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 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(button, bdata->input);
  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         ddata->input = input;
 102
 103         for (i = 0; i < pdata->nbuttons; i++) {
 104                 struct gpio_keys_button *button = &pdata->buttons[i];
 105                 struct gpio_button_data *bdata = &ddata->data[i];
 106                 int irq;
 107                 unsigned int type = button->type ?: EV_KEY;
 108
 109                 bdata->input = input;
 110                 setup_timer(&bdata->timer,
 111                             gpio_check_button, (unsigned long)bdata);
 112
 113                 error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
 114                 if (error < 0) {
 115                         pr_err("gpio-keys: failed to request GPIO %d,"
 116                                 " error %d\n", button->gpio, error);
 117                         goto fail2;
 118                 }
 119
 120                 error = gpio_direction_input(button->gpio);
 121                 if (error < 0) {
 122                         pr_err("gpio-keys: failed to configure input"
 123                                 " direction for GPIO %d, error %d\n",
 124                                 button->gpio, error);
 125                         gpio_free(button->gpio);
 126                         goto fail2;
 127                 }
 128
 129                 irq = gpio_to_irq(button->gpio);
 130                 if (irq < 0) {
 131                         error = irq;
 132                         pr_err("gpio-keys: Unable to get irq number"
 133                                 " for GPIO %d, error %d\n",
 134                                 button->gpio, error);
 135                         gpio_free(button->gpio);
 136                         goto fail2;
 137                 }
 138
 139                 error = request_irq(irq, gpio_keys_isr,
 140                                     IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING |
 141                                         IRQF_TRIGGER_FALLING,
 142                                     button->desc ? button->desc : "gpio_keys",
 143                                     bdata);
 144                 if (error) {
 145                         pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
 146                                 irq, error);
 147                         gpio_free(button->gpio);
 148                         goto fail2;
 149                 }
 150
 151                 if (button->wakeup)
 152                         wakeup = 1;
 153
 154                 input_set_capability(input, type, button->code);
 155         }
 156
 157         error = input_register_device(input);
 158         if (error) {
 159                 pr_err("gpio-keys: Unable to register input device, "
 160                         "error: %d\n", error);
 161                 goto fail2;
 162         }
 163
 164         device_init_wakeup(&pdev->dev, wakeup);
 165
 166         return 0;
 167
 168  fail2:
 169         while (--i >= 0) {
 170                 free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]);
 171                 if (pdata->buttons[i].debounce_interval)
 172                         del_timer_sync(&ddata->data[i].timer);
 173                 gpio_free(pdata->buttons[i].gpio);
 174         }
 175
 176         platform_set_drvdata(pdev, NULL);
 177  fail1:
 178         input_free_device(input);
 179         kfree(ddata);
 180
 181         return error;
 182 }
 183
 184 static int __devexit gpio_keys_remove(struct platform_device *pdev)
 185 {
 186         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 187         struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev);
 188         struct input_dev *input = ddata->input;
 189         int i;
 190
 191         device_init_wakeup(&pdev->dev, 0);
 192
 193         for (i = 0; i < pdata->nbuttons; i++) {
 194                 int irq = gpio_to_irq(pdata->buttons[i].gpio);
 195                 free_irq(irq, &ddata->data[i]);
 196                 if (pdata->buttons[i].debounce_interval)
 197                         del_timer_sync(&ddata->data[i].timer);
 198                 gpio_free(pdata->buttons[i].gpio);
 199         }
 200
 201         input_unregister_device(input);
 202
 203         return 0;
 204 }
 205
 206
 207 #ifdef CONFIG_PM
 208 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
 209 {
 210         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 211         int i;
 212
 213         if (device_may_wakeup(&pdev->dev)) {
 214                 for (i = 0; i < pdata->nbuttons; i++) {
 215                         struct gpio_keys_button *button = &pdata->buttons[i];
 216                         if (button->wakeup) {
 217                                 int irq = gpio_to_irq(button->gpio);
 218                                 enable_irq_wake(irq);
 219                         }
 220                 }
 221         }
 222
 223         return 0;
 224 }
 225
 226 static int gpio_keys_resume(struct platform_device *pdev)
 227 {
 228         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 229         int i;
 230
 231         if (device_may_wakeup(&pdev->dev)) {
 232                 for (i = 0; i < pdata->nbuttons; i++) {
 233                         struct gpio_keys_button *button = &pdata->buttons[i];
 234                         if (button->wakeup) {
 235                                 int irq = gpio_to_irq(button->gpio);
 236                                 disable_irq_wake(irq);
 237                         }
 238                 }
 239         }
 240
 241         return 0;
 242 }
 243 #else
 244 #define gpio_keys_suspend       NULL
 245 #define gpio_keys_resume        NULL
 246 #endif
 247
 248 struct platform_driver gpio_keys_device_driver = {
 249         .probe          = gpio_keys_probe,
 250         .remove         = __devexit_p(gpio_keys_remove),
 251         .suspend        = gpio_keys_suspend,
 252         .resume         = gpio_keys_resume,
 253         .driver         = {
 254                 .name   = "gpio-keys",
 255                 .owner  = THIS_MODULE,
 256         }
 257 };
 258
 259 static int __init gpio_keys_init(void)
 260 {
 261         return platform_driver_register(&gpio_keys_device_driver);
 262 }
 263
 264 static void __exit gpio_keys_exit(void)
 265 {
 266         platform_driver_unregister(&gpio_keys_device_driver);
 267 }
 268
 269 module_init(gpio_keys_init);
 270 module_exit(gpio_keys_exit);
 271
 272 MODULE_LICENSE("GPL");
 273 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
 274 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
 275 MODULE_ALIAS("platform:gpio-keys");