linux/drivers/hwmon/gpio-fan.c

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/*
* gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
*
* Copyright (C) 2010 LaCie
*
* Author: Simon Guinot <sguinot@lacie.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; either version 2 of the License, or
* (at your option) any later version.
*
* 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/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/hwmon.h>
#include <linux/gpio.h>
#include <linux/gpio-fan.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/thermal.h>
struct gpio_fan_data {
struct platform_device *pdev;
struct device *hwmon_dev;
/* Cooling device if any */
struct thermal_cooling_device *cdev;
struct mutex lock; /* lock GPIOs operations. */
int num_ctrl;
unsigned *ctrl;
int num_speed;
struct gpio_fan_speed *speed;
int speed_index;
#ifdef CONFIG_PM_SLEEP
int resume_speed;
#endif
bool pwm_enable;
struct gpio_fan_alarm *alarm;
struct work_struct alarm_work;
};
/*
* Alarm GPIO.
*/
static void fan_alarm_notify(struct work_struct *ws)
{
struct gpio_fan_data *fan_data =
container_of(ws, struct gpio_fan_data, alarm_work);
sysfs_notify(&fan_data->pdev->dev.kobj, NULL, "fan1_alarm");
kobject_uevent(&fan_data->pdev->dev.kobj, KOBJ_CHANGE);
}
static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
{
struct gpio_fan_data *fan_data = dev_id;
schedule_work(&fan_data->alarm_work);
return IRQ_NONE;
}
static ssize_t fan1_alarm_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
struct gpio_fan_alarm *alarm = fan_data->alarm;
hwmon: (gpio-fan) Allow usage of gpio operations that may sleep Certain I2C based GPIO expanders could be used in sleepable context, this results in: [ 115.890569] ------------[ cut here ]------------ [ 115.895422] WARNING: CPU: 0 PID: 1115 at drivers/gpio/gpiolib.c:1370 gpiod_set_raw_value+0x40/0x4c() [ 115.905024] Modules linked in: [ 115.908229] CPU: 0 PID: 1115 Comm: sh Tainted: G W 3.18.0-rc7-next-20141203-dirty #1 [ 115.917461] Hardware name: Generic DRA74X (Flattened Device Tree) [ 115.923876] [<c0015368>] (unwind_backtrace) from [<c00119f4>] (show_stack+0x10/0x14) [ 115.932013] [<c00119f4>] (show_stack) from [<c05b78e8>] (dump_stack+0x78/0x94) [ 115.939594] [<c05b78e8>] (dump_stack) from [<c003de28>] (warn_slowpath_common+0x7c/0xb4) [ 115.948094] [<c003de28>] (warn_slowpath_common) from [<c003de7c>] (warn_slowpath_null+0x1c/0x24) [ 115.957315] [<c003de7c>] (warn_slowpath_null) from [<c03461e8>] (gpiod_set_raw_value+0x40/0x4c) [ 115.966457] [<c03461e8>] (gpiod_set_raw_value) from [<c04866f4>] (set_fan_speed+0x4c/0x64) [ 115.975145] [<c04866f4>] (set_fan_speed) from [<c04868a8>] (set_rpm+0x98/0xac) [ 115.982742] [<c04868a8>] (set_rpm) from [<c039fb4c>] (dev_attr_store+0x18/0x24) [ 115.990426] [<c039fb4c>] (dev_attr_store) from [<c01b0a28>] (sysfs_kf_write+0x4c/0x50) [ 115.998742] [<c01b0a28>] (sysfs_kf_write) from [<c01afe1c>] (kernfs_fop_write+0xbc/0x19c) [ 116.007333] [<c01afe1c>] (kernfs_fop_write) from [<c0148cc4>] (vfs_write+0xb0/0x1a0) [ 116.015461] [<c0148cc4>] (vfs_write) from [<c0148fbc>] (SyS_write+0x44/0x84) [ 116.022881] [<c0148fbc>] (SyS_write) from [<c000e5c0>] (ret_fast_syscall+0x0/0x48) [ 116.030833] ---[ end trace 3a0b636123acab82 ]--- So, switch over to sleepable GPIO operations as there is no mandatory need for non-sleepable gpio operations in the fan driver. This allows the fan driver to be used with i2c based gpio expanders such as palmas_gpio. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-12-04 16:58:47 +00:00
int value = gpio_get_value_cansleep(alarm->gpio);
if (alarm->active_low)
value = !value;
return sprintf(buf, "%d\n", value);
}
static DEVICE_ATTR_RO(fan1_alarm);
static int fan_alarm_init(struct gpio_fan_data *fan_data,
struct gpio_fan_alarm *alarm)
{
int err;
int alarm_irq;
struct platform_device *pdev = fan_data->pdev;
fan_data->alarm = alarm;
err = devm_gpio_request(&pdev->dev, alarm->gpio, "GPIO fan alarm");
if (err)
return err;
err = gpio_direction_input(alarm->gpio);
if (err)
return err;
/*
* If the alarm GPIO don't support interrupts, just leave
* without initializing the fail notification support.
*/
alarm_irq = gpio_to_irq(alarm->gpio);
if (alarm_irq < 0)
return 0;
INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
IRQF_SHARED, "GPIO fan alarm", fan_data);
return err;
}
/*
* Control GPIOs.
*/
/* Must be called with fan_data->lock held, except during initialization. */
static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
{
int i;
for (i = 0; i < fan_data->num_ctrl; i++)
hwmon: (gpio-fan) Allow usage of gpio operations that may sleep Certain I2C based GPIO expanders could be used in sleepable context, this results in: [ 115.890569] ------------[ cut here ]------------ [ 115.895422] WARNING: CPU: 0 PID: 1115 at drivers/gpio/gpiolib.c:1370 gpiod_set_raw_value+0x40/0x4c() [ 115.905024] Modules linked in: [ 115.908229] CPU: 0 PID: 1115 Comm: sh Tainted: G W 3.18.0-rc7-next-20141203-dirty #1 [ 115.917461] Hardware name: Generic DRA74X (Flattened Device Tree) [ 115.923876] [<c0015368>] (unwind_backtrace) from [<c00119f4>] (show_stack+0x10/0x14) [ 115.932013] [<c00119f4>] (show_stack) from [<c05b78e8>] (dump_stack+0x78/0x94) [ 115.939594] [<c05b78e8>] (dump_stack) from [<c003de28>] (warn_slowpath_common+0x7c/0xb4) [ 115.948094] [<c003de28>] (warn_slowpath_common) from [<c003de7c>] (warn_slowpath_null+0x1c/0x24) [ 115.957315] [<c003de7c>] (warn_slowpath_null) from [<c03461e8>] (gpiod_set_raw_value+0x40/0x4c) [ 115.966457] [<c03461e8>] (gpiod_set_raw_value) from [<c04866f4>] (set_fan_speed+0x4c/0x64) [ 115.975145] [<c04866f4>] (set_fan_speed) from [<c04868a8>] (set_rpm+0x98/0xac) [ 115.982742] [<c04868a8>] (set_rpm) from [<c039fb4c>] (dev_attr_store+0x18/0x24) [ 115.990426] [<c039fb4c>] (dev_attr_store) from [<c01b0a28>] (sysfs_kf_write+0x4c/0x50) [ 115.998742] [<c01b0a28>] (sysfs_kf_write) from [<c01afe1c>] (kernfs_fop_write+0xbc/0x19c) [ 116.007333] [<c01afe1c>] (kernfs_fop_write) from [<c0148cc4>] (vfs_write+0xb0/0x1a0) [ 116.015461] [<c0148cc4>] (vfs_write) from [<c0148fbc>] (SyS_write+0x44/0x84) [ 116.022881] [<c0148fbc>] (SyS_write) from [<c000e5c0>] (ret_fast_syscall+0x0/0x48) [ 116.030833] ---[ end trace 3a0b636123acab82 ]--- So, switch over to sleepable GPIO operations as there is no mandatory need for non-sleepable gpio operations in the fan driver. This allows the fan driver to be used with i2c based gpio expanders such as palmas_gpio. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-12-04 16:58:47 +00:00
gpio_set_value_cansleep(fan_data->ctrl[i], (ctrl_val >> i) & 1);
}
static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
{
int i;
int ctrl_val = 0;
for (i = 0; i < fan_data->num_ctrl; i++) {
int value;
hwmon: (gpio-fan) Allow usage of gpio operations that may sleep Certain I2C based GPIO expanders could be used in sleepable context, this results in: [ 115.890569] ------------[ cut here ]------------ [ 115.895422] WARNING: CPU: 0 PID: 1115 at drivers/gpio/gpiolib.c:1370 gpiod_set_raw_value+0x40/0x4c() [ 115.905024] Modules linked in: [ 115.908229] CPU: 0 PID: 1115 Comm: sh Tainted: G W 3.18.0-rc7-next-20141203-dirty #1 [ 115.917461] Hardware name: Generic DRA74X (Flattened Device Tree) [ 115.923876] [<c0015368>] (unwind_backtrace) from [<c00119f4>] (show_stack+0x10/0x14) [ 115.932013] [<c00119f4>] (show_stack) from [<c05b78e8>] (dump_stack+0x78/0x94) [ 115.939594] [<c05b78e8>] (dump_stack) from [<c003de28>] (warn_slowpath_common+0x7c/0xb4) [ 115.948094] [<c003de28>] (warn_slowpath_common) from [<c003de7c>] (warn_slowpath_null+0x1c/0x24) [ 115.957315] [<c003de7c>] (warn_slowpath_null) from [<c03461e8>] (gpiod_set_raw_value+0x40/0x4c) [ 115.966457] [<c03461e8>] (gpiod_set_raw_value) from [<c04866f4>] (set_fan_speed+0x4c/0x64) [ 115.975145] [<c04866f4>] (set_fan_speed) from [<c04868a8>] (set_rpm+0x98/0xac) [ 115.982742] [<c04868a8>] (set_rpm) from [<c039fb4c>] (dev_attr_store+0x18/0x24) [ 115.990426] [<c039fb4c>] (dev_attr_store) from [<c01b0a28>] (sysfs_kf_write+0x4c/0x50) [ 115.998742] [<c01b0a28>] (sysfs_kf_write) from [<c01afe1c>] (kernfs_fop_write+0xbc/0x19c) [ 116.007333] [<c01afe1c>] (kernfs_fop_write) from [<c0148cc4>] (vfs_write+0xb0/0x1a0) [ 116.015461] [<c0148cc4>] (vfs_write) from [<c0148fbc>] (SyS_write+0x44/0x84) [ 116.022881] [<c0148fbc>] (SyS_write) from [<c000e5c0>] (ret_fast_syscall+0x0/0x48) [ 116.030833] ---[ end trace 3a0b636123acab82 ]--- So, switch over to sleepable GPIO operations as there is no mandatory need for non-sleepable gpio operations in the fan driver. This allows the fan driver to be used with i2c based gpio expanders such as palmas_gpio. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-12-04 16:58:47 +00:00
value = gpio_get_value_cansleep(fan_data->ctrl[i]);
ctrl_val |= (value << i);
}
return ctrl_val;
}
/* Must be called with fan_data->lock held, except during initialization. */
static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
{
if (fan_data->speed_index == speed_index)
return;
__set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
fan_data->speed_index = speed_index;
}
static int get_fan_speed_index(struct gpio_fan_data *fan_data)
{
int ctrl_val = __get_fan_ctrl(fan_data);
int i;
for (i = 0; i < fan_data->num_speed; i++)
if (fan_data->speed[i].ctrl_val == ctrl_val)
return i;
dev_warn(&fan_data->pdev->dev,
"missing speed array entry for GPIO value 0x%x\n", ctrl_val);
return -ENODEV;
}
static int rpm_to_speed_index(struct gpio_fan_data *fan_data, unsigned long rpm)
{
struct gpio_fan_speed *speed = fan_data->speed;
int i;
for (i = 0; i < fan_data->num_speed; i++)
if (speed[i].rpm >= rpm)
return i;
return fan_data->num_speed - 1;
}
static ssize_t pwm1_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
return sprintf(buf, "%d\n", pwm);
}
static ssize_t pwm1_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
unsigned long pwm;
int speed_index;
int ret = count;
if (kstrtoul(buf, 10, &pwm) || pwm > 255)
return -EINVAL;
mutex_lock(&fan_data->lock);
if (!fan_data->pwm_enable) {
ret = -EPERM;
goto exit_unlock;
}
speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
set_fan_speed(fan_data, speed_index);
exit_unlock:
mutex_unlock(&fan_data->lock);
return ret;
}
static ssize_t pwm1_enable_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", fan_data->pwm_enable);
}
static ssize_t pwm1_enable_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
unsigned long val;
if (kstrtoul(buf, 10, &val) || val > 1)
return -EINVAL;
if (fan_data->pwm_enable == val)
return count;
mutex_lock(&fan_data->lock);
fan_data->pwm_enable = val;
/* Disable manual control mode: set fan at full speed. */
if (val == 0)
set_fan_speed(fan_data, fan_data->num_speed - 1);
mutex_unlock(&fan_data->lock);
return count;
}
static ssize_t pwm1_mode_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "0\n");
}
static ssize_t fan1_min_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
}
static ssize_t fan1_max_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
return sprintf(buf, "%d\n",
fan_data->speed[fan_data->num_speed - 1].rpm);
}
static ssize_t fan1_input_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
}
static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
unsigned long rpm;
int ret = count;
if (kstrtoul(buf, 10, &rpm))
return -EINVAL;
mutex_lock(&fan_data->lock);
if (!fan_data->pwm_enable) {
ret = -EPERM;
goto exit_unlock;
}
set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
exit_unlock:
mutex_unlock(&fan_data->lock);
return ret;
}
static DEVICE_ATTR_RW(pwm1);
static DEVICE_ATTR_RW(pwm1_enable);
static DEVICE_ATTR_RO(pwm1_mode);
static DEVICE_ATTR_RO(fan1_min);
static DEVICE_ATTR_RO(fan1_max);
static DEVICE_ATTR_RO(fan1_input);
static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, fan1_input_show, set_rpm);
static umode_t gpio_fan_is_visible(struct kobject *kobj,
struct attribute *attr, int index)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct gpio_fan_data *data = dev_get_drvdata(dev);
if (index == 0 && !data->alarm)
return 0;
if (index > 0 && !data->ctrl)
return 0;
return attr->mode;
}
static struct attribute *gpio_fan_attributes[] = {
&dev_attr_fan1_alarm.attr, /* 0 */
&dev_attr_pwm1.attr, /* 1 */
&dev_attr_pwm1_enable.attr,
&dev_attr_pwm1_mode.attr,
&dev_attr_fan1_input.attr,
&dev_attr_fan1_target.attr,
&dev_attr_fan1_min.attr,
&dev_attr_fan1_max.attr,
NULL
};
static const struct attribute_group gpio_fan_group = {
.attrs = gpio_fan_attributes,
.is_visible = gpio_fan_is_visible,
};
static const struct attribute_group *gpio_fan_groups[] = {
&gpio_fan_group,
NULL
};
static int fan_ctrl_init(struct gpio_fan_data *fan_data,
struct gpio_fan_platform_data *pdata)
{
struct platform_device *pdev = fan_data->pdev;
int num_ctrl = pdata->num_ctrl;
unsigned *ctrl = pdata->ctrl;
int i, err;
for (i = 0; i < num_ctrl; i++) {
err = devm_gpio_request(&pdev->dev, ctrl[i],
"GPIO fan control");
if (err)
return err;
hwmon: (gpio-fan) Allow usage of gpio operations that may sleep Certain I2C based GPIO expanders could be used in sleepable context, this results in: [ 115.890569] ------------[ cut here ]------------ [ 115.895422] WARNING: CPU: 0 PID: 1115 at drivers/gpio/gpiolib.c:1370 gpiod_set_raw_value+0x40/0x4c() [ 115.905024] Modules linked in: [ 115.908229] CPU: 0 PID: 1115 Comm: sh Tainted: G W 3.18.0-rc7-next-20141203-dirty #1 [ 115.917461] Hardware name: Generic DRA74X (Flattened Device Tree) [ 115.923876] [<c0015368>] (unwind_backtrace) from [<c00119f4>] (show_stack+0x10/0x14) [ 115.932013] [<c00119f4>] (show_stack) from [<c05b78e8>] (dump_stack+0x78/0x94) [ 115.939594] [<c05b78e8>] (dump_stack) from [<c003de28>] (warn_slowpath_common+0x7c/0xb4) [ 115.948094] [<c003de28>] (warn_slowpath_common) from [<c003de7c>] (warn_slowpath_null+0x1c/0x24) [ 115.957315] [<c003de7c>] (warn_slowpath_null) from [<c03461e8>] (gpiod_set_raw_value+0x40/0x4c) [ 115.966457] [<c03461e8>] (gpiod_set_raw_value) from [<c04866f4>] (set_fan_speed+0x4c/0x64) [ 115.975145] [<c04866f4>] (set_fan_speed) from [<c04868a8>] (set_rpm+0x98/0xac) [ 115.982742] [<c04868a8>] (set_rpm) from [<c039fb4c>] (dev_attr_store+0x18/0x24) [ 115.990426] [<c039fb4c>] (dev_attr_store) from [<c01b0a28>] (sysfs_kf_write+0x4c/0x50) [ 115.998742] [<c01b0a28>] (sysfs_kf_write) from [<c01afe1c>] (kernfs_fop_write+0xbc/0x19c) [ 116.007333] [<c01afe1c>] (kernfs_fop_write) from [<c0148cc4>] (vfs_write+0xb0/0x1a0) [ 116.015461] [<c0148cc4>] (vfs_write) from [<c0148fbc>] (SyS_write+0x44/0x84) [ 116.022881] [<c0148fbc>] (SyS_write) from [<c000e5c0>] (ret_fast_syscall+0x0/0x48) [ 116.030833] ---[ end trace 3a0b636123acab82 ]--- So, switch over to sleepable GPIO operations as there is no mandatory need for non-sleepable gpio operations in the fan driver. This allows the fan driver to be used with i2c based gpio expanders such as palmas_gpio. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-12-04 16:58:47 +00:00
err = gpio_direction_output(ctrl[i],
gpio_get_value_cansleep(ctrl[i]));
if (err)
return err;
}
fan_data->num_ctrl = num_ctrl;
fan_data->ctrl = ctrl;
fan_data->num_speed = pdata->num_speed;
fan_data->speed = pdata->speed;
fan_data->pwm_enable = true; /* Enable manual fan speed control. */
fan_data->speed_index = get_fan_speed_index(fan_data);
if (fan_data->speed_index < 0)
return fan_data->speed_index;
return 0;
}
static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
struct gpio_fan_data *fan_data = cdev->devdata;
if (!fan_data)
return -EINVAL;
*state = fan_data->num_speed - 1;
return 0;
}
static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
struct gpio_fan_data *fan_data = cdev->devdata;
if (!fan_data)
return -EINVAL;
*state = fan_data->speed_index;
return 0;
}
static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
unsigned long state)
{
struct gpio_fan_data *fan_data = cdev->devdata;
if (!fan_data)
return -EINVAL;
set_fan_speed(fan_data, state);
return 0;
}
static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
.get_max_state = gpio_fan_get_max_state,
.get_cur_state = gpio_fan_get_cur_state,
.set_cur_state = gpio_fan_set_cur_state,
};
#ifdef CONFIG_OF_GPIO
/*
* Translate OpenFirmware node properties into platform_data
*/
static int gpio_fan_get_of_pdata(struct device *dev,
struct gpio_fan_platform_data *pdata)
{
struct device_node *node;
struct gpio_fan_speed *speed;
unsigned *ctrl;
unsigned i;
u32 u;
struct property *prop;
const __be32 *p;
node = dev->of_node;
/* Alarm GPIO if one exists */
if (of_gpio_named_count(node, "alarm-gpios") > 0) {
struct gpio_fan_alarm *alarm;
int val;
enum of_gpio_flags flags;
alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
GFP_KERNEL);
if (!alarm)
return -ENOMEM;
val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
if (val < 0)
return val;
alarm->gpio = val;
alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
pdata->alarm = alarm;
}
/* Fill GPIO pin array */
pdata->num_ctrl = of_gpio_count(node);
if (pdata->num_ctrl <= 0) {
if (pdata->alarm)
return 0;
dev_err(dev, "DT properties empty / missing");
return -ENODEV;
}
ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
GFP_KERNEL);
if (!ctrl)
return -ENOMEM;
for (i = 0; i < pdata->num_ctrl; i++) {
int val;
val = of_get_gpio(node, i);
if (val < 0)
return val;
ctrl[i] = val;
}
pdata->ctrl = ctrl;
/* Get number of RPM/ctrl_val pairs in speed map */
prop = of_find_property(node, "gpio-fan,speed-map", &i);
if (!prop) {
dev_err(dev, "gpio-fan,speed-map DT property missing");
return -ENODEV;
}
i = i / sizeof(u32);
if (i == 0 || i & 1) {
dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
return -ENODEV;
}
pdata->num_speed = i / 2;
/*
* Populate speed map
* Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
* this needs splitting into pairs to create gpio_fan_speed structs
*/
speed = devm_kzalloc(dev,
pdata->num_speed * sizeof(struct gpio_fan_speed),
GFP_KERNEL);
if (!speed)
return -ENOMEM;
p = NULL;
for (i = 0; i < pdata->num_speed; i++) {
p = of_prop_next_u32(prop, p, &u);
if (!p)
return -ENODEV;
speed[i].rpm = u;
p = of_prop_next_u32(prop, p, &u);
if (!p)
return -ENODEV;
speed[i].ctrl_val = u;
}
pdata->speed = speed;
return 0;
}
static const struct of_device_id of_gpio_fan_match[] = {
{ .compatible = "gpio-fan", },
{},
};
MODULE_DEVICE_TABLE(of, of_gpio_fan_match);
#endif /* CONFIG_OF_GPIO */
static int gpio_fan_probe(struct platform_device *pdev)
{
int err;
struct gpio_fan_data *fan_data;
struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev);
fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
GFP_KERNEL);
if (!fan_data)
return -ENOMEM;
#ifdef CONFIG_OF_GPIO
if (!pdata) {
pdata = devm_kzalloc(&pdev->dev,
sizeof(struct gpio_fan_platform_data),
GFP_KERNEL);
if (!pdata)
return -ENOMEM;
err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
if (err)
return err;
}
#else /* CONFIG_OF_GPIO */
if (!pdata)
return -EINVAL;
#endif /* CONFIG_OF_GPIO */
fan_data->pdev = pdev;
platform_set_drvdata(pdev, fan_data);
mutex_init(&fan_data->lock);
/* Configure alarm GPIO if available. */
if (pdata->alarm) {
err = fan_alarm_init(fan_data, pdata->alarm);
if (err)
return err;
}
/* Configure control GPIOs if available. */
if (pdata->ctrl && pdata->num_ctrl > 0) {
if (!pdata->speed || pdata->num_speed <= 1)
return -EINVAL;
err = fan_ctrl_init(fan_data, pdata);
if (err)
return err;
}
/* Make this driver part of hwmon class. */
fan_data->hwmon_dev =
devm_hwmon_device_register_with_groups(&pdev->dev,
"gpio_fan", fan_data,
gpio_fan_groups);
if (IS_ERR(fan_data->hwmon_dev))
return PTR_ERR(fan_data->hwmon_dev);
hwmon: (gpio-fan) Move the thermal registration after registration is complete Thermal framework may already be ready and cooling policies might already be functional when we are attempting to register gpio fan as a cooling device. This can be reproduced by changing probe order in which registration of various modules are done in a system. In such a case, kernel generates an oops since the data structures are not completely populated with the wrong assumption that thermal framework is not yet ready. Fix this by reordering the thermal framework registration to occur after hwmon registration of the fan is complete. Example kernel oops: [ 149.005828] Unable to handle kernel NULL pointer dereference at virtual address 0000008c [ 149.014369] pgd = ecf48000 [ 149.017204] [0000008c] *pgd=ac065831, *pte=00000000, *ppte=00000000 [ 149.023820] Internal error: Oops: 17 [#1] SMP ARM [ 149.028745] Modules linked in: gpio_fan(+) cpufreq_dt ipv6 evdev leds_gpio led_class omap_wdt phy_omap_usb2 rtc_palmas palmas_pwrbutton tmp102 ti_soc_thermal dwc3_omap thermal_sys extcon rtc_omap rtc_ds1307 hwmon [ 149.048629] CPU: 1 PID: 1183 Comm: modprobe Not tainted 4.0.0-rc7-next-20150407-00002-g7a82da074c99 #3 [ 149.058383] Hardware name: Generic DRA74X (Flattened Device Tree) [ 149.064763] task: edec1240 ti: ec0e0000 task.ti: ec0e0000 [ 149.070421] PC is at dev_driver_string+0x0/0x38 [ 149.075165] LR is at __dev_printk+0x24/0x70 [ 149.079540] pc : [<c03d6cd0>] lr : [<c03d72c4>] psr: 20000013 [ 149.079540] sp : ec0e1c28 ip : edec1240 fp : 00000000 [ 149.091568] r10: edf3eee0 r9 : 00000000 r8 : ffffffff [ 149.097040] r7 : edf3eea0 r6 : 00000034 r5 : 00000010 r4 : ec0e1c44 [ 149.103871] r3 : ec0e1c4c r2 : ec0e1c44 r1 : c079d800 r0 : 00000010 [ 149.110709] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 149.118182] Control: 10c5387d Table: acf4806a DAC: 00000015 [ 149.124198] Process modprobe (pid: 1183, stack limit = 0xec0e0218) [ 149.130673] Stack: (0xec0e1c28 to 0xec0e2000) [ 149.135235] 1c20: 60000013 c05e2ae0 00000000 edf3ec00 ec934a10 c03d73d4 ... [ 149.392230] 1fe0: befe1888 befe1878 00019418 b6ea08f0 80000010 00000003 00000000 00000000 [ 149.400798] [<c03d6cd0>] (dev_driver_string) from [<c03d72c4>] (__dev_printk+0x24/0x70) [ 149.409193] [<c03d72c4>] (__dev_printk) from [<c03d73d4>] (dev_warn+0x34/0x48) [ 149.416767] [<c03d73d4>] (dev_warn) from [<bf0f54fc>] (get_fan_speed_index+0x94/0xa4 [gpio_fan]) [ 149.425980] [<bf0f54fc>] (get_fan_speed_index [gpio_fan]) from [<bf0f5524>] (gpio_fan_get_cur_state+0x18/0x30 [gpio_fan]) [ 149.437476] [<bf0f5524>] (gpio_fan_get_cur_state [gpio_fan]) from [<bf02767c>] (thermal_zone_trip_update+0xe8/0x2a4 [thermal_sys]) [ 149.449794] [<bf02767c>] (thermal_zone_trip_update [thermal_sys]) from [<bf027844>] (step_wise_throttle+0xc/0x74 [thermal_sys]) [ 149.461832] [<bf027844>] (step_wise_throttle [thermal_sys]) from [<bf024ff4>] (handle_thermal_trip+0x5c/0x188 [thermal_sys]) [ 149.473603] [<bf024ff4>] (handle_thermal_trip [thermal_sys]) from [<bf0256c4>] (thermal_zone_device_update+0x94/0x108 [thermal_sys]) [ 149.486104] [<bf0256c4>] (thermal_zone_device_update [thermal_sys]) from [<bf026470>] (__thermal_cooling_device_register+0x2e8/0x374 [thermal_sys]) [ 149.499956] [<bf026470>] (__thermal_cooling_device_register [thermal_sys]) from [<bf0f58e4>] (gpio_fan_probe+0x350/0x4d0 [gpio_fan]) [ 149.512438] [<bf0f58e4>] (gpio_fan_probe [gpio_fan]) from [<c03db8a0>] (platform_drv_probe+0x48/0x98) [ 149.522109] [<c03db8a0>] (platform_drv_probe) from [<c03da30c>] (driver_probe_device+0x1b0/0x26c) [ 149.531399] [<c03da30c>] (driver_probe_device) from [<c03da45c>] (__driver_attach+0x94/0x98) [ 149.540238] [<c03da45c>] (__driver_attach) from [<c03d8bb0>] (bus_for_each_dev+0x54/0x88) [ 149.548814] [<c03d8bb0>] (bus_for_each_dev) from [<c03d9a34>] (bus_add_driver+0xdc/0x1d4) [ 149.557381] [<c03d9a34>] (bus_add_driver) from [<c03dac30>] (driver_register+0x78/0xf4) [ 149.565765] [<c03dac30>] (driver_register) from [<c0009784>] (do_one_initcall+0x80/0x1d8) [ 149.574340] [<c0009784>] (do_one_initcall) from [<c00c2278>] (do_init_module+0x5c/0x1b8) [ 149.582833] [<c00c2278>] (do_init_module) from [<c00c3bbc>] (load_module+0x1720/0x1dcc) [ 149.591212] [<c00c3bbc>] (load_module) from [<c00c43d0>] (SyS_finit_module+0x68/0x6c) [ 149.599418] [<c00c43d0>] (SyS_finit_module) from [<c000f3c0>] (ret_fast_syscall+0x0/0x4c) [ 149.607994] Code: 15830000 e1a00006 e28dd008 e8bd8070 (e590307c) Cc: Eduardo Valentin <edubezval@gmail.com> Fixes: b5cf88e46bad ("(gpio-fan): Add thermal control hooks") Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2015-04-08 23:23:52 +00:00
#ifdef CONFIG_OF_GPIO
/* Optional cooling device register for Device tree platforms */
fan_data->cdev = thermal_of_cooling_device_register(pdev->dev.of_node,
"gpio-fan",
fan_data,
&gpio_fan_cool_ops);
#else /* CONFIG_OF_GPIO */
/* Optional cooling device register for non Device tree platforms */
fan_data->cdev = thermal_cooling_device_register("gpio-fan", fan_data,
&gpio_fan_cool_ops);
#endif /* CONFIG_OF_GPIO */
dev_info(&pdev->dev, "GPIO fan initialized\n");
return 0;
}
static int gpio_fan_remove(struct platform_device *pdev)
{
struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
if (!IS_ERR(fan_data->cdev))
thermal_cooling_device_unregister(fan_data->cdev);
if (fan_data->ctrl)
set_fan_speed(fan_data, 0);
return 0;
}
static void gpio_fan_shutdown(struct platform_device *pdev)
{
gpio_fan_remove(pdev);
}
#ifdef CONFIG_PM_SLEEP
static int gpio_fan_suspend(struct device *dev)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
if (fan_data->ctrl) {
fan_data->resume_speed = fan_data->speed_index;
set_fan_speed(fan_data, 0);
}
return 0;
}
static int gpio_fan_resume(struct device *dev)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
if (fan_data->ctrl)
set_fan_speed(fan_data, fan_data->resume_speed);
return 0;
}
static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
#define GPIO_FAN_PM (&gpio_fan_pm)
#else
#define GPIO_FAN_PM NULL
#endif
static struct platform_driver gpio_fan_driver = {
.probe = gpio_fan_probe,
.remove = gpio_fan_remove,
.shutdown = gpio_fan_shutdown,
.driver = {
.name = "gpio-fan",
.pm = GPIO_FAN_PM,
#ifdef CONFIG_OF_GPIO
.of_match_table = of_match_ptr(of_gpio_fan_match),
#endif
},
};
module_platform_driver(gpio_fan_driver);
MODULE_AUTHOR("Simon Guinot <sguinot@lacie.com>");
MODULE_DESCRIPTION("GPIO FAN driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-fan");