1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Watchdog timer for PowerPC Book-E systems
8  * Copyright 2005, 2008, 2010-2011 Freescale Semiconductor Inc.
22  * Also, the wdt_period sets the watchdog timer period timeout.
23  * For E500 cpus the wdt_period sets which bit changing from 0->1 will
24  * trigger a watchdog timeout. This watchdog timeout will occur 3 times, the
55  * 2.5 * (2^(63-period+1)) / timebase_freq
58  * at least 1.  This will still result in a very long timeout.
62 	unsigned long long tmp = 1ULL << (64 - period);  in period_to_sec()
75  * This procedure will find the highest period which will give a timeout
77  * a parameter of 2 secs, then this procedure will return a value of 38.
79 static unsigned int sec_to_period(unsigned int secs)  in sec_to_period()  argument
82 	for (period = 63; period > 0; period--) {  in sec_to_period()
83 		if (period_to_sec(period) >= secs)  in sec_to_period()
98 static unsigned int sec_to_period(unsigned int secs)  in sec_to_period()  argument
100 	return secs;  in sec_to_period()
114 	val |= WDTP(sec_to_period(wdog->timeout));  in __booke_wdt_set()
145 	val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(sec_to_period(wdog->timeout)));  in __booke_wdt_enable()
151  * __booke_wdt_disable - disable the watchdog on the given CPU
155  * TCR[WRC] cannot be changed once it has been set to non-zero, but we can
174 	pr_debug("watchdog enabled (timeout = %u sec)\n", wdog->timeout);  in booke_wdt_start()
188 				 unsigned int timeout)  in booke_wdt_set_timeout()  argument
190 	wdt_dev->timeout = timeout;  in booke_wdt_set_timeout()
198 	.identity = "PowerPC Book-E Watchdog",
224 	pr_info("powerpc book-e watchdog driver loaded\n");  in booke_wdt_init()
225 	booke_wdt_info.firmware_version = cur_cpu_spec->pvr_value;  in booke_wdt_init()
242 MODULE_DESCRIPTION("PowerPC Book-E watchdog driver");