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 unsigned int row_shift; 31 32 uint32_t last_key_state[MATRIX_MAX_COLS]; 33 struct delayed_work work; 34 bool scan_pending; 35 bool stopped; 36 spinlock_t lock; 37 }; 38 39 /* 40 * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause 41 * minmal side effect when scanning other columns, here it is configured to 42 * be input, and it should work on most platforms. 43 */ 44 static void __activate_col(const struct matrix_keypad_platform_data *pdata, 45 int col, bool on) 46 { 47 bool level_on = !pdata->active_low; 48 49 if (on) { 50 gpio_direction_output(pdata->col_gpios[col], level_on); 51 } else { 52 gpio_set_value_cansleep(pdata->col_gpios[col], !level_on); 53 gpio_direction_input(pdata->col_gpios[col]); 54 } 55 } 56 57 static void activate_col(const struct matrix_keypad_platform_data *pdata, 58 int col, bool on) 59 { 60 __activate_col(pdata, col, on); 61 62 if (on && pdata->col_scan_delay_us) 63 udelay(pdata->col_scan_delay_us); 64 } 65 66 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata, 67 bool on) 68 { 69 int col; 70 71 for (col = 0; col < pdata->num_col_gpios; col++) 72 __activate_col(pdata, col, on); 73 } 74 75 static bool row_asserted(const struct matrix_keypad_platform_data *pdata, 76 int row) 77 { 78 return gpio_get_value_cansleep(pdata->row_gpios[row]) ? 79 !pdata->active_low : pdata->active_low; 80 } 81 82 static void enable_row_irqs(struct matrix_keypad *keypad) 83 { 84 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 85 int i; 86 87 for (i = 0; i < pdata->num_row_gpios; i++) 88 enable_irq(gpio_to_irq(pdata->row_gpios[i])); 89 } 90 91 static void disable_row_irqs(struct matrix_keypad *keypad) 92 { 93 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 94 int i; 95 96 for (i = 0; i < pdata->num_row_gpios; i++) 97 disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i])); 98 } 99 100 /* 101 * This gets the keys from keyboard and reports it to input subsystem 102 */ 103 static void matrix_keypad_scan(struct work_struct *work) 104 { 105 struct matrix_keypad *keypad = 106 container_of(work, struct matrix_keypad, work.work); 107 struct input_dev *input_dev = keypad->input_dev; 108 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 109 uint32_t new_state[MATRIX_MAX_COLS]; 110 int row, col, code; 111 112 /* de-activate all columns for scanning */ 113 activate_all_cols(pdata, false); 114 115 memset(new_state, 0, sizeof(new_state)); 116 117 /* assert each column and read the row status out */ 118 for (col = 0; col < pdata->num_col_gpios; col++) { 119 120 activate_col(pdata, col, true); 121 122 for (row = 0; row < pdata->num_row_gpios; row++) 123 new_state[col] |= 124 row_asserted(pdata, row) ? (1 << row) : 0; 125 126 activate_col(pdata, col, false); 127 } 128 129 for (col = 0; col < pdata->num_col_gpios; col++) { 130 uint32_t bits_changed; 131 132 bits_changed = keypad->last_key_state[col] ^ new_state[col]; 133 if (bits_changed == 0) 134 continue; 135 136 for (row = 0; row < pdata->num_row_gpios; row++) { 137 if ((bits_changed & (1 << row)) == 0) 138 continue; 139 140 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift); 141 input_event(input_dev, EV_MSC, MSC_SCAN, code); 142 input_report_key(input_dev, 143 keypad->keycodes[code], 144 new_state[col] & (1 << row)); 145 } 146 } 147 input_sync(input_dev); 148 149 memcpy(keypad->last_key_state, new_state, sizeof(new_state)); 150 151 activate_all_cols(pdata, true); 152 153 /* Enable IRQs again */ 154 spin_lock_irq(&keypad->lock); 155 keypad->scan_pending = false; 156 enable_row_irqs(keypad); 157 spin_unlock_irq(&keypad->lock); 158 } 159 160 static irqreturn_t matrix_keypad_interrupt(int irq, void *id) 161 { 162 struct matrix_keypad *keypad = id; 163 unsigned long flags; 164 165 spin_lock_irqsave(&keypad->lock, flags); 166 167 /* 168 * See if another IRQ beaten us to it and scheduled the 169 * scan already. In that case we should not try to 170 * disable IRQs again. 171 */ 172 if (unlikely(keypad->scan_pending || keypad->stopped)) 173 goto out; 174 175 disable_row_irqs(keypad); 176 keypad->scan_pending = true; 177 schedule_delayed_work(&keypad->work, 178 msecs_to_jiffies(keypad->pdata->debounce_ms)); 179 180 out: 181 spin_unlock_irqrestore(&keypad->lock, flags); 182 return IRQ_HANDLED; 183 } 184 185 static int matrix_keypad_start(struct input_dev *dev) 186 { 187 struct matrix_keypad *keypad = input_get_drvdata(dev); 188 189 keypad->stopped = false; 190 mb(); 191 192 /* 193 * Schedule an immediate key scan to capture current key state; 194 * columns will be activated and IRQs be enabled after the scan. 195 */ 196 schedule_delayed_work(&keypad->work, 0); 197 198 return 0; 199 } 200 201 static void matrix_keypad_stop(struct input_dev *dev) 202 { 203 struct matrix_keypad *keypad = input_get_drvdata(dev); 204 205 keypad->stopped = true; 206 mb(); 207 flush_work(&keypad->work.work); 208 /* 209 * matrix_keypad_scan() will leave IRQs enabled; 210 * we should disable them now. 211 */ 212 disable_row_irqs(keypad); 213 } 214 215 #ifdef CONFIG_PM 216 static int matrix_keypad_suspend(struct platform_device *pdev, pm_message_t state) 217 { 218 struct matrix_keypad *keypad = platform_get_drvdata(pdev); 219 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 220 int i; 221 222 matrix_keypad_stop(keypad->input_dev); 223 224 if (device_may_wakeup(&pdev->dev)) 225 for (i = 0; i < pdata->num_row_gpios; i++) 226 enable_irq_wake(gpio_to_irq(pdata->row_gpios[i])); 227 228 return 0; 229 } 230 231 static int matrix_keypad_resume(struct platform_device *pdev) 232 { 233 struct matrix_keypad *keypad = platform_get_drvdata(pdev); 234 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 235 int i; 236 237 if (device_may_wakeup(&pdev->dev)) 238 for (i = 0; i < pdata->num_row_gpios; i++) 239 disable_irq_wake(gpio_to_irq(pdata->row_gpios[i])); 240 241 matrix_keypad_start(keypad->input_dev); 242 243 return 0; 244 } 245 #else 246 #define matrix_keypad_suspend NULL 247 #define matrix_keypad_resume NULL 248 #endif 249 250 static int __devinit init_matrix_gpio(struct platform_device *pdev, 251 struct matrix_keypad *keypad) 252 { 253 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 254 int i, err = -EINVAL; 255 256 /* initialized strobe lines as outputs, activated */ 257 for (i = 0; i < pdata->num_col_gpios; i++) { 258 err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col"); 259 if (err) { 260 dev_err(&pdev->dev, 261 "failed to request GPIO%d for COL%d\n", 262 pdata->col_gpios[i], i); 263 goto err_free_cols; 264 } 265 266 gpio_direction_output(pdata->col_gpios[i], !pdata->active_low); 267 } 268 269 for (i = 0; i < pdata->num_row_gpios; i++) { 270 err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row"); 271 if (err) { 272 dev_err(&pdev->dev, 273 "failed to request GPIO%d for ROW%d\n", 274 pdata->row_gpios[i], i); 275 goto err_free_rows; 276 } 277 278 gpio_direction_input(pdata->row_gpios[i]); 279 } 280 281 for (i = 0; i < pdata->num_row_gpios; i++) { 282 err = request_irq(gpio_to_irq(pdata->row_gpios[i]), 283 matrix_keypad_interrupt, 284 IRQF_DISABLED | 285 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, 286 "matrix-keypad", keypad); 287 if (err) { 288 dev_err(&pdev->dev, 289 "Unable to acquire interrupt for GPIO line %i\n", 290 pdata->row_gpios[i]); 291 goto err_free_irqs; 292 } 293 } 294 295 /* initialized as disabled - enabled by input->open */ 296 disable_row_irqs(keypad); 297 return 0; 298 299 err_free_irqs: 300 while (--i >= 0) 301 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad); 302 i = pdata->num_row_gpios; 303 err_free_rows: 304 while (--i >= 0) 305 gpio_free(pdata->row_gpios[i]); 306 i = pdata->num_col_gpios; 307 err_free_cols: 308 while (--i >= 0) 309 gpio_free(pdata->col_gpios[i]); 310 311 return err; 312 } 313 314 static int __devinit matrix_keypad_probe(struct platform_device *pdev) 315 { 316 const struct matrix_keypad_platform_data *pdata; 317 const struct matrix_keymap_data *keymap_data; 318 struct matrix_keypad *keypad; 319 struct input_dev *input_dev; 320 unsigned short *keycodes; 321 unsigned int row_shift; 322 int i; 323 int err; 324 325 pdata = pdev->dev.platform_data; 326 if (!pdata) { 327 dev_err(&pdev->dev, "no platform data defined\n"); 328 return -EINVAL; 329 } 330 331 keymap_data = pdata->keymap_data; 332 if (!keymap_data) { 333 dev_err(&pdev->dev, "no keymap data defined\n"); 334 return -EINVAL; 335 } 336 337 row_shift = get_count_order(pdata->num_col_gpios); 338 339 keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL); 340 keycodes = kzalloc((pdata->num_row_gpios << row_shift) * 341 sizeof(*keycodes), 342 GFP_KERNEL); 343 input_dev = input_allocate_device(); 344 if (!keypad || !keycodes || !input_dev) { 345 err = -ENOMEM; 346 goto err_free_mem; 347 } 348 349 keypad->input_dev = input_dev; 350 keypad->pdata = pdata; 351 keypad->keycodes = keycodes; 352 keypad->row_shift = row_shift; 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 = pdata->num_row_gpios << keypad->row_shift; 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[MATRIX_SCAN_CODE(row, col, row_shift)] = 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