mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-27 22:24:11 +08:00
cdd440fe9f
The Windfarm PID module lacks a licence, it should be GPL, here it is Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
150 lines
3.7 KiB
C
150 lines
3.7 KiB
C
/*
|
|
* Windfarm PowerMac thermal control. Generic PID helpers
|
|
*
|
|
* (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
|
|
* <benh@kernel.crashing.org>
|
|
*
|
|
* Released under the term of the GNU GPL v2.
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/module.h>
|
|
|
|
#include "windfarm_pid.h"
|
|
|
|
#undef DEBUG
|
|
|
|
#ifdef DEBUG
|
|
#define DBG(args...) printk(args)
|
|
#else
|
|
#define DBG(args...) do { } while(0)
|
|
#endif
|
|
|
|
void wf_pid_init(struct wf_pid_state *st, struct wf_pid_param *param)
|
|
{
|
|
memset(st, 0, sizeof(struct wf_pid_state));
|
|
st->param = *param;
|
|
st->first = 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(wf_pid_init);
|
|
|
|
s32 wf_pid_run(struct wf_pid_state *st, s32 new_sample)
|
|
{
|
|
s64 error, integ, deriv;
|
|
s32 target;
|
|
int i, hlen = st->param.history_len;
|
|
|
|
/* Calculate error term */
|
|
error = new_sample - st->param.itarget;
|
|
|
|
/* Get samples into our history buffer */
|
|
if (st->first) {
|
|
for (i = 0; i < hlen; i++) {
|
|
st->samples[i] = new_sample;
|
|
st->errors[i] = error;
|
|
}
|
|
st->first = 0;
|
|
st->index = 0;
|
|
} else {
|
|
st->index = (st->index + 1) % hlen;
|
|
st->samples[st->index] = new_sample;
|
|
st->errors[st->index] = error;
|
|
}
|
|
|
|
/* Calculate integral term */
|
|
for (i = 0, integ = 0; i < hlen; i++)
|
|
integ += st->errors[(st->index + hlen - i) % hlen];
|
|
integ *= st->param.interval;
|
|
|
|
/* Calculate derivative term */
|
|
deriv = st->errors[st->index] -
|
|
st->errors[(st->index + hlen - 1) % hlen];
|
|
deriv /= st->param.interval;
|
|
|
|
/* Calculate target */
|
|
target = (s32)((integ * (s64)st->param.gr + deriv * (s64)st->param.gd +
|
|
error * (s64)st->param.gp) >> 36);
|
|
if (st->param.additive)
|
|
target += st->target;
|
|
target = max(target, st->param.min);
|
|
target = min(target, st->param.max);
|
|
st->target = target;
|
|
|
|
return st->target;
|
|
}
|
|
EXPORT_SYMBOL_GPL(wf_pid_run);
|
|
|
|
void wf_cpu_pid_init(struct wf_cpu_pid_state *st,
|
|
struct wf_cpu_pid_param *param)
|
|
{
|
|
memset(st, 0, sizeof(struct wf_cpu_pid_state));
|
|
st->param = *param;
|
|
st->first = 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(wf_cpu_pid_init);
|
|
|
|
s32 wf_cpu_pid_run(struct wf_cpu_pid_state *st, s32 new_power, s32 new_temp)
|
|
{
|
|
s64 integ, deriv, prop;
|
|
s32 error, target, sval, adj;
|
|
int i, hlen = st->param.history_len;
|
|
|
|
/* Calculate error term */
|
|
error = st->param.pmaxadj - new_power;
|
|
|
|
/* Get samples into our history buffer */
|
|
if (st->first) {
|
|
for (i = 0; i < hlen; i++) {
|
|
st->powers[i] = new_power;
|
|
st->errors[i] = error;
|
|
}
|
|
st->temps[0] = st->temps[1] = new_temp;
|
|
st->first = 0;
|
|
st->index = st->tindex = 0;
|
|
} else {
|
|
st->index = (st->index + 1) % hlen;
|
|
st->powers[st->index] = new_power;
|
|
st->errors[st->index] = error;
|
|
st->tindex = (st->tindex + 1) % 2;
|
|
st->temps[st->tindex] = new_temp;
|
|
}
|
|
|
|
/* Calculate integral term */
|
|
for (i = 0, integ = 0; i < hlen; i++)
|
|
integ += st->errors[(st->index + hlen - i) % hlen];
|
|
integ *= st->param.interval;
|
|
integ *= st->param.gr;
|
|
sval = st->param.tmax - (s32)(integ >> 20);
|
|
adj = min(st->param.ttarget, sval);
|
|
|
|
DBG("integ: %lx, sval: %lx, adj: %lx\n", integ, sval, adj);
|
|
|
|
/* Calculate derivative term */
|
|
deriv = st->temps[st->tindex] -
|
|
st->temps[(st->tindex + 2 - 1) % 2];
|
|
deriv /= st->param.interval;
|
|
deriv *= st->param.gd;
|
|
|
|
/* Calculate proportional term */
|
|
prop = st->last_delta = (new_temp - adj);
|
|
prop *= st->param.gp;
|
|
|
|
DBG("deriv: %lx, prop: %lx\n", deriv, prop);
|
|
|
|
/* Calculate target */
|
|
target = st->target + (s32)((deriv + prop) >> 36);
|
|
target = max(target, st->param.min);
|
|
target = min(target, st->param.max);
|
|
st->target = target;
|
|
|
|
return st->target;
|
|
}
|
|
EXPORT_SYMBOL_GPL(wf_cpu_pid_run);
|
|
|
|
MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
|
|
MODULE_DESCRIPTION("PID algorithm for PowerMacs thermal control");
|
|
MODULE_LICENSE("GPL");
|