linux/drivers/thermal/rcar_thermal.c
Patrick Titiano 9477165ec5 thermal: rcar-thermal: update thermal zone only when temperature changes
Avoid updating the thermal zone in case an IRQ was triggered but the
temperature didn't effectively change.
Note this is not a driver issue.
Below is a captured debug trace illustrating the purpose of this patch:
out of 8 thermal zone updates, only 2 are actually necessary.

[   41.120000] rcar_thermal_work(): cctemp=25000
[   41.120000] rcar_thermal_work(): nctemp=30000
[   41.120000] rcar_thermal_work(): temp is now 30000C, update thermal zone
[   58.990000] rcar_thermal_work(): cctemp=30000
[   58.990000] rcar_thermal_work(): nctemp=30000
[   58.990000] rcar_thermal_work(): same temp, do not update thermal zone
[   59.290000] rcar_thermal_work(): cctemp=30000
[   59.290000] rcar_thermal_work(): nctemp=30000
[   59.290000] rcar_thermal_work(): same temp, do not update thermal zone
[   59.590000] rcar_thermal_work(): cctemp=30000
[   59.590000] rcar_thermal_work(): nctemp=30000
[   59.590000] rcar_thermal_work(): same temp, do not update thermal zone
[   59.890000] rcar_thermal_work(): cctemp=30000
[   59.890000] rcar_thermal_work(): nctemp=30000
[   59.890000] rcar_thermal_work(): same temp, do not update thermal zone
[   60.190000] rcar_thermal_work(): cctemp=30000
[   60.190000] rcar_thermal_work(): nctemp=30000
[   60.190000] rcar_thermal_work(): same temp, do not update thermal zone
[   60.490000] rcar_thermal_work(): cctemp=30000
[   60.490000] rcar_thermal_work(): nctemp=30000
[   60.490000] rcar_thermal_work(): same temp, do not update thermal zone
[   60.790000] rcar_thermal_work(): cctemp=30000
[   60.790000] rcar_thermal_work(): nctemp=35000
[   60.790000] rcar_thermal_work(): temp is now 35000C, update thermal zone

I suspect this may be due to sensor sampling accuracy / fluctuation,
but no formal proof.

Signed-off-by: Patrick Titiano <ptitiano@baylibre.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2014-04-08 09:01:39 +08:00

516 lines
12 KiB
C

/*
* R-Car THS/TSC thermal sensor driver
*
* Copyright (C) 2012 Renesas Solutions Corp.
* Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/thermal.h>
#define IDLE_INTERVAL 5000
#define COMMON_STR 0x00
#define COMMON_ENR 0x04
#define COMMON_INTMSK 0x0c
#define REG_POSNEG 0x20
#define REG_FILONOFF 0x28
#define REG_THSCR 0x2c
#define REG_THSSR 0x30
#define REG_INTCTRL 0x34
/* THSCR */
#define CPCTL (1 << 12)
/* THSSR */
#define CTEMP 0x3f
struct rcar_thermal_common {
void __iomem *base;
struct device *dev;
struct list_head head;
spinlock_t lock;
};
struct rcar_thermal_priv {
void __iomem *base;
struct rcar_thermal_common *common;
struct thermal_zone_device *zone;
struct delayed_work work;
struct mutex lock;
struct list_head list;
int id;
int ctemp;
};
#define rcar_thermal_for_each_priv(pos, common) \
list_for_each_entry(pos, &common->head, list)
#define MCELSIUS(temp) ((temp) * 1000)
#define rcar_zone_to_priv(zone) ((zone)->devdata)
#define rcar_priv_to_dev(priv) ((priv)->common->dev)
#define rcar_has_irq_support(priv) ((priv)->common->base)
#define rcar_id_to_shift(priv) ((priv)->id * 8)
#ifdef DEBUG
# define rcar_force_update_temp(priv) 1
#else
# define rcar_force_update_temp(priv) 0
#endif
/*
* basic functions
*/
#define rcar_thermal_common_read(c, r) \
_rcar_thermal_common_read(c, COMMON_ ##r)
static u32 _rcar_thermal_common_read(struct rcar_thermal_common *common,
u32 reg)
{
return ioread32(common->base + reg);
}
#define rcar_thermal_common_write(c, r, d) \
_rcar_thermal_common_write(c, COMMON_ ##r, d)
static void _rcar_thermal_common_write(struct rcar_thermal_common *common,
u32 reg, u32 data)
{
iowrite32(data, common->base + reg);
}
#define rcar_thermal_common_bset(c, r, m, d) \
_rcar_thermal_common_bset(c, COMMON_ ##r, m, d)
static void _rcar_thermal_common_bset(struct rcar_thermal_common *common,
u32 reg, u32 mask, u32 data)
{
u32 val;
val = ioread32(common->base + reg);
val &= ~mask;
val |= (data & mask);
iowrite32(val, common->base + reg);
}
#define rcar_thermal_read(p, r) _rcar_thermal_read(p, REG_ ##r)
static u32 _rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg)
{
return ioread32(priv->base + reg);
}
#define rcar_thermal_write(p, r, d) _rcar_thermal_write(p, REG_ ##r, d)
static void _rcar_thermal_write(struct rcar_thermal_priv *priv,
u32 reg, u32 data)
{
iowrite32(data, priv->base + reg);
}
#define rcar_thermal_bset(p, r, m, d) _rcar_thermal_bset(p, REG_ ##r, m, d)
static void _rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg,
u32 mask, u32 data)
{
u32 val;
val = ioread32(priv->base + reg);
val &= ~mask;
val |= (data & mask);
iowrite32(val, priv->base + reg);
}
/*
* zone device functions
*/
static int rcar_thermal_update_temp(struct rcar_thermal_priv *priv)
{
struct device *dev = rcar_priv_to_dev(priv);
int i;
int ctemp, old, new;
int ret = -EINVAL;
mutex_lock(&priv->lock);
/*
* TSC decides a value of CPTAP automatically,
* and this is the conditions which validate interrupt.
*/
rcar_thermal_bset(priv, THSCR, CPCTL, CPCTL);
ctemp = 0;
old = ~0;
for (i = 0; i < 128; i++) {
/*
* we need to wait 300us after changing comparator offset
* to get stable temperature.
* see "Usage Notes" on datasheet
*/
udelay(300);
new = rcar_thermal_read(priv, THSSR) & CTEMP;
if (new == old) {
ctemp = new;
break;
}
old = new;
}
if (!ctemp) {
dev_err(dev, "thermal sensor was broken\n");
goto err_out_unlock;
}
/*
* enable IRQ
*/
if (rcar_has_irq_support(priv)) {
rcar_thermal_write(priv, FILONOFF, 0);
/* enable Rising/Falling edge interrupt */
rcar_thermal_write(priv, POSNEG, 0x1);
rcar_thermal_write(priv, INTCTRL, (((ctemp - 0) << 8) |
((ctemp - 1) << 0)));
}
dev_dbg(dev, "thermal%d %d -> %d\n", priv->id, priv->ctemp, ctemp);
priv->ctemp = ctemp;
ret = 0;
err_out_unlock:
mutex_unlock(&priv->lock);
return ret;
}
static int rcar_thermal_get_temp(struct thermal_zone_device *zone,
unsigned long *temp)
{
struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
if (!rcar_has_irq_support(priv) || rcar_force_update_temp(priv))
rcar_thermal_update_temp(priv);
mutex_lock(&priv->lock);
*temp = MCELSIUS((priv->ctemp * 5) - 65);
mutex_unlock(&priv->lock);
return 0;
}
static int rcar_thermal_get_trip_type(struct thermal_zone_device *zone,
int trip, enum thermal_trip_type *type)
{
struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
struct device *dev = rcar_priv_to_dev(priv);
/* see rcar_thermal_get_temp() */
switch (trip) {
case 0: /* +90 <= temp */
*type = THERMAL_TRIP_CRITICAL;
break;
default:
dev_err(dev, "rcar driver trip error\n");
return -EINVAL;
}
return 0;
}
static int rcar_thermal_get_trip_temp(struct thermal_zone_device *zone,
int trip, unsigned long *temp)
{
struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
struct device *dev = rcar_priv_to_dev(priv);
/* see rcar_thermal_get_temp() */
switch (trip) {
case 0: /* +90 <= temp */
*temp = MCELSIUS(90);
break;
default:
dev_err(dev, "rcar driver trip error\n");
return -EINVAL;
}
return 0;
}
static int rcar_thermal_notify(struct thermal_zone_device *zone,
int trip, enum thermal_trip_type type)
{
struct rcar_thermal_priv *priv = rcar_zone_to_priv(zone);
struct device *dev = rcar_priv_to_dev(priv);
switch (type) {
case THERMAL_TRIP_CRITICAL:
/* FIXME */
dev_warn(dev, "Thermal reached to critical temperature\n");
break;
default:
break;
}
return 0;
}
static struct thermal_zone_device_ops rcar_thermal_zone_ops = {
.get_temp = rcar_thermal_get_temp,
.get_trip_type = rcar_thermal_get_trip_type,
.get_trip_temp = rcar_thermal_get_trip_temp,
.notify = rcar_thermal_notify,
};
/*
* interrupt
*/
#define rcar_thermal_irq_enable(p) _rcar_thermal_irq_ctrl(p, 1)
#define rcar_thermal_irq_disable(p) _rcar_thermal_irq_ctrl(p, 0)
static void _rcar_thermal_irq_ctrl(struct rcar_thermal_priv *priv, int enable)
{
struct rcar_thermal_common *common = priv->common;
unsigned long flags;
u32 mask = 0x3 << rcar_id_to_shift(priv); /* enable Rising/Falling */
spin_lock_irqsave(&common->lock, flags);
rcar_thermal_common_bset(common, INTMSK, mask, enable ? 0 : mask);
spin_unlock_irqrestore(&common->lock, flags);
}
static void rcar_thermal_work(struct work_struct *work)
{
struct rcar_thermal_priv *priv;
unsigned long cctemp, nctemp;
priv = container_of(work, struct rcar_thermal_priv, work.work);
rcar_thermal_get_temp(priv->zone, &cctemp);
rcar_thermal_update_temp(priv);
rcar_thermal_irq_enable(priv);
rcar_thermal_get_temp(priv->zone, &nctemp);
if (nctemp != cctemp)
thermal_zone_device_update(priv->zone);
}
static u32 rcar_thermal_had_changed(struct rcar_thermal_priv *priv, u32 status)
{
struct device *dev = rcar_priv_to_dev(priv);
status = (status >> rcar_id_to_shift(priv)) & 0x3;
if (status) {
dev_dbg(dev, "thermal%d %s%s\n",
priv->id,
(status & 0x2) ? "Rising " : "",
(status & 0x1) ? "Falling" : "");
}
return status;
}
static irqreturn_t rcar_thermal_irq(int irq, void *data)
{
struct rcar_thermal_common *common = data;
struct rcar_thermal_priv *priv;
unsigned long flags;
u32 status, mask;
spin_lock_irqsave(&common->lock, flags);
mask = rcar_thermal_common_read(common, INTMSK);
status = rcar_thermal_common_read(common, STR);
rcar_thermal_common_write(common, STR, 0x000F0F0F & mask);
spin_unlock_irqrestore(&common->lock, flags);
status = status & ~mask;
/*
* check the status
*/
rcar_thermal_for_each_priv(priv, common) {
if (rcar_thermal_had_changed(priv, status)) {
rcar_thermal_irq_disable(priv);
schedule_delayed_work(&priv->work,
msecs_to_jiffies(300));
}
}
return IRQ_HANDLED;
}
/*
* platform functions
*/
static int rcar_thermal_probe(struct platform_device *pdev)
{
struct rcar_thermal_common *common;
struct rcar_thermal_priv *priv;
struct device *dev = &pdev->dev;
struct resource *res, *irq;
int mres = 0;
int i;
int ret = -ENODEV;
int idle = IDLE_INTERVAL;
common = devm_kzalloc(dev, sizeof(*common), GFP_KERNEL);
if (!common) {
dev_err(dev, "Could not allocate common\n");
return -ENOMEM;
}
INIT_LIST_HEAD(&common->head);
spin_lock_init(&common->lock);
common->dev = dev;
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (irq) {
int ret;
/*
* platform has IRQ support.
* Then, drier use common register
*/
ret = devm_request_irq(dev, irq->start, rcar_thermal_irq, 0,
dev_name(dev), common);
if (ret) {
dev_err(dev, "irq request failed\n ");
return ret;
}
/*
* rcar_has_irq_support() will be enabled
*/
res = platform_get_resource(pdev, IORESOURCE_MEM, mres++);
common->base = devm_ioremap_resource(dev, res);
if (IS_ERR(common->base))
return PTR_ERR(common->base);
/* enable temperature comparation */
rcar_thermal_common_write(common, ENR, 0x00030303);
idle = 0; /* polling delay is not needed */
}
for (i = 0;; i++) {
res = platform_get_resource(pdev, IORESOURCE_MEM, mres++);
if (!res)
break;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv) {
dev_err(dev, "Could not allocate priv\n");
ret = -ENOMEM;
goto error_unregister;
}
priv->base = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->base)) {
ret = PTR_ERR(priv->base);
goto error_unregister;
}
priv->common = common;
priv->id = i;
mutex_init(&priv->lock);
INIT_LIST_HEAD(&priv->list);
INIT_DELAYED_WORK(&priv->work, rcar_thermal_work);
rcar_thermal_update_temp(priv);
priv->zone = thermal_zone_device_register("rcar_thermal",
1, 0, priv,
&rcar_thermal_zone_ops, NULL, 0,
idle);
if (IS_ERR(priv->zone)) {
dev_err(dev, "can't register thermal zone\n");
ret = PTR_ERR(priv->zone);
goto error_unregister;
}
if (rcar_has_irq_support(priv))
rcar_thermal_irq_enable(priv);
list_move_tail(&priv->list, &common->head);
}
platform_set_drvdata(pdev, common);
dev_info(dev, "%d sensor probed\n", i);
return 0;
error_unregister:
rcar_thermal_for_each_priv(priv, common) {
thermal_zone_device_unregister(priv->zone);
if (rcar_has_irq_support(priv))
rcar_thermal_irq_disable(priv);
}
pm_runtime_put_sync(dev);
pm_runtime_disable(dev);
return ret;
}
static int rcar_thermal_remove(struct platform_device *pdev)
{
struct rcar_thermal_common *common = platform_get_drvdata(pdev);
struct device *dev = &pdev->dev;
struct rcar_thermal_priv *priv;
rcar_thermal_for_each_priv(priv, common) {
thermal_zone_device_unregister(priv->zone);
if (rcar_has_irq_support(priv))
rcar_thermal_irq_disable(priv);
}
pm_runtime_put_sync(dev);
pm_runtime_disable(dev);
return 0;
}
static const struct of_device_id rcar_thermal_dt_ids[] = {
{ .compatible = "renesas,rcar-thermal", },
{},
};
MODULE_DEVICE_TABLE(of, rcar_thermal_dt_ids);
static struct platform_driver rcar_thermal_driver = {
.driver = {
.name = "rcar_thermal",
.of_match_table = rcar_thermal_dt_ids,
},
.probe = rcar_thermal_probe,
.remove = rcar_thermal_remove,
};
module_platform_driver(rcar_thermal_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver");
MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");