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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>
24#include <linux/init.h>
25#include <linux/miscdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/interrupt.h>
27#include <linux/ioport.h>
28#include <linux/timer.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Arnd Bergmann613655f2010-06-02 14:28:52 +020030#include <linux/mutex.h>
Andrew Morton347e03d2007-07-15 23:42:03 -070031#include <linux/io.h>
David S. Millerc5f85562008-08-29 17:05:51 -070032#include <linux/of.h>
33#include <linux/of_device.h>
Wim Van Sebroeck278aefc2009-03-18 09:09:26 +000034#include <linux/uaccess.h>
David S. Millerc5f85562008-08-29 17:05:51 -070035
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <asm/irq.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <asm/watchdog.h>
38
David S. Millerc5f85562008-08-29 17:05:51 -070039#define DRIVER_NAME "cpwd"
David S. Millerc5f85562008-08-29 17:05:51 -070040
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#define WD_OBPNAME "watchdog"
David S. Millerc5f85562008-08-29 17:05:51 -070042#define WD_BADMODEL "SUNW,501-5336"
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#define WD_BTIMEOUT (jiffies + (HZ * 1000))
44#define WD_BLIMIT 0xFFFF
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#define WD0_MINOR 212
Wim Van Sebroeck927d6962009-03-18 08:05:24 +000047#define WD1_MINOR 213
48#define WD2_MINOR 214
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
David S. Millerc5f85562008-08-29 17:05:51 -070050/* Internal driver definitions. */
51#define WD0_ID 0
52#define WD1_ID 1
53#define WD2_ID 2
54#define WD_NUMDEVS 3
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
David S. Millerc5f85562008-08-29 17:05:51 -070056#define WD_INTR_OFF 0
57#define WD_INTR_ON 1
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59#define WD_STAT_INIT 0x01 /* Watchdog timer is initialized */
60#define WD_STAT_BSTOP 0x02 /* Watchdog timer is brokenstopped */
61#define WD_STAT_SVCD 0x04 /* Watchdog interrupt occurred */
62
63/* Register value definitions
64 */
65#define WD0_INTR_MASK 0x01 /* Watchdog device interrupt masks */
66#define WD1_INTR_MASK 0x02
67#define WD2_INTR_MASK 0x04
68
69#define WD_S_RUNNING 0x01 /* Watchdog device status running */
70#define WD_S_EXPIRED 0x02 /* Watchdog device status expired */
71
David S. Millerc5f85562008-08-29 17:05:51 -070072struct cpwd {
73 void __iomem *regs;
74 spinlock_t lock;
75
76 unsigned int irq;
77
78 unsigned long timeout;
79 bool enabled;
80 bool reboot;
81 bool broken;
82 bool initialized;
83
84 struct {
85 struct miscdevice misc;
86 void __iomem *regs;
87 u8 intr_mask;
88 u8 runstatus;
89 u16 timeout;
90 } devs[WD_NUMDEVS];
91};
92
Arnd Bergmann613655f2010-06-02 14:28:52 +020093static DEFINE_MUTEX(cpwd_mutex);
David S. Millerc5f85562008-08-29 17:05:51 -070094static struct cpwd *cpwd_device;
95
Wim Van Sebroeck927d6962009-03-18 08:05:24 +000096/* Sun uses Altera PLD EPF8820ATC144-4
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 * providing three hardware watchdogs:
98 *
Wim Van Sebroeck927d6962009-03-18 08:05:24 +000099 * 1) RIC - sends an interrupt when triggered
100 * 2) XIR - asserts XIR_B_RESET when triggered, resets CPU
101 * 3) POR - asserts POR_B_RESET when triggered, resets CPU, backplane, board
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 *
103 *** Timer register block definition (struct wd_timer_regblk)
104 *
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000105 * dcntr and limit registers (halfword access):
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 * -------------------
107 * | 15 | ...| 1 | 0 |
108 * -------------------
109 * |- counter val -|
110 * -------------------
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000111 * dcntr - Current 16-bit downcounter value.
112 * When downcounter reaches '0' watchdog expires.
113 * Reading this register resets downcounter with
114 * 'limit' value.
115 * limit - 16-bit countdown value in 1/10th second increments.
116 * Writing this register begins countdown with input value.
117 * Reading from this register does not affect counter.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 * NOTES: After watchdog reset, dcntr and limit contain '1'
119 *
120 * status register (byte access):
121 * ---------------------------
122 * | 7 | ... | 2 | 1 | 0 |
123 * --------------+------------
124 * |- UNUSED -| EXP | RUN |
125 * ---------------------------
126 * status- Bit 0 - Watchdog is running
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000127 * Bit 1 - Watchdog has expired
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 *
129 *** PLD register block definition (struct wd_pld_regblk)
130 *
131 * intr_mask register (byte access):
132 * ---------------------------------
133 * | 7 | ... | 3 | 2 | 1 | 0 |
134 * +-------------+------------------
135 * |- UNUSED -| WD3 | WD2 | WD1 |
136 * ---------------------------------
137 * WD3 - 1 == Interrupt disabled for watchdog 3
138 * WD2 - 1 == Interrupt disabled for watchdog 2
139 * WD1 - 1 == Interrupt disabled for watchdog 1
140 *
141 * pld_status register (byte access):
142 * UNKNOWN, MAGICAL MYSTERY REGISTER
143 *
144 */
145#define WD_TIMER_REGSZ 16
146#define WD0_OFF 0
147#define WD1_OFF (WD_TIMER_REGSZ * 1)
148#define WD2_OFF (WD_TIMER_REGSZ * 2)
149#define PLD_OFF (WD_TIMER_REGSZ * 3)
150
151#define WD_DCNTR 0x00
152#define WD_LIMIT 0x04
153#define WD_STATUS 0x08
154
155#define PLD_IMASK (PLD_OFF + 0x00)
156#define PLD_STATUS (PLD_OFF + 0x04)
157
David S. Millerc5f85562008-08-29 17:05:51 -0700158static struct timer_list cpwd_timer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
Wim Van Sebroecka77dba72009-04-14 20:20:07 +0000160static int wd0_timeout;
161static int wd1_timeout;
162static int wd2_timeout;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000164module_param(wd0_timeout, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs");
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000166module_param(wd1_timeout, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs");
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000168module_param(wd2_timeout, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs");
170
David S. Millerc5f85562008-08-29 17:05:51 -0700171MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
172MODULE_DESCRIPTION("Hardware watchdog driver for Sun Microsystems CP1400/1500");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173MODULE_LICENSE("GPL");
David S. Millerc5f85562008-08-29 17:05:51 -0700174MODULE_SUPPORTED_DEVICE("watchdog");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
David S. Millerc5f85562008-08-29 17:05:51 -0700176static void cpwd_writew(u16 val, void __iomem *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177{
David S. Millerc5f85562008-08-29 17:05:51 -0700178 writew(cpu_to_le16(val), addr);
179}
180static u16 cpwd_readw(void __iomem *addr)
181{
182 u16 val = readw(addr);
183
184 return le16_to_cpu(val);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185}
186
David S. Millerc5f85562008-08-29 17:05:51 -0700187static void cpwd_writeb(u8 val, void __iomem *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188{
David S. Millerc5f85562008-08-29 17:05:51 -0700189 writeb(val, addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190}
191
David S. Millerc5f85562008-08-29 17:05:51 -0700192static u8 cpwd_readb(void __iomem *addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193{
David S. Millerc5f85562008-08-29 17:05:51 -0700194 return readb(addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195}
196
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197/* Enable or disable watchdog interrupts
198 * Because of the CP1400 defect this should only be
199 * called during initialzation or by wd_[start|stop]timer()
200 *
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000201 * index - sub-device index, or -1 for 'all'
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 * enable - non-zero to enable interrupts, zero to disable
203 */
David S. Millerc5f85562008-08-29 17:05:51 -0700204static void cpwd_toggleintr(struct cpwd *p, int index, int enable)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205{
David S. Millerc5f85562008-08-29 17:05:51 -0700206 unsigned char curregs = cpwd_readb(p->regs + PLD_IMASK);
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000207 unsigned char setregs =
208 (index == -1) ?
209 (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) :
David S. Millerc5f85562008-08-29 17:05:51 -0700210 (p->devs[index].intr_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
David S. Millerc5f85562008-08-29 17:05:51 -0700212 if (enable == WD_INTR_ON)
213 curregs &= ~setregs;
214 else
215 curregs |= setregs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
David S. Millerc5f85562008-08-29 17:05:51 -0700217 cpwd_writeb(curregs, p->regs + PLD_IMASK);
218}
219
220/* Restarts timer with maximum limit value and
221 * does not unset 'brokenstop' value.
222 */
223static void cpwd_resetbrokentimer(struct cpwd *p, int index)
224{
225 cpwd_toggleintr(p, index, WD_INTR_ON);
226 cpwd_writew(WD_BLIMIT, p->devs[index].regs + WD_LIMIT);
227}
228
229/* Timer method called to reset stopped watchdogs--
230 * because of the PLD bug on CP1400, we cannot mask
231 * interrupts within the PLD so me must continually
232 * reset the timers ad infinitum.
233 */
234static void cpwd_brokentimer(unsigned long data)
235{
236 struct cpwd *p = (struct cpwd *) data;
237 int id, tripped = 0;
238
239 /* kill a running timer instance, in case we
240 * were called directly instead of by kernel timer
241 */
242 if (timer_pending(&cpwd_timer))
243 del_timer(&cpwd_timer);
244
245 for (id = 0; id < WD_NUMDEVS; id++) {
246 if (p->devs[id].runstatus & WD_STAT_BSTOP) {
247 ++tripped;
248 cpwd_resetbrokentimer(p, id);
249 }
250 }
251
252 if (tripped) {
253 /* there is at least one timer brokenstopped-- reschedule */
254 cpwd_timer.expires = WD_BTIMEOUT;
255 add_timer(&cpwd_timer);
256 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257}
258
259/* Reset countdown timer with 'limit' value and continue countdown.
260 * This will not start a stopped timer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 */
David S. Millerc5f85562008-08-29 17:05:51 -0700262static void cpwd_pingtimer(struct cpwd *p, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263{
David S. Millerc5f85562008-08-29 17:05:51 -0700264 if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING)
265 cpwd_readw(p->devs[index].regs + WD_DCNTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266}
267
268/* Stop a running watchdog timer-- the timer actually keeps
269 * running, but the interrupt is masked so that no action is
270 * taken upon expiration.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 */
David S. Millerc5f85562008-08-29 17:05:51 -0700272static void cpwd_stoptimer(struct cpwd *p, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273{
David S. Millerc5f85562008-08-29 17:05:51 -0700274 if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING) {
275 cpwd_toggleintr(p, index, WD_INTR_OFF);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276
David S. Millerc5f85562008-08-29 17:05:51 -0700277 if (p->broken) {
278 p->devs[index].runstatus |= WD_STAT_BSTOP;
279 cpwd_brokentimer((unsigned long) p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 }
281 }
282}
283
284/* Start a watchdog timer with the specified limit value
285 * If the watchdog is running, it will be restarted with
286 * the provided limit value.
287 *
288 * This function will enable interrupts on the specified
289 * watchdog.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 */
David S. Millerc5f85562008-08-29 17:05:51 -0700291static void cpwd_starttimer(struct cpwd *p, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292{
David S. Millerc5f85562008-08-29 17:05:51 -0700293 if (p->broken)
294 p->devs[index].runstatus &= ~WD_STAT_BSTOP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
David S. Millerc5f85562008-08-29 17:05:51 -0700296 p->devs[index].runstatus &= ~WD_STAT_SVCD;
297
298 cpwd_writew(p->devs[index].timeout, p->devs[index].regs + WD_LIMIT);
299 cpwd_toggleintr(p, index, WD_INTR_ON);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300}
301
David S. Millerc5f85562008-08-29 17:05:51 -0700302static int cpwd_getstatus(struct cpwd *p, int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303{
David S. Millerc5f85562008-08-29 17:05:51 -0700304 unsigned char stat = cpwd_readb(p->devs[index].regs + WD_STATUS);
305 unsigned char intr = cpwd_readb(p->devs[index].regs + PLD_IMASK);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 unsigned char ret = WD_STOPPED;
307
308 /* determine STOPPED */
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000309 if (!stat)
David S. Millerc5f85562008-08-29 17:05:51 -0700310 return ret;
311
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 /* determine EXPIRED vs FREERUN vs RUNNING */
David S. Millerc5f85562008-08-29 17:05:51 -0700313 else if (WD_S_EXPIRED & stat) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 ret = WD_EXPIRED;
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000315 } else if (WD_S_RUNNING & stat) {
David S. Millerc5f85562008-08-29 17:05:51 -0700316 if (intr & p->devs[index].intr_mask) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 ret = WD_FREERUN;
David S. Millerc5f85562008-08-29 17:05:51 -0700318 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 /* Fudge WD_EXPIRED status for defective CP1400--
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000320 * IF timer is running
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000321 * AND brokenstop is set
322 * AND an interrupt has been serviced
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 * we are WD_EXPIRED.
324 *
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000325 * IF timer is running
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000326 * AND brokenstop is set
327 * AND no interrupt has been serviced
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 * we are WD_FREERUN.
329 */
David S. Millerc5f85562008-08-29 17:05:51 -0700330 if (p->broken &&
331 (p->devs[index].runstatus & WD_STAT_BSTOP)) {
332 if (p->devs[index].runstatus & WD_STAT_SVCD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 ret = WD_EXPIRED;
David S. Millerc5f85562008-08-29 17:05:51 -0700334 } else {
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000335 /* we could as well pretend
336 * we are expired */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 ret = WD_FREERUN;
338 }
David S. Millerc5f85562008-08-29 17:05:51 -0700339 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 ret = WD_RUNNING;
341 }
342 }
343 }
344
345 /* determine SERVICED */
David S. Millerc5f85562008-08-29 17:05:51 -0700346 if (p->devs[index].runstatus & WD_STAT_SVCD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 ret |= WD_SERVICED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000349 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350}
351
David S. Millerc5f85562008-08-29 17:05:51 -0700352static irqreturn_t cpwd_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353{
David S. Millerc5f85562008-08-29 17:05:51 -0700354 struct cpwd *p = dev_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355
David S. Millerc5f85562008-08-29 17:05:51 -0700356 /* Only WD0 will interrupt-- others are NMI and we won't
357 * see them here....
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 */
David S. Millerc5f85562008-08-29 17:05:51 -0700359 spin_lock_irq(&p->lock);
360
361 cpwd_stoptimer(p, WD0_ID);
362 p->devs[WD0_ID].runstatus |= WD_STAT_SVCD;
363
364 spin_unlock_irq(&p->lock);
365
366 return IRQ_HANDLED;
367}
368
369static int cpwd_open(struct inode *inode, struct file *f)
370{
371 struct cpwd *p = cpwd_device;
372
Arnd Bergmann613655f2010-06-02 14:28:52 +0200373 mutex_lock(&cpwd_mutex);
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000374 switch (iminor(inode)) {
375 case WD0_MINOR:
376 case WD1_MINOR:
377 case WD2_MINOR:
378 break;
David S. Millerc5f85562008-08-29 17:05:51 -0700379
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000380 default:
Arnd Bergmann613655f2010-06-02 14:28:52 +0200381 mutex_unlock(&cpwd_mutex);
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000382 return -ENODEV;
David S. Millerc5f85562008-08-29 17:05:51 -0700383 }
384
385 /* Register IRQ on first open of device */
386 if (!p->initialized) {
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000387 if (request_irq(p->irq, &cpwd_interrupt,
David S. Millerc5f85562008-08-29 17:05:51 -0700388 IRQF_SHARED, DRIVER_NAME, p)) {
Joe Perches27c766a2012-02-15 15:06:19 -0800389 pr_err("Cannot register IRQ %d\n", p->irq);
Arnd Bergmann613655f2010-06-02 14:28:52 +0200390 mutex_unlock(&cpwd_mutex);
David S. Millerc5f85562008-08-29 17:05:51 -0700391 return -EBUSY;
392 }
393 p->initialized = true;
394 }
395
Arnd Bergmann613655f2010-06-02 14:28:52 +0200396 mutex_unlock(&cpwd_mutex);
David S. Millerc5f85562008-08-29 17:05:51 -0700397
398 return nonseekable_open(inode, f);
399}
400
401static int cpwd_release(struct inode *inode, struct file *file)
402{
403 return 0;
404}
405
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +0000406static long cpwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
David S. Millerc5f85562008-08-29 17:05:51 -0700407{
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000408 static const struct watchdog_info info = {
David S. Millerc5f85562008-08-29 17:05:51 -0700409 .options = WDIOF_SETTIMEOUT,
410 .firmware_version = 1,
411 .identity = DRIVER_NAME,
412 };
413 void __user *argp = (void __user *)arg;
Al Viro496ad9a2013-01-23 17:07:38 -0500414 struct inode *inode = file_inode(file);
David S. Millerc5f85562008-08-29 17:05:51 -0700415 int index = iminor(inode) - WD0_MINOR;
416 struct cpwd *p = cpwd_device;
417 int setopt = 0;
418
419 switch (cmd) {
420 /* Generic Linux IOCTLs */
421 case WDIOC_GETSUPPORT:
422 if (copy_to_user(argp, &info, sizeof(struct watchdog_info)))
423 return -EFAULT;
424 break;
425
426 case WDIOC_GETSTATUS:
427 case WDIOC_GETBOOTSTATUS:
428 if (put_user(0, (int __user *)argp))
429 return -EFAULT;
430 break;
431
432 case WDIOC_KEEPALIVE:
433 cpwd_pingtimer(p, index);
434 break;
435
436 case WDIOC_SETOPTIONS:
437 if (copy_from_user(&setopt, argp, sizeof(unsigned int)))
438 return -EFAULT;
439
440 if (setopt & WDIOS_DISABLECARD) {
441 if (p->enabled)
442 return -EINVAL;
443 cpwd_stoptimer(p, index);
444 } else if (setopt & WDIOS_ENABLECARD) {
445 cpwd_starttimer(p, index);
446 } else {
447 return -EINVAL;
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000448 }
David S. Millerc5f85562008-08-29 17:05:51 -0700449 break;
450
451 /* Solaris-compatible IOCTLs */
452 case WIOCGSTAT:
453 setopt = cpwd_getstatus(p, index);
454 if (copy_to_user(argp, &setopt, sizeof(unsigned int)))
455 return -EFAULT;
456 break;
457
458 case WIOCSTART:
459 cpwd_starttimer(p, index);
460 break;
461
462 case WIOCSTOP:
463 if (p->enabled)
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000464 return -EINVAL;
David S. Millerc5f85562008-08-29 17:05:51 -0700465
466 cpwd_stoptimer(p, index);
467 break;
468
469 default:
470 return -EINVAL;
471 }
472
473 return 0;
474}
475
476static long cpwd_compat_ioctl(struct file *file, unsigned int cmd,
477 unsigned long arg)
478{
479 int rval = -ENOIOCTLCMD;
480
481 switch (cmd) {
482 /* solaris ioctls are specific to this driver */
483 case WIOCSTART:
484 case WIOCSTOP:
485 case WIOCGSTAT:
Arnd Bergmann613655f2010-06-02 14:28:52 +0200486 mutex_lock(&cpwd_mutex);
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +0000487 rval = cpwd_ioctl(file, cmd, arg);
Arnd Bergmann613655f2010-06-02 14:28:52 +0200488 mutex_unlock(&cpwd_mutex);
David S. Millerc5f85562008-08-29 17:05:51 -0700489 break;
490
491 /* everything else is handled by the generic compat layer */
492 default:
493 break;
494 }
495
496 return rval;
497}
498
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000499static ssize_t cpwd_write(struct file *file, const char __user *buf,
David S. Millerc5f85562008-08-29 17:05:51 -0700500 size_t count, loff_t *ppos)
501{
Al Viro496ad9a2013-01-23 17:07:38 -0500502 struct inode *inode = file_inode(file);
David S. Millerc5f85562008-08-29 17:05:51 -0700503 struct cpwd *p = cpwd_device;
504 int index = iminor(inode);
505
506 if (count) {
507 cpwd_pingtimer(p, index);
508 return 1;
509 }
510
511 return 0;
512}
513
Wim Van Sebroeck927d6962009-03-18 08:05:24 +0000514static ssize_t cpwd_read(struct file *file, char __user *buffer,
David S. Millerc5f85562008-08-29 17:05:51 -0700515 size_t count, loff_t *ppos)
516{
517 return -EINVAL;
518}
519
520static const struct file_operations cpwd_fops = {
Wim Van Sebroeck9626dd72009-01-21 11:13:11 +0000521 .owner = THIS_MODULE,
522 .unlocked_ioctl = cpwd_ioctl,
523 .compat_ioctl = cpwd_compat_ioctl,
524 .open = cpwd_open,
525 .write = cpwd_write,
526 .read = cpwd_read,
527 .release = cpwd_release,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200528 .llseek = no_llseek,
David S. Millerc5f85562008-08-29 17:05:51 -0700529};
530
Bill Pemberton2d991a12012-11-19 13:21:41 -0500531static int cpwd_probe(struct platform_device *op)
David S. Millerc5f85562008-08-29 17:05:51 -0700532{
533 struct device_node *options;
534 const char *str_prop;
535 const void *prop_val;
536 int i, err = -EINVAL;
537 struct cpwd *p;
538
539 if (cpwd_device)
540 return -EINVAL;
541
542 p = kzalloc(sizeof(*p), GFP_KERNEL);
543 err = -ENOMEM;
544 if (!p) {
Joe Perches27c766a2012-02-15 15:06:19 -0800545 pr_err("Unable to allocate struct cpwd\n");
David S. Millerc5f85562008-08-29 17:05:51 -0700546 goto out;
547 }
548
Grant Likely1636f8a2010-06-18 11:09:58 -0600549 p->irq = op->archdata.irqs[0];
David S. Millerc5f85562008-08-29 17:05:51 -0700550
551 spin_lock_init(&p->lock);
552
553 p->regs = of_ioremap(&op->resource[0], 0,
554 4 * WD_TIMER_REGSZ, DRIVER_NAME);
555 if (!p->regs) {
Joe Perches27c766a2012-02-15 15:06:19 -0800556 pr_err("Unable to map registers\n");
David S. Millerc5f85562008-08-29 17:05:51 -0700557 goto out_free;
558 }
559
560 options = of_find_node_by_path("/options");
561 err = -ENODEV;
562 if (!options) {
Joe Perches27c766a2012-02-15 15:06:19 -0800563 pr_err("Unable to find /options node\n");
David S. Millerc5f85562008-08-29 17:05:51 -0700564 goto out_iounmap;
565 }
566
567 prop_val = of_get_property(options, "watchdog-enable?", NULL);
568 p->enabled = (prop_val ? true : false);
569
570 prop_val = of_get_property(options, "watchdog-reboot?", NULL);
571 p->reboot = (prop_val ? true : false);
572
573 str_prop = of_get_property(options, "watchdog-timeout", NULL);
574 if (str_prop)
575 p->timeout = simple_strtoul(str_prop, NULL, 10);
576
577 /* CP1400s seem to have broken PLD implementations-- the
578 * interrupt_mask register cannot be written, so no timer
579 * interrupts can be masked within the PLD.
580 */
Grant Likely61c7a082010-04-13 16:12:29 -0700581 str_prop = of_get_property(op->dev.of_node, "model", NULL);
David S. Millerc5f85562008-08-29 17:05:51 -0700582 p->broken = (str_prop && !strcmp(str_prop, WD_BADMODEL));
583
584 if (!p->enabled)
585 cpwd_toggleintr(p, -1, WD_INTR_OFF);
586
587 for (i = 0; i < WD_NUMDEVS; i++) {
588 static const char *cpwd_names[] = { "RIC", "XIR", "POR" };
589 static int *parms[] = { &wd0_timeout,
590 &wd1_timeout,
591 &wd2_timeout };
592 struct miscdevice *mp = &p->devs[i].misc;
593
594 mp->minor = WD0_MINOR + i;
595 mp->name = cpwd_names[i];
596 mp->fops = &cpwd_fops;
597
598 p->devs[i].regs = p->regs + (i * WD_TIMER_REGSZ);
599 p->devs[i].intr_mask = (WD0_INTR_MASK << i);
600 p->devs[i].runstatus &= ~WD_STAT_BSTOP;
601 p->devs[i].runstatus |= WD_STAT_INIT;
602 p->devs[i].timeout = p->timeout;
603 if (*parms[i])
604 p->devs[i].timeout = *parms[i];
605
606 err = misc_register(&p->devs[i].misc);
607 if (err) {
Joe Perches27c766a2012-02-15 15:06:19 -0800608 pr_err("Could not register misc device for dev %d\n",
609 i);
David S. Millerc5f85562008-08-29 17:05:51 -0700610 goto out_unregister;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 }
612 }
613
David S. Millerc5f85562008-08-29 17:05:51 -0700614 if (p->broken) {
615 init_timer(&cpwd_timer);
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000616 cpwd_timer.function = cpwd_brokentimer;
David S. Millerc5f85562008-08-29 17:05:51 -0700617 cpwd_timer.data = (unsigned long) p;
618 cpwd_timer.expires = WD_BTIMEOUT;
619
Joe Perches27c766a2012-02-15 15:06:19 -0800620 pr_info("PLD defect workaround enabled for model %s\n",
621 WD_BADMODEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 }
David S. Millerc5f85562008-08-29 17:05:51 -0700623
Jingoo Han26556b62013-05-23 19:43:43 +0900624 platform_set_drvdata(op, p);
David S. Millerc5f85562008-08-29 17:05:51 -0700625 cpwd_device = p;
626 err = 0;
627
628out:
629 return err;
630
631out_unregister:
632 for (i--; i >= 0; i--)
633 misc_deregister(&p->devs[i].misc);
634
635out_iounmap:
636 of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
637
638out_free:
639 kfree(p);
640 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641}
642
Bill Pemberton4b12b892012-11-19 13:26:24 -0500643static int cpwd_remove(struct platform_device *op)
David S. Millerc5f85562008-08-29 17:05:51 -0700644{
Jingoo Han26556b62013-05-23 19:43:43 +0900645 struct cpwd *p = platform_get_drvdata(op);
David S. Millerc5f85562008-08-29 17:05:51 -0700646 int i;
647
Wim Van Sebroeckbbd562d2011-02-21 10:52:43 +0000648 for (i = 0; i < WD_NUMDEVS; i++) {
David S. Millerc5f85562008-08-29 17:05:51 -0700649 misc_deregister(&p->devs[i].misc);
650
651 if (!p->enabled) {
652 cpwd_stoptimer(p, i);
653 if (p->devs[i].runstatus & WD_STAT_BSTOP)
654 cpwd_resetbrokentimer(p, i);
655 }
656 }
657
658 if (p->broken)
659 del_timer_sync(&cpwd_timer);
660
661 if (p->initialized)
662 free_irq(p->irq, p);
663
664 of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
665 kfree(p);
666
667 cpwd_device = NULL;
668
669 return 0;
670}
671
David S. Millerfd098312008-08-31 01:23:17 -0700672static const struct of_device_id cpwd_match[] = {
David S. Millerc5f85562008-08-29 17:05:51 -0700673 {
674 .name = "watchdog",
675 },
676 {},
677};
678MODULE_DEVICE_TABLE(of, cpwd_match);
679
Grant Likely1c48a5c2011-02-17 02:43:24 -0700680static struct platform_driver cpwd_driver = {
Grant Likely40182942010-04-13 16:13:02 -0700681 .driver = {
682 .name = DRIVER_NAME,
683 .owner = THIS_MODULE,
684 .of_match_table = cpwd_match,
685 },
David S. Millerc5f85562008-08-29 17:05:51 -0700686 .probe = cpwd_probe,
Bill Pemberton82268712012-11-19 13:21:12 -0500687 .remove = cpwd_remove,
David S. Millerc5f85562008-08-29 17:05:51 -0700688};
689
Axel Linb8ec6112011-11-29 13:56:27 +0800690module_platform_driver(cpwd_driver);