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