drivers/macintosh/windfarm_pid.c

25 void wf_pid_init(struct wf_pid_state *st, struct wf_pid_param *param)
27 	memset(st, 0, sizeof(struct wf_pid_state));
28 	st->param = *param;
29 	st->first = 1;
33 s32 wf_pid_run(struct wf_pid_state *st, s32 new_sample)
37 	int	i, hlen = st->param.history_len;
40 	error = new_sample - st->param.itarget;
43 	if (st->first) {
45 			st->samples[i] = new_sample;
46 			st->errors[i] = error;
48 		st->first = 0;
49 		st->index = 0;
51 		st->index = (st->index + 1) % hlen;
52 		st->samples[st->index] = new_sample;
53 		st->errors[st->index] = error;
58 		integ += st->errors[(st->index + hlen - i) % hlen];
59 	integ *= st->param.interval;
62 	deriv = st->errors[st->index] -
63 		st->errors[(st->index + hlen - 1) % hlen];
64 	deriv /= st->param.interval;
67 	target = (s32)((integ * (s64)st->param.gr + deriv * (s64)st->param.gd +
68 		  error * (s64)st->param.gp) >> 36);
69 	if (st->param.additive)
70 		target += st->target;
71 	target = max(target, st->param.min);
72 	target = min(target, st->param.max);
73 	st->target = target;
75 	return st->target;
79 void wf_cpu_pid_init(struct wf_cpu_pid_state *st,
82 	memset(st, 0, sizeof(struct wf_cpu_pid_state));
83 	st->param = *param;
84 	st->first = 1;
88 s32 wf_cpu_pid_run(struct wf_cpu_pid_state *st, s32 new_power, s32 new_temp)
92 	int	i, hlen = st->param.history_len;
95 	error = st->param.pmaxadj - new_power;
98 	if (st->first) {
100 			st->powers[i] = new_power;
101 			st->errors[i] = error;
103 		st->temps[0] = st->temps[1] = new_temp;
104 		st->first = 0;
105 		st->index = st->tindex = 0;
107 		st->index = (st->index + 1) % hlen;
108 		st->powers[st->index] = new_power;
109 		st->errors[st->index] = error;
110 		st->tindex = (st->tindex + 1) % 2;
111 		st->temps[st->tindex] = new_temp;
116 		integ += st->errors[(st->index + hlen - i) % hlen];
117 	integ *= st->param.interval;
118 	integ *= st->param.gr;
119 	sval = st->param.tmax - (s32)(integ >> 20);
120 	adj = min(st->param.ttarget, sval);
125 	deriv = st->temps[st->tindex] -
126 		st->temps[(st->tindex + 2 - 1) % 2];
127 	deriv /= st->param.interval;
128 	deriv *= st->param.gd;
131 	prop = st->last_delta = (new_temp - adj);
132 	prop *= st->param.gp;
137 	target = st->target + (s32)((deriv + prop) >> 36);
138 	target = max(target, st->param.min);
139 	target = min(target, st->param.max);
140 	st->target = target;
142 	return st->target;