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