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_SHARED | 151 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, 152 button->desc ? button->desc : "gpio_keys", 153 bdata); 154 if (error) { 155 pr_err("gpio-keys: Unable to claim irq %d; error %d\n", 156 irq, error); 157 gpio_free(button->gpio); 158 goto fail2; 159 } 160 161 if (button->wakeup) 162 wakeup = 1; 163 164 input_set_capability(input, type, button->code); 165 } 166 167 error = input_register_device(input); 168 if (error) { 169 pr_err("gpio-keys: Unable to register input device, " 170 "error: %d\n", error); 171 goto fail2; 172 } 173 174 device_init_wakeup(&pdev->dev, wakeup); 175 176 return 0; 177 178 fail2: 179 while (--i >= 0) { 180 free_irq(gpio_to_irq(pdata->buttons[i].gpio), &ddata->data[i]); 181 if (pdata->buttons[i].debounce_interval) 182 del_timer_sync(&ddata->data[i].timer); 183 cancel_work_sync(&ddata->data[i].work); 184 gpio_free(pdata->buttons[i].gpio); 185 } 186 187 platform_set_drvdata(pdev, NULL); 188 fail1: 189 input_free_device(input); 190 kfree(ddata); 191 192 return error; 193 } 194 195 static int __devexit gpio_keys_remove(struct platform_device *pdev) 196 { 197 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 198 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); 199 struct input_dev *input = ddata->input; 200 int i; 201 202 device_init_wakeup(&pdev->dev, 0); 203 204 for (i = 0; i < pdata->nbuttons; i++) { 205 int irq = gpio_to_irq(pdata->buttons[i].gpio); 206 free_irq(irq, &ddata->data[i]); 207 if (pdata->buttons[i].debounce_interval) 208 del_timer_sync(&ddata->data[i].timer); 209 cancel_work_sync(&ddata->data[i].work); 210 gpio_free(pdata->buttons[i].gpio); 211 } 212 213 input_unregister_device(input); 214 215 return 0; 216 } 217 218 219 #ifdef CONFIG_PM 220 static int gpio_keys_suspend(struct device *dev) 221 { 222 struct platform_device *pdev = to_platform_device(dev); 223 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 224 int i; 225 226 if (device_may_wakeup(&pdev->dev)) { 227 for (i = 0; i < pdata->nbuttons; i++) { 228 struct gpio_keys_button *button = &pdata->buttons[i]; 229 if (button->wakeup) { 230 int irq = gpio_to_irq(button->gpio); 231 enable_irq_wake(irq); 232 } 233 } 234 } 235 236 return 0; 237 } 238 239 static int gpio_keys_resume(struct device *dev) 240 { 241 struct platform_device *pdev = to_platform_device(dev); 242 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 243 int i; 244 245 if (device_may_wakeup(&pdev->dev)) { 246 for (i = 0; i < pdata->nbuttons; i++) { 247 struct gpio_keys_button *button = &pdata->buttons[i]; 248 if (button->wakeup) { 249 int irq = gpio_to_irq(button->gpio); 250 disable_irq_wake(irq); 251 } 252 } 253 } 254 255 return 0; 256 } 257 258 static const struct dev_pm_ops gpio_keys_pm_ops = { 259 .suspend = gpio_keys_suspend, 260 .resume = gpio_keys_resume, 261 }; 262 #endif 263 264 static struct platform_driver gpio_keys_device_driver = { 265 .probe = gpio_keys_probe, 266 .remove = __devexit_p(gpio_keys_remove), 267 .driver = { 268 .name = "gpio-keys", 269 .owner = THIS_MODULE, 270 #ifdef CONFIG_PM 271 .pm = &gpio_keys_pm_ops, 272 #endif 273 } 274 }; 275 276 static int __init gpio_keys_init(void) 277 { 278 return platform_driver_register(&gpio_keys_device_driver); 279 } 280 281 static void __exit gpio_keys_exit(void) 282 { 283 platform_driver_unregister(&gpio_keys_device_driver); 284 } 285 286 module_init(gpio_keys_init); 287 module_exit(gpio_keys_exit); 288 289 MODULE_LICENSE("GPL"); 290 MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>"); 291 MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs"); 292 MODULE_ALIAS("platform:gpio-keys"); 293