windfarm_pm81.c

来自「linux 内核源代码」· C语言 代码 · 共 814 行 · 第 1/2 页

/*
 * Windfarm PowerMac thermal control. iMac G5
 *
 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
 *                    <[e-mail]>
 *
 * 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:
 *
 * PowerMac8,1 and PowerMac8,2
 * ===========================
 *
 * System Fans control loop. Different based on models. In addition to the
 * usual PID algorithm, the control loop gets 2 additional pairs of linear
 * scaling factors (scale/offsets) expressed as 4.12 fixed point values
 * signed offset, unsigned scale)
 *
 * The targets are modified such as:
 *  - the linked control (second control) gets the target value as-is
 *    (typically the drive fan)
 *  - the main control (first control) gets the target value scaled with
 *    the first pair of factors, and is then modified as below
 *  - the value of the target of the CPU Fan control loop is retrieved,
 *    scaled with the second pair of factors, and the max of that and
 *    the scaled target is applied to the main control.
 *
 * # model_id: 2
 *   controls       : system-fan, drive-bay-fan
 *   sensors        : hd-temp
 *   PID params     : G_d = 0x15400000
 *                    G_p = 0x00200000
 *                    G_r = 0x000002fd
 *                    History = 2 entries
 *                    Input target = 0x3a0000
 *                    Interval = 5s
 *   linear-factors : offset = 0xff38 scale  = 0x0ccd
 *                    offset = 0x0208 scale  = 0x07ae
 *
 * # model_id: 3
 *   controls       : system-fan, drive-bay-fan
 *   sensors        : hd-temp
 *   PID params     : G_d = 0x08e00000
 *                    G_p = 0x00566666
 *                    G_r = 0x0000072b
 *                    History = 2 entries
 *                    Input target = 0x350000
 *                    Interval = 5s
 *   linear-factors : offset = 0xff38 scale  = 0x0ccd
 *                    offset = 0x0000 scale  = 0x0000
 *
 * # model_id: 5
 *   controls       : system-fan
 *   sensors        : hd-temp
 *   PID params     : G_d = 0x15400000
 *                    G_p = 0x00233333
 *                    G_r = 0x000002fd
 *                    History = 2 entries
 *                    Input target = 0x3a0000
 *                    Interval = 5s
 *   linear-factors : offset = 0x0000 scale  = 0x1000
 *                    offset = 0x0091 scale  = 0x0bae
 *
 * CPU Fan control loop. The loop is identical for all models. it
 * has an additional pair of scaling factor. This is used to scale the
 * systems fan control loop target result (the one before it gets scaled
 * by the System Fans control loop itself). Then, the max value of the
 * calculated target value and system fan value is sent to the fans
 *
 *   controls       : cpu-fan
 *   sensors        : cpu-temp cpu-power
 *   PID params     : From SMU sdb partition
 *   linear-factors : offset = 0xfb50 scale  = 0x1000
 *
 * CPU Slew control loop. Not implemented. The cpufreq driver in linux is
 * completely separate for now, though we could find a way to link it, either
 * as a client reacting to overtemp notifications, or directling monitoring
 * the CPU temperature
 *
 * WARNING ! The CPU control loop requires the CPU tmax for the current
 * operating point. However, we currently are completely separated from
 * the cpufreq driver and thus do not know what the current operating
 * point is. Fortunately, we also do not have any hardware supporting anything
 * but operating point 0 at the moment, thus we just peek that value directly
 * from the SDB partition. If we ever end up with actually slewing the system
 * clock and thus changing operating points, we'll have to find a way to
 * communicate with the CPU freq driver;
 *
 */

#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/system.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

static int wf_smu_mach_model;	/* machine model id */

/* 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_control *fan_cpu_main;
static struct wf_control *fan_hd;
static struct wf_control *fan_system;
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, wf_smu_started;

/* 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;

/*
 * ****** System Fans Control Loop ******
 *
 */

/* Parameters for the System Fans control loop. Parameters
 * not in this table such as interval, history size, ...
 * are common to all versions and thus hard coded for now.
 */
struct wf_smu_sys_fans_param {
	int	model_id;
	s32	itarget;
	s32	gd, gp, gr;

	s16	offset0;
	u16	scale0;
	s16	offset1;
	u16	scale1;
};

#define WF_SMU_SYS_FANS_INTERVAL	5
#define WF_SMU_SYS_FANS_HISTORY_SIZE	2

/* State data used by the system fans control loop
 */
struct wf_smu_sys_fans_state {
	int			ticks;
	s32			sys_setpoint;
	s32			hd_setpoint;
	s16			offset0;
	u16			scale0;
	s16			offset1;
	u16			scale1;
	struct wf_pid_state	pid;
};

/*
 * Configs for SMU Sytem Fan control loop
 */
static struct wf_smu_sys_fans_param wf_smu_sys_all_params[] = {
	/* Model ID 2 */
	{
		.model_id	= 2,
		.itarget	= 0x3a0000,
		.gd		= 0x15400000,
		.gp		= 0x00200000,
		.gr		= 0x000002fd,
		.offset0	= 0xff38,
		.scale0		= 0x0ccd,
		.offset1	= 0x0208,
		.scale1		= 0x07ae,
	},
	/* Model ID 3 */
	{
		.model_id	= 3,
		.itarget	= 0x350000,
		.gd		= 0x08e00000,
		.gp		= 0x00566666,
		.gr		= 0x0000072b,
		.offset0	= 0xff38,
		.scale0		= 0x0ccd,
		.offset1	= 0x0000,
		.scale1		= 0x0000,
	},
	/* Model ID 5 */
	{
		.model_id	= 5,
		.itarget	= 0x3a0000,
		.gd		= 0x15400000,
		.gp		= 0x00233333,
		.gr		= 0x000002fd,
		.offset0	= 0x0000,
		.scale0		= 0x1000,
		.offset1	= 0x0091,
		.scale1		= 0x0bae,
	},
};
#define WF_SMU_SYS_FANS_NUM_CONFIGS ARRAY_SIZE(wf_smu_sys_all_params)

static struct wf_smu_sys_fans_state *wf_smu_sys_fans;

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


#define WF_SMU_CPU_FANS_INTERVAL	1
#define WF_SMU_CPU_FANS_MAX_HISTORY	16
#define WF_SMU_CPU_FANS_SIBLING_SCALE	0x00001000
#define WF_SMU_CPU_FANS_SIBLING_OFFSET	0xfffffb50

/* State data used by the cpu fans control loop
 */
struct wf_smu_cpu_fans_state {
	int			ticks;
	s32			cpu_setpoint;
	s32			scale;
	s32			offset;
	struct wf_cpu_pid_state	pid;
};

static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;



/*
 * ***** Implementation *****
 *
 */

static void wf_smu_create_sys_fans(void)
{
	struct wf_smu_sys_fans_param *param = NULL;
	struct wf_pid_param pid_param;
	int i;

	/* First, locate the params for this model */
	for (i = 0; i < WF_SMU_SYS_FANS_NUM_CONFIGS; i++)
		if (wf_smu_sys_all_params[i].model_id == wf_smu_mach_model) {
			param = &wf_smu_sys_all_params[i];
			break;
		}

	/* No params found, put fans to max */
	if (param == NULL) {
		printk(KERN_WARNING "windfarm: System fan config not found "
		       "for this machine model, max fan speed\n");
		goto fail;
	}

	/* Alloc & initialize state */
	wf_smu_sys_fans = kmalloc(sizeof(struct wf_smu_sys_fans_state),
				  GFP_KERNEL);
	if (wf_smu_sys_fans == NULL) {
		printk(KERN_WARNING "windfarm: Memory allocation error"
		       " max fan speed\n");
		goto fail;
	}
	wf_smu_sys_fans->ticks = 1;
	wf_smu_sys_fans->scale0 = param->scale0;
	wf_smu_sys_fans->offset0 = param->offset0;
	wf_smu_sys_fans->scale1 = param->scale1;
	wf_smu_sys_fans->offset1 = param->offset1;

	/* Fill PID params */
	pid_param.gd = param->gd;
	pid_param.gp = param->gp;
	pid_param.gr = param->gr;
	pid_param.interval = WF_SMU_SYS_FANS_INTERVAL;
	pid_param.history_len = WF_SMU_SYS_FANS_HISTORY_SIZE;
	pid_param.itarget = param->itarget;
	pid_param.min = fan_system->ops->get_min(fan_system);
	pid_param.max = fan_system->ops->get_max(fan_system);
	if (fan_hd) {
		pid_param.min =
			max(pid_param.min,fan_hd->ops->get_min(fan_hd));
		pid_param.max =
			min(pid_param.max,fan_hd->ops->get_max(fan_hd));
	}
	wf_pid_init(&wf_smu_sys_fans->pid, &pid_param);

	DBG("wf: System Fan control initialized.\n");
	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
	    FIX32TOPRINT(pid_param.itarget), pid_param.min, pid_param.max);
	return;

 fail:

	if (fan_system)
		wf_control_set_max(fan_system);
	if (fan_hd)
		wf_control_set_max(fan_hd);
}

static void wf_smu_sys_fans_tick(struct wf_smu_sys_fans_state *st)
{
	s32 new_setpoint, temp, scaled, cputarget;
	int rc;

	if (--st->ticks != 0) {
		if (wf_smu_readjust)
			goto readjust;
		return;
	}
	st->ticks = WF_SMU_SYS_FANS_INTERVAL;

	rc = sensor_hd_temp->ops->get_value(sensor_hd_temp, &temp);
	if (rc) {
		printk(KERN_WARNING "windfarm: HD temp sensor error %d\n",
		       rc);
		wf_smu_failure_state |= FAILURE_SENSOR;
		return;
	}

	DBG("wf_smu: System Fans tick ! HD temp: %d.%03d\n",
	    FIX32TOPRINT(temp));

	if (temp > (st->pid.param.itarget + 0x50000))
		wf_smu_failure_state |= FAILURE_OVERTEMP;

	new_setpoint = wf_pid_run(&st->pid, temp);

	DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);

	scaled = ((((s64)new_setpoint) * (s64)st->scale0) >> 12) + st->offset0;

	DBG("wf_smu: scaled setpoint: %d RPM\n", (int)scaled);

	cputarget = wf_smu_cpu_fans ? wf_smu_cpu_fans->pid.target : 0;
	cputarget = ((((s64)cputarget) * (s64)st->scale1) >> 12) + st->offset1;
	scaled = max(scaled, cputarget);
	scaled = max(scaled, st->pid.param.min);
	scaled = min(scaled, st->pid.param.max);

	DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)scaled);

	if (st->sys_setpoint == scaled && new_setpoint == st->hd_setpoint)
		return;
	st->sys_setpoint = scaled;
	st->hd_setpoint = new_setpoint;
 readjust:
	if (fan_system && wf_smu_failure_state == 0) {
		rc = fan_system->ops->set_value(fan_system, st->sys_setpoint);
		if (rc) {
			printk(KERN_WARNING "windfarm: Sys fan error %d\n",
			       rc);
			wf_smu_failure_state |= FAILURE_FAN;
		}
	}
	if (fan_hd && wf_smu_failure_state == 0) {
		rc = fan_hd->ops->set_value(fan_hd, st->hd_setpoint);
		if (rc) {
			printk(KERN_WARNING "windfarm: HD fan error %d\n",
			       rc);
			wf_smu_failure_state |= FAILURE_FAN;
		}
	}
}

static void wf_smu_create_cpu_fans(void)
{
	struct wf_cpu_pid_param pid_param;
	const struct smu_sdbp_header *hdr;
	struct smu_sdbp_cpupiddata *piddata;
	struct smu_sdbp_fvt *fvt;
	s32 tmax, tdelta, maxpow, powadj;

	/* First, locate the PID params in SMU SBD */
	hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
	if (hdr == 0) {
		printk(KERN_WARNING "windfarm: CPU PID fan config not found "
		       "max fan speed\n");
		goto fail;