Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/drivers/extcon/extcon-gpio.c

  1 /*
  2  * extcon_gpio.c - Single-state GPIO extcon driver based on extcon class
  3  *
  4  * Copyright (C) 2008 Google, Inc.
  5  * Author: Mike Lockwood <lockwood@android.com>
  6  *
  7  * Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
  8  * (originally switch class is supported)
  9  *
 10  * This software is licensed under the terms of the GNU General Public
 11  * License version 2, as published by the Free Software Foundation, and
 12  * may be copied, distributed, and modified under those terms.
 13  *
 14  * This program is distributed in the hope that it will be useful,
 15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17  * GNU General Public License for more details.
 18  */
 19 
 20 #include <linux/extcon.h>
 21 #include <linux/extcon/extcon-gpio.h>
 22 #include <linux/gpio.h>
 23 #include <linux/gpio/consumer.h>
 24 #include <linux/init.h>
 25 #include <linux/interrupt.h>
 26 #include <linux/kernel.h>
 27 #include <linux/module.h>
 28 #include <linux/platform_device.h>
 29 #include <linux/slab.h>
 30 #include <linux/workqueue.h>
 31 
 32 struct gpio_extcon_data {
 33         struct extcon_dev *edev;
 34         int irq;
 35         struct delayed_work work;
 36         unsigned long debounce_jiffies;
 37 
 38         struct gpio_desc *id_gpiod;
 39         struct gpio_extcon_pdata *pdata;
 40 };
 41 
 42 static void gpio_extcon_work(struct work_struct *work)
 43 {
 44         int state;
 45         struct gpio_extcon_data *data =
 46                 container_of(to_delayed_work(work), struct gpio_extcon_data,
 47                              work);
 48 
 49         state = gpiod_get_value_cansleep(data->id_gpiod);
 50         if (data->pdata->gpio_active_low)
 51                 state = !state;
 52 
 53         extcon_set_state_sync(data->edev, data->pdata->extcon_id, state);
 54 }
 55 
 56 static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
 57 {
 58         struct gpio_extcon_data *data = dev_id;
 59 
 60         queue_delayed_work(system_power_efficient_wq, &data->work,
 61                               data->debounce_jiffies);
 62         return IRQ_HANDLED;
 63 }
 64 
 65 static int gpio_extcon_init(struct device *dev, struct gpio_extcon_data *data)
 66 {
 67         struct gpio_extcon_pdata *pdata = data->pdata;
 68         int ret;
 69 
 70         ret = devm_gpio_request_one(dev, pdata->gpio, GPIOF_DIR_IN,
 71                                 dev_name(dev));
 72         if (ret < 0)
 73                 return ret;
 74 
 75         data->id_gpiod = gpio_to_desc(pdata->gpio);
 76         if (!data->id_gpiod)
 77                 return -EINVAL;
 78 
 79         if (pdata->debounce) {
 80                 ret = gpiod_set_debounce(data->id_gpiod,
 81                                         pdata->debounce * 1000);
 82                 if (ret < 0)
 83                         data->debounce_jiffies =
 84                                 msecs_to_jiffies(pdata->debounce);
 85         }
 86 
 87         data->irq = gpiod_to_irq(data->id_gpiod);
 88         if (data->irq < 0)
 89                 return data->irq;
 90 
 91         return 0;
 92 }
 93 
 94 static int gpio_extcon_probe(struct platform_device *pdev)
 95 {
 96         struct gpio_extcon_pdata *pdata = dev_get_platdata(&pdev->dev);
 97         struct gpio_extcon_data *data;
 98         int ret;
 99 
100         if (!pdata)
101                 return -EBUSY;
102         if (!pdata->irq_flags || pdata->extcon_id > EXTCON_NONE)
103                 return -EINVAL;
104 
105         data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
106                                    GFP_KERNEL);
107         if (!data)
108                 return -ENOMEM;
109         data->pdata = pdata;
110 
111         /* Initialize the gpio */
112         ret = gpio_extcon_init(&pdev->dev, data);
113         if (ret < 0)
114                 return ret;
115 
116         /* Allocate the memory of extcon devie and register extcon device */
117         data->edev = devm_extcon_dev_allocate(&pdev->dev, &pdata->extcon_id);
118         if (IS_ERR(data->edev)) {
119                 dev_err(&pdev->dev, "failed to allocate extcon device\n");
120                 return -ENOMEM;
121         }
122 
123         ret = devm_extcon_dev_register(&pdev->dev, data->edev);
124         if (ret < 0)
125                 return ret;
126 
127         INIT_DELAYED_WORK(&data->work, gpio_extcon_work);
128 
129         /*
130          * Request the interrupt of gpio to detect whether external connector
131          * is attached or detached.
132          */
133         ret = devm_request_any_context_irq(&pdev->dev, data->irq,
134                                         gpio_irq_handler, pdata->irq_flags,
135                                         pdev->name, data);
136         if (ret < 0)
137                 return ret;
138 
139         platform_set_drvdata(pdev, data);
140         /* Perform initial detection */
141         gpio_extcon_work(&data->work.work);
142 
143         return 0;
144 }
145 
146 static int gpio_extcon_remove(struct platform_device *pdev)
147 {
148         struct gpio_extcon_data *data = platform_get_drvdata(pdev);
149 
150         cancel_delayed_work_sync(&data->work);
151 
152         return 0;
153 }
154 
155 #ifdef CONFIG_PM_SLEEP
156 static int gpio_extcon_resume(struct device *dev)
157 {
158         struct gpio_extcon_data *data;
159 
160         data = dev_get_drvdata(dev);
161         if (data->pdata->check_on_resume)
162                 queue_delayed_work(system_power_efficient_wq,
163                         &data->work, data->debounce_jiffies);
164 
165         return 0;
166 }
167 #endif
168 
169 static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);
170 
171 static struct platform_driver gpio_extcon_driver = {
172         .probe          = gpio_extcon_probe,
173         .remove         = gpio_extcon_remove,
174         .driver         = {
175                 .name   = "extcon-gpio",
176                 .pm     = &gpio_extcon_pm_ops,
177         },
178 };
179 
180 module_platform_driver(gpio_extcon_driver);
181 
182 MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
183 MODULE_DESCRIPTION("GPIO extcon driver");
184 MODULE_LICENSE("GPL");
185 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us