linux-imx

/*

 * Windfarm PowerMac thermal control.

 * Control loops for machines with SMU and PPC970MP processors.

 *

 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>

 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.

 *

 * Use and redistribute under the terms of the GNU GPL v2.

 */

#include <linux/types.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/device.h>

#include <linux/platform_device.h>

#include <linux/reboot.h>

#include <asm/prom.h>

#include <asm/smu.h>

​

#include "windfarm.h"

#include "windfarm_pid.h"

​

#define VERSION "0.2"

​

#define DEBUG

#undef LOTSA_DEBUG

​

#ifdef DEBUG

#define DBG(args...)    printk(args)

#else

#define DBG(args...)    do { } while(0)

#endif

​

#ifdef LOTSA_DEBUG

#define DBG_LOTS(args...)   printk(args)

#else

#define DBG_LOTS(args...)   do { } while(0)

#endif

​

/* define this to force CPU overtemp to 60 degree, useful for testing

 * the overtemp code

 */

#undef HACKED_OVERTEMP

​

/* We currently only handle 2 chips, 4 cores... */

#define NR_CHIPS    2

#define NR_CORES    4

#define NR_CPU_FANS 3 * NR_CHIPS

​

/* Controls and sensors */

static struct wf_sensor *sens_cpu_temp[NR_CORES];

static struct wf_sensor *sens_cpu_power[NR_CORES];

static struct wf_sensor *hd_temp;

static struct wf_sensor *slots_power;

static struct wf_sensor *u4_temp;

​

static struct wf_control *cpu_fans[NR_CPU_FANS];

static char *cpu_fan_names[NR_CPU_FANS] = {

    "cpu-rear-fan-0",

    "cpu-rear-fan-1",

    "cpu-front-fan-0",

    "cpu-front-fan-1",

    "cpu-pump-0",

    "cpu-pump-1",

};

static struct wf_control *cpufreq_clamp;

​

/* Second pump isn't required (and isn't actually present) */

#define CPU_FANS_REQD       (NR_CPU_FANS - 2)

#define FIRST_PUMP      4

#define LAST_PUMP       5

​

/* We keep a temperature history for average calculation of 180s */

#define CPU_TEMP_HIST_SIZE  180

​

/* Scale factor for fan speed, *100 */

static int cpu_fan_scale[NR_CPU_FANS] = {

    100,

    100,

    97,     /* inlet fans run at 97% of exhaust fan */

    97,

    100,        /* updated later */

    100,        /* updated later */

};

​

static struct wf_control *backside_fan;

static struct wf_control *slots_fan;

static struct wf_control *drive_bay_fan;

​

/* PID loop state */

static struct wf_cpu_pid_state cpu_pid[NR_CORES];

static u32 cpu_thist[CPU_TEMP_HIST_SIZE];

static int cpu_thist_pt;