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_MASK(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;
  79                 unsigned int type = button->type ?: EV_KEY;
  80
  81                 error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
  82                 if (error < 0) {
  83                         pr_err("gpio-keys: failed to request GPIO %d,"
  84                                 " error %d\n", button->gpio, error);
  85                         goto fail;
  86                 }
  87
  88                 error = gpio_direction_input(button->gpio);
  89                 if (error < 0) {
  90                         pr_err("gpio-keys: failed to configure input"
  91                                 " direction for GPIO %d, error %d\n",
  92                                 button->gpio, error);
  93                         gpio_free(button->gpio);
  94                         goto fail;
  95                 }
  96
  97                 irq = gpio_to_irq(button->gpio);
  98                 if (irq < 0) {
  99                         error = irq;
 100                         pr_err("gpio-keys: Unable to get irq number"
 101                                 " for GPIO %d, error %d\n",
 102                                 button->gpio, error);
 103                         gpio_free(button->gpio);
 104                         goto fail;
 105                 }
 106
 107                 error = request_irq(irq, gpio_keys_isr,
 108                                     IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING |
 109                                         IRQF_TRIGGER_FALLING,
 110                                     button->desc ? button->desc : "gpio_keys",
 111                                     pdev);
 112                 if (error) {
 113                         pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
 114                                 irq, error);
 115                         gpio_free(button->gpio);
 116                         goto fail;
 117                 }
 118
 119                 if (button->wakeup)
 120                         wakeup = 1;
 121
 122                 input_set_capability(input, type, button->code);
 123         }
 124
 125         error = input_register_device(input);
 126         if (error) {
 127                 pr_err("gpio-keys: Unable to register input device, "
 128                         "error: %d\n", error);
 129                 goto fail;
 130         }
 131
 132         device_init_wakeup(&pdev->dev, wakeup);
 133
 134         return 0;
 135
 136  fail:
 137         while (--i >= 0) {
 138                 free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);
 139                 gpio_free(pdata->buttons[i].gpio);
 140         }
 141
 142         platform_set_drvdata(pdev, NULL);
 143         input_free_device(input);
 144
 145         return error;
 146 }
 147
 148 static int __devexit gpio_keys_remove(struct platform_device *pdev)
 149 {
 150         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 151         struct input_dev *input = platform_get_drvdata(pdev);
 152         int i;
 153
 154         device_init_wakeup(&pdev->dev, 0);
 155
 156         for (i = 0; i < pdata->nbuttons; i++) {
 157                 int irq = gpio_to_irq(pdata->buttons[i].gpio);
 158                 free_irq(irq, pdev);
 159                 gpio_free(pdata->buttons[i].gpio);
 160         }
 161
 162         input_unregister_device(input);
 163
 164         return 0;
 165 }
 166
 167
 168 #ifdef CONFIG_PM
 169 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
 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                                 enable_irq_wake(irq);
 180                         }
 181                 }
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int gpio_keys_resume(struct platform_device *pdev)
 188 {
 189         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 190         int i;
 191
 192         if (device_may_wakeup(&pdev->dev)) {
 193                 for (i = 0; i < pdata->nbuttons; i++) {
 194                         struct gpio_keys_button *button = &pdata->buttons[i];
 195                         if (button->wakeup) {
 196                                 int irq = gpio_to_irq(button->gpio);
 197                                 disable_irq_wake(irq);
 198                         }
 199                 }
 200         }
 201
 202         return 0;
 203 }
 204 #else
 205 #define gpio_keys_suspend       NULL
 206 #define gpio_keys_resume        NULL
 207 #endif
 208
 209 struct platform_driver gpio_keys_device_driver = {
 210         .probe          = gpio_keys_probe,
 211         .remove         = __devexit_p(gpio_keys_remove),
 212         .suspend        = gpio_keys_suspend,
 213         .resume         = gpio_keys_resume,
 214         .driver         = {
 215                 .name   = "gpio-keys",
 216         }
 217 };
 218
 219 static int __init gpio_keys_init(void)
 220 {
 221         return platform_driver_register(&gpio_keys_device_driver);
 222 }
 223
 224 static void __exit gpio_keys_exit(void)
 225 {
 226         platform_driver_unregister(&gpio_keys_device_driver);
 227 }
 228
 229 module_init(gpio_keys_init);
 230 module_exit(gpio_keys_exit);
 231
 232 MODULE_LICENSE("GPL");
 233 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
 234 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");