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Commit a78a4a03 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
Browse files

powerpc/windfarm: Add Fan Control Unit controls for G5s 



The FCU operates the fans on the earlier generation G5 machines,
this module will be used by upcoming windfarm drivers.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent d839ba2a

drivers/macintosh/windfarm_fcu_controls.c

0 → 100644
+617 −0
Original line number Diff line number Diff line 
/*

 * Windfarm PowerMac thermal control. FCU fan control

 *

 * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.

 *

 * Released under the term of the GNU GPL v2.

 */

#undef DEBUG



#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/wait.h>

#include <linux/i2c.h>

#include <asm/prom.h>

#include <asm/machdep.h>

#include <asm/io.h>

#include <asm/sections.h>



#include "windfarm.h"

#include "windfarm_mpu.h"



#define VERSION "1.0"



#ifdef DEBUG

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

#else

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

#endif



/*

 * This option is "weird" :) Basically, if you define this to 1

 * the control loop for the RPMs fans (not PWMs) will apply the

 * correction factor obtained from the PID to the actual RPM

 * speed read from the FCU.

 *

 * If you define the below constant to 0, then it will be

 * applied to the setpoint RPM speed, that is basically the

 * speed we proviously "asked" for.

 *

 * I'm not sure which of these Apple's algorithm is supposed

 * to use

 */

#define RPM_PID_USE_ACTUAL_SPEED	1



/* Default min/max for pumps */

#define CPU_PUMP_OUTPUT_MAX		3200

#define CPU_PUMP_OUTPUT_MIN		1250



#define FCU_FAN_RPM		0

#define FCU_FAN_PWM		1



struct wf_fcu_priv {

	struct kref		ref;

	struct i2c_client	*i2c;

	struct mutex		lock;

	struct list_head	fan_list;

	int			rpm_shift;

};



struct wf_fcu_fan {

	struct list_head	link;

	int			id;

	s32			min, max, target;

	struct wf_fcu_priv	*fcu_priv;

	struct wf_control	ctrl;

};



static void wf_fcu_release(struct kref *ref)

{

	struct wf_fcu_priv *pv = container_of(ref, struct wf_fcu_priv, ref);



	kfree(pv);

}



static void wf_fcu_fan_release(struct wf_control *ct)

{

	struct wf_fcu_fan *fan = ct->priv;



	kref_put(&fan->fcu_priv->ref, wf_fcu_release);

	kfree(fan);

}



static int wf_fcu_read_reg(struct wf_fcu_priv *pv, int reg,

			   unsigned char *buf, int nb)

{

	int tries, nr, nw;



	mutex_lock(&pv->lock);



	buf[0] = reg;

	tries = 0;

	for (;;) {

		nw = i2c_master_send(pv->i2c, buf, 1);

		if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)

			break;

		msleep(10);

		++tries;

	}

	if (nw <= 0) {

		pr_err("Failure writing address to FCU: %d", nw);

		nr = nw;

		goto bail;

	}

	tries = 0;

	for (;;) {

		nr = i2c_master_recv(pv->i2c, buf, nb);

		if (nr > 0 || (nr < 0 && nr != -ENODEV) || tries >= 100)

			break;

		msleep(10);

		++tries;

	}

	if (nr <= 0)

		pr_err("wf_fcu: Failure reading data from FCU: %d", nw);

 bail:

	mutex_unlock(&pv->lock);

	return nr;

}



static int wf_fcu_write_reg(struct wf_fcu_priv *pv, int reg,

			    const unsigned char *ptr, int nb)

{

	int tries, nw;

	unsigned char buf[16];



	buf[0] = reg;

	memcpy(buf+1, ptr, nb);

	++nb;

	tries = 0;

	for (;;) {

		nw = i2c_master_send(pv->i2c, buf, nb);

		if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)

			break;

		msleep(10);

		++tries;

	}

	if (nw < 0)

		pr_err("wf_fcu: Failure writing to FCU: %d", nw);

	return nw;

}



static int wf_fcu_fan_set_rpm(struct wf_control *ct, s32 value)

{

	struct wf_fcu_fan *fan = ct->priv;

	struct wf_fcu_priv *pv = fan->fcu_priv;

	int rc, shift = pv->rpm_shift;

	unsigned char buf[2];



	if (value < fan->min)

		value = fan->min;

	if (value > fan->max)

		value = fan->max;



	if (fan->target && fan->target == value)

		return 0;

	fan->target = value;



	buf[0] = value >> (8 - shift);

	buf[1] = value << shift;

	rc = wf_fcu_write_reg(pv, 0x10 + (fan->id * 2), buf, 2);

	if (rc < 0)

		return -EIO;

	return 0;

}



static int wf_fcu_fan_get_rpm(struct wf_control *ct, s32 *value)

{

	struct wf_fcu_fan *fan = ct->priv;

	struct wf_fcu_priv *pv = fan->fcu_priv;

	int rc, reg_base, shift = pv->rpm_shift;

	unsigned char failure;

	unsigned char active;

	unsigned char buf[2];



	rc = wf_fcu_read_reg(pv, 0xb, &failure, 1);

	if (rc != 1)

		return -EIO;

	if ((failure & (1 << fan->id)) != 0)

		return -EFAULT;

	rc = wf_fcu_read_reg(pv, 0xd, &active, 1);

	if (rc != 1)

		return -EIO;

	if ((active & (1 << fan->id)) == 0)

		return -ENXIO;



	/* Programmed value or real current speed */

#if RPM_PID_USE_ACTUAL_SPEED

	reg_base = 0x11;

#else

	reg_base = 0x10;

#endif

	rc = wf_fcu_read_reg(pv, reg_base + (fan->id * 2), buf, 2);

	if (rc != 2)

		return -EIO;



	*value = (buf[0] << (8 - shift)) | buf[1] >> shift;



	return 0;

}



static int wf_fcu_fan_set_pwm(struct wf_control *ct, s32 value)

{

	struct wf_fcu_fan *fan = ct->priv;

	struct wf_fcu_priv *pv = fan->fcu_priv;

	unsigned char buf[2];

	int rc;



	if (value < fan->min)

		value = fan->min;

	if (value > fan->max)

		value = fan->max;



	if (fan->target && fan->target == value)

		return 0;

	fan->target = value;



	value = (value * 2559) / 1000;

	buf[0] = value;

	rc = wf_fcu_write_reg(pv, 0x30 + (fan->id * 2), buf, 1);

	if (rc < 0)

		return -EIO;

	return 0;

}



static int wf_fcu_fan_get_pwm(struct wf_control *ct, s32 *value)

{

	struct wf_fcu_fan *fan = ct->priv;

	struct wf_fcu_priv *pv = fan->fcu_priv;

	unsigned char failure;

	unsigned char active;

	unsigned char buf[2];

	int rc;



	rc = wf_fcu_read_reg(pv, 0x2b, &failure, 1);

	if (rc != 1)

		return -EIO;

	if ((failure & (1 << fan->id)) != 0)

		return -EFAULT;

	rc = wf_fcu_read_reg(pv, 0x2d, &active, 1);

	if (rc != 1)

		return -EIO;

	if ((active & (1 << fan->id)) == 0)

		return -ENXIO;



	rc = wf_fcu_read_reg(pv, 0x30 + (fan->id * 2), buf, 1);

	if (rc != 1)

		return -EIO;



	*value = (((s32)buf[0]) * 1000) / 2559;



	return 0;

}



static s32 wf_fcu_fan_min(struct wf_control *ct)

{

	struct wf_fcu_fan *fan = ct->priv;



	return fan->min;

}



static s32 wf_fcu_fan_max(struct wf_control *ct)

{

	struct wf_fcu_fan *fan = ct->priv;



	return fan->max;

}



static const struct wf_control_ops wf_fcu_fan_rpm_ops = {

	.set_value	= wf_fcu_fan_set_rpm,

	.get_value	= wf_fcu_fan_get_rpm,

	.get_min	= wf_fcu_fan_min,

	.get_max	= wf_fcu_fan_max,

	.release	= wf_fcu_fan_release,

	.owner		= THIS_MODULE,

};



static const struct wf_control_ops wf_fcu_fan_pwm_ops = {

	.set_value	= wf_fcu_fan_set_pwm,

	.get_value	= wf_fcu_fan_get_pwm,

	.get_min	= wf_fcu_fan_min,

	.get_max	= wf_fcu_fan_max,

	.release	= wf_fcu_fan_release,

	.owner		= THIS_MODULE,

};



static void __devinit wf_fcu_get_pump_minmax(struct wf_fcu_fan *fan)

{

	const struct mpu_data *mpu = wf_get_mpu(0);

	u16 pump_min = 0, pump_max = 0xffff;

	u16 tmp[4];



	/* Try to fetch pumps min/max infos from eeprom */

	if (mpu) {

		memcpy(&tmp, mpu->processor_part_num, 8);

		if (tmp[0] != 0xffff && tmp[1] != 0xffff) {

			pump_min = max(pump_min, tmp[0]);

			pump_max = min(pump_max, tmp[1]);

		}

		if (tmp[2] != 0xffff && tmp[3] != 0xffff) {

			pump_min = max(pump_min, tmp[2]);

			pump_max = min(pump_max, tmp[3]);

		}

	}



	/* Double check the values, this _IS_ needed as the EEPROM on

	 * some dual 2.5Ghz G5s seem, at least, to have both min & max

	 * same to the same value ... (grrrr)

	 */

	if (pump_min == pump_max || pump_min == 0 || pump_max == 0xffff) {

		pump_min = CPU_PUMP_OUTPUT_MIN;

		pump_max = CPU_PUMP_OUTPUT_MAX;

	}



	fan->min = pump_min;

	fan->max = pump_max;



	DBG("wf_fcu: pump min/max for %s set to: [%d..%d] RPM\n",

	    fan->ctrl.name, pump_min, pump_max);

}



static void __devinit wf_fcu_get_rpmfan_minmax(struct wf_fcu_fan *fan)

{

	struct wf_fcu_priv *pv = fan->fcu_priv;

	const struct mpu_data *mpu0 = wf_get_mpu(0);

	const struct mpu_data *mpu1 = wf_get_mpu(1);



	/* Default */

	fan->min = 2400 >> pv->rpm_shift;

	fan->max = 56000 >> pv->rpm_shift;



	/* CPU fans have min/max in MPU */

	if (mpu0 && !strcmp(fan->ctrl.name, "cpu-front-fan-0")) {

		fan->min = max(fan->min, (s32)mpu0->rminn_intake_fan);

		fan->max = min(fan->max, (s32)mpu0->rmaxn_intake_fan);

		goto bail;

	}

	if (mpu1 && !strcmp(fan->ctrl.name, "cpu-front-fan-1")) {

		fan->min = max(fan->min, (s32)mpu1->rminn_intake_fan);

		fan->max = min(fan->max, (s32)mpu1->rmaxn_intake_fan);

		goto bail;

	}

	if (mpu0 && !strcmp(fan->ctrl.name, "cpu-rear-fan-0")) {

		fan->min = max(fan->min, (s32)mpu0->rminn_exhaust_fan);

		fan->max = min(fan->max, (s32)mpu0->rmaxn_exhaust_fan);

		goto bail;

	}

	if (mpu1 && !strcmp(fan->ctrl.name, "cpu-rear-fan-1")) {

		fan->min = max(fan->min, (s32)mpu1->rminn_exhaust_fan);

		fan->max = min(fan->max, (s32)mpu1->rmaxn_exhaust_fan);

		goto bail;

	}

	/* Rackmac variants, we just use mpu0 intake */

	if (!strncmp(fan->ctrl.name, "cpu-fan", 7)) {

		fan->min = max(fan->min, (s32)mpu0->rminn_intake_fan);

		fan->max = min(fan->max, (s32)mpu0->rmaxn_intake_fan);

		goto bail;

	}

 bail:

	DBG("wf_fcu: fan min/max for %s set to: [%d..%d] RPM\n",

	    fan->ctrl.name, fan->min, fan->max);

}



static void __devinit wf_fcu_add_fan(struct wf_fcu_priv *pv,

				     const char *name,

				     int type, int id)

{

	struct wf_fcu_fan *fan;



	fan = kzalloc(sizeof(*fan), GFP_KERNEL);

	if (!fan)

		return;

	fan->fcu_priv = pv;

	fan->id = id;

	fan->ctrl.name = name;

	fan->ctrl.priv = fan;



	/* min/max is oddball but the code comes from

	 * therm_pm72 which seems to work so ...

	 */

	if (type == FCU_FAN_RPM) {

		if (!strncmp(name, "cpu-pump", strlen("cpu-pump")))

			wf_fcu_get_pump_minmax(fan);

		else

			wf_fcu_get_rpmfan_minmax(fan);

		fan->ctrl.type = WF_CONTROL_RPM_FAN;

		fan->ctrl.ops = &wf_fcu_fan_rpm_ops;

	} else {

		fan->min = 10;

		fan->max = 100;

		fan->ctrl.type = WF_CONTROL_PWM_FAN;

		fan->ctrl.ops = &wf_fcu_fan_pwm_ops;

	}



	if (wf_register_control(&fan->ctrl)) {

		pr_err("wf_fcu: Failed to register fan %s\n", name);

		kfree(fan);

		return;

	}

	list_add(&fan->link, &pv->fan_list);

	kref_get(&pv->ref);

}



static void __devinit wf_fcu_lookup_fans(struct wf_fcu_priv *pv)

{

	/* Translation of device-tree location properties to

	 * windfarm fan names

	 */

	static const struct {

		const char *dt_name;	/* Device-tree name */

		const char *ct_name;	/* Control name */

	} loc_trans[] = {

		{ "BACKSIDE",		"backside-fan",		},

		{ "SYS CTRLR FAN",	"backside-fan",		},

		{ "DRIVE BAY",		"drive-bay-fan",	},

		{ "SLOT",		"slots-fan",		},

		{ "PCI FAN",		"slots-fan",		},

		{ "CPU A INTAKE",	"cpu-front-fan-0",	},

		{ "CPU A EXHAUST",	"cpu-rear-fan-0",	},

		{ "CPU B INTAKE",	"cpu-front-fan-1",	},

		{ "CPU B EXHAUST",	"cpu-rear-fan-1",	},

		{ "CPU A PUMP",		"cpu-pump-0",		},

		{ "CPU B PUMP",		"cpu-pump-1",		},

		{ "CPU A 1",		"cpu-fan-a-0",		},

		{ "CPU A 2",		"cpu-fan-b-0",		},

		{ "CPU A 3",		"cpu-fan-c-0",		},

		{ "CPU B 1",		"cpu-fan-a-1",		},

		{ "CPU B 2",		"cpu-fan-b-1",		},

		{ "CPU B 3",		"cpu-fan-c-1",		},

	};

	struct device_node *np = NULL, *fcu = pv->i2c->dev.of_node;

	int i;



	DBG("Looking up FCU controls in device-tree...\n");



	while ((np = of_get_next_child(fcu, np)) != NULL) {

		int id, type = -1;

		const char *loc;

		const char *name;

		const u32 *reg;



		DBG(" control: %s, type: %s\n", np->name, np->type);



		/* Detect control type */

		if (!strcmp(np->type, "fan-rpm-control") ||

		    !strcmp(np->type, "fan-rpm"))

			type = FCU_FAN_RPM;

		if (!strcmp(np->type, "fan-pwm-control") ||

		    !strcmp(np->type, "fan-pwm"))

			type = FCU_FAN_PWM;

		/* Only care about fans for now */

		if (type == -1)

			continue;



		/* Lookup for a matching location */

		loc = of_get_property(np, "location", NULL);

		reg = of_get_property(np, "reg", NULL);

		if (loc == NULL || reg == NULL)

			continue;

		DBG(" matching location: %s, reg: 0x%08x\n", loc, *reg);



		for (i = 0; i < ARRAY_SIZE(loc_trans); i++) {

			if (strncmp(loc, loc_trans[i].dt_name,

				    strlen(loc_trans[i].dt_name)))

				continue;

			name = loc_trans[i].ct_name;



			DBG(" location match, name: %s\n", name);



			if (type == FCU_FAN_RPM)

				id = ((*reg) - 0x10) / 2;

			else

				id = ((*reg) - 0x30) / 2;

			if (id > 7) {

				pr_warning("wf_fcu: Can't parse "

				       "fan ID in device-tree for %s\n",

					   np->full_name);

				break;

			}

			wf_fcu_add_fan(pv, name, type, id);

			break;

		}

	}

}



static void __devinit wf_fcu_default_fans(struct wf_fcu_priv *pv)

{

	/* We only support the default fans for PowerMac7,2 */

	if (!of_machine_is_compatible("PowerMac7,2"))

		return;



	wf_fcu_add_fan(pv, "backside-fan",	FCU_FAN_PWM, 1);

	wf_fcu_add_fan(pv, "drive-bay-fan",	FCU_FAN_RPM, 2);

	wf_fcu_add_fan(pv, "slots-fan",		FCU_FAN_PWM, 2);

	wf_fcu_add_fan(pv, "cpu-front-fan-0",	FCU_FAN_RPM, 3);

	wf_fcu_add_fan(pv, "cpu-rear-fan-0",	FCU_FAN_RPM, 4);

	wf_fcu_add_fan(pv, "cpu-front-fan-1",	FCU_FAN_RPM, 5);

	wf_fcu_add_fan(pv, "cpu-rear-fan-1",	FCU_FAN_RPM, 6);

}



static int __devinit wf_fcu_init_chip(struct wf_fcu_priv *pv)

{

	unsigned char buf = 0xff;

	int rc;



	rc = wf_fcu_write_reg(pv, 0xe, &buf, 1);

	if (rc < 0)

		return -EIO;

	rc = wf_fcu_write_reg(pv, 0x2e, &buf, 1);

	if (rc < 0)

		return -EIO;

	rc = wf_fcu_read_reg(pv, 0, &buf, 1);

	if (rc < 0)

		return -EIO;

	pv->rpm_shift = (buf == 1) ? 2 : 3;



	pr_debug("wf_fcu: FCU Initialized, RPM fan shift is %d\n",

		 pv->rpm_shift);



	return 0;

}



static int __devinit wf_fcu_probe(struct i2c_client *client,

				  const struct i2c_device_id *id)

{

	struct wf_fcu_priv *pv;



	pv = kzalloc(sizeof(*pv), GFP_KERNEL);

	if (!pv)

		return -ENOMEM;



	kref_init(&pv->ref);

	mutex_init(&pv->lock);

	INIT_LIST_HEAD(&pv->fan_list);

	pv->i2c = client;



	/*

	 * First we must start the FCU which will query the

	 * shift value to apply to RPMs

	 */

	if (wf_fcu_init_chip(pv)) {

		pr_err("wf_fcu: Initialization failed !\n");

		kfree(pv);

		return -ENXIO;

	}



	/* First lookup fans in the device-tree */

	wf_fcu_lookup_fans(pv);



	/*

	 * Older machines don't have the device-tree entries

	 * we are looking for, just hard code the list

	 */

	if (list_empty(&pv->fan_list))

		wf_fcu_default_fans(pv);



	/* Still no fans ? FAIL */

	if (list_empty(&pv->fan_list)) {

		pr_err("wf_fcu: Failed to find fans for your machine\n");

		kfree(pv);

		return -ENODEV;

	}



	dev_set_drvdata(&client->dev, pv);



	return 0;

}



static int __devexit wf_fcu_remove(struct i2c_client *client)

{

	struct wf_fcu_priv *pv = dev_get_drvdata(&client->dev);

	struct wf_fcu_fan *fan;



	while (!list_empty(&pv->fan_list)) {

		fan = list_first_entry(&pv->fan_list, struct wf_fcu_fan, link);

		list_del(&fan->link);

		wf_unregister_control(&fan->ctrl);

	}

	kref_put(&pv->ref, wf_fcu_release);

	return 0;

}



static const struct i2c_device_id wf_fcu_id[] = {

	{ "MAC,fcu", 0 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, wf_fcu_id);



static struct i2c_driver wf_fcu_driver = {

	.driver = {

		.name	= "wf_fcu",

	},

	.probe		= wf_fcu_probe,

	.remove		= wf_fcu_remove,

	.id_table	= wf_fcu_id,

};



static int __init wf_fcu_init(void)

{

	return i2c_add_driver(&wf_fcu_driver);

}



static void __exit wf_fcu_exit(void)

{

	i2c_del_driver(&wf_fcu_driver);

}





module_init(wf_fcu_init);

module_exit(wf_fcu_exit);



MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");

MODULE_DESCRIPTION("FCU control objects for PowerMacs thermal control");

MODULE_LICENSE("GPL");