607 lines
14 KiB
C
607 lines
14 KiB
C
/*
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* gpio-fan.c - Hwmon driver for fans connected to GPIO lines.
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*
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* Copyright (C) 2010 LaCie
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*
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* Author: Simon Guinot <sguinot@lacie.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/platform_device.h>
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/hwmon.h>
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#include <linux/gpio.h>
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#include <linux/gpio-fan.h>
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#include <linux/of.h>
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#include <linux/of_platform.h>
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#include <linux/of_gpio.h>
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struct gpio_fan_data {
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struct platform_device *pdev;
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struct device *hwmon_dev;
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struct mutex lock; /* lock GPIOs operations. */
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int num_ctrl;
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unsigned *ctrl;
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int num_speed;
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struct gpio_fan_speed *speed;
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int speed_index;
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#ifdef CONFIG_PM_SLEEP
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int resume_speed;
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#endif
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bool pwm_enable;
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struct gpio_fan_alarm *alarm;
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struct work_struct alarm_work;
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};
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/*
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* Alarm GPIO.
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*/
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static void fan_alarm_notify(struct work_struct *ws)
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{
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struct gpio_fan_data *fan_data =
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container_of(ws, struct gpio_fan_data, alarm_work);
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sysfs_notify(&fan_data->pdev->dev.kobj, NULL, "fan1_alarm");
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kobject_uevent(&fan_data->pdev->dev.kobj, KOBJ_CHANGE);
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}
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static irqreturn_t fan_alarm_irq_handler(int irq, void *dev_id)
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{
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struct gpio_fan_data *fan_data = dev_id;
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schedule_work(&fan_data->alarm_work);
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return IRQ_NONE;
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}
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static ssize_t show_fan_alarm(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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struct gpio_fan_alarm *alarm = fan_data->alarm;
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int value = gpio_get_value(alarm->gpio);
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if (alarm->active_low)
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value = !value;
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return sprintf(buf, "%d\n", value);
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}
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static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);
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static int fan_alarm_init(struct gpio_fan_data *fan_data,
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struct gpio_fan_alarm *alarm)
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{
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int err;
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int alarm_irq;
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struct platform_device *pdev = fan_data->pdev;
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fan_data->alarm = alarm;
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err = devm_gpio_request(&pdev->dev, alarm->gpio, "GPIO fan alarm");
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if (err)
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return err;
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err = gpio_direction_input(alarm->gpio);
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if (err)
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return err;
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/*
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* If the alarm GPIO don't support interrupts, just leave
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* without initializing the fail notification support.
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*/
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alarm_irq = gpio_to_irq(alarm->gpio);
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if (alarm_irq < 0)
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return 0;
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INIT_WORK(&fan_data->alarm_work, fan_alarm_notify);
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irq_set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH);
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err = devm_request_irq(&pdev->dev, alarm_irq, fan_alarm_irq_handler,
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IRQF_SHARED, "GPIO fan alarm", fan_data);
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return err;
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}
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/*
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* Control GPIOs.
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*/
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/* Must be called with fan_data->lock held, except during initialization. */
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static void __set_fan_ctrl(struct gpio_fan_data *fan_data, int ctrl_val)
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{
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int i;
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for (i = 0; i < fan_data->num_ctrl; i++)
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gpio_set_value(fan_data->ctrl[i], (ctrl_val >> i) & 1);
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}
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static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
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{
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int i;
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int ctrl_val = 0;
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for (i = 0; i < fan_data->num_ctrl; i++) {
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int value;
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value = gpio_get_value(fan_data->ctrl[i]);
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ctrl_val |= (value << i);
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}
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return ctrl_val;
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}
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/* Must be called with fan_data->lock held, except during initialization. */
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static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
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{
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if (fan_data->speed_index == speed_index)
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return;
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__set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
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fan_data->speed_index = speed_index;
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}
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static int get_fan_speed_index(struct gpio_fan_data *fan_data)
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{
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int ctrl_val = __get_fan_ctrl(fan_data);
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int i;
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for (i = 0; i < fan_data->num_speed; i++)
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if (fan_data->speed[i].ctrl_val == ctrl_val)
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return i;
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dev_warn(&fan_data->pdev->dev,
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"missing speed array entry for GPIO value 0x%x\n", ctrl_val);
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return -ENODEV;
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}
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static int rpm_to_speed_index(struct gpio_fan_data *fan_data, int rpm)
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{
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struct gpio_fan_speed *speed = fan_data->speed;
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int i;
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for (i = 0; i < fan_data->num_speed; i++)
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if (speed[i].rpm >= rpm)
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return i;
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return fan_data->num_speed - 1;
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}
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static ssize_t show_pwm(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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u8 pwm = fan_data->speed_index * 255 / (fan_data->num_speed - 1);
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return sprintf(buf, "%d\n", pwm);
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}
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static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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unsigned long pwm;
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int speed_index;
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int ret = count;
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if (kstrtoul(buf, 10, &pwm) || pwm > 255)
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return -EINVAL;
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mutex_lock(&fan_data->lock);
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if (!fan_data->pwm_enable) {
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ret = -EPERM;
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goto exit_unlock;
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}
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speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
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set_fan_speed(fan_data, speed_index);
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exit_unlock:
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mutex_unlock(&fan_data->lock);
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return ret;
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}
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static ssize_t show_pwm_enable(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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return sprintf(buf, "%d\n", fan_data->pwm_enable);
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}
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static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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unsigned long val;
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if (kstrtoul(buf, 10, &val) || val > 1)
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return -EINVAL;
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if (fan_data->pwm_enable == val)
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return count;
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mutex_lock(&fan_data->lock);
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fan_data->pwm_enable = val;
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/* Disable manual control mode: set fan at full speed. */
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if (val == 0)
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set_fan_speed(fan_data, fan_data->num_speed - 1);
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mutex_unlock(&fan_data->lock);
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return count;
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}
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static ssize_t show_pwm_mode(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "0\n");
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}
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static ssize_t show_rpm_min(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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return sprintf(buf, "%d\n", fan_data->speed[0].rpm);
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}
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static ssize_t show_rpm_max(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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return sprintf(buf, "%d\n",
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fan_data->speed[fan_data->num_speed - 1].rpm);
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}
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static ssize_t show_rpm(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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return sprintf(buf, "%d\n", fan_data->speed[fan_data->speed_index].rpm);
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}
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static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
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unsigned long rpm;
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int ret = count;
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if (kstrtoul(buf, 10, &rpm))
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return -EINVAL;
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mutex_lock(&fan_data->lock);
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if (!fan_data->pwm_enable) {
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ret = -EPERM;
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goto exit_unlock;
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}
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set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
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exit_unlock:
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mutex_unlock(&fan_data->lock);
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return ret;
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}
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static DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm);
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static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR,
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show_pwm_enable, set_pwm_enable);
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static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL);
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static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL);
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static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL);
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static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL);
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static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm);
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static umode_t gpio_fan_is_visible(struct kobject *kobj,
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struct attribute *attr, int index)
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{
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struct device *dev = container_of(kobj, struct device, kobj);
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struct gpio_fan_data *data = dev_get_drvdata(dev);
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if (index == 0 && !data->alarm)
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return 0;
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if (index > 0 && !data->ctrl)
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return 0;
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return attr->mode;
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}
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static struct attribute *gpio_fan_attributes[] = {
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&dev_attr_fan1_alarm.attr, /* 0 */
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&dev_attr_pwm1.attr, /* 1 */
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&dev_attr_pwm1_enable.attr,
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&dev_attr_pwm1_mode.attr,
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&dev_attr_fan1_input.attr,
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&dev_attr_fan1_target.attr,
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&dev_attr_fan1_min.attr,
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&dev_attr_fan1_max.attr,
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NULL
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};
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static const struct attribute_group gpio_fan_group = {
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.attrs = gpio_fan_attributes,
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.is_visible = gpio_fan_is_visible,
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};
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static const struct attribute_group *gpio_fan_groups[] = {
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&gpio_fan_group,
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NULL
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};
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static int fan_ctrl_init(struct gpio_fan_data *fan_data,
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struct gpio_fan_platform_data *pdata)
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{
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struct platform_device *pdev = fan_data->pdev;
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int num_ctrl = pdata->num_ctrl;
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unsigned *ctrl = pdata->ctrl;
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int i, err;
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for (i = 0; i < num_ctrl; i++) {
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err = devm_gpio_request(&pdev->dev, ctrl[i],
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"GPIO fan control");
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if (err)
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return err;
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err = gpio_direction_output(ctrl[i], gpio_get_value(ctrl[i]));
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if (err)
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return err;
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}
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fan_data->num_ctrl = num_ctrl;
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fan_data->ctrl = ctrl;
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fan_data->num_speed = pdata->num_speed;
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fan_data->speed = pdata->speed;
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fan_data->pwm_enable = true; /* Enable manual fan speed control. */
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fan_data->speed_index = get_fan_speed_index(fan_data);
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if (fan_data->speed_index < 0)
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return fan_data->speed_index;
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return 0;
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}
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#ifdef CONFIG_OF_GPIO
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/*
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* Translate OpenFirmware node properties into platform_data
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*/
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static int gpio_fan_get_of_pdata(struct device *dev,
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struct gpio_fan_platform_data *pdata)
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{
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struct device_node *node;
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struct gpio_fan_speed *speed;
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unsigned *ctrl;
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unsigned i;
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u32 u;
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struct property *prop;
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const __be32 *p;
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node = dev->of_node;
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/* Fill GPIO pin array */
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pdata->num_ctrl = of_gpio_count(node);
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if (pdata->num_ctrl <= 0) {
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dev_err(dev, "gpios DT property empty / missing");
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return -ENODEV;
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}
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ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
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GFP_KERNEL);
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if (!ctrl)
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return -ENOMEM;
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for (i = 0; i < pdata->num_ctrl; i++) {
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int val;
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val = of_get_gpio(node, i);
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if (val < 0)
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return val;
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ctrl[i] = val;
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}
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pdata->ctrl = ctrl;
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/* Get number of RPM/ctrl_val pairs in speed map */
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prop = of_find_property(node, "gpio-fan,speed-map", &i);
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if (!prop) {
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dev_err(dev, "gpio-fan,speed-map DT property missing");
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return -ENODEV;
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}
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i = i / sizeof(u32);
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if (i == 0 || i & 1) {
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dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
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return -ENODEV;
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}
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pdata->num_speed = i / 2;
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/*
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* Populate speed map
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* Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
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* this needs splitting into pairs to create gpio_fan_speed structs
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*/
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speed = devm_kzalloc(dev,
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pdata->num_speed * sizeof(struct gpio_fan_speed),
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GFP_KERNEL);
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if (!speed)
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return -ENOMEM;
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p = NULL;
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for (i = 0; i < pdata->num_speed; i++) {
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p = of_prop_next_u32(prop, p, &u);
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if (!p)
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return -ENODEV;
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speed[i].rpm = u;
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p = of_prop_next_u32(prop, p, &u);
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if (!p)
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return -ENODEV;
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speed[i].ctrl_val = u;
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}
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pdata->speed = speed;
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/* Alarm GPIO if one exists */
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if (of_gpio_named_count(node, "alarm-gpios") > 0) {
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struct gpio_fan_alarm *alarm;
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int val;
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enum of_gpio_flags flags;
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alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
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GFP_KERNEL);
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if (!alarm)
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return -ENOMEM;
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val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
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if (val < 0)
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return val;
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alarm->gpio = val;
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alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
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pdata->alarm = alarm;
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}
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return 0;
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}
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static struct of_device_id of_gpio_fan_match[] = {
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{ .compatible = "gpio-fan", },
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{},
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};
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#endif /* CONFIG_OF_GPIO */
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static int gpio_fan_probe(struct platform_device *pdev)
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{
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int err;
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struct gpio_fan_data *fan_data;
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struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev);
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#ifdef CONFIG_OF_GPIO
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if (!pdata) {
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pdata = devm_kzalloc(&pdev->dev,
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sizeof(struct gpio_fan_platform_data),
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GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
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if (err)
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return err;
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}
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#else /* CONFIG_OF_GPIO */
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if (!pdata)
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return -EINVAL;
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#endif /* CONFIG_OF_GPIO */
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fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
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GFP_KERNEL);
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if (!fan_data)
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return -ENOMEM;
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fan_data->pdev = pdev;
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platform_set_drvdata(pdev, fan_data);
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mutex_init(&fan_data->lock);
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|
/* 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 = 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);
|
|
|
|
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);
|
|
|
|
hwmon_device_unregister(fan_data->hwmon_dev);
|
|
|
|
return 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->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,
|
|
.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");
|