linux/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
Tony Lindgren ba817a8cfc thermal: ti-soc-thermal: Fix ti_thermal_unregister_cpu_cooling NULL pointer on unload
While debugging some PM issues and trying to remove all the loaded modules, I ran
across the following when unloading ti-soc-thermal:

Unable to handle kernel NULL pointer dereference at virtual address 000000b4
...
[<c08db340>] (kobject_put) from [<bf28954c>] (ti_thermal_unregister_cpu_cooling+0x20/0x28 [ti_soc_thermal])
[<bf28954c>] (ti_thermal_unregister_cpu_cooling [ti_soc_thermal]) from [<bf287c88>] (ti_bandgap_remove+0x3c/0x104 [ti_soc_thermal])
[<bf287c88>] (ti_bandgap_remove [ti_soc_thermal]) from [<c0610d48>] (platform_drv_remove+0x24/0x3c)
[<c0610d48>] (platform_drv_remove) from [<c060f114>] (device_release_driver_internal+0x160/0x208)
[<c060f114>] (device_release_driver_internal) from [<c060f200>] (driver_detach+0x38/0x6c)
[<c060f200>] (driver_detach) from [<c060e2d4>] (bus_remove_driver+0x4c/0xa0)
[<c060e2d4>] (bus_remove_driver) from [<c01f2370>] (SyS_delete_module+0x168/0x238)
[<c01f2370>] (SyS_delete_module) from [<c0108240>] (ret_fast_syscall+0x0/0x28)

Cc: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-10-31 19:32:14 -07:00

287 lines
6.8 KiB
C

/*
* OMAP thermal driver interface
*
* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
* Contact:
* Eduardo Valentin <eduardo.valentin@ti.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/workqueue.h>
#include <linux/thermal.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/cpu_cooling.h>
#include <linux/of.h>
#include "ti-thermal.h"
#include "ti-bandgap.h"
/* common data structures */
struct ti_thermal_data {
struct cpufreq_policy *policy;
struct thermal_zone_device *ti_thermal;
struct thermal_zone_device *pcb_tz;
struct thermal_cooling_device *cool_dev;
struct ti_bandgap *bgp;
enum thermal_device_mode mode;
struct work_struct thermal_wq;
int sensor_id;
bool our_zone;
};
static void ti_thermal_work(struct work_struct *work)
{
struct ti_thermal_data *data = container_of(work,
struct ti_thermal_data, thermal_wq);
thermal_zone_device_update(data->ti_thermal, THERMAL_EVENT_UNSPECIFIED);
dev_dbg(&data->ti_thermal->device, "updated thermal zone %s\n",
data->ti_thermal->type);
}
/**
* ti_thermal_hotspot_temperature - returns sensor extrapolated temperature
* @t: omap sensor temperature
* @s: omap sensor slope value
* @c: omap sensor const value
*/
static inline int ti_thermal_hotspot_temperature(int t, int s, int c)
{
int delta = t * s / 1000 + c;
if (delta < 0)
delta = 0;
return t + delta;
}
/* thermal zone ops */
/* Get temperature callback function for thermal zone */
static inline int __ti_thermal_get_temp(void *devdata, int *temp)
{
struct thermal_zone_device *pcb_tz = NULL;
struct ti_thermal_data *data = devdata;
struct ti_bandgap *bgp;
const struct ti_temp_sensor *s;
int ret, tmp, slope, constant;
int pcb_temp;
if (!data)
return 0;
bgp = data->bgp;
s = &bgp->conf->sensors[data->sensor_id];
ret = ti_bandgap_read_temperature(bgp, data->sensor_id, &tmp);
if (ret)
return ret;
/* Default constants */
slope = thermal_zone_get_slope(data->ti_thermal);
constant = thermal_zone_get_offset(data->ti_thermal);
pcb_tz = data->pcb_tz;
/* In case pcb zone is available, use the extrapolation rule with it */
if (!IS_ERR(pcb_tz)) {
ret = thermal_zone_get_temp(pcb_tz, &pcb_temp);
if (!ret) {
tmp -= pcb_temp; /* got a valid PCB temp */
slope = s->slope_pcb;
constant = s->constant_pcb;
} else {
dev_err(bgp->dev,
"Failed to read PCB state. Using defaults\n");
ret = 0;
}
}
*temp = ti_thermal_hotspot_temperature(tmp, slope, constant);
return ret;
}
static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal,
int *temp)
{
struct ti_thermal_data *data = thermal->devdata;
return __ti_thermal_get_temp(data, temp);
}
static int __ti_thermal_get_trend(void *p, int trip, enum thermal_trend *trend)
{
struct ti_thermal_data *data = p;
struct ti_bandgap *bgp;
int id, tr, ret = 0;
bgp = data->bgp;
id = data->sensor_id;
ret = ti_bandgap_get_trend(bgp, id, &tr);
if (ret)
return ret;
if (tr > 0)
*trend = THERMAL_TREND_RAISING;
else if (tr < 0)
*trend = THERMAL_TREND_DROPPING;
else
*trend = THERMAL_TREND_STABLE;
return 0;
}
static const struct thermal_zone_of_device_ops ti_of_thermal_ops = {
.get_temp = __ti_thermal_get_temp,
.get_trend = __ti_thermal_get_trend,
};
static struct ti_thermal_data
*ti_thermal_build_data(struct ti_bandgap *bgp, int id)
{
struct ti_thermal_data *data;
data = devm_kzalloc(bgp->dev, sizeof(*data), GFP_KERNEL);
if (!data) {
dev_err(bgp->dev, "kzalloc fail\n");
return NULL;
}
data->sensor_id = id;
data->bgp = bgp;
data->mode = THERMAL_DEVICE_ENABLED;
/* pcb_tz will be either valid or PTR_ERR() */
data->pcb_tz = thermal_zone_get_zone_by_name("pcb");
INIT_WORK(&data->thermal_wq, ti_thermal_work);
return data;
}
int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id,
char *domain)
{
struct ti_thermal_data *data;
data = ti_bandgap_get_sensor_data(bgp, id);
if (!data || IS_ERR(data))
data = ti_thermal_build_data(bgp, id);
if (!data)
return -EINVAL;
/* in case this is specified by DT */
data->ti_thermal = devm_thermal_zone_of_sensor_register(bgp->dev, id,
data, &ti_of_thermal_ops);
if (IS_ERR(data->ti_thermal)) {
dev_err(bgp->dev, "thermal zone device is NULL\n");
return PTR_ERR(data->ti_thermal);
}
ti_bandgap_set_sensor_data(bgp, id, data);
ti_bandgap_write_update_interval(bgp, data->sensor_id,
data->ti_thermal->polling_delay);
return 0;
}
int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id)
{
struct ti_thermal_data *data;
data = ti_bandgap_get_sensor_data(bgp, id);
if (data && data->ti_thermal) {
if (data->our_zone)
thermal_zone_device_unregister(data->ti_thermal);
}
return 0;
}
int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id)
{
struct ti_thermal_data *data;
data = ti_bandgap_get_sensor_data(bgp, id);
schedule_work(&data->thermal_wq);
return 0;
}
int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id)
{
struct ti_thermal_data *data;
struct device_node *np = bgp->dev->of_node;
/*
* We are assuming here that if one deploys the zone
* using DT, then it must be aware that the cooling device
* loading has to happen via cpufreq driver.
*/
if (of_find_property(np, "#thermal-sensor-cells", NULL))
return 0;
data = ti_bandgap_get_sensor_data(bgp, id);
if (!data || IS_ERR(data))
data = ti_thermal_build_data(bgp, id);
if (!data)
return -EINVAL;
data->policy = cpufreq_cpu_get(0);
if (!data->policy) {
pr_debug("%s: CPUFreq policy not found\n", __func__);
return -EPROBE_DEFER;
}
/* Register cooling device */
data->cool_dev = cpufreq_cooling_register(data->policy);
if (IS_ERR(data->cool_dev)) {
int ret = PTR_ERR(data->cool_dev);
dev_err(bgp->dev, "Failed to register cpu cooling device %d\n",
ret);
cpufreq_cpu_put(data->policy);
return ret;
}
ti_bandgap_set_sensor_data(bgp, id, data);
return 0;
}
int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
{
struct ti_thermal_data *data;
data = ti_bandgap_get_sensor_data(bgp, id);
if (data) {
cpufreq_cooling_unregister(data->cool_dev);
if (data->policy)
cpufreq_cpu_put(data->policy);
}
return 0;
}