[PATCH] ppc64: Thermal control for SMU based machines

This adds a new thermal control framework for PowerMac, along with the
implementation for PowerMac8,1, PowerMac8,2 (iMac G5 rev 1 and 2), and
PowerMac9,1 (latest single CPU desktop). In the future, I expect to move
the older G5 thermal control to the new framework as well.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

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 000000000000..a364c2a2499c
--- /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);