// SPDX-License-Identifier: GPL-2.0-only
/*
* Windfarm PowerMac thermal control. FCU fan control
*
* Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
*/
#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/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 using 0 for now which is what therm_pm72 used to do and
* what Darwin -apparently- does based on observed behaviour.
*/
#define RPM_PID_USE_ACTUAL_SPEED 0
/* 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;
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;
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 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 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 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 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, *fcu = pv->i2c->dev.of_node;
int i;
DBG("Looking up FCU controls in device-tree...\n");
for_each_child_of_node(fcu, np) {
int id, type = -1;
const char *loc;
const char *name;
const u32 *reg;
DBG(" control: %pOFn, type: %s\n", np, of_node_get_device_type(np));
/* Detect control type */
if (of_node_is_type(np, "fan-rpm-control") ||
of_node_is_type(np, "fan-rpm"))
type = FCU_FAN_RPM;
if (of_node_is_type(np, "fan-pwm-control") ||
of_node_is_type(np, "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_warn("wf_fcu: Can't parse fan ID in device-tree for %pOF\n", np);
break;
}
wf_fcu_add_fan(pv, name, type, id);
break;
}
}
}
static void 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 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 wf_fcu_probe(struct i2c_client *client)
{
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 void 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);
}
static const struct i2c_device_id wf_fcu_id[] = {
{ "MAC,fcu" },
{ }
};
MODULE_DEVICE_TABLE(i2c, wf_fcu_id);
static const struct of_device_id wf_fcu_of_id[] = {
{ .compatible = "fcu", },
{ }
};
MODULE_DEVICE_TABLE(of, wf_fcu_of_id);
static struct i2c_driver wf_fcu_driver = {
.driver = {
.name = "wf_fcu",
.of_match_table = wf_fcu_of_id,
},
.probe = wf_fcu_probe,
.remove = wf_fcu_remove,
.id_table = wf_fcu_id,
};
module_i2c_driver(wf_fcu_driver);
MODULE_AUTHOR("Benjamin Herrenschmidt <[email protected]>");
MODULE_DESCRIPTION("FCU control objects for PowerMacs thermal control");
MODULE_LICENSE("GPL");
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