From d6fe1360f42e86262153927986dea6502daff703 Mon Sep 17 00:00:00 2001 From: Simon Guinot Date: Fri, 22 Oct 2010 00:44:19 +0200 Subject: hwmon: add generic GPIO fan driver This patch adds hwmon support for fans connected to GPIO lines. Platform specific information such as GPIO pinout and speed conversion array (rpm from/to GPIO value) are passed to the driver via platform_data. Signed-off-by: Simon Guinot Signed-off-by: Guenter Roeck --- drivers/hwmon/gpio-fan.c | 558 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 558 insertions(+) create mode 100644 drivers/hwmon/gpio-fan.c (limited to 'drivers/hwmon/gpio-fan.c') diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c new file mode 100644 index 000000000000..aa701a183707 --- /dev/null +++ b/drivers/hwmon/gpio-fan.c @@ -0,0 +1,558 @@ +/* + * gpio-fan.c - Hwmon driver for fans connected to GPIO lines. + * + * Copyright (C) 2010 LaCie + * + * Author: Simon Guinot + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct gpio_fan_data { + struct platform_device *pdev; + struct device *hwmon_dev; + 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 + 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 show_fan_alarm(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; + int value = gpio_get_value(alarm->gpio); + + if (alarm->active_low) + value = !value; + + return sprintf(buf, "%d\n", value); +} + +static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL); + +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 = gpio_request(alarm->gpio, "GPIO fan alarm"); + if (err) + return err; + + err = gpio_direction_input(alarm->gpio); + if (err) + goto err_free_gpio; + + err = device_create_file(&pdev->dev, &dev_attr_fan1_alarm); + if (err) + goto err_free_gpio; + + /* + * 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); + set_irq_type(alarm_irq, IRQ_TYPE_EDGE_BOTH); + err = request_irq(alarm_irq, fan_alarm_irq_handler, IRQF_SHARED, + "GPIO fan alarm", fan_data); + if (err) + goto err_free_sysfs; + + return 0; + +err_free_sysfs: + device_remove_file(&pdev->dev, &dev_attr_fan1_alarm); +err_free_gpio: + gpio_free(alarm->gpio); + + return err; +} + +static void fan_alarm_free(struct gpio_fan_data *fan_data) +{ + struct platform_device *pdev = fan_data->pdev; + int alarm_irq = gpio_to_irq(fan_data->alarm->gpio); + + if (alarm_irq >= 0) + free_irq(alarm_irq, fan_data); + device_remove_file(&pdev->dev, &dev_attr_fan1_alarm); + gpio_free(fan_data->alarm->gpio); +} + +/* + * 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++) + gpio_set_value(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; + + value = gpio_get_value(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 -EINVAL; +} + +static int rpm_to_speed_index(struct gpio_fan_data *fan_data, int 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 show_pwm(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 set_pwm(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 (strict_strtoul(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 show_pwm_enable(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 set_pwm_enable(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 (strict_strtoul(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 show_pwm_mode(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "0\n"); +} + +static ssize_t show_rpm_min(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 show_rpm_max(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 show_rpm(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 (strict_strtoul(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(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm); +static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR, + show_pwm_enable, set_pwm_enable); +static DEVICE_ATTR(pwm1_mode, S_IRUGO, show_pwm_mode, NULL); +static DEVICE_ATTR(fan1_min, S_IRUGO, show_rpm_min, NULL); +static DEVICE_ATTR(fan1_max, S_IRUGO, show_rpm_max, NULL); +static DEVICE_ATTR(fan1_input, S_IRUGO, show_rpm, NULL); +static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_rpm, set_rpm); + +static struct attribute *gpio_fan_ctrl_attributes[] = { + &dev_attr_pwm1.attr, + &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_ctrl_group = { + .attrs = gpio_fan_ctrl_attributes, +}; + +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 = gpio_request(ctrl[i], "GPIO fan control"); + if (err) + goto err_free_gpio; + + err = gpio_direction_output(ctrl[i], gpio_get_value(ctrl[i])); + if (err) { + gpio_free(ctrl[i]); + goto err_free_gpio; + } + } + + err = sysfs_create_group(&pdev->dev.kobj, &gpio_fan_ctrl_group); + if (err) + goto err_free_gpio; + + 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) { + err = -ENODEV; + goto err_free_gpio; + } + + return 0; + +err_free_gpio: + for (i = i - 1; i >= 0; i--) + gpio_free(ctrl[i]); + + return err; +} + +static void fan_ctrl_free(struct gpio_fan_data *fan_data) +{ + struct platform_device *pdev = fan_data->pdev; + int i; + + sysfs_remove_group(&pdev->dev.kobj, &gpio_fan_ctrl_group); + for (i = 0; i < fan_data->num_ctrl; i++) + gpio_free(fan_data->ctrl[i]); +} + +/* + * Platform driver. + */ + +static ssize_t show_name(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "gpio-fan\n"); +} + +static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); + +static int __devinit gpio_fan_probe(struct platform_device *pdev) +{ + int err; + struct gpio_fan_data *fan_data; + struct gpio_fan_platform_data *pdata = pdev->dev.platform_data; + + if (!pdata) + return -EINVAL; + + fan_data = kzalloc(sizeof(struct gpio_fan_data), GFP_KERNEL); + if (!fan_data) + return -ENOMEM; + + 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) + goto err_free_data; + } + + /* Configure control GPIOs if available. */ + if (pdata->ctrl && pdata->num_ctrl > 0) { + if (!pdata->speed || pdata->num_speed <= 1) { + err = -EINVAL; + goto err_free_alarm; + } + err = fan_ctrl_init(fan_data, pdata); + if (err) + goto err_free_alarm; + } + + err = device_create_file(&pdev->dev, &dev_attr_name); + if (err) + goto err_free_ctrl; + + /* Make this driver part of hwmon class. */ + fan_data->hwmon_dev = hwmon_device_register(&pdev->dev); + if (IS_ERR(fan_data->hwmon_dev)) { + err = PTR_ERR(fan_data->hwmon_dev); + goto err_remove_name; + } + + dev_info(&pdev->dev, "GPIO fan initialized\n"); + + return 0; + +err_remove_name: + device_remove_file(&pdev->dev, &dev_attr_name); +err_free_ctrl: + if (fan_data->ctrl) + fan_ctrl_free(fan_data); +err_free_alarm: + if (fan_data->alarm) + fan_alarm_free(fan_data); +err_free_data: + platform_set_drvdata(pdev, NULL); + kfree(fan_data); + + return err; +} + +static int __devexit gpio_fan_remove(struct platform_device *pdev) +{ + struct gpio_fan_data *fan_data = platform_get_drvdata(pdev); + + hwmon_device_unregister(fan_data->hwmon_dev); + device_remove_file(&pdev->dev, &dev_attr_name); + if (fan_data->alarm) + fan_alarm_free(fan_data); + if (fan_data->ctrl) + fan_ctrl_free(fan_data); + kfree(fan_data); + + return 0; +} + +#ifdef CONFIG_PM +static int gpio_fan_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct gpio_fan_data *fan_data = platform_get_drvdata(pdev); + + 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 platform_device *pdev) +{ + struct gpio_fan_data *fan_data = platform_get_drvdata(pdev); + + if (fan_data->ctrl) + set_fan_speed(fan_data, fan_data->resume_speed); + + return 0; +} +#else +#define gpio_fan_suspend NULL +#define gpio_fan_resume NULL +#endif + +static struct platform_driver gpio_fan_driver = { + .probe = gpio_fan_probe, + .remove = __devexit_p(gpio_fan_remove), + .suspend = gpio_fan_suspend, + .resume = gpio_fan_resume, + .driver = { + .name = "gpio-fan", + }, +}; + +static int __init gpio_fan_init(void) +{ + return platform_driver_register(&gpio_fan_driver); +} + +static void __exit gpio_fan_exit(void) +{ + platform_driver_unregister(&gpio_fan_driver); +} + +module_init(gpio_fan_init); +module_exit(gpio_fan_exit); + +MODULE_AUTHOR("Simon Guinot "); +MODULE_DESCRIPTION("GPIO FAN driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:gpio-fan"); -- cgit