drivers/input/keyboard/gpio_keys.c

   1 /*
   2  * Driver for keys on GPIO lines capable of generating interrupts.
   3  *
   4  * Copyright 2005 Phil Blundell
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/module.h>
  12
  13 #include <linux/init.h>
  14 #include <linux/fs.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <linux/sched.h>
  18 #include <linux/pm.h>
  19 #include <linux/sysctl.h>
  20 #include <linux/proc_fs.h>
  21 #include <linux/delay.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/input.h>
  24 #include <linux/gpio_keys.h>
  25 #include <linux/workqueue.h>
  26
  27 #include <asm/gpio.h>
  28
  29 struct gpio_button_data {
  30         struct gpio_keys_button *button;
  31         struct input_dev *input;
  32         struct timer_list timer;
  33         struct work_struct work;
  34 };
  35
  36 struct gpio_keys_drvdata {
  37         struct input_dev *input;
  38         struct gpio_button_data data[0];
  39 };
  40
  41 static void gpio_keys_report_event(struct work_struct *work)
  42 {
  43         struct gpio_button_data *bdata =
  44                 container_of(work, struct gpio_button_data, work);
  45         struct gpio_keys_button *button = bdata->button;
  46         struct input_dev *input = bdata->input;
  47         unsigned int type = button->type ?: EV_KEY;
  48         int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low;
  49
  50         input_event(input, type, button->code, !!state);
  51         input_sync(input);
  52 }
  53
  54 static void gpio_keys_timer(unsigned long _data)
  55 {
  56         struct gpio_button_data *data = (struct gpio_button_data *)_data;
  57
  58         schedule_work(&data->work);
  59 }
  60
  61 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
  62 {
  63         struct gpio_button_data *bdata = dev_id;
  64         struct gpio_keys_button *button = bdata->button;
  65
  66         BUG_ON(irq != gpio_to_irq(button->gpio));
  67
  68         if (button->debounce_interval)
  69                 mod_timer(&bdata->timer,
  70                         jiffies + msecs_to_jiffies(button->debounce_interval));
  71         else
  72                 schedule_work(&bdata->work);
  73
  74         return IRQ_HANDLED;
  75 }
  76
  77 static int __devinit gpio_keys_probe(struct platform_device *pdev)
  78 {
  79         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
  80         struct gpio_keys_drvdata *ddata;
  81         struct input_dev *input;
  82         int i, error;
  83         int wakeup = 0;
  84
  85         ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
  86                         pdata->nbuttons * sizeof(struct gpio_button_data),
  87                         GFP_KERNEL);
  88         input = input_allocate_device();
  89         if (!ddata || !input) {
  90                 error = -ENOMEM;
  91                 goto fail1;
  92         }
  93
  94         platform_set_drvdata(pdev, ddata);
  95
  96         input->name = pdev->name;
  97         input->phys = "gpio-keys/input0";
  98         input->dev.parent = &pdev->dev;
  99
 100         input->id.bustype = BUS_HOST;
 101         input->id.vendor = 0x0001;
 102         input->id.product = 0x0001;
 103         input->id.version = 0x0100;
 104
 105         /* Enable auto repeat feature of Linux input subsystem */
 106         if (pdata->rep)
 107                 __set_bit(EV_REP, input->evbit);
 108
 109         ddata->input = input;
 110
 111         for (i = 0; i < pdata->nbuttons; i++) {
 112                 struct gpio_keys_button *button = &pdata->buttons[i];
 113                 struct gpio_button_data *bdata = &ddata->data[i];
 114                 int irq;
 115                 unsigned int type = button->type ?: EV_KEY;
 116
 117                 bdata->input = input;
 118                 bdata->button = button;
 119                 setup_timer(&bdata->timer,
 120                             gpio_keys_timer, (unsigned long)bdata);
 121                 INIT_WORK(&bdata->work, gpio_keys_report_event);
 122
 123                 error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
 124                 if (error < 0) {
 125                         pr_err("gpio-keys: failed to request GPIO %d,"
 126                                 " error %d\n", button->gpio, error);
 127                         goto fail2;
 128                 }
 129
 130                 error = gpio_direction_input(button->gpio);
 131                 if (error < 0) {
 132                         pr_err("gpio-keys: failed to configure input"
 133                                 " direction for GPIO %d, error %d\n",
 134                                 button->gpio, error);
 135                         gpio_free(button->gpio);
 136                         goto fail2;
 137                 }
 138
 139                 irq = gpio_to_irq(button->gpio);
 140                 if (irq < 0) {
 141                         error = irq;
 142                         pr_err("gpio-keys: Unable to get irq number"
 143                                 " for GPIO %d, error %d\n",
 144                                 button->gpio, error);
 145                         gpio_free(button->gpio);
 146                         goto fail2;
 147                 }
 148
 149                 error = request_irq(irq, gpio_keys_isr,
 150                                     IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 151                                     button->desc ? button->desc : "gpio_keys",
 152                                     bdata);
 153                 if (error) {
 154                         pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
 155                                 irq, error);
 156                         gpio_free(button->gpio);
 157                         goto fail2;
 158                 }
 159
 160                 if (button->wakeup)
 161                         wakeup = 1;
 162
 163                 input_set_capability(input, type, button->code);
 164         }
 165
 166         error = input_register_device(input);
 167         if (error) {
 168                 pr_err("gpio-keys: Unable to register input device, "
 169                         "error: %d\n", error);
 170                 goto fail2;
 171         }
 172
 173         device_init_wakeup(&pdev->dev, wakeup);
 174
 175         return 0;
 176
 177  fail2:
 178         while (--i >= 0) {
 179                 free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
 180                 if (pdata->buttons[i].debounce_interval)
 181                         del_timer_sync(&ddata->data[i].timer);
 182                 cancel_work_sync(&ddata->data[i].work);
 183                 gpio_free(pdata->buttons[i].gpio);
 184         }
 185
 186         platform_set_drvdata(pdev, NULL);
 187  fail1:
 188         input_free_device(input);
 189         kfree(ddata);
 190
 191         return error;
 192 }
 193
 194 static int __devexit gpio_keys_remove(struct platform_device *pdev)
 195 {
 196         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 197         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
 198         struct input_dev *input = ddata->input;
 199         int i;
 200
 201         device_init_wakeup(&pdev->dev, 0);
 202
 203         for (i = 0; i < pdata->nbuttons; i++) {
 204                 int irq = gpio_to_irq(pdata->buttons[i].gpio);
 205                 free_irq(irq, &ddata->data[i]);
 206                 if (pdata->buttons[i].debounce_interval)
 207                         del_timer_sync(&ddata->data[i].timer);
 208                 cancel_work_sync(&ddata->data[i].work);
 209                 gpio_free(pdata->buttons[i].gpio);
 210         }
 211
 212         input_unregister_device(input);
 213
 214         return 0;
 215 }
 216
 217
 218 #ifdef CONFIG_PM
 219 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
 220 {
 221         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 222         int i;
 223
 224         if (device_may_wakeup(&pdev->dev)) {
 225                 for (i = 0; i < pdata->nbuttons; i++) {
 226                         struct gpio_keys_button *button = &pdata->buttons[i];
 227                         if (button->wakeup) {
 228                                 int irq = gpio_to_irq(button->gpio);
 229                                 enable_irq_wake(irq);
 230                         }
 231                 }
 232         }
 233
 234         return 0;
 235 }
 236
 237 static int gpio_keys_resume(struct platform_device *pdev)
 238 {
 239         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 240         int i;
 241
 242         if (device_may_wakeup(&pdev->dev)) {
 243                 for (i = 0; i < pdata->nbuttons; i++) {
 244                         struct gpio_keys_button *button = &pdata->buttons[i];
 245                         if (button->wakeup) {
 246                                 int irq = gpio_to_irq(button->gpio);
 247                                 disable_irq_wake(irq);
 248                         }
 249                 }
 250         }
 251
 252         return 0;
 253 }
 254 #else
 255 #define gpio_keys_suspend       NULL
 256 #define gpio_keys_resume        NULL
 257 #endif
 258
 259 static struct platform_driver gpio_keys_device_driver = {
 260         .probe          = gpio_keys_probe,
 261         .remove         = __devexit_p(gpio_keys_remove),
 262         .suspend        = gpio_keys_suspend,
 263         .resume         = gpio_keys_resume,
 264         .driver         = {
 265                 .name   = "gpio-keys",
 266                 .owner  = THIS_MODULE,
 267         }
 268 };
 269
 270 static int __init gpio_keys_init(void)
 271 {
 272         return platform_driver_register(&gpio_keys_device_driver);
 273 }
 274
 275 static void __exit gpio_keys_exit(void)
 276 {
 277         platform_driver_unregister(&gpio_keys_device_driver);
 278 }
 279
 280 module_init(gpio_keys_init);
 281 module_exit(gpio_keys_exit);
 282
 283 MODULE_LICENSE("GPL");
 284 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
 285 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
 286 MODULE_ALIAS("platform:gpio-keys");