175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt/* 275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * Windfarm PowerMac thermal control. Generic PID helpers 375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * 475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp. 575722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * <benh@kernel.crashing.org> 675722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * 775722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * Released under the term of the GNU GPL v2. 875722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * 975722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * This is a pair of generic PID helpers that can be used by 1075722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * control loops. One is the basic PID implementation, the 1175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * other one is more specifically tailored to the loops used 1275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * for CPU control with 2 input sample types (temp and power) 1375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt */ 1475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 1575722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt/* 1675722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * *** Simple PID *** 1775722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt */ 1875722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 1975722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt#define WF_PID_MAX_HISTORY 32 2075722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 2175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt/* This parameter array is passed to the PID algorithm. Currently, 2275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * we don't support changing parameters on the fly as it's not needed 2375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * but could be implemented (with necessary adjustment of the history 2475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * buffer 2575722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt */ 2675722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidtstruct wf_pid_param { 2775722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int interval; /* Interval between samples in seconds */ 2875722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int history_len; /* Size of history buffer */ 2975722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int additive; /* 1: target relative to previous value */ 3075722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 gd, gp, gr; /* PID gains */ 3175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 itarget; /* PID input target */ 3275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 min,max; /* min and max target values */ 3375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt}; 3475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 3575722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidtstruct wf_pid_state { 3675722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int first; /* first run of the loop */ 3775722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int index; /* index of current sample */ 3875722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 target; /* current target value */ 3975722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 samples[WF_PID_MAX_HISTORY]; /* samples history buffer */ 4075722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 errors[WF_PID_MAX_HISTORY]; /* error history buffer */ 4175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 4275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt struct wf_pid_param param; 4375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt}; 4475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 4575722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidtextern void wf_pid_init(struct wf_pid_state *st, struct wf_pid_param *param); 4675722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidtextern s32 wf_pid_run(struct wf_pid_state *st, s32 sample); 4775722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 4875722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 4975722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt/* 5075722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * *** CPU PID *** 5175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt */ 5275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 5375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt#define WF_CPU_PID_MAX_HISTORY 32 5475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 5575722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt/* This parameter array is passed to the CPU PID algorithm. Currently, 5675722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * we don't support changing parameters on the fly as it's not needed 5775722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * but could be implemented (with necessary adjustment of the history 5875722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt * buffer 5975722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt */ 6075722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidtstruct wf_cpu_pid_param { 6175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int interval; /* Interval between samples in seconds */ 6275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int history_len; /* Size of history buffer */ 6375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 gd, gp, gr; /* PID gains */ 6475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 pmaxadj; /* PID max power adjust */ 6575722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 ttarget; /* PID input target */ 6675722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 tmax; /* PID input max */ 6775722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 min,max; /* min and max target values */ 6875722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt}; 6975722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 7075722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidtstruct wf_cpu_pid_state { 7175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int first; /* first run of the loop */ 7275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int index; /* index of current power */ 7375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt int tindex; /* index of current temp */ 7475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 target; /* current target value */ 75ac171c46667c1cb2ee9e22312291df6ed78e1b6eBenjamin Herrenschmidt s32 last_delta; /* last Tactual - Ttarget */ 7675722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 powers[WF_PID_MAX_HISTORY]; /* power history buffer */ 7775722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 errors[WF_PID_MAX_HISTORY]; /* error history buffer */ 7875722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt s32 temps[2]; /* temp. history buffer */ 7975722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 8075722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt struct wf_cpu_pid_param param; 8175722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt}; 8275722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt 8375722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidtextern void wf_cpu_pid_init(struct wf_cpu_pid_state *st, 8475722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidt struct wf_cpu_pid_param *param); 8575722d3992f57375c0cc029dcceb2334a45ceff1Benjamin Herrenschmidtextern s32 wf_cpu_pid_run(struct wf_cpu_pid_state *st, s32 power, s32 temp); 86