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/irq.h>
  26 #include <linux/gpio_keys.h>
  27
  28 #include <asm/gpio.h>
  29
  30 static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
  31 {
  32         int i;
  33         struct platform_device *pdev = dev_id;
  34         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
  35         struct input_dev *input = platform_get_drvdata(pdev);
  36
  37         for (i = 0; i < pdata->nbuttons; i++) {
  38                 struct gpio_keys_button *button = &pdata->buttons[i];
  39                 int gpio = button->gpio;
  40
  41                 if (irq == gpio_to_irq(gpio)) {
  42                         unsigned int type = button->type ?: EV_KEY;
  43                         int state = (gpio_get_value(gpio) ? 1 : 0) ^ button->active_low;
  44
  45                         input_event(input, type, button->code, !!state);
  46                         input_sync(input);
  47                 }
  48         }
  49
  50         return IRQ_HANDLED;
  51 }
  52
  53 static int __devinit gpio_keys_probe(struct platform_device *pdev)
  54 {
  55         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
  56         struct input_dev *input;
  57         int i, error;
  58         int wakeup = 0;
  59
  60         input = input_allocate_device();
  61         if (!input)
  62                 return -ENOMEM;
  63
  64         platform_set_drvdata(pdev, input);
  65
  66         input->evbit[0] = BIT(EV_KEY);
  67
  68         input->name = pdev->name;
  69         input->phys = "gpio-keys/input0";
  70         input->dev.parent = &pdev->dev;
  71
  72         input->id.bustype = BUS_HOST;
  73         input->id.vendor = 0x0001;
  74         input->id.product = 0x0001;
  75         input->id.version = 0x0100;
  76
  77         for (i = 0; i < pdata->nbuttons; i++) {
  78                 struct gpio_keys_button *button = &pdata->buttons[i];
  79                 int irq = gpio_to_irq(button->gpio);
  80                 unsigned int type = button->type ?: EV_KEY;
  81
  82                 if (irq < 0) {
  83                         error = irq;
  84                         printk(KERN_ERR
  85                                 "gpio-keys: "
  86                                 "Unable to get irq number for GPIO %d,"
  87                                 "error %d\n",
  88                                 button->gpio, error);
  89                         goto fail;
  90                 }
  91
  92                 error = request_irq(irq, gpio_keys_isr,
  93                                     IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING |
  94                                         IRQF_TRIGGER_FALLING,
  95                                     button->desc ? button->desc : "gpio_keys",
  96                                     pdev);
  97                 if (error) {
  98                         printk(KERN_ERR
  99                                 "gpio-keys: Unable to claim irq %d; error %d\n",
 100                                 irq, error);
 101                         goto fail;
 102                 }
 103
 104                 if (button->wakeup)
 105                         wakeup = 1;
 106
 107                 input_set_capability(input, type, button->code);
 108         }
 109
 110         error = input_register_device(input);
 111         if (error) {
 112                 printk(KERN_ERR
 113                         "gpio-keys: Unable to register input device, "
 114                         "error: %d\n", error);
 115                 goto fail;
 116         }
 117
 118         device_init_wakeup(&pdev->dev, wakeup);
 119
 120         return 0;
 121
 122  fail:
 123         while (--i >= 0)
 124                 free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);
 125
 126         platform_set_drvdata(pdev, NULL);
 127         input_free_device(input);
 128
 129         return error;
 130 }
 131
 132 static int __devexit gpio_keys_remove(struct platform_device *pdev)
 133 {
 134         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 135         struct input_dev *input = platform_get_drvdata(pdev);
 136         int i;
 137
 138         device_init_wakeup(&pdev->dev, 0);
 139
 140         for (i = 0; i < pdata->nbuttons; i++) {
 141                 int irq = gpio_to_irq(pdata->buttons[i].gpio);
 142                 free_irq(irq, pdev);
 143         }
 144
 145         input_unregister_device(input);
 146
 147         return 0;
 148 }
 149
 150
 151 #ifdef CONFIG_PM
 152 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
 153 {
 154         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 155         int i;
 156
 157         if (device_may_wakeup(&pdev->dev)) {
 158                 for (i = 0; i < pdata->nbuttons; i++) {
 159                         struct gpio_keys_button *button = &pdata->buttons[i];
 160                         if (button->wakeup) {
 161                                 int irq = gpio_to_irq(button->gpio);
 162                                 enable_irq_wake(irq);
 163                         }
 164                 }
 165         }
 166
 167         return 0;
 168 }
 169
 170 static int gpio_keys_resume(struct platform_device *pdev)
 171 {
 172         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 173         int i;
 174
 175         if (device_may_wakeup(&pdev->dev)) {
 176                 for (i = 0; i < pdata->nbuttons; i++) {
 177                         struct gpio_keys_button *button = &pdata->buttons[i];
 178                         if (button->wakeup) {
 179                                 int irq = gpio_to_irq(button->gpio);
 180                                 disable_irq_wake(irq);
 181                         }
 182                 }
 183         }
 184
 185         return 0;
 186 }
 187 #else
 188 #define gpio_keys_suspend       NULL
 189 #define gpio_keys_resume        NULL
 190 #endif
 191
 192 struct platform_driver gpio_keys_device_driver = {
 193         .probe          = gpio_keys_probe,
 194         .remove         = __devexit_p(gpio_keys_remove),
 195         .suspend        = gpio_keys_suspend,
 196         .resume         = gpio_keys_resume,
 197         .driver         = {
 198                 .name   = "gpio-keys",
 199         }
 200 };
 201
 202 static int __init gpio_keys_init(void)
 203 {
 204         return platform_driver_register(&gpio_keys_device_driver);
 205 }
 206
 207 static void __exit gpio_keys_exit(void)
 208 {
 209         platform_driver_unregister(&gpio_keys_device_driver);
 210 }
 211
 212 module_init(gpio_keys_init);
 213 module_exit(gpio_keys_exit);
 214
 215 MODULE_LICENSE("GPL");
 216 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
 217 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");