xref: /src/sys/arch/macppc/dev/smu.c

/*-
 * Copyright (c) 2013 Phileas Fogg
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/device.h>
#include <sys/proc.h>
#include <sys/mutex.h>
#include <sys/time.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/kthread.h>

#include <machine/autoconf.h>

#include <dev/ofw/openfirm.h>
#include <dev/i2c/i2cvar.h>
#include <dev/clock_subr.h>
#include <dev/sysmon/sysmonvar.h>
#include <dev/sysmon/sysmon_taskq.h>

#include <macppc/dev/obiovar.h>
#include <macppc/dev/smuvar.h>

#include "opt_smu.h"

struct smu_softc;

struct smu_cmd {
	u_char cmd;
	u_char len;
	u_char data[254];
};

struct smu_fan {
	struct smu_softc* sc;

	char location[32];
	int reg;
	int zone;
	int rpm_ctl;
	int min_rpm;
	int max_rpm;
	int default_rpm;
	int current_rpm;
	time_t last_update;
};

struct smu_iicbus {
	struct smu_softc* sc;

	int reg;
	struct i2c_controller i2c;
};

#define SMU_MAX_FANS		8
#define SMU_MAX_IICBUS		3
#define SMU_MAX_SME_SENSORS	SMU_MAX_FANS

struct smu_zone {
	bool (*filter)(const envsys_data_t *);
	int nfans;
	int fans[SMU_MAX_FANS];
	int threshold, step;
	int duty;
};


#define SMU_ZONE_CPUS	0
#define SMU_ZONE_DRIVES	1
#define SMU_ZONE_SLOTS	2
#define SMU_ZONES	3

#define C_TO_uK(n) (n * 1000000 + 273150000)

struct smu_softc {
	device_t sc_dev;
	int sc_node;
	struct sysctlnode *sc_sysctl_me;

	kmutex_t sc_cmd_lock;
	kmutex_t sc_msg_lock;
	struct smu_cmd *sc_cmd;
	paddr_t sc_cmd_paddr;
	int sc_dbell_mbox;
	int sc_dbell_gpio;

	int sc_num_fans;
	struct smu_fan sc_fans[SMU_MAX_FANS];

	kmutex_t sc_iicbus_lock;
	int sc_num_iicbus;
	struct smu_iicbus sc_iicbus[SMU_MAX_IICBUS];

	struct todr_chip_handle sc_todr;

	struct sysmon_envsys *sc_sme;
	envsys_data_t sc_sme_sensors[SMU_MAX_SME_SENSORS];

	struct smu_zone sc_zones[SMU_ZONES];
	lwp_t *sc_thread;
	bool sc_dying;
};

#define SMU_CMD_FAN	0x4a
#define SMU_CMD_RTC	0x8e
#define SMU_CMD_I2C	0x9a
#define SMU_CMD_POWER	0xaa

#ifdef SMU_DEBUG
#define DPRINTF printf
#else
#define DPRINTF while (0) printf
#endif

static int smu_match(device_t, struct cfdata *, void *);
static void smu_attach(device_t, device_t, void *);
static int smu_setup_doorbell(struct smu_softc *);
static void smu_setup_fans(struct smu_softc *);
static void smu_setup_iicbus(struct smu_softc *);
static void smu_setup_sme(struct smu_softc *);
static int smu_iicbus_print(void *, const char *);
static void smu_sme_refresh(struct sysmon_envsys *, envsys_data_t *);
static int smu_do_cmd(struct smu_softc *, struct smu_cmd *, int);
static int smu_dbell_gpio_intr(void *);
static int smu_todr_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
static int smu_todr_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
static int smu_fan_update_rpm(struct smu_fan *);
static int smu_fan_get_rpm(struct smu_fan *, int *);
static int smu_fan_set_rpm(struct smu_fan *, int);
static int smu_iicbus_acquire_bus(void *, int);
static void smu_iicbus_release_bus(void *, int);
static int smu_iicbus_exec(void *, i2c_op_t, i2c_addr_t, const void *,
    size_t, void *, size_t, int);
static int smu_sysctl_fan_rpm(SYSCTLFN_ARGS);

static void smu_setup_zones(struct smu_softc *);
static void smu_adjust_zone(struct smu_softc *, int);
static void smu_adjust(void *);
static bool is_cpu_sensor(const envsys_data_t *);
static bool is_drive_sensor(const envsys_data_t *);
static bool is_slots_sensor(const envsys_data_t *);

CFATTACH_DECL_NEW(smu, sizeof(struct smu_softc),
    smu_match, smu_attach, NULL, NULL);

static struct smu_softc *smu0 = NULL;

static int
smu_match(device_t parent, struct cfdata *cf, void *aux)
{
	struct confargs *ca = aux;

	if (strcmp(ca->ca_name, "smu") == 0)
		return 5;

	return 0;
}

static void
smu_attach(device_t parent, device_t self, void *aux)
{
	struct confargs *ca = aux;
	struct smu_softc *sc = device_private(self);

	sc->sc_dev = self;
	sc->sc_node = ca->ca_node;

	sysctl_createv(NULL, 0, NULL, (void *) &sc->sc_sysctl_me,
	    CTLFLAG_READWRITE,
	    CTLTYPE_NODE, device_xname(sc->sc_dev), NULL,
	    NULL, 0, NULL, 0,
	    CTL_MACHDEP, CTL_CREATE, CTL_EOL);

	if (smu_setup_doorbell(sc) != 0) {
		aprint_normal(": unable to set up doorbell\n");
		return;
	}

	smu_setup_fans(sc);
	smu_setup_iicbus(sc);

	sc->sc_todr.todr_gettime_ymdhms = smu_todr_gettime_ymdhms;
	sc->sc_todr.todr_settime_ymdhms = smu_todr_settime_ymdhms;
	sc->sc_todr.cookie = sc;
	todr_attach(&sc->sc_todr);

	smu_setup_sme(sc);

	if (smu0 == NULL)
		smu0 = sc;

	printf("\n");
	smu_setup_zones(sc);
}

static int
smu_setup_doorbell(struct smu_softc *sc)
{
	int node, parent, reg[4], gpio_base, irq;

	mutex_init(&sc->sc_cmd_lock, MUTEX_DEFAULT, IPL_NONE);
	sc->sc_cmd = malloc(4096, M_DEVBUF, M_NOWAIT);
	sc->sc_cmd_paddr = vtophys((vaddr_t) sc->sc_cmd);

	DPRINTF("%s: cmd vaddr 0x%x paddr 0x%x\n",
	    __func__, (unsigned int) sc->sc_cmd,
	    (unsigned int) sc->sc_cmd_paddr);

	if (OF_getprop(sc->sc_node, "platform-doorbell-buff",
	        &node, sizeof(node)) <= 0)
		return -1;

	if (OF_getprop(node, "platform-do-doorbell-buff",
	        reg, sizeof(reg)) < sizeof(reg))
		return -1;

	sc->sc_dbell_mbox = reg[3];

	if (OF_getprop(sc->sc_node, "platform-doorbell-ack",
	        &node, sizeof(node)) <= 0)
		return -1;

	parent = OF_parent(node);
	if (parent == 0)
		return -1;

	if (OF_getprop(parent, "reg", &gpio_base, sizeof(gpio_base)) <= 0)
		return -1;

	if (OF_getprop(node, "reg", reg, sizeof(reg)) <= 0)
		return -1;

	if (OF_getprop(node, "interrupts", &irq, sizeof(irq)) <= 0)
		return -1;

	sc->sc_dbell_gpio = gpio_base + reg[0];

	aprint_normal(" mbox 0x%x gpio 0x%x irq %d",
	    sc->sc_dbell_mbox, sc->sc_dbell_gpio, irq);

	intr_establish(irq, IST_EDGE_FALLING, IPL_TTY, smu_dbell_gpio_intr, sc);

	return 0;
}

static void
smu_setup_fans(struct smu_softc *sc)
{
	struct smu_fan *fan;
	struct sysctlnode *sysctl_fans, *sysctl_fan, *sysctl_node;
	char type[32], sysctl_fan_name[32];
	int node, i, j;

	node = of_getnode_byname(sc->sc_node, "fans");
	for (node = OF_child(node);
	    (node != 0) && (sc->sc_num_fans < SMU_MAX_FANS);
	    node = OF_peer(node)) {
		fan = &sc->sc_fans[sc->sc_num_fans];
		fan->sc = sc;

		memset(fan->location, 0, sizeof(fan->location));
		OF_getprop(node, "location", fan->location,
		    sizeof(fan->location));

		if (OF_getprop(node, "reg", &fan->reg,
		        sizeof(fan->reg)) <= 0)
			continue;

		if (OF_getprop(node, "zone", &fan->zone,
		        sizeof(fan->zone)) <= 0)
			continue;

		memset(type, 0, sizeof(type));
		OF_getprop(node, "device_type", type, sizeof(type));
		if (strcmp(type, "fan-rpm-control") == 0)
			fan->rpm_ctl = 1;
		else
			fan->rpm_ctl = 0;

		if (OF_getprop(node, "min-value", &fan->min_rpm,
		    sizeof(fan->min_rpm)) <= 0)
			fan->min_rpm = 0;

		if (OF_getprop(node, "max-value", &fan->max_rpm,
		    sizeof(fan->max_rpm)) <= 0)
			fan->max_rpm = 0xffff;

		if (OF_getprop(node, "unmanage-value", &fan->default_rpm,
		    sizeof(fan->default_rpm)) <= 0)
			fan->default_rpm = fan->max_rpm;

		DPRINTF("fan: location %s reg %x zone %d rpm_ctl %d "
		    "min_rpm %d max_rpm %d default_rpm %d\n",
		    fan->location, fan->reg, fan->zone, fan->rpm_ctl,
		    fan->min_rpm, fan->max_rpm, fan->default_rpm);

		sc->sc_num_fans++;
	}

	for (i = 0; i < sc->sc_num_fans; i++) {
		fan = &sc->sc_fans[i];
		smu_fan_set_rpm(fan, fan->default_rpm);
		smu_fan_get_rpm(fan, &fan->current_rpm);
	}

	/* Create sysctl nodes for each fan */

	sysctl_createv(NULL, 0, NULL, (void *) &sysctl_fans,
	    CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
	    CTLTYPE_NODE, "fans", NULL,
	    NULL, 0, NULL, 0,
	    CTL_MACHDEP,
	    sc->sc_sysctl_me->sysctl_num,
	    CTL_CREATE, CTL_EOL);

	for (i = 0; i < sc->sc_num_fans; i++) {
		fan = &sc->sc_fans[i];

		for (j = 0; j < strlen(fan->location); j++) {
			sysctl_fan_name[j] = tolower(fan->location[j]);
			if (sysctl_fan_name[j] == ' ')
				sysctl_fan_name[j] = '_';
		}
		sysctl_fan_name[j] = '\0';

		sysctl_createv(NULL, 0, NULL, (void *) &sysctl_fan,
		    CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
		    CTLTYPE_NODE, sysctl_fan_name, "fan information",
		    NULL, 0, NULL, 0,
		    CTL_MACHDEP,
		    sc->sc_sysctl_me->sysctl_num,
		    sysctl_fans->sysctl_num,
		    CTL_CREATE, CTL_EOL);

		sysctl_createv(NULL, 0, NULL, (void *) &sysctl_node,
		    CTLFLAG_READONLY | CTLFLAG_OWNDESC,
		    CTLTYPE_INT, "zone", "fan zone",
		    NULL, 0, &fan->zone, 0,
		    CTL_MACHDEP,
		    sc->sc_sysctl_me->sysctl_num,
		    sysctl_fans->sysctl_num,
		    sysctl_fan->sysctl_num,
		    CTL_CREATE, CTL_EOL);

		sysctl_createv(NULL, 0, NULL, (void *) &sysctl_node,
		    CTLFLAG_READONLY | CTLFLAG_OWNDESC,
		    CTLTYPE_INT, "min_rpm", "fan minimum rpm",
		    NULL, 0, &fan->min_rpm, 0,
		    CTL_MACHDEP,
		    sc->sc_sysctl_me->sysctl_num,
		    sysctl_fans->sysctl_num,
		    sysctl_fan->sysctl_num,
		    CTL_CREATE, CTL_EOL);

		sysctl_createv(NULL, 0, NULL, (void *) &sysctl_node,
		    CTLFLAG_READONLY | CTLFLAG_OWNDESC,
		    CTLTYPE_INT, "max_rpm", "fan maximum rpm",
		    NULL, 0, &fan->max_rpm, 0,
		    CTL_MACHDEP,
		    sc->sc_sysctl_me->sysctl_num,
		    sysctl_fans->sysctl_num,
		    sysctl_fan->sysctl_num,
		    CTL_CREATE, CTL_EOL);

		sysctl_createv(NULL, 0, NULL, (void *) &sysctl_node,
		    CTLFLAG_READONLY | CTLFLAG_OWNDESC,
		    CTLTYPE_INT, "default_rpm", "fan default rpm",
		    NULL, 0, &fan->default_rpm, 0,
		    CTL_MACHDEP,
		    sc->sc_sysctl_me->sysctl_num,
		    sysctl_fans->sysctl_num,
		    sysctl_fan->sysctl_num,
		    CTL_CREATE, CTL_EOL);

		sysctl_createv(NULL, 0, NULL, (void *) &sysctl_node,
		    CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
		    CTLTYPE_INT, "rpm", "fan current rpm",
		    smu_sysctl_fan_rpm, 0, (void *) fan, 0,
		    CTL_MACHDEP,
		    sc->sc_sysctl_me->sysctl_num,
		    sysctl_fans->sysctl_num,
		    sysctl_fan->sysctl_num,
		    CTL_CREATE, CTL_EOL);
	}
}

static void
smu_setup_iicbus(struct smu_softc *sc)
{
	struct smu_iicbus *iicbus;
	struct i2c_controller *i2c;
	struct smu_iicbus_confargs ca;
	int node;
	char name[32];

	mutex_init(&sc->sc_iicbus_lock, MUTEX_DEFAULT, IPL_NONE);

	node = of_getnode_byname(sc->sc_node, "smu-i2c-control");
	for (node = OF_child(node);
	    (node != 0) && (sc->sc_num_iicbus < SMU_MAX_IICBUS);
	    node = OF_peer(node)) {
		memset(name, 0, sizeof(name));
		OF_getprop(node, "name", name, sizeof(name));
		if (strcmp(name, "i2c-bus") != 0)
			continue;

		iicbus = &sc->sc_iicbus[sc->sc_num_iicbus];
		iicbus->sc = sc;
		i2c = &iicbus->i2c;

		if (OF_getprop(node, "reg", &iicbus->reg, sizeof(iicbus->reg)) <= 0)
			continue;

		DPRINTF("iicbus: reg %x\n", iicbus->reg);

		i2c->ic_cookie = iicbus;
		i2c->ic_acquire_bus = smu_iicbus_acquire_bus;
		i2c->ic_release_bus = smu_iicbus_release_bus;
		i2c->ic_send_start = NULL;
		i2c->ic_send_stop = NULL;
		i2c->ic_initiate_xfer = NULL;
		i2c->ic_read_byte = NULL;
		i2c->ic_write_byte = NULL;
		i2c->ic_exec = smu_iicbus_exec;

		ca.ca_name = name;
		ca.ca_node = node;
		ca.ca_tag = i2c;
		config_found_ia(sc->sc_dev, "smu", &ca, smu_iicbus_print);

		sc->sc_num_iicbus++;
	}
}

static void
smu_setup_sme(struct smu_softc *sc)
{
	struct smu_fan *fan;
	envsys_data_t *sme_sensor;
	int i;

	sc->sc_sme = sysmon_envsys_create();

	for (i = 0; i < sc->sc_num_fans; i++) {
		sme_sensor = &sc->sc_sme_sensors[i];
		fan = &sc->sc_fans[i];

		sme_sensor->units = ENVSYS_SFANRPM;
		sme_sensor->state = ENVSYS_SINVALID;
		snprintf(sme_sensor->desc, sizeof(sme_sensor->desc),
		    "%s", fan->location);

		if (sysmon_envsys_sensor_attach(sc->sc_sme, sme_sensor)) {
			sysmon_envsys_destroy(sc->sc_sme);
			return;
		}
	}

	sc->sc_sme->sme_name = device_xname(sc->sc_dev);
	sc->sc_sme->sme_cookie = sc;
	sc->sc_sme->sme_refresh = smu_sme_refresh;

	if (sysmon_envsys_register(sc->sc_sme)) {
		aprint_error_dev(sc->sc_dev,
		    "unable to register with sysmon\n");
		sysmon_envsys_destroy(sc->sc_sme);
	}
}

static int
smu_iicbus_print(void *aux, const char *smu)
{
	struct smu_iicbus_confargs *ca = aux;

	if (smu)
		aprint_normal("%s at %s", ca->ca_name, smu);

	return UNCONF;
}

static void
smu_sme_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
	struct smu_softc *sc = sme->sme_cookie;
	struct smu_fan *fan;
	int which = edata->sensor;
	int ret;

	edata->state = ENVSYS_SINVALID;

	if (which < sc->sc_num_fans) {
		fan = &sc->sc_fans[which];

		ret = smu_fan_get_rpm(fan, &fan->current_rpm);
		if (ret == 0) {
			edata->value_cur = fan->current_rpm;
			edata->state = ENVSYS_SVALID;
		}
	}
}

static int
smu_do_cmd(struct smu_softc *sc, struct smu_cmd *cmd, int timo)
{
	int gpio, ret, bail;
	u_char ack;

	mutex_enter(&sc->sc_cmd_lock);

	DPRINTF("%s: cmd %02x len %02x\n", __func__, cmd->cmd, cmd->len);
	DPRINTF("%s: data %02x %02x %02x %02x %02x %02x %02x %02x\n", __func__,
	    cmd->data[0], cmd->data[1], cmd->data[2], cmd->data[3],
	    cmd->data[4], cmd->data[5], cmd->data[6], cmd->data[7]);

	sc->sc_cmd->cmd = cmd->cmd;
	sc->sc_cmd->len = cmd->len;
	memcpy(sc->sc_cmd->data, cmd->data, cmd->len);

	__asm volatile ("dcbf 0,%0; sync" :: "r"(sc->sc_cmd) : "memory");

	obio_write_4(sc->sc_dbell_mbox, sc->sc_cmd_paddr);
	obio_write_1(sc->sc_dbell_gpio, 0x04);

	bail = 0;

	gpio = obio_read_1(sc->sc_dbell_gpio);

	while (((gpio & 0x07) != 0x07) && (bail < timo)) {
		ret = tsleep(sc->sc_cmd, PWAIT, "smu_cmd", mstohz(10));
		if (ret != 0) {
			bail++;
		}
		gpio = obio_read_1(sc->sc_dbell_gpio);
	}

	if ((gpio & 0x07) != 0x07) {
		mutex_exit(&sc->sc_cmd_lock);
		return EWOULDBLOCK;
	}

	__asm volatile ("dcbf 0,%0; sync" :: "r"(sc->sc_cmd) : "memory");

	ack = (~cmd->cmd) & 0xff;
	if (sc->sc_cmd->cmd != ack) {
		DPRINTF("%s: invalid ack, got %x expected %x\n",
		    __func__, sc->sc_cmd->cmd, ack);
		mutex_exit(&sc->sc_cmd_lock);
		return EIO;
	}

	cmd->cmd = sc->sc_cmd->cmd;
	cmd->len = sc->sc_cmd->len;
	memcpy(cmd->data, sc->sc_cmd->data, sc->sc_cmd->len);

	mutex_exit(&sc->sc_cmd_lock);

	return 0;
}


static int
smu_dbell_gpio_intr(void *arg)
{
	struct smu_softc *sc = arg;

	DPRINTF("%s\n", __func__);

	wakeup(sc->sc_cmd);

	return 1;
}

void
smu_poweroff(void)
{
	struct smu_cmd cmd;

	if (smu0 == NULL)
		return;

	cmd.cmd = SMU_CMD_POWER;
	strcpy(cmd.data, "SHUTDOWN");
	cmd.len = strlen(cmd.data) + 1;
	smu_do_cmd(smu0, &cmd, 800);

	for (;;);
}

void
smu_restart(void)
{
	struct smu_cmd cmd;

	if (smu0 == NULL)
		return;

	cmd.cmd = SMU_CMD_POWER;
	strcpy(cmd.data, "RESTART");
	cmd.len = strlen(cmd.data) + 1;
	smu_do_cmd(smu0, &cmd, 800);

	for (;;);
}

static int
smu_todr_gettime_ymdhms(todr_chip_handle_t tch, struct clock_ymdhms *dt)
{
	struct smu_softc *sc = tch->cookie;
	struct smu_cmd cmd;
	int ret;

	cmd.cmd = SMU_CMD_RTC;
	cmd.len = 1;
	cmd.data[0] = 0x81;

	ret = smu_do_cmd(sc, &cmd, 800);
	if (ret != 0)
		return ret;

	dt->dt_sec = bcdtobin(cmd.data[0]);
	dt->dt_min = bcdtobin(cmd.data[1]);
	dt->dt_hour = bcdtobin(cmd.data[2]);
	dt->dt_wday = bcdtobin(cmd.data[3]);
	dt->dt_day = bcdtobin(cmd.data[4]);
	dt->dt_mon = bcdtobin(cmd.data[5]);
	dt->dt_year = bcdtobin(cmd.data[6]) + 2000;

	return 0;
}

static int
smu_todr_settime_ymdhms(todr_chip_handle_t tch, struct clock_ymdhms *dt)
{
	struct smu_softc *sc = tch->cookie;
	struct smu_cmd cmd;

	cmd.cmd = SMU_CMD_RTC;
	cmd.len = 8;
	cmd.data[0] = 0x80;
	cmd.data[1] = bintobcd(dt->dt_sec);
	cmd.data[2] = bintobcd(dt->dt_min);
	cmd.data[3] = bintobcd(dt->dt_hour);
	cmd.data[4] = bintobcd(dt->dt_wday);
	cmd.data[5] = bintobcd(dt->dt_day);
	cmd.data[6] = bintobcd(dt->dt_mon);
	cmd.data[7] = bintobcd(dt->dt_year - 2000);

	return smu_do_cmd(sc, &cmd, 800);
}

static int
smu_fan_update_rpm(struct smu_fan *fan)
{
	struct smu_softc *sc = fan->sc;
	struct smu_cmd cmd;
	int ret;

	cmd.cmd = SMU_CMD_FAN;
	cmd.len = 2;
	cmd.data[0] = 0x31;
	cmd.data[1] = fan->reg;

	ret = smu_do_cmd(sc, &cmd, 800);
	if (ret == 0) {
		fan->last_update = time_uptime;
		fan->current_rpm = (cmd.data[0] << 8) | cmd.data[1];
	} else {
		cmd.cmd = SMU_CMD_FAN;
		cmd.len = 1;
		cmd.data[0] = 0x01;

		ret = smu_do_cmd(sc, &cmd, 800);
		if (ret == 0) {
			fan->last_update = time_uptime;
			fan->current_rpm = (cmd.data[1 + fan->reg * 2] << 8) |
			    cmd.data[2 + fan->reg * 2];
		}
	}

	return ret;
}

static int
smu_fan_get_rpm(struct smu_fan *fan, int *rpm)
{
	int ret;

	if (time_uptime - fan->last_update > 1) {
		ret = smu_fan_update_rpm(fan);
		if (ret != 0)
			return ret;
	}

	*rpm = fan->current_rpm;

	return ret;
}

static int
smu_fan_set_rpm(struct smu_fan *fan, int rpm)
{
	struct smu_softc *sc = fan->sc;
	struct smu_cmd cmd;
	int ret;

	DPRINTF("%s: fan %s rpm %d\n", __func__, fan->location, rpm);

	rpm = max(fan->min_rpm, rpm);
	rpm = min(fan->max_rpm, rpm);

	cmd.cmd = SMU_CMD_FAN;
	cmd.len = 4;
	cmd.data[0] = 0x30;
	cmd.data[1] = fan->reg;
	cmd.data[2] = (rpm >> 8) & 0xff;
	cmd.data[3] = rpm & 0xff;

	ret = smu_do_cmd(sc, &cmd, 800);
	if (ret != 0) {
		cmd.cmd = SMU_CMD_FAN;
		cmd.len = 14;
		cmd.data[0] = fan->rpm_ctl ? 0x00 : 0x10;
		cmd.data[1] = 1 << fan->reg;
		cmd.data[2] = cmd.data[2 + fan->reg * 2] = (rpm >> 8) & 0xff;
		cmd.data[3] = cmd.data[3 + fan->reg * 2] = rpm & 0xff;

		ret = smu_do_cmd(sc, &cmd, 800);
	}

	return ret;
}

static int
smu_iicbus_acquire_bus(void *cookie, int flags)
{
	struct smu_iicbus *iicbus = cookie;
	struct smu_softc *sc = iicbus->sc;

	mutex_enter(&sc->sc_iicbus_lock);

	return 0;
}

static void
smu_iicbus_release_bus(void *cookie, int flags)
{
	struct smu_iicbus *iicbus = cookie;
	struct smu_softc *sc = iicbus->sc;

	mutex_exit(&sc->sc_iicbus_lock);
}

static int
smu_iicbus_exec(void *cookie, i2c_op_t op, i2c_addr_t addr, const void *send,
    size_t send_len, void *recv, size_t recv_len, int flags)
{
	struct smu_iicbus *iicbus = cookie;
	struct smu_softc *sc = iicbus->sc;
	struct smu_cmd cmd;
	int retries, ret;

	DPRINTF("%s: op %x addr %x send_len %d recv_len %d\n",
	    __func__, op, addr, send_len, recv_len);

	cmd.cmd = SMU_CMD_I2C;
	cmd.len = 9 + recv_len;
	cmd.data[0] = iicbus->reg;
	cmd.data[1] = I2C_OP_READ_P(op) ? 0x02 : 0x00;
	cmd.data[2] = addr;
	cmd.data[3] = send_len;
	memcpy(&cmd.data[4], send, send_len);
	cmd.data[7] = addr;
	if (I2C_OP_READ_P(op))
		cmd.data[7] |= 0x01;
	cmd.data[8] = recv_len;
	memcpy(&cmd.data[9], recv, recv_len);

	ret = smu_do_cmd(sc, &cmd, 800);
	if (ret != 0)
		return (ret);

	for (retries = 0; retries < 10; retries++) {
		cmd.cmd = SMU_CMD_I2C;
		cmd.len = 1;
		cmd.data[0] = 0x00;
		memset(&cmd.data[1], 0xff, recv_len);

		ret = smu_do_cmd(sc, &cmd, 800);

		DPRINTF("%s: cmd data[0] %x\n", __func__, cmd.data[0]);

		if (ret == 0 && (cmd.data[0] & 0x80) == 0)
			break;

		DELAY(10000);
	}

	if (cmd.data[0] & 0x80)
		return EIO;

	if (I2C_OP_READ_P(op))
		memcpy(recv, &cmd.data[1], recv_len);

	return 0;
}

static int
smu_sysctl_fan_rpm(SYSCTLFN_ARGS)
{
	struct sysctlnode node = *rnode;
	struct smu_fan *fan = node.sysctl_data;
	int rpm = 0;
	int ret;

	node.sysctl_data = &rpm;

	if (newp) {
		if (sysctl_lookup(SYSCTLFN_CALL(&node)) == 0) {
			rpm = *(int *) node.sysctl_data;
			return smu_fan_set_rpm(fan, rpm);
		}
		return EINVAL;
	} else {
		ret = smu_fan_get_rpm(fan, &rpm);
		if (ret != 0)
			return (ret);

		return sysctl_lookup(SYSCTLFN_CALL(&node));
	}

	return 0;
}

SYSCTL_SETUP(smu_sysctl_setup, "SMU sysctl subtree setup")
{
	sysctl_createv(NULL, 0, NULL, NULL,
	    CTLFLAG_PERMANENT, CTLTYPE_NODE, "machdep", NULL,
	    NULL, 0, NULL, 0, CTL_MACHDEP, CTL_EOL);
}

static void
smu_setup_zones(struct smu_softc *sc)
{
	struct smu_zone *z;
	struct smu_fan *f;
	int i;

	/* find CPU fans */
	z = &sc->sc_zones[SMU_ZONE_CPUS];
	z->nfans = 0;
	for (i = 0; i < SMU_MAX_FANS; i++) {
		f = &sc->sc_fans[i];
		if (strstr(f->location, "CPU") != NULL) {
			z->fans[z->nfans] = i;
			z->nfans++;
		}
	}
	printf("using %d fans for CPU zone\n", z->nfans);
	z->threshold = C_TO_uK(45);
	z->duty = 150;
	z->step = 3;
	z->filter = is_cpu_sensor;

	z = &sc->sc_zones[SMU_ZONE_DRIVES];
	z->nfans = 0;
	for (i = 0; i < SMU_MAX_FANS; i++) {
		f = &sc->sc_fans[i];
		if (strstr(f->location, "DRIVE") != NULL) {
			z->fans[z->nfans] = i;
			z->nfans++;
		}
	}
	printf("using %d fans for drive bay zone\n", z->nfans);
	z->threshold = C_TO_uK(40);
	z->duty = 150;
	z->step = 2;
	z->filter = is_drive_sensor;

	z = &sc->sc_zones[SMU_ZONE_SLOTS];
	z->nfans = 0;
	for (i = 0; i < SMU_MAX_FANS; i++) {
		f = &sc->sc_fans[i];
		if ((strstr(f->location, "BACKSIDE") != NULL) ||
		    (strstr(f->location, "SLOTS") != NULL)) {
			z->fans[z->nfans] = i;
			z->nfans++;
		}
	}
	printf("using %d fans for expansion slots zone\n", z->nfans);
	z->threshold = C_TO_uK(40);
	z->duty = 150;
	z->step = 2;
	z->filter = is_slots_sensor;

	sc->sc_dying = false;
	kthread_create(PRI_NONE, 0, curcpu(), smu_adjust, sc, &sc->sc_thread,
	    "fan control");
}

static void
smu_adjust_zone(struct smu_softc *sc, int which)
{
	struct smu_zone *z = &sc->sc_zones[which];
	struct smu_fan *f;
	long temp, newduty, i, speed, diff;

	DPRINTF("%s %d\n", __func__, which);

	temp = sysmon_envsys_get_max_value(z->filter, true);
	if (temp == 0) {
		/* no sensor data - leave fan alone */
		DPRINTF("nodata\n");
		return;
	}
	DPRINTF("temp %ld ", (temp - 273150000) / 1000000);
	diff = ((temp - z->threshold) / 1000000) * z->step;

	if (diff < 0) newduty = 0;
	else if (diff > 100) newduty = 100;
	else newduty = diff;

	DPRINTF("newduty %ld diff %ld \n", newduty, diff);
	if (newduty == z->duty) {
		DPRINTF("no change\n");
		return;
	}
	z->duty = newduty;
	/* now adjust each fan to the new duty cycle */
	for (i = 0; i < z->nfans; i++) {
		f = &sc->sc_fans[z->fans[i]];
		speed = f->min_rpm + ((f->max_rpm - f->min_rpm) * newduty) / 100;
		DPRINTF("fan %d speed %ld ", z->fans[i], speed);
		smu_fan_set_rpm(f, speed);
	}
	DPRINTF("\n");
}

static void
smu_adjust(void *cookie)
{
	struct smu_softc *sc = cookie;
	int i;

	while (!sc->sc_dying) {
		for (i = 0; i < SMU_ZONES; i++)
			smu_adjust_zone(sc, i);
		kpause("fanctrl", true, mstohz(30000), NULL);
	}
	kthread_exit(0);
}

static bool is_cpu_sensor(const envsys_data_t *edata)
{
	if (edata->units != ENVSYS_STEMP)
		return false;
	if ((strstr(edata->desc, "CPU") != NULL) &&
	    (strstr(edata->desc, "DIODE") != NULL))
		return TRUE;
	if (strstr(edata->desc, "TUNNEL") != NULL)
		return TRUE;
	return false;
}

static bool is_drive_sensor(const envsys_data_t *edata)
{
	if (edata->units != ENVSYS_STEMP)
		return false;
	if (strstr(edata->desc, "DRIVE BAY") != NULL)
		return TRUE;
	/* XXX until we support the actual drive bay sensor */
	if (strstr(edata->desc, "BACKSIDE") != NULL)
		return TRUE;
	return false;
}

static bool is_slots_sensor(const envsys_data_t *edata)
{
	if (edata->units != ENVSYS_STEMP)
		return false;
	if (strstr(edata->desc, "BACKSIDE") != NULL)
		return TRUE;
	if (strstr(edata->desc, "INLET") != NULL)
		return TRUE;
	return false;
}