1 /* 2 * GPIO driven matrix keyboard driver 3 * 4 * Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com> 5 * 6 * Based on corgikbd.c 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 */ 13 14 #include <linux/types.h> 15 #include <linux/delay.h> 16 #include <linux/platform_device.h> 17 #include <linux/init.h> 18 #include <linux/input.h> 19 #include <linux/irq.h> 20 #include <linux/interrupt.h> 21 #include <linux/jiffies.h> 22 #include <linux/module.h> 23 #include <linux/gpio.h> 24 #include <linux/input/matrix_keypad.h> 25 26 struct matrix_keypad { 27 const struct matrix_keypad_platform_data *pdata; 28 struct input_dev *input_dev; 29 unsigned short *keycodes; 30 31 uint32_t last_key_state[MATRIX_MAX_COLS]; 32 struct delayed_work work; 33 bool scan_pending; 34 bool stopped; 35 spinlock_t lock; 36 }; 37 38 /* 39 * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause 40 * minmal side effect when scanning other columns, here it is configured to 41 * be input, and it should work on most platforms. 42 */ 43 static void __activate_col(const struct matrix_keypad_platform_data *pdata, 44 int col, bool on) 45 { 46 bool level_on = !pdata->active_low; 47 48 if (on) { 49 gpio_direction_output(pdata->col_gpios[col], level_on); 50 } else { 51 gpio_set_value_cansleep(pdata->col_gpios[col], !level_on); 52 gpio_direction_input(pdata->col_gpios[col]); 53 } 54 } 55 56 static void activate_col(const struct matrix_keypad_platform_data *pdata, 57 int col, bool on) 58 { 59 __activate_col(pdata, col, on); 60 61 if (on && pdata->col_scan_delay_us) 62 udelay(pdata->col_scan_delay_us); 63 } 64 65 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata, 66 bool on) 67 { 68 int col; 69 70 for (col = 0; col < pdata->num_col_gpios; col++) 71 __activate_col(pdata, col, on); 72 } 73 74 static bool row_asserted(const struct matrix_keypad_platform_data *pdata, 75 int row) 76 { 77 return gpio_get_value_cansleep(pdata->row_gpios[row]) ? 78 !pdata->active_low : pdata->active_low; 79 } 80 81 static void enable_row_irqs(struct matrix_keypad *keypad) 82 { 83 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 84 int i; 85 86 for (i = 0; i < pdata->num_row_gpios; i++) 87 enable_irq(gpio_to_irq(pdata->row_gpios[i])); 88 } 89 90 static void disable_row_irqs(struct matrix_keypad *keypad) 91 { 92 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 93 int i; 94 95 for (i = 0; i < pdata->num_row_gpios; i++) 96 disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i])); 97 } 98 99 /* 100 * This gets the keys from keyboard and reports it to input subsystem 101 */ 102 static void matrix_keypad_scan(struct work_struct *work) 103 { 104 struct matrix_keypad *keypad = 105 container_of(work, struct matrix_keypad, work.work); 106 struct input_dev *input_dev = keypad->input_dev; 107 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 108 uint32_t new_state[MATRIX_MAX_COLS]; 109 int row, col, code; 110 111 /* de-activate all columns for scanning */ 112 activate_all_cols(pdata, false); 113 114 memset(new_state, 0, sizeof(new_state)); 115 116 /* assert each column and read the row status out */ 117 for (col = 0; col < pdata->num_col_gpios; col++) { 118 119 activate_col(pdata, col, true); 120 121 for (row = 0; row < pdata->num_row_gpios; row++) 122 new_state[col] |= 123 row_asserted(pdata, row) ? (1 << row) : 0; 124 125 activate_col(pdata, col, false); 126 } 127 128 for (col = 0; col < pdata->num_col_gpios; col++) { 129 uint32_t bits_changed; 130 131 bits_changed = keypad->last_key_state[col] ^ new_state[col]; 132 if (bits_changed == 0) 133 continue; 134 135 for (row = 0; row < pdata->num_row_gpios; row++) { 136 if ((bits_changed & (1 << row)) == 0) 137 continue; 138 139 code = (row << 4) + col; 140 input_event(input_dev, EV_MSC, MSC_SCAN, code); 141 input_report_key(input_dev, 142 keypad->keycodes[code], 143 new_state[col] & (1 << row)); 144 } 145 } 146 input_sync(input_dev); 147 148 memcpy(keypad->last_key_state, new_state, sizeof(new_state)); 149 150 activate_all_cols(pdata, true); 151 152 /* Enable IRQs again */ 153 spin_lock_irq(&keypad->lock); 154 keypad->scan_pending = false; 155 enable_row_irqs(keypad); 156 spin_unlock_irq(&keypad->lock); 157 } 158 159 static irqreturn_t matrix_keypad_interrupt(int irq, void *id) 160 { 161 struct matrix_keypad *keypad = id; 162 unsigned long flags; 163 164 spin_lock_irqsave(&keypad->lock, flags); 165 166 /* 167 * See if another IRQ beaten us to it and scheduled the 168 * scan already. In that case we should not try to 169 * disable IRQs again. 170 */ 171 if (unlikely(keypad->scan_pending || keypad->stopped)) 172 goto out; 173 174 disable_row_irqs(keypad); 175 keypad->scan_pending = true; 176 schedule_delayed_work(&keypad->work, 177 msecs_to_jiffies(keypad->pdata->debounce_ms)); 178 179 out: 180 spin_unlock_irqrestore(&keypad->lock, flags); 181 return IRQ_HANDLED; 182 } 183 184 static int matrix_keypad_start(struct input_dev *dev) 185 { 186 struct matrix_keypad *keypad = input_get_drvdata(dev); 187 188 keypad->stopped = false; 189 mb(); 190 191 /* 192 * Schedule an immediate key scan to capture current key state; 193 * columns will be activated and IRQs be enabled after the scan. 194 */ 195 schedule_delayed_work(&keypad->work, 0); 196 197 return 0; 198 } 199 200 static void matrix_keypad_stop(struct input_dev *dev) 201 { 202 struct matrix_keypad *keypad = input_get_drvdata(dev); 203 204 keypad->stopped = true; 205 mb(); 206 flush_work(&keypad->work.work); 207 /* 208 * matrix_keypad_scan() will leave IRQs enabled; 209 * we should disable them now. 210 */ 211 disable_row_irqs(keypad); 212 } 213 214 #ifdef CONFIG_PM 215 static int matrix_keypad_suspend(struct platform_device *pdev, pm_message_t state) 216 { 217 struct matrix_keypad *keypad = platform_get_drvdata(pdev); 218 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 219 int i; 220 221 matrix_keypad_stop(keypad->input_dev); 222 223 if (device_may_wakeup(&pdev->dev)) 224 for (i = 0; i < pdata->num_row_gpios; i++) 225 enable_irq_wake(gpio_to_irq(pdata->row_gpios[i])); 226 227 return 0; 228 } 229 230 static int matrix_keypad_resume(struct platform_device *pdev) 231 { 232 struct matrix_keypad *keypad = platform_get_drvdata(pdev); 233 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 234 int i; 235 236 if (device_may_wakeup(&pdev->dev)) 237 for (i = 0; i < pdata->num_row_gpios; i++) 238 disable_irq_wake(gpio_to_irq(pdata->row_gpios[i])); 239 240 matrix_keypad_start(keypad->input_dev); 241 242 return 0; 243 } 244 #else 245 #define matrix_keypad_suspend NULL 246 #define matrix_keypad_resume NULL 247 #endif 248 249 static int __devinit init_matrix_gpio(struct platform_device *pdev, 250 struct matrix_keypad *keypad) 251 { 252 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 253 int i, err = -EINVAL; 254 255 /* initialized strobe lines as outputs, activated */ 256 for (i = 0; i < pdata->num_col_gpios; i++) { 257 err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col"); 258 if (err) { 259 dev_err(&pdev->dev, 260 "failed to request GPIO%d for COL%d\n", 261 pdata->col_gpios[i], i); 262 goto err_free_cols; 263 } 264 265 gpio_direction_output(pdata->col_gpios[i], !pdata->active_low); 266 } 267 268 for (i = 0; i < pdata->num_row_gpios; i++) { 269 err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row"); 270 if (err) { 271 dev_err(&pdev->dev, 272 "failed to request GPIO%d for ROW%d\n", 273 pdata->row_gpios[i], i); 274 goto err_free_rows; 275 } 276 277 gpio_direction_input(pdata->row_gpios[i]); 278 } 279 280 for (i = 0; i < pdata->num_row_gpios; i++) { 281 err = request_irq(gpio_to_irq(pdata->row_gpios[i]), 282 matrix_keypad_interrupt, 283 IRQF_DISABLED | 284 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, 285 "matrix-keypad", keypad); 286 if (err) { 287 dev_err(&pdev->dev, 288 "Unable to acquire interrupt for GPIO line %i\n", 289 pdata->row_gpios[i]); 290 goto err_free_irqs; 291 } 292 } 293 294 /* initialized as disabled - enabled by input->open */ 295 disable_row_irqs(keypad); 296 return 0; 297 298 err_free_irqs: 299 while (--i >= 0) 300 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad); 301 i = pdata->num_row_gpios; 302 err_free_rows: 303 while (--i >= 0) 304 gpio_free(pdata->row_gpios[i]); 305 i = pdata->num_col_gpios; 306 err_free_cols: 307 while (--i >= 0) 308 gpio_free(pdata->col_gpios[i]); 309 310 return err; 311 } 312 313 static int __devinit matrix_keypad_probe(struct platform_device *pdev) 314 { 315 const struct matrix_keypad_platform_data *pdata; 316 const struct matrix_keymap_data *keymap_data; 317 struct matrix_keypad *keypad; 318 struct input_dev *input_dev; 319 unsigned short *keycodes; 320 int i; 321 int err; 322 323 pdata = pdev->dev.platform_data; 324 if (!pdata) { 325 dev_err(&pdev->dev, "no platform data defined\n"); 326 return -EINVAL; 327 } 328 329 keymap_data = pdata->keymap_data; 330 if (!keymap_data) { 331 dev_err(&pdev->dev, "no keymap data defined\n"); 332 return -EINVAL; 333 } 334 335 if (!keymap_data->max_keymap_size) { 336 dev_err(&pdev->dev, "invalid keymap data supplied\n"); 337 return -EINVAL; 338 } 339 340 keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL); 341 keycodes = kzalloc(keymap_data->max_keymap_size * 342 sizeof(keypad->keycodes), 343 GFP_KERNEL); 344 input_dev = input_allocate_device(); 345 if (!keypad || !keycodes || !input_dev) { 346 err = -ENOMEM; 347 goto err_free_mem; 348 } 349 350 keypad->input_dev = input_dev; 351 keypad->pdata = pdata; 352 keypad->keycodes = keycodes; 353 keypad->stopped = true; 354 INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan); 355 spin_lock_init(&keypad->lock); 356 357 input_dev->name = pdev->name; 358 input_dev->id.bustype = BUS_HOST; 359 input_dev->dev.parent = &pdev->dev; 360 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); 361 input_dev->open = matrix_keypad_start; 362 input_dev->close = matrix_keypad_stop; 363 364 input_dev->keycode = keycodes; 365 input_dev->keycodesize = sizeof(*keycodes); 366 input_dev->keycodemax = keymap_data->max_keymap_size; 367 368 for (i = 0; i < keymap_data->keymap_size; i++) { 369 unsigned int key = keymap_data->keymap[i]; 370 unsigned int row = KEY_ROW(key); 371 unsigned int col = KEY_COL(key); 372 unsigned short code = KEY_VAL(key); 373 374 keycodes[(row << 4) + col] = code; 375 __set_bit(code, input_dev->keybit); 376 } 377 __clear_bit(KEY_RESERVED, input_dev->keybit); 378 379 input_set_capability(input_dev, EV_MSC, MSC_SCAN); 380 input_set_drvdata(input_dev, keypad); 381 382 err = init_matrix_gpio(pdev, keypad); 383 if (err) 384 goto err_free_mem; 385 386 err = input_register_device(keypad->input_dev); 387 if (err) 388 goto err_free_mem; 389 390 device_init_wakeup(&pdev->dev, pdata->wakeup); 391 platform_set_drvdata(pdev, keypad); 392 393 return 0; 394 395 err_free_mem: 396 input_free_device(input_dev); 397 kfree(keycodes); 398 kfree(keypad); 399 return err; 400 } 401 402 static int __devexit matrix_keypad_remove(struct platform_device *pdev) 403 { 404 struct matrix_keypad *keypad = platform_get_drvdata(pdev); 405 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 406 int i; 407 408 device_init_wakeup(&pdev->dev, 0); 409 410 for (i = 0; i < pdata->num_row_gpios; i++) { 411 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad); 412 gpio_free(pdata->row_gpios[i]); 413 } 414 415 for (i = 0; i < pdata->num_col_gpios; i++) 416 gpio_free(pdata->col_gpios[i]); 417 418 input_unregister_device(keypad->input_dev); 419 platform_set_drvdata(pdev, NULL); 420 kfree(keypad->keycodes); 421 kfree(keypad); 422 423 return 0; 424 } 425 426 static struct platform_driver matrix_keypad_driver = { 427 .probe = matrix_keypad_probe, 428 .remove = __devexit_p(matrix_keypad_remove), 429 .suspend = matrix_keypad_suspend, 430 .resume = matrix_keypad_resume, 431 .driver = { 432 .name = "matrix-keypad", 433 .owner = THIS_MODULE, 434 }, 435 }; 436 437 static int __init matrix_keypad_init(void) 438 { 439 return platform_driver_register(&matrix_keypad_driver); 440 } 441 442 static void __exit matrix_keypad_exit(void) 443 { 444 platform_driver_unregister(&matrix_keypad_driver); 445 } 446 447 module_init(matrix_keypad_init); 448 module_exit(matrix_keypad_exit); 449 450 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>"); 451 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver"); 452 MODULE_LICENSE("GPL v2"); 453 MODULE_ALIAS("platform:matrix-keypad"); 454