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 struct gpio_button_data { 30 struct gpio_keys_button *button; 31 struct input_dev *input; 32 struct timer_list timer; 33 }; 34 35 struct gpio_keys_drvdata { 36 struct input_dev *input; 37 struct gpio_button_data data[0]; 38 }; 39 40 static void gpio_keys_report_event(struct gpio_keys_button *button, 41 struct input_dev *input) 42 { 43 unsigned int type = button->type ?: EV_KEY; 44 int state = (gpio_get_value(button->gpio) ? 1 : 0) ^ button->active_low; 45 46 input_event(input, type, button->code, !!state); 47 input_sync(input); 48 } 49 50 static void gpio_check_button(unsigned long _data) 51 { 52 struct gpio_button_data *data = (struct gpio_button_data *)_data; 53 54 gpio_keys_report_event(data->button, data->input); 55 } 56 57 static irqreturn_t gpio_keys_isr(int irq, void *dev_id) 58 { 59 struct platform_device *pdev = dev_id; 60 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 61 struct gpio_keys_drvdata *ddata = platform_get_drvdata(pdev); 62 int i; 63 64 for (i = 0; i < pdata->nbuttons; i++) { 65 struct gpio_keys_button *button = &pdata->buttons[i]; 66 67 if (irq == gpio_to_irq(button->gpio)) { 68 struct gpio_button_data *bdata = &ddata->data[i]; 69 70 if (button->debounce_interval) 71 mod_timer(&bdata->timer, 72 jiffies + 73 msecs_to_jiffies(button->debounce_interval)); 74 else 75 gpio_keys_report_event(button, bdata->input); 76 77 return IRQ_HANDLED; 78 } 79 } 80 81 return IRQ_NONE; 82 } 83 84 static int __devinit gpio_keys_probe(struct platform_device *pdev) 85 { 86 struct gpio_keys_platform_data *pdata = pdev->dev.platform_data; 87 struct gpio_keys_drvdata *ddata; 88 struct input_dev *input; 89 int i, error; 90 int wakeup = 0; 91 92 ddata = kzalloc(sizeof(struct gpio_keys_drvdata) + 93 pdata->nbuttons * sizeof(struct gpio_button_data), 94 GFP_KERNEL); 95 input = input_allocate_device(); 96 if (!ddata || !input) { 97 error = -ENOMEM; 98 goto fail1; 99 } 100 101 platform_set_drvdata(pdev, ddata); 102 103 input->name = pdev->name; 104 input->phys = "gpio-keys/input0"; 105 input->dev.parent = &pdev->dev; 106 107 input->id.bustype = BUS_HOST; 108 input->id.vendor = 0x0001; 109 input->id.product = 0x0001; 110 input->id.version = 0x0100; 111 112 ddata->input = input; 113 114 for (i = 0; i < pdata->nbuttons; i++) { 115 struct gpio_keys_button *button = &pdata->buttons[i]; 116 struct gpio_button_data *bdata = &ddata->data[i]; 117 int irq; 118 unsigned int type = button->type ?: EV_KEY; 119 120 bdata->input = input; 121 setup_timer(&bdata->timer, 122 gpio_check_button, (unsigned long)bdata); 123 124 error = gpio_request(button->gpio, button->desc ?: "gpio_keys"); 125 if (error < 0) { 126 pr_err("gpio-keys: failed to request GPIO %d," 127 " error %d\n", button->gpio, error); 128 goto fail2; 129 } 130 131 error = gpio_direction_input(button->gpio); 132 if (error < 0) { 133 pr_err("gpio-keys: failed to configure input" 134 " direction for GPIO %d, error %d\n", 135 button->gpio, error); 136 gpio_free(button->gpio); 137 goto fail2; 138 } 139 140 irq = gpio_to_irq(button->gpio); 141 if (irq < 0) { 142 error = irq; 143 pr_err("gpio-keys: Unable to get irq number" 144 " for GPIO %d, error %d\n", 145 button->gpio, error); 146 gpio_free(button->gpio); 147 goto fail2; 148 } 149 150 error = request_irq(irq, gpio_keys_isr, 151 IRQF_SAMPLE_RANDOM | IRQF_TRIGGER_RISING | 152 IRQF_TRIGGER_FALLING, 153 button->desc ? button->desc : "gpio_keys", 154 pdev); 155 if (error) { 156 pr_err("gpio-keys: Unable to claim irq %d; error %d\n", 157 irq, error); 158 gpio_free(button->gpio); 159 goto fail2; 160 } 161 162 if (button->wakeup) 163 wakeup = 1; 164 165 input_set_capability(input, type, button->code); 166 } 167 168 error = input_register_device(input); 169 if (error) { 170 pr_err("gpio-keys: Unable to register input device, " 171 "error: %d\n", error); 172 goto fail2; 173 } 174 175 device_init_wakeup(&pdev->dev, wakeup); 176 177 return 0; 178 179 fail2: 180 while (--i >= 0) { 181 free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev); 182 if (pdata->buttons[i].debounce_interval) 183 del_timer_sync(&ddata->data[i].timer); 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, pdev); 207 if (pdata->buttons[i].debounce_interval) 208 del_timer_sync(&ddata->data[i].timer); 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 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