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 13 #include <linux/init.h> 14 #include <linux/fs.h> 15 #include <linux/interrupt.h> 16 #include <linux/irq.h> 17 #include <linux/sched.h> 18 #include <linux/pm.h> 19 #include <linux/sysctl.h> 20 #include <linux/proc_fs.h> 21 #include <linux/delay.h> 22 #include <linux/platform_device.h> 23 #include <linux/input.h> 24 #include <linux/gpio_keys.h> 25 #include <linux/workqueue.h> 26 27 #include <asm/gpio.h> 28 29 struct gpio_button_data { 30 struct gpio_keys_button *button; 31 struct input_dev *input; 32 struct timer_list timer; 33 struct work_struct work; 34 }; 35 36 struct gpio_keys_drvdata { 37 struct input_dev *input; 38 struct gpio_button_data data[0]; 39 }; 40 41 static void gpio_keys_report_event(struct work_struct *work) 42 { 43 struct gpio_button_data *bdata = 44 container_of(work, struct gpio_button_data, work); 45 struct gpio_keys_button *button = bdata->button; 46 struct input_dev *input = bdata->input; 47 unsigned int type = button->type ?: EV_KEY; 48 int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low; 49 50 input_event(input, type, button->code, !!state); 51 input_sync(input); 52 } 53 54 static void gpio_keys_timer(unsigned long _data) 55 { 56 struct gpio_button_data *data = (struct gpio_button_data *)_data; 57 58 schedule_work(&data->work); 59 } 60 61 static irqreturn_t gpio_keys_isr(int irq, void *dev_id) 62 { 63 struct gpio_button_data *bdata = dev_id; 64 struct gpio_keys_button *button = bdata->button; 65 66 BUG_ON(irq != gpio_to_irq(button->gpio)); 67 68 if (button->debounce_interval) 69 mod_timer(&bdata->timer, 70 jiffies + msecs_to_jiffies(button->debounce_interval)); 71 else 72 schedule_work(&bdata->work); 73 74 return IRQ_HANDLED; 75 } 76 77 static int __devinit gpio_keys_probe(struct platform_device *pdev) 78 { 79 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 80 struct gpio_keys_drvdata *ddata; 81 struct input_dev *input; 82 int i, error; 83 int wakeup = 0; 84 85 ddata = kzalloc(sizeof(struct gpio_keys_drvdata) + 86 pdata->nbuttons * sizeof(struct gpio_button_data), 87 GFP_KERNEL); 88 input = input_allocate_device(); 89 if (!ddata || !input) { 90 error = -ENOMEM; 91 goto fail1; 92 } 93 94 platform_set_drvdata(pdev, ddata); 95 96 input->name = pdev->name; 97 input->phys = "gpio-keys/input0"; 98 input->dev.parent = &pdev->dev; 99 100 input->id.bustype = BUS_HOST; 101 input->id.vendor = 0x0001; 102 input->id.product = 0x0001; 103 input->id.version = 0x0100; 104 105 /* Enable auto repeat feature of Linux input subsystem */ 106 if (pdata->rep) 107 __set_bit(EV_REP, input->evbit); 108 109 ddata->input = input; 110 111 for (i = 0; i < pdata->nbuttons; i++) { 112 struct gpio_keys_button *button = &pdata->buttons[i]; 113 struct gpio_button_data *bdata = &ddata->data[i]; 114 int irq; 115 unsigned int type = button->type ?: EV_KEY; 116 117 bdata->input = input; 118 bdata->button = button; 119 setup_timer(&bdata->timer, 120 gpio_keys_timer, (unsigned long)bdata); 121 INIT_WORK(&bdata->work, gpio_keys_report_event); 122 123 error = gpio_request(button->gpio, button->desc ?: "gpio_keys"); 124 if (error < 0) { 125 pr_err("gpio-keys: failed to request GPIO %d," 126 " error %d\n", button->gpio, error); 127 goto fail2; 128 } 129 130 error = gpio_direction_input(button->gpio); 131 if (error < 0) { 132 pr_err("gpio-keys: failed to configure input" 133 " direction for GPIO %d, error %d\n", 134 button->gpio, error); 135 gpio_free(button->gpio); 136 goto fail2; 137 } 138 139 irq = gpio_to_irq(button->gpio); 140 if (irq < 0) { 141 error = irq; 142 pr_err("gpio-keys: Unable to get irq number" 143 " for GPIO %d, error %d\n", 144 button->gpio, error); 145 gpio_free(button->gpio); 146 goto fail2; 147 } 148 149 error = request_irq(irq, gpio_keys_isr, 150 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, 151 button->desc ? button->desc : "gpio_keys", 152 bdata); 153 if (error) { 154 pr_err("gpio-keys: Unable to claim irq %d; error %d\n", 155 irq, error); 156 gpio_free(button->gpio); 157 goto fail2; 158 } 159 160 if (button->wakeup) 161 wakeup = 1; 162 163 input_set_capability(input, type, button->code); 164 } 165 166 error = input_register_device(input); 167 if (error) { 168 pr_err("gpio-keys: Unable to register input device, " 169 "error: %d\n", error); 170 goto fail2; 171 } 172 173 device_init_wakeup(&pdev->dev, wakeup); 174 175 return 0; 176 177 fail2: 178 while (--i >= 0) { 179 free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]); 180 if (pdata->buttons[i].debounce_interval) 181 del_timer_sync(&ddata->data[i].timer); 182 cancel_work_sync(&ddata->data[i].work); 183 gpio_free(pdata->buttons[i].gpio); 184 } 185 186 platform_set_drvdata(pdev, NULL); 187 fail1: 188 input_free_device(input); 189 kfree(ddata); 190 191 return error; 192 } 193 194 static int __devexit gpio_keys_remove(struct platform_device *pdev) 195 { 196 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 197 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); 198 struct input_dev *input = ddata->input; 199 int i; 200 201 device_init_wakeup(&pdev->dev, 0); 202 203 for (i = 0; i < pdata->nbuttons; i++) { 204 int irq = gpio_to_irq(pdata->buttons[i].gpio); 205 free_irq(irq, &ddata->data[i]); 206 if (pdata->buttons[i].debounce_interval) 207 del_timer_sync(&ddata->data[i].timer); 208 cancel_work_sync(&ddata->data[i].work); 209 gpio_free(pdata->buttons[i].gpio); 210 } 211 212 input_unregister_device(input); 213 214 return 0; 215 } 216 217 218 #ifdef CONFIG_PM 219 static int gpio_keys_suspend(struct platform_device *pdev, pm_message_t state) 220 { 221 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 222 int i; 223 224 if (device_may_wakeup(&pdev->dev)) { 225 for (i = 0; i < pdata->nbuttons; i++) { 226 struct gpio_keys_button *button = &pdata->buttons[i]; 227 if (button->wakeup) { 228 int irq = gpio_to_irq(button->gpio); 229 enable_irq_wake(irq); 230 } 231 } 232 } 233 234 return 0; 235 } 236 237 static int gpio_keys_resume(struct platform_device *pdev) 238 { 239 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 240 int i; 241 242 if (device_may_wakeup(&pdev->dev)) { 243 for (i = 0; i < pdata->nbuttons; i++) { 244 struct gpio_keys_button *button = &pdata->buttons[i]; 245 if (button->wakeup) { 246 int irq = gpio_to_irq(button->gpio); 247 disable_irq_wake(irq); 248 } 249 } 250 } 251 252 return 0; 253 } 254 #else 255 #define gpio_keys_suspend NULL 256 #define gpio_keys_resume NULL 257 #endif 258 259 static struct platform_driver gpio_keys_device_driver = { 260 .probe = gpio_keys_probe, 261 .remove = __devexit_p(gpio_keys_remove), 262 .suspend = gpio_keys_suspend, 263 .resume = gpio_keys_resume, 264 .driver = { 265 .name = "gpio-keys", 266 .owner = THIS_MODULE, 267 } 268 }; 269 270 static int __init gpio_keys_init(void) 271 { 272 return platform_driver_register(&gpio_keys_device_driver); 273 } 274 275 static void __exit gpio_keys_exit(void) 276 { 277 platform_driver_unregister(&gpio_keys_device_driver); 278 } 279 280 module_init(gpio_keys_init); 281 module_exit(gpio_keys_exit); 282 283 MODULE_LICENSE("GPL"); 284 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>"); 285 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs"); 286 MODULE_ALIAS("platform:gpio-keys"); 287