1 // SPDX-License-Identifier: GPL-2.0
8  * dynamic power management to limit peak CPU temp (using ICTC)
11  * Silly, crazy ideas: use cpu load (from scheduler) and ICTC to extend battery
38 	unsigned char low;  member
39 	unsigned char high;  member
46  * dynamic adjustment to minimize # of interrupts */
47 /* configurable values for step size and how much to expand the window when
60 	mtspr(SPRN_THRM1, THRM1_THRES(tau[cpu].low) | THRM1_V | maybe_tie | THRM1_TID);  in set_thresholds()
63 	mtspr(SPRN_THRM2, THRM1_THRES(tau[cpu].high) | THRM1_V | maybe_tie);  in set_thresholds()
77 		if (tau[cpu].low >= step_size) {  in TAUupdate()
78 			tau[cpu].low -= step_size;  in TAUupdate()
79 			tau[cpu].high -= (step_size - window_expand);  in TAUupdate()
82 		pr_debug("%s: low threshold crossed\n", __func__);  in TAUupdate()
88 		if (tau[cpu].high <= 127 - step_size) {  in TAUupdate()
89 			tau[cpu].low += (step_size - window_expand);  in TAUupdate()
90 			tau[cpu].high += step_size;  in TAUupdate()
93 		pr_debug("%s: high threshold crossed\n", __func__);  in TAUupdate()
99  * TAU interrupts - called when we have a thermal assist unit interrupt
127 	size = tau[cpu].high - tau[cpu].low;  in tau_timeout()
130 		shrink = (2 + size - min_window) / 4;  in tau_timeout()
132 			tau[cpu].low += shrink;  in tau_timeout()
133 			tau[cpu].high -= shrink;  in tau_timeout()
135 			tau[cpu].low += 1;  in tau_timeout()
137 			if ((tau[cpu].high - tau[cpu].low) != min_window){  in tau_timeout()
162 	/* schedule ourselves to be run again */  in tau_work_func()
171  * Set things up to use THRM1 as a temperature lower bound, and THRM2 as an upper bound.
181 	/* set these to a reasonable value and let the timer shrink the  in TAU_init_smp()
183 	tau[cpu].low = 5;  in TAU_init_smp()
184 	tau[cpu].high = 120;  in TAU_init_smp()
192 	 * all have it --BenH  in TAU_init()
201 			 !strcmp(cur_cpu_spec->platform, "ppc750");  in TAU_init()
205 		return -ENOMEM;  in TAU_init()
226 	return ((tau[cpu].high << 16) | tau[cpu].low);  in cpu_temp_both()
231 	return ((tau[cpu].high + tau[cpu].low) / 2);  in cpu_temp()