1 // SPDX-License-Identifier: GPL-2.0-only
7  * A clock source registers using mISDN_register_clock:
8  *	name = text string to name clock source
9  *	priority = value to priorize clock sources (0 = default)
10  *	ctl = callback function to enable/disable clock source
11  *	priv = private pointer of clock source
12  *	return = pointer to clock source structure;
17  * A clock source calls mISDN_clock_update with given samples elapsed, if
21  * A clock source unregisters using mISDN_unregister_clock.
23  * To get current clock, call mISDN_clock_get. The signed short value
24  * counts the number of samples since. Time since last clock event is added.
39 static u16 iclock_count;		/* counter of last clock */
40 static ktime_t iclock_timestamp;	/* time stamp of last clock */
55 	int pri = -128;  in select_iclock()
58 		if (iclock->pri > pri) {  in select_iclock()
59 			pri = iclock->pri;  in select_iclock()
66 		/* last used clock source still exists but changes, disable */  in select_iclock()
68 			printk(KERN_DEBUG "Old clock source '%s' disable.\n",  in select_iclock()
69 			       lastclock->name);  in select_iclock()
70 		lastclock->ctl(lastclock->priv, 0);  in select_iclock()
73 		/* new clock source selected, enable */  in select_iclock()
75 			printk(KERN_DEBUG "New clock source '%s' enable.\n",  in select_iclock()
76 			       bestclock->name);  in select_iclock()
77 		bestclock->ctl(bestclock->priv, 1);  in select_iclock()
80 		/* no clock received yet */  in select_iclock()
96 		printk(KERN_ERR "%s: No memory for clock entry.\n", __func__);  in mISDN_register_clock()
99 	strscpy(iclock->name, name, sizeof(iclock->name));  in mISDN_register_clock()
100 	iclock->pri = pri;  in mISDN_register_clock()
101 	iclock->priv = priv;  in mISDN_register_clock()
102 	iclock->ctl = ctl;  in mISDN_register_clock()
104 	list_add_tail(&iclock->list, &iclock_list);  in mISDN_register_clock()
117 		printk(KERN_DEBUG "%s: %s %d\n", __func__, iclock->name,  in mISDN_unregister_clock()
118 		       iclock->pri);  in mISDN_unregister_clock()
123 			       "Current clock source '%s' unregisters.\n",  in mISDN_unregister_clock()
124 			       iclock->name);  in mISDN_unregister_clock()
125 		iclock->ctl(iclock->priv, 0);  in mISDN_unregister_clock()
127 	list_del(&iclock->list);  in mISDN_unregister_clock()
142 		printk(KERN_ERR "%s: '%s' sends us clock updates, but we do "  in mISDN_clock_update()
144 		       iclock->name,  in mISDN_clock_update()
145 		       iclock_current ? iclock_current->name : "nothing");  in mISDN_clock_update()
146 		iclock->ctl(iclock->priv, 0);  in mISDN_clock_update()
159 		/* calc elapsed time by system clock */  in mISDN_clock_update()
172 			printk("Received first clock from source '%s'.\n",  in mISDN_clock_update()
173 			       iclock_current ? iclock_current->name : "nothing");  in mISDN_clock_update()
188 	/* calc elapsed time by system clock */  in mISDN_clock_get()