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                         return IRQ_HANDLED;
  47                 }
  48         }
  49
  50         return IRQ_NONE;
  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_MASK(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;
  80                 unsigned int type = button->type ?: EV_KEY;
  81
  82                 error = gpio_request(button->gpio, button->desc ?: "gpio_keys");
  83                 if (error < 0) {
  84                         pr_err("gpio-keys: failed to request GPIO %d,"
  85                                 " error %d\n", button->gpio, error);
  86                         goto fail;
  87                 }
  88
  89                 error = gpio_direction_input(button->gpio);
  90                 if (error < 0) {
  91                         pr_err("gpio-keys: failed to configure input"
  92                                 " direction for GPIO %d, error %d\n",
  93                                 button->gpio, error);
  94                         gpio_free(button->gpio);
  95                         goto fail;
  96                 }
  97
  98                 irq = gpio_to_irq(button->gpio);
  99                 if (irq < 0) {
 100                         error = irq;
 101                         pr_err("gpio-keys: Unable to get irq number"
 102                                 " for GPIO %d, error %d\n",
 103                                 button->gpio, error);
 104                         gpio_free(button->gpio);
 105                         goto fail;
 106                 }
 107
 108                 error = request_irq(irq, gpio_keys_isr,
 109                                     IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING |
 110                                         IRQF_TRIGGER_FALLING,
 111                                     button->desc ? button->desc : "gpio_keys",
 112                                     pdev);
 113                 if (error) {
 114                         pr_err("gpio-keys: Unable to claim irq %d; error %d\n",
 115                                 irq, error);
 116                         gpio_free(button->gpio);
 117                         goto fail;
 118                 }
 119
 120                 if (button->wakeup)
 121                         wakeup = 1;
 122
 123                 input_set_capability(input, type, button->code);
 124         }
 125
 126         error = input_register_device(input);
 127         if (error) {
 128                 pr_err("gpio-keys: Unable to register input device, "
 129                         "error: %d\n", error);
 130                 goto fail;
 131         }
 132
 133         device_init_wakeup(&pdev->dev, wakeup);
 134
 135         return 0;
 136
 137  fail:
 138         while (--i >= 0) {
 139                 free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);
 140                 gpio_free(pdata->buttons[i].gpio);
 141         }
 142
 143         platform_set_drvdata(pdev, NULL);
 144         input_free_device(input);
 145
 146         return error;
 147 }
 148
 149 static int __devexit gpio_keys_remove(struct platform_device *pdev)
 150 {
 151         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 152         struct input_dev *input = platform_get_drvdata(pdev);
 153         int i;
 154
 155         device_init_wakeup(&pdev->dev, 0);
 156
 157         for (i = 0; i < pdata->nbuttons; i++) {
 158                 int irq = gpio_to_irq(pdata->buttons[i].gpio);
 159                 free_irq(irq, pdev);
 160                 gpio_free(pdata->buttons[i].gpio);
 161         }
 162
 163         input_unregister_device(input);
 164
 165         return 0;
 166 }
 167
 168
 169 #ifdef CONFIG_PM
 170 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state)
 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                                 enable_irq_wake(irq);
 181                         }
 182                 }
 183         }
 184
 185         return 0;
 186 }
 187
 188 static int gpio_keys_resume(struct platform_device *pdev)
 189 {
 190         struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
 191         int i;
 192
 193         if (device_may_wakeup(&pdev->dev)) {
 194                 for (i = 0; i < pdata->nbuttons; i++) {
 195                         struct gpio_keys_button *button = &pdata->buttons[i];
 196                         if (button->wakeup) {
 197                                 int irq = gpio_to_irq(button->gpio);
 198                                 disable_irq_wake(irq);
 199                         }
 200                 }
 201         }
 202
 203         return 0;
 204 }
 205 #else
 206 #define gpio_keys_suspend       NULL
 207 #define gpio_keys_resume        NULL
 208 #endif
 209
 210 struct platform_driver gpio_keys_device_driver = {
 211         .probe          = gpio_keys_probe,
 212         .remove         = __devexit_p(gpio_keys_remove),
 213         .suspend        = gpio_keys_suspend,
 214         .resume         = gpio_keys_resume,
 215         .driver         = {
 216                 .name   = "gpio-keys",
 217                 .owner  = THIS_MODULE,
 218         }
 219 };
 220
 221 static int __init gpio_keys_init(void)
 222 {
 223         return platform_driver_register(&gpio_keys_device_driver);
 224 }
 225
 226 static void __exit gpio_keys_exit(void)
 227 {
 228         platform_driver_unregister(&gpio_keys_device_driver);
 229 }
 230
 231 module_init(gpio_keys_init);
 232 module_exit(gpio_keys_exit);
 233
 234 MODULE_LICENSE("GPL");
 235 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
 236 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");
 237 MODULE_ALIAS("platform:gpio-keys");