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