alistair23-linux/drivers/hwmon/gpio-fan.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

600 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
*
* Copyright (C) 2010 LaCie
*
* Author: Simon Guinot <sguinot@lacie.com>
*/
#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/consumer.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/thermal.h>
struct gpio_fan_speed {
int rpm;
int ctrl_val;
};
struct gpio_fan_data {
struct device *dev;
struct device *hwmon_dev;
/* Cooling device if any */
struct thermal_cooling_device *cdev;
struct mutex lock; /* lock GPIOs operations. */
int num_gpios;
struct gpio_desc **gpios;
int num_speed;
struct gpio_fan_speed *speed;
int speed_index;
#ifdef CONFIG_PM_SLEEP
int resume_speed;
#endif
bool pwm_enable;
struct gpio_desc *alarm_gpio;
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->dev->kobj, NULL, "fan1_alarm");
kobject_uevent(&fan_data->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);
return sprintf(buf, "%d\n",
gpiod_get_value_cansleep(fan_data->alarm_gpio));
}
static DEVICE_ATTR_RO(fan1_alarm);
static int fan_alarm_init(struct gpio_fan_data *fan_data)
{
int alarm_irq;
struct device *dev = fan_data->dev;
/*
* If the alarm GPIO don't support interrupts, just leave
* without initializing the fail notification support.
*/
alarm_irq = gpiod_to_irq(fan_data->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);
return devm_request_irq(dev, alarm_irq, fan_alarm_irq_handler,
IRQF_SHARED, "GPIO fan alarm", fan_data);
}
/*
* 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_gpios; i++)
gpiod_set_value_cansleep(fan_data->gpios[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_gpios; i++) {
int value;
value = gpiod_get_value_cansleep(fan_data->gpios[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->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, 0644, 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_gpio)
return 0;
if (index > 0 && !data->gpios)
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)
{
int num_gpios = fan_data->num_gpios;
struct gpio_desc **gpios = fan_data->gpios;
int i, err;
for (i = 0; i < num_gpios; i++) {
/*
* The GPIO descriptors were retrieved with GPIOD_ASIS so here
* we set the GPIO into output mode, carefully preserving the
* current value by setting it to whatever it is already set
* (no surprise changes in default fan speed).
*/
err = gpiod_direction_output(gpios[i],
gpiod_get_value_cansleep(gpios[i]));
if (err)
return err;
}
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,
};
/*
* Translate OpenFirmware node properties into platform_data
*/
static int gpio_fan_get_of_data(struct gpio_fan_data *fan_data)
{
struct gpio_fan_speed *speed;
struct device *dev = fan_data->dev;
struct device_node *np = dev->of_node;
struct gpio_desc **gpios;
unsigned i;
u32 u;
struct property *prop;
const __be32 *p;
/* Alarm GPIO if one exists */
fan_data->alarm_gpio = devm_gpiod_get_optional(dev, "alarm", GPIOD_IN);
if (IS_ERR(fan_data->alarm_gpio))
return PTR_ERR(fan_data->alarm_gpio);
/* Fill GPIO pin array */
fan_data->num_gpios = gpiod_count(dev, NULL);
if (fan_data->num_gpios <= 0) {
if (fan_data->alarm_gpio)
return 0;
dev_err(dev, "DT properties empty / missing");
return -ENODEV;
}
gpios = devm_kcalloc(dev,
fan_data->num_gpios, sizeof(struct gpio_desc *),
GFP_KERNEL);
if (!gpios)
return -ENOMEM;
for (i = 0; i < fan_data->num_gpios; i++) {
gpios[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
if (IS_ERR(gpios[i]))
return PTR_ERR(gpios[i]);
}
fan_data->gpios = gpios;
/* Get number of RPM/ctrl_val pairs in speed map */
prop = of_find_property(np, "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;
}
fan_data->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_kcalloc(dev,
fan_data->num_speed, sizeof(struct gpio_fan_speed),
GFP_KERNEL);
if (!speed)
return -ENOMEM;
p = NULL;
for (i = 0; i < fan_data->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;
}
fan_data->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);
static void gpio_fan_stop(void *data)
{
set_fan_speed(data, 0);
}
static int gpio_fan_probe(struct platform_device *pdev)
{
int err;
struct gpio_fan_data *fan_data;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
fan_data = devm_kzalloc(dev, sizeof(struct gpio_fan_data),
GFP_KERNEL);
if (!fan_data)
return -ENOMEM;
fan_data->dev = dev;
err = gpio_fan_get_of_data(fan_data);
if (err)
return err;
platform_set_drvdata(pdev, fan_data);
mutex_init(&fan_data->lock);
/* Configure alarm GPIO if available. */
if (fan_data->alarm_gpio) {
err = fan_alarm_init(fan_data);
if (err)
return err;
}
/* Configure control GPIOs if available. */
if (fan_data->gpios && fan_data->num_gpios > 0) {
if (!fan_data->speed || fan_data->num_speed <= 1)
return -EINVAL;
err = fan_ctrl_init(fan_data);
if (err)
return err;
devm_add_action_or_reset(dev, gpio_fan_stop, fan_data);
}
/* Make this driver part of hwmon class. */
fan_data->hwmon_dev =
devm_hwmon_device_register_with_groups(dev,
"gpio_fan", fan_data,
gpio_fan_groups);
if (IS_ERR(fan_data->hwmon_dev))
return PTR_ERR(fan_data->hwmon_dev);
/* Optional cooling device register for Device tree platforms */
fan_data->cdev = devm_thermal_of_cooling_device_register(dev, np,
"gpio-fan", fan_data, &gpio_fan_cool_ops);
dev_info(dev, "GPIO fan initialized\n");
return 0;
}
static void gpio_fan_shutdown(struct platform_device *pdev)
{
struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);
if (fan_data->gpios)
set_fan_speed(fan_data, 0);
}
#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->gpios) {
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->gpios)
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,
.shutdown = gpio_fan_shutdown,
.driver = {
.name = "gpio-fan",
.pm = GPIO_FAN_PM,
.of_match_table = of_match_ptr(of_gpio_fan_match),
},
};
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");