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 58 input = input_allocate_device(); 59 if (!input) 60 return -ENOMEM; 61 62 platform_set_drvdata(pdev, input); 63 64 input->evbit[0] = BIT(EV_KEY); 65 66 input->name = pdev->name; 67 input->phys = "gpio-keys/input0"; 68 input->dev.parent = &pdev->dev; 69 70 input->id.bustype = BUS_HOST; 71 input->id.vendor = 0x0001; 72 input->id.product = 0x0001; 73 input->id.version = 0x0100; 74 75 for (i = 0; i < pdata->nbuttons; i++) { 76 struct gpio_keys_button *button = &pdata->buttons[i]; 77 int irq = gpio_to_irq(button->gpio); 78 unsigned int type = button->type ?: EV_KEY; 79 80 set_irq_type(irq, IRQ_TYPE_EDGE_BOTH); 81 error = request_irq(irq, gpio_keys_isr, IRQF_SAMPLE_RANDOM, 82 button->desc ? button->desc : "gpio_keys", 83 pdev); 84 if (error) { 85 printk(KERN_ERR "gpio-keys: unable to claim irq %d; error %d\n", 86 irq, error); 87 goto fail; 88 } 89 90 input_set_capability(input, type, button->code); 91 } 92 93 error = input_register_device(input); 94 if (error) { 95 printk(KERN_ERR "Unable to register gpio-keys input device\n"); 96 goto fail; 97 } 98 99 return 0; 100 101 fail: 102 for (i = i - 1; i >= 0; i--) 103 free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev); 104 105 input_free_device(input); 106 107 return error; 108 } 109 110 static int __devexit gpio_keys_remove(struct platform_device *pdev) 111 { 112 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 113 struct input_dev *input = platform_get_drvdata(pdev); 114 int i; 115 116 for (i = 0; i < pdata->nbuttons; i++) { 117 int irq = gpio_to_irq(pdata->buttons[i].gpio); 118 free_irq(irq, pdev); 119 } 120 121 input_unregister_device(input); 122 123 return 0; 124 } 125 126 struct platform_driver gpio_keys_device_driver = { 127 .probe = gpio_keys_probe, 128 .remove = __devexit_p(gpio_keys_remove), 129 .driver = { 130 .name = "gpio-keys", 131 } 132 }; 133 134 static int __init gpio_keys_init(void) 135 { 136 return platform_driver_register(&gpio_keys_device_driver); 137 } 138 139 static void __exit gpio_keys_exit(void) 140 { 141 platform_driver_unregister(&gpio_keys_device_driver); 142 } 143 144 module_init(gpio_keys_init); 145 module_exit(gpio_keys_exit); 146 147 MODULE_LICENSE("GPL"); 148 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>"); 149 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs"); 150