linux-imx

/*

 * Windfarm PowerMac thermal control. SMU based 1 CPU desktop control loops

 *

 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.

 *                    <benh@kernel.crashing.org>

 *

 * Released under the term of the GNU GPL v2.

 *

 * The algorithm used is the PID control algorithm, used the same

 * way the published Darwin code does, using the same values that

 * are present in the Darwin 8.2 snapshot property lists (note however

 * that none of the code has been re-used, it's a complete re-implementation

 *

 * The various control loops found in Darwin config file are:

 *

 * PowerMac9,1

 * ===========

 *

 * Has 3 control loops: CPU fans is similar to PowerMac8,1 (though it doesn't

 * try to play with other control loops fans). Drive bay is rather basic PID

 * with one sensor and one fan. Slots area is a bit different as the Darwin

 * driver is supposed to be capable of working in a special "AGP" mode which

 * involves the presence of an AGP sensor and an AGP fan (possibly on the

 * AGP card itself). I can't deal with that special mode as I don't have

 * access to those additional sensor/fans for now (though ultimately, it would

 * be possible to add sensor objects for them) so I'm only implementing the

 * basic PCI slot control loop

 */

​

#include <linux/types.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/delay.h>

#include <linux/slab.h>

#include <linux/init.h>

#include <linux/spinlock.h>

#include <linux/wait.h>

#include <linux/kmod.h>

#include <linux/device.h>

#include <linux/platform_device.h>

#include <asm/prom.h>

#include <asm/machdep.h>

#include <asm/io.h>

#include <asm/sections.h>

#include <asm/smu.h>

​

#include "windfarm.h"

#include "windfarm_pid.h"

​

#define VERSION "0.4"

​

#undef DEBUG

​

#ifdef DEBUG

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

#else

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

#endif

​

/* define this to force CPU overtemp to 74 degree, useful for testing

 * the overtemp code

 */

#undef HACKED_OVERTEMP

​

/* Controls & sensors */

static struct wf_sensor *sensor_cpu_power;

static struct wf_sensor *sensor_cpu_temp;

static struct wf_sensor *sensor_hd_temp;

static struct wf_sensor *sensor_slots_power;

static struct wf_control *fan_cpu_main;

static struct wf_control *fan_cpu_second;

static struct wf_control *fan_cpu_third;

static struct wf_control *fan_hd;

static struct wf_control *fan_slots;

static struct wf_control *cpufreq_clamp;

​

/* Set to kick the control loop into life */

static int wf_smu_all_controls_ok, wf_smu_all_sensors_ok;

static bool wf_smu_started;

static bool wf_smu_overtemp;

​

/* Failure handling.. could be nicer */

#define FAILURE_FAN     0x01

#define FAILURE_SENSOR      0x02

#define FAILURE_OVERTEMP    0x04

​

static unsigned int wf_smu_failure_state;

static int wf_smu_readjust, wf_smu_skipping;

​

/*

 * ****** CPU Fans Control Loop ******

 *