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Diffstat (limited to 'drivers/macintosh/windfarm_pid.h')
-rw-r--r-- | drivers/macintosh/windfarm_pid.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/drivers/macintosh/windfarm_pid.h b/drivers/macintosh/windfarm_pid.h new file mode 100644 index 00000000000..a364c2a2499 --- /dev/null +++ b/drivers/macintosh/windfarm_pid.h @@ -0,0 +1,84 @@ +/* + * 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. + * + * This is a pair of generic PID helpers that can be used by + * control loops. One is the basic PID implementation, the + * other one is more specifically tailored to the loops used + * for CPU control with 2 input sample types (temp and power) + */ + +/* + * *** Simple PID *** + */ + +#define WF_PID_MAX_HISTORY 32 + +/* This parameter array is passed to the PID algorithm. Currently, + * we don't support changing parameters on the fly as it's not needed + * but could be implemented (with necessary adjustment of the history + * buffer + */ +struct wf_pid_param { + int interval; /* Interval between samples in seconds */ + int history_len; /* Size of history buffer */ + int additive; /* 1: target relative to previous value */ + s32 gd, gp, gr; /* PID gains */ + s32 itarget; /* PID input target */ + s32 min,max; /* min and max target values */ +}; + +struct wf_pid_state { + int first; /* first run of the loop */ + int index; /* index of current sample */ + s32 target; /* current target value */ + s32 samples[WF_PID_MAX_HISTORY]; /* samples history buffer */ + s32 errors[WF_PID_MAX_HISTORY]; /* error history buffer */ + + struct wf_pid_param param; +}; + +extern void wf_pid_init(struct wf_pid_state *st, struct wf_pid_param *param); +extern s32 wf_pid_run(struct wf_pid_state *st, s32 sample); + + +/* + * *** CPU PID *** + */ + +#define WF_CPU_PID_MAX_HISTORY 32 + +/* This parameter array is passed to the CPU PID algorithm. Currently, + * we don't support changing parameters on the fly as it's not needed + * but could be implemented (with necessary adjustment of the history + * buffer + */ +struct wf_cpu_pid_param { + int interval; /* Interval between samples in seconds */ + int history_len; /* Size of history buffer */ + s32 gd, gp, gr; /* PID gains */ + s32 pmaxadj; /* PID max power adjust */ + s32 ttarget; /* PID input target */ + s32 tmax; /* PID input max */ + s32 min,max; /* min and max target values */ +}; + +struct wf_cpu_pid_state { + int first; /* first run of the loop */ + int index; /* index of current power */ + int tindex; /* index of current temp */ + s32 target; /* current target value */ + s32 powers[WF_PID_MAX_HISTORY]; /* power history buffer */ + s32 errors[WF_PID_MAX_HISTORY]; /* error history buffer */ + s32 temps[2]; /* temp. history buffer */ + + struct wf_cpu_pid_param param; +}; + +extern void wf_cpu_pid_init(struct wf_cpu_pid_state *st, + struct wf_cpu_pid_param *param); +extern s32 wf_cpu_pid_run(struct wf_cpu_pid_state *st, s32 power, s32 temp); |