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 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 set_irq_type(irq, IRQ_TYPE_EDGE_BOTH); 82 error = request_irq(irq, gpio_keys_isr, IRQF_SAMPLE_RANDOM, 83 button->desc ? button->desc : "gpio_keys", 84 pdev); 85 if (error) { 86 printk(KERN_ERR "gpio-keys: unable to claim irq %d; error %d\n", 87 irq, error); 88 goto fail; 89 } 90 91 input_set_capability(input, type, button->code); 92 } 93 94 error = input_register_device(input); 95 if (error) { 96 printk(KERN_ERR "Unable to register gpio-keys input device\n"); 97 goto fail; 98 } 99 100 return 0; 101 102 fail: 103 for (i = i - 1; i >= 0; i--) 104 free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev); 105 106 input_free_device(input); 107 108 return error; 109 } 110 111 static int __devexit gpio_keys_remove(struct platform_device *pdev) 112 { 113 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 114 struct input_dev *input = platform_get_drvdata(pdev); 115 int i; 116 117 for (i = 0; i < pdata->nbuttons; i++) { 118 int irq = gpio_to_irq(pdata->buttons[i].gpio); 119 free_irq(irq, pdev); 120 } 121 122 input_unregister_device(input); 123 124 return 0; 125 } 126 127 struct platform_driver gpio_keys_device_driver = { 128 .probe = gpio_keys_probe, 129 .remove = __devexit_p(gpio_keys_remove), 130 .driver = { 131 .name = "gpio-keys", 132 } 133 }; 134 135 static int __init gpio_keys_init(void) 136 { 137 return platform_driver_register(&gpio_keys_device_driver); 138 } 139 140 static void __exit gpio_keys_exit(void) 141 { 142 platform_driver_unregister(&gpio_keys_device_driver); 143 } 144 145 module_init(gpio_keys_init); 146 module_exit(gpio_keys_exit); 147 148 MODULE_LICENSE("GPL"); 149 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>"); 150 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs"); 151