1 // SPDX-License-Identifier: GPL-2.0-only
15 /* Default constants for DevFreq-Simple-Ondemand (DFSO) */
19 					unsigned long *freq)  in devfreq_simple_ondemand_func()  argument
26 	struct devfreq_simple_ondemand_data *data = df->data;  in devfreq_simple_ondemand_func()
32 	stat = &df->last_status;  in devfreq_simple_ondemand_func()
35 		if (data->upthreshold)  in devfreq_simple_ondemand_func()
36 			dfso_upthreshold = data->upthreshold;  in devfreq_simple_ondemand_func()
37 		if (data->downdifferential)  in devfreq_simple_ondemand_func()
38 			dfso_downdifferential = data->downdifferential;  in devfreq_simple_ondemand_func()
42 		return -EINVAL;  in devfreq_simple_ondemand_func()
44 	/* Assume MAX if it is going to be divided by zero */  in devfreq_simple_ondemand_func()
45 	if (stat->total_time == 0) {  in devfreq_simple_ondemand_func()
46 		*freq = DEVFREQ_MAX_FREQ;  in devfreq_simple_ondemand_func()
51 	if (stat->busy_time >= (1 << 24) || stat->total_time >= (1 << 24)) {  in devfreq_simple_ondemand_func()
52 		stat->busy_time >>= 7;  in devfreq_simple_ondemand_func()
53 		stat->total_time >>= 7;  in devfreq_simple_ondemand_func()
56 	/* Set MAX if it's busy enough */  in devfreq_simple_ondemand_func()
57 	if (stat->busy_time * 100 >  in devfreq_simple_ondemand_func()
58 	    stat->total_time * dfso_upthreshold) {  in devfreq_simple_ondemand_func()
59 		*freq = DEVFREQ_MAX_FREQ;  in devfreq_simple_ondemand_func()
63 	/* Set MAX if we do not know the initial frequency */  in devfreq_simple_ondemand_func()
64 	if (stat->current_frequency == 0) {  in devfreq_simple_ondemand_func()
65 		*freq = DEVFREQ_MAX_FREQ;  in devfreq_simple_ondemand_func()
70 	if (stat->busy_time * 100 >  in devfreq_simple_ondemand_func()
71 	    stat->total_time * (dfso_upthreshold - dfso_downdifferential)) {  in devfreq_simple_ondemand_func()
72 		*freq = stat->current_frequency;  in devfreq_simple_ondemand_func()
77 	a = stat->busy_time;  in devfreq_simple_ondemand_func()
78 	a *= stat->current_frequency;  in devfreq_simple_ondemand_func()
79 	b = div_u64(a, stat->total_time);  in devfreq_simple_ondemand_func()
81 	b = div_u64(b, (dfso_upthreshold - dfso_downdifferential / 2));  in devfreq_simple_ondemand_func()
82 	*freq = (unsigned long) b;  in devfreq_simple_ondemand_func()
143 MODULE_DESCRIPTION("DEVFREQ Simple On-demand governor");