *regs;
73 spinlock_t lock;
74
75 unsigned int irq;
76
77 unsigned long timeout;
78 bool enabled;
79 bool reboot;
80 bool broken;
81 bool initialized;
82
83 struct {
84 struct miscdevice misc;
85 void __iomem *regs;
86 u8 intr_mask;
87 u8 runstatus;
88 u16 timeout;
89 } devs[WD_NUMDEVS];
90};
91
Arnd Bergmann613655f2010-06-02 14:28:52 +020092static DEFINE_MUTEX(cpwd_mutex);
David S. Millerc5f85562008-08-29 17:05:51 -070093static struct cpwd *cpwd_device;
94
Wim Van Sebroeck927d6962009-03-18 08:05:24 +000095/* Sun uses Altera PLD EPF8820ATC144-4
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 * providing three hardware watchdogs:
97 *
Wim Van Sebroeck927d6962009-03-18 08:05:24 +000098 * 1) RIC - sends an interrupt when triggered
99 * 2) XIR - asserts XIR_B_RESET when triggered, resets CPU
100 * 3) POR - asserts POR_B_RESET when triggered, resets CPU, backplane, board
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 *
102 *** Timer register block definition (struct wd_timer_regblk)
103 *
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000104 * dcntr and limit registers (halfword access):
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 * -------------------
106 * | 15 | ...| 1 | 0 |
107 * -------------------
108 * |- counter val -|
109 * -------------------
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000110 * dcntr - Current 16-bit downcounter value.
111 * When downcounter reaches '0' watchdog expires.
112 * Reading this register resets downcounter with
113 * 'limit' value.
114 * limit - 16-bit countdown value in 1/10th second increments.
115 * Writing this register begins countdown with input value.
116 * Reading from this register does not affect counter.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 * NOTES: After watchdog reset, dcntr and limit contain '1'
118 *
119 * status register (byte access):
120 * ---------------------------
121 * | 7 | ... | 2 | 1 | 0 |
122 * --------------+------------
123 * |- UNUSED -| EXP | RUN |
124 * ---------------------------
125 * status- Bit 0 - Watchdog is running
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000126 * Bit 1 - Watchdog has expired
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 *
128 *** PLD register block definition (struct wd_pld_regblk)
129 *
130 * intr_mask register (byte access):
131 * ---------------------------------
132 * | 7 | ... | 3 | 2 | 1 | 0 |
133 * +-------------+------------------
134 * |- UNUSED -| WD3 | WD2 | WD1 |
135 * ---------------------------------
136 * WD3 - 1 == Interrupt disabled for watchdog 3
137 * WD2 - 1 == Interrupt disabled for watchdog 2
138 * WD1 - 1 == Interrupt disabled for watchdog 1
139 *
140 * pld_status register (byte access):
141 * UNKNOWN, MAGICAL MYSTERY REGISTER
142 *
143 */
144#define WD_TIMER_REGSZ 16
145#define WD0_OFF 0
146#define WD1_OFF (WD_TIMER_REGSZ * 1)
147#define WD2_OFF (WD_TIMER_REGSZ * 2)
148#define PLD_OFF (WD_TIMER_REGSZ * 3)
149
150#define WD_DCNTR 0x00
151#define WD_LIMIT 0x04
152#define WD_STATUS 0x08
153
154#define PLD_IMASK (PLD_OFF + 0x00)
155#define PLD_STATUS (PLD_OFF + 0x04)
156
David S. Millerc5f85562008-08-29 17:05:51 -0700157static struct timer_list cpwd_timer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
Wim Van Sebroecka77dba72009-04-14 20:20:07 +0000159static int wd0_timeout;
160static int wd1_timeout;
161static int wd2_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000163module_param(wd0_timeout, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs");
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000165module_param(wd1_timeout, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs");
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000167module_param(wd2_timeout, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs");
169
David S. Millerc5f85562008-08-29 17:05:51 -0700170MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
171MODULE_DESCRIPTION("Hardware watchdog driver for Sun Microsystems CP1400/1500");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172MODULE_LICENSE("GPL");
David S. Millerc5f85562008-08-29 17:05:51 -0700173MODULE_SUPPORTED_DEVICE("watchdog");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
David S. Millerc5f85562008-08-29 17:05:51 -0700175static void cpwd_writew(u16 val, void __iomem *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176{
David S. Millerc5f85562008-08-29 17:05:51 -0700177 writew(cpu_to_le16(val), addr);
178}
179static u16 cpwd_readw(void __iomem *addr)
180{
181 u16 val = readw(addr);
182
183 return le16_to_cpu(val);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184}
185
David S. Millerc5f85562008-08-29 17:05:51 -0700186static void cpwd_writeb(u8 val, void __iomem *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187{
David S. Millerc5f85562008-08-29 17:05:51 -0700188 writeb(val, addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189}
190
David S. Millerc5f85562008-08-29 17:05:51 -0700191static u8 cpwd_readb(void __iomem *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
David S. Millerc5f85562008-08-29 17:05:51 -0700193 return readb(addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194}
195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196/* Enable or disable watchdog interrupts
197 * Because of the CP1400 defect this should only be
198 * called during initialzation or by wd_[start|stop]timer()
199 *
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000200 * index - sub-device index, or -1 for 'all'
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 * enable - non-zero to enable interrupts, zero to disable
202 */
David S. Millerc5f85562008-08-29 17:05:51 -0700203static void cpwd_toggleintr(struct cpwd *p, int index, int enable)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204{
David S. Millerc5f85562008-08-29 17:05:51 -0700205 unsigned char curregs = cpwd_readb(p->regs + PLD_IMASK);
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000206 unsigned char setregs =
207 (index == -1) ?
208 (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) :
David S. Millerc5f85562008-08-29 17:05:51 -0700209 (p->devs[index].intr_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
David S. Millerc5f85562008-08-29 17:05:51 -0700211 if (enable == WD_INTR_ON)
212 curregs &= ~setregs;
213 else
214 curregs |= setregs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
David S. Millerc5f85562008-08-29 17:05:51 -0700216 cpwd_writeb(curregs, p->regs + PLD_IMASK);
217}
218
219/* Restarts timer with maximum limit value and
220 * does not unset 'brokenstop' value.
221 */
222static void cpwd_resetbrokentimer(struct cpwd *p, int index)
223{
224 cpwd_toggleintr(p, index, WD_INTR_ON);
225 cpwd_writew(WD_BLIMIT, p->devs[index].regs + WD_LIMIT);
226}
227
228/* Timer method called to reset stopped watchdogs--
229 * because of the PLD bug on CP1400, we cannot mask
230 * interrupts within the PLD so me must continually
231 * reset the timers ad infinitum.
232 */
233static void cpwd_brokentimer(unsigned long data)
234{
235 struct cpwd *p = (struct cpwd *) data;
236 int id, tripped = 0;
237
238 /* kill a running timer instance, in case we
239 * were called directly instead of by kernel timer
240 */
241 if (timer_pending(&cpwd_timer))
242 del_timer(&cpwd_timer);
243
244 for (id = 0; id < WD_NUMDEVS; id++) {
245 if (p->devs[id].runstatus & WD_STAT_BSTOP) {
246 ++tripped;
247 cpwd_resetbrokentimer(p, id);
248 }
249 }
250
251 if (tripped) {
252 /* there is at least one timer brokenstopped-- reschedule */
253 cpwd_timer.expires = WD_BTIMEOUT;
254 add_timer(&cpwd_timer);
255 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256}
257
258/* Reset countdown timer with 'limit' value and continue countdown.
259 * This will not start a stopped timer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 */
David S. Millerc5f85562008-08-29 17:05:51 -0700261static void cpwd_pingtimer(struct cpwd *p, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262{
David S. Millerc5f85562008-08-29 17:05:51 -0700263 if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING)
264 cpwd_readw(p->devs[index].regs + WD_DCNTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
267/* Stop a running watchdog timer-- the timer actually keeps
268 * running, but the interrupt is masked so that no action is
269 * taken upon expiration.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 */
David S. Millerc5f85562008-08-29 17:05:51 -0700271static void cpwd_stoptimer(struct cpwd *p, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272{
David S. Millerc5f85562008-08-29 17:05:51 -0700273 if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING) {
274 cpwd_toggleintr(p, index, WD_INTR_OFF);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
David S. Millerc5f85562008-08-29 17:05:51 -0700276 if (p->broken) {
277 p->devs[index].runstatus |= WD_STAT_BSTOP;
278 cpwd_brokentimer((unsigned long) p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 }
280 }
281}
282
283/* Start a watchdog timer with the specified limit value
284 * If the watchdog is running, it will be restarted with
285 * the provided limit value.
286 *
287 * This function will enable interrupts on the specified
288 * watchdog.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 */
David S. Millerc5f85562008-08-29 17:05:51 -0700290static void cpwd_starttimer(struct cpwd *p, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291{
David S. Millerc5f85562008-08-29 17:05:51 -0700292 if (p->broken)
293 p->devs[index].runstatus &= ~WD_STAT_BSTOP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294
David S. Millerc5f85562008-08-29 17:05:51 -0700295 p->devs[index].runstatus &= ~WD_STAT_SVCD;
296
297 cpwd_writew(p->devs[index].timeout, p->devs[index].regs + WD_LIMIT);
298 cpwd_toggleintr(p, index, WD_INTR_ON);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299}
300
David S. Millerc5f85562008-08-29 17:05:51 -0700301static int cpwd_getstatus(struct cpwd *p, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302{
David S. Millerc5f85562008-08-29 17:05:51 -0700303 unsigned char stat = cpwd_readb(p->devs[index].regs + WD_STATUS);
304 unsigned char intr = cpwd_readb(p->devs[index].regs + PLD_IMASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 unsigned char ret = WD_STOPPED;
306
307 /* determine STOPPED */
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000308 if (!stat)
David S. Millerc5f85562008-08-29 17:05:51 -0700309 return ret;
310
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 /* determine EXPIRED vs FREERUN vs RUNNING */
David S. Millerc5f85562008-08-29 17:05:51 -0700312 else if (WD_S_EXPIRED & stat) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 ret = WD_EXPIRED;
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000314 } else if (WD_S_RUNNING & stat) {
David S. Millerc5f85562008-08-29 17:05:51 -0700315 if (intr & p->devs[index].intr_mask) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 ret = WD_FREERUN;
David S. Millerc5f85562008-08-29 17:05:51 -0700317 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 /* Fudge WD_EXPIRED status for defective CP1400--
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000319 * IF timer is running
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000320 * AND brokenstop is set
321 * AND an interrupt has been serviced
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 * we are WD_EXPIRED.
323 *
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000324 * IF timer is running
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000325 * AND brokenstop is set
326 * AND no interrupt has been serviced
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 * we are WD_FREERUN.
328 */
David S. Millerc5f85562008-08-29 17:05:51 -0700329 if (p->broken &&
330 (p->devs[index].runstatus & WD_STAT_BSTOP)) {
331 if (p->devs[index].runstatus & WD_STAT_SVCD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 ret = WD_EXPIRED;
David S. Millerc5f85562008-08-29 17:05:51 -0700333 } else {
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000334 /* we could as well pretend
335 * we are expired */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 ret = WD_FREERUN;
337 }
David S. Millerc5f85562008-08-29 17:05:51 -0700338 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 ret = WD_RUNNING;
340 }
341 }
342 }
343
344 /* determine SERVICED */
David S. Millerc5f85562008-08-29 17:05:51 -0700345 if (p->devs[index].runstatus & WD_STAT_SVCD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 ret |= WD_SERVICED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000348 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349}
350
David S. Millerc5f85562008-08-29 17:05:51 -0700351static irqreturn_t cpwd_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352{
David S. Millerc5f85562008-08-29 17:05:51 -0700353 struct cpwd *p = dev_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
David S. Millerc5f85562008-08-29 17:05:51 -0700355 /* Only WD0 will interrupt-- others are NMI and we won't
356 * see them here....
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 */
David S. Millerc5f85562008-08-29 17:05:51 -0700358 spin_lock_irq(&p->lock);
359
360 cpwd_stoptimer(p, WD0_ID);
361 p->devs[WD0_ID].runstatus |= WD_STAT_SVCD;
362
363 spin_unlock_irq(&p->lock);
364
365 return IRQ_HANDLED;
366}
367
368static int cpwd_open(struct inode *inode, struct file *f)
369{
370 struct cpwd *p = cpwd_device;
371
Arnd Bergmann613655f2010-06-02 14:28:52 +0200372 mutex_lock(&cpwd_mutex);
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000373 switch (iminor(inode)) {
374 case WD0_MINOR:
375 case WD1_MINOR:
376 case WD2_MINOR:
377 break;
David S. Millerc5f85562008-08-29 17:05:51 -0700378
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000379 default:
Arnd Bergmann613655f2010-06-02 14:28:52 +0200380 mutex_unlock(&cpwd_mutex);
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000381 return -ENODEV;
David S. Millerc5f85562008-08-29 17:05:51 -0700382 }
383
384 /* Register IRQ on first open of device */
385 if (!p->initialized) {
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000386 if (request_irq(p->irq, &cpwd_interrupt,
David S. Millerc5f85562008-08-29 17:05:51 -0700387 IRQF_SHARED, DRIVER_NAME, p)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800388 pr_err("Cannot register IRQ %d\n", p->irq);
Arnd Bergmann613655f2010-06-02 14:28:52 +0200389 mutex_unlock(&cpwd_mutex);
David S. Millerc5f85562008-08-29 17:05:51 -0700390 return -EBUSY;
391 }
392 p->initialized = true;
393 }
394
Arnd Bergmann613655f2010-06-02 14:28:52 +0200395 mutex_unlock(&cpwd_mutex);
David S. Millerc5f85562008-08-29 17:05:51 -0700396
397 return nonseekable_open(inode, f);
398}
399
400static int cpwd_release(struct inode *inode, struct file *file)
401{
402 return 0;
403}
404
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +0000405static long cpwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
David S. Millerc5f85562008-08-29 17:05:51 -0700406{
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000407 static const struct watchdog_info info = {
David S. Millerc5f85562008-08-29 17:05:51 -0700408 .options = WDIOF_SETTIMEOUT,
409 .firmware_version = 1,
410 .identity = DRIVER_NAME,
411 };
412 void __user *argp = (void __user *)arg;
Al Viro496ad9a2013-01-23 17:07:38 -0500413 struct inode *inode = file_inode(file);
David S. Millerc5f85562008-08-29 17:05:51 -0700414 int index = iminor(inode) - WD0_MINOR;
415 struct cpwd *p = cpwd_device;
416 int setopt = 0;
417
418 switch (cmd) {
419 /* Generic Linux IOCTLs */
420 case WDIOC_GETSUPPORT:
421 if (copy_to_user(argp, &info, sizeof(struct watchdog_info)))
422 return -EFAULT;
423 break;
424
425 case WDIOC_GETSTATUS:
426 case WDIOC_GETBOOTSTATUS:
427 if (put_user(0, (int __user *)argp))
428 return -EFAULT;
429 break;
430
431 case WDIOC_KEEPALIVE:
432 cpwd_pingtimer(p, index);
433 break;
434
435 case WDIOC_SETOPTIONS:
436 if (copy_from_user(&setopt, argp, sizeof(unsigned int)))
437 return -EFAULT;
438
439 if (setopt & WDIOS_DISABLECARD) {
440 if (p->enabled)
441 return -EINVAL;
442 cpwd_stoptimer(p, index);
443 } else if (setopt & WDIOS_ENABLECARD) {
444 cpwd_starttimer(p, index);
445 } else {
446 return -EINVAL;
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000447 }
David S. Millerc5f85562008-08-29 17:05:51 -0700448 break;
449
450 /* Solaris-compatible IOCTLs */
451 case WIOCGSTAT:
452 setopt = cpwd_getstatus(p, index);
453 if (copy_to_user(argp, &setopt, sizeof(unsigned int)))
454 return -EFAULT;
455 break;
456
457 case WIOCSTART:
458 cpwd_starttimer(p, index);
459 break;
460
461 case WIOCSTOP:
462 if (p->enabled)
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000463 return -EINVAL;
David S. Millerc5f85562008-08-29 17:05:51 -0700464
465 cpwd_stoptimer(p, index);
466 break;
467
468 default:
469 return -EINVAL;
470 }
471
472 return 0;
473}
474
475static long cpwd_compat_ioctl(struct file *file, unsigned int cmd,
476 unsigned long arg)
477{
478 int rval = -ENOIOCTLCMD;
479
480 switch (cmd) {
481 /* solaris ioctls are specific to this driver */
482 case WIOCSTART:
483 case WIOCSTOP:
484 case WIOCGSTAT:
Arnd Bergmann613655f2010-06-02 14:28:52 +0200485 mutex_lock(&cpwd_mutex);
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +0000486 rval = cpwd_ioctl(file, cmd, arg);
Arnd Bergmann613655f2010-06-02 14:28:52 +0200487 mutex_unlock(&cpwd_mutex);
David S. Millerc5f85562008-08-29 17:05:51 -0700488 break;
489
490 /* everything else is handled by the generic compat layer */
491 default:
492 break;
493 }
494
495 return rval;
496}
497
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000498static ssize_t cpwd_write(struct file *file, const char __user *buf,
David S. Millerc5f85562008-08-29 17:05:51 -0700499 size_t count, loff_t *ppos)
500{
Al Viro496ad9a2013-01-23 17:07:38 -0500501 struct inode *inode = file_inode(file);
David S. Millerc5f85562008-08-29 17:05:51 -0700502 struct cpwd *p = cpwd_device;
503 int index = iminor(inode);
504
505 if (count) {
506 cpwd_pingtimer(p, index);
507 return 1;
508 }
509
510 return 0;
511}
512
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000513static ssize_t cpwd_read(struct file *file, char __user *buffer,
David S. Millerc5f85562008-08-29 17:05:51 -0700514 size_t count, loff_t *ppos)
515{
516 return -EINVAL;
517}
518
519static const struct file_operations cpwd_fops = {
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +0000520 .owner = THIS_MODULE,
521 .unlocked_ioctl = cpwd_ioctl,
522 .compat_ioctl = cpwd_compat_ioctl,
523 .open = cpwd_open,
524 .write = cpwd_write,
525 .read = cpwd_read,
526 .release = cpwd_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200527 .llseek = no_llseek,
David S. Millerc5f85562008-08-29 17:05:51 -0700528};
529
Bill Pemberton2d991a12012-11-19 13:21:41 -0500530static int cpwd_probe(struct platform_device *op)
David S. Millerc5f85562008-08-29 17:05:51 -0700531{
532 struct device_node *options;
533 const char *str_prop;
534 const void *prop_val;
535 int i, err = -EINVAL;
536 struct cpwd *p;
537
538 if (cpwd_device)
539 return -EINVAL;
540
541 p = kzalloc(sizeof(*p), GFP_KERNEL);
542 err = -ENOMEM;
543 if (!p) {
Joe Perches27c766a2012-02-15 15:06:19 -0800544 pr_err("Unable to allocate struct cpwd\n");
David S. Millerc5f85562008-08-29 17:05:51 -0700545 goto out;
546 }
547
Grant Likely1636f8a2010-06-18 11:09:58 -0600548 p->irq = op->archdata.irqs[0];
David S. Millerc5f85562008-08-29 17:05:51 -0700549
550 spin_lock_init(&p->lock);
551
552 p->regs = of_ioremap(&op->resource[0], 0,
553 4 * WD_TIMER_REGSZ, DRIVER_NAME);
554 if (!p->regs) {
Joe Perches27c766a2012-02-15 15:06:19 -0800555 pr_err("Unable to map registers\n");
David S. Millerc5f85562008-08-29 17:05:51 -0700556 goto out_free;
557 }
558
559 options = of_find_node_by_path("/options");
560 err = -ENODEV;
561 if (!options) {
Joe Perches27c766a2012-02-15 15:06:19 -0800562 pr_err("Unable to find /options node\n");
David S. Millerc5f85562008-08-29 17:05:51 -0700563 goto out_iounmap;
564 }
565
566 prop_val = of_get_property(options, "watchdog-enable?", NULL);
567 p->enabled = (prop_val ? true : false);
568
569 prop_val = of_get_property(options, "watchdog-reboot?", NULL);
570 p->reboot = (prop_val ? true : false);
571
572 str_prop = of_get_property(options, "watchdog-timeout", NULL);
573 if (str_prop)
574 p->timeout = simple_strtoul(str_prop, NULL, 10);
575
576 /* CP1400s seem to have broken PLD implementations-- the
577 * interrupt_mask register cannot be written, so no timer
578 * interrupts can be masked within the PLD.
579 */
Grant Likely61c7a082010-04-13 16:12:29 -0700580 str_prop = of_get_property(op->dev.of_node, "model", NULL);
David S. Millerc5f85562008-08-29 17:05:51 -0700581 p->broken = (str_prop && !strcmp(str_prop, WD_BADMODEL));
582
583 if (!p->enabled)
584 cpwd_toggleintr(p, -1, WD_INTR_OFF);
585
586 for (i = 0; i < WD_NUMDEVS; i++) {
587 static const char *cpwd_names[] = { "RIC", "XIR", "POR" };
588 static int *parms[] = { &wd0_timeout,
589 &wd1_timeout,
590 &wd2_timeout };
591 struct miscdevice *mp = &p->devs[i].misc;
592
593 mp->minor = WD0_MINOR + i;
594 mp->name = cpwd_names[i];
595 mp->fops = &cpwd_fops;
596
597 p->devs[i].regs = p->regs + (i * WD_TIMER_REGSZ);
598 p->devs[i].intr_mask = (WD0_INTR_MASK << i);
599 p->devs[i].runstatus &= ~WD_STAT_BSTOP;
600 p->devs[i].runstatus |= WD_STAT_INIT;
601 p->devs[i].timeout = p->timeout;
602 if (*parms[i])
603 p->devs[i].timeout = *parms[i];
604
605 err = misc_register(&p->devs[i].misc);
606 if (err) {
Joe Perches27c766a2012-02-15 15:06:19 -0800607 pr_err("Could not register misc device for dev %d\n",
608 i);
David S. Millerc5f85562008-08-29 17:05:51 -0700609 goto out_unregister;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 }
611 }
612
David S. Millerc5f85562008-08-29 17:05:51 -0700613 if (p->broken) {
614 init_timer(&cpwd_timer);
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000615 cpwd_timer.function = cpwd_brokentimer;
David S. Millerc5f85562008-08-29 17:05:51 -0700616 cpwd_timer.data = (unsigned long) p;
617 cpwd_timer.expires = WD_BTIMEOUT;
618
Joe Perches27c766a2012-02-15 15:06:19 -0800619 pr_info("PLD defect workaround enabled for model %s\n",
620 WD_BADMODEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 }
David S. Millerc5f85562008-08-29 17:05:51 -0700622
Jingoo Han26556b62013-05-23 19:43:43 +0900623 platform_set_drvdata(op, p);
David S. Millerc5f85562008-08-29 17:05:51 -0700624 cpwd_device = p;
625 err = 0;
626
627out:
628 return err;
629
630out_unregister:
631 for (i--; i >= 0; i--)
632 misc_deregister(&p->devs[i].misc);
633
634out_iounmap:
635 of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
636
637out_free:
638 kfree(p);
639 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640}
641
Bill Pemberton4b12b892012-11-19 13:26:24 -0500642static int cpwd_remove(struct platform_device *op)
David S. Millerc5f85562008-08-29 17:05:51 -0700643{
Jingoo Han26556b62013-05-23 19:43:43 +0900644 struct cpwd *p = platform_get_drvdata(op);
David S. Millerc5f85562008-08-29 17:05:51 -0700645 int i;
646
Wim Van Sebroeckbbd562d2011-02-21 10:52:43 +0000647 for (i = 0; i < WD_NUMDEVS; i++) {
David S. Millerc5f85562008-08-29 17:05:51 -0700648 misc_deregister(&p->devs[i].misc);
649
650 if (!p->enabled) {
651 cpwd_stoptimer(p, i);
652 if (p->devs[i].runstatus & WD_STAT_BSTOP)
653 cpwd_resetbrokentimer(p, i);
654 }
655 }
656
657 if (p->broken)
658 del_timer_sync(&cpwd_timer);
659
660 if (p->initialized)
661 free_irq(p->irq, p);
662
663 of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
664 kfree(p);
665
666 cpwd_device = NULL;
667
668 return 0;
669}
670
David S. Millerfd098312008-08-31 01:23:17 -0700671static const struct of_device_id cpwd_match[] = {
David S. Millerc5f85562008-08-29 17:05:51 -0700672 {
673 .name = "watchdog",
674 },
675 {},
676};
677MODULE_DEVICE_TABLE(of, cpwd_match);
678
Grant Likely1c48a5c2011-02-17 02:43:24 -0700679static struct platform_driver cpwd_driver = {
Grant Likely40182942010-04-13 16:13:02 -0700680 .driver = {
681 .name = DRIVER_NAME,
Grant Likely40182942010-04-13 16:13:02 -0700682 .of_match_table = cpwd_match,
683 },
David S. Millerc5f85562008-08-29 17:05:51 -0700684 .probe = cpwd_probe,
Bill Pemberton82268712012-11-19 13:21:12 -0500685 .remove = cpwd_remove,
David S. Millerc5f85562008-08-29 17:05:51 -0700686};
687
Axel Linb8ec6112011-11-29 13:56:27 +0800688module_platform_driver(cpwd_driver);