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 device *dev) 217 { 218 struct platform_device *pdev = to_platform_device(dev); 219 struct matrix_keypad *keypad = platform_get_drvdata(pdev); 220 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 221 int i; 222 223 matrix_keypad_stop(keypad->input_dev); 224 225 if (device_may_wakeup(&pdev->dev)) 226 for (i = 0; i < pdata->num_row_gpios; i++) 227 enable_irq_wake(gpio_to_irq(pdata->row_gpios[i])); 228 229 return 0; 230 } 231 232 static int matrix_keypad_resume(struct device *dev) 233 { 234 struct platform_device *pdev = to_platform_device(dev); 235 struct matrix_keypad *keypad = platform_get_drvdata(pdev); 236 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 237 int i; 238 239 if (device_may_wakeup(&pdev->dev)) 240 for (i = 0; i < pdata->num_row_gpios; i++) 241 disable_irq_wake(gpio_to_irq(pdata->row_gpios[i])); 242 243 matrix_keypad_start(keypad->input_dev); 244 245 return 0; 246 } 247 248 static const SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops, 249 matrix_keypad_suspend, matrix_keypad_resume); 250 #endif 251 252 static int __devinit init_matrix_gpio(struct platform_device *pdev, 253 struct matrix_keypad *keypad) 254 { 255 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 256 int i, err = -EINVAL; 257 258 /* initialized strobe lines as outputs, activated */ 259 for (i = 0; i < pdata->num_col_gpios; i++) { 260 err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col"); 261 if (err) { 262 dev_err(&pdev->dev, 263 "failed to request GPIO%d for COL%d\n", 264 pdata->col_gpios[i], i); 265 goto err_free_cols; 266 } 267 268 gpio_direction_output(pdata->col_gpios[i], !pdata->active_low); 269 } 270 271 for (i = 0; i < pdata->num_row_gpios; i++) { 272 err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row"); 273 if (err) { 274 dev_err(&pdev->dev, 275 "failed to request GPIO%d for ROW%d\n", 276 pdata->row_gpios[i], i); 277 goto err_free_rows; 278 } 279 280 gpio_direction_input(pdata->row_gpios[i]); 281 } 282 283 for (i = 0; i < pdata->num_row_gpios; i++) { 284 err = request_irq(gpio_to_irq(pdata->row_gpios[i]), 285 matrix_keypad_interrupt, 286 IRQF_DISABLED | 287 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, 288 "matrix-keypad", keypad); 289 if (err) { 290 dev_err(&pdev->dev, 291 "Unable to acquire interrupt for GPIO line %i\n", 292 pdata->row_gpios[i]); 293 goto err_free_irqs; 294 } 295 } 296 297 /* initialized as disabled - enabled by input->open */ 298 disable_row_irqs(keypad); 299 return 0; 300 301 err_free_irqs: 302 while (--i >= 0) 303 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad); 304 i = pdata->num_row_gpios; 305 err_free_rows: 306 while (--i >= 0) 307 gpio_free(pdata->row_gpios[i]); 308 i = pdata->num_col_gpios; 309 err_free_cols: 310 while (--i >= 0) 311 gpio_free(pdata->col_gpios[i]); 312 313 return err; 314 } 315 316 static int __devinit matrix_keypad_probe(struct platform_device *pdev) 317 { 318 const struct matrix_keypad_platform_data *pdata; 319 const struct matrix_keymap_data *keymap_data; 320 struct matrix_keypad *keypad; 321 struct input_dev *input_dev; 322 unsigned short *keycodes; 323 unsigned int row_shift; 324 int err; 325 326 pdata = pdev->dev.platform_data; 327 if (!pdata) { 328 dev_err(&pdev->dev, "no platform data defined\n"); 329 return -EINVAL; 330 } 331 332 keymap_data = pdata->keymap_data; 333 if (!keymap_data) { 334 dev_err(&pdev->dev, "no keymap data defined\n"); 335 return -EINVAL; 336 } 337 338 row_shift = get_count_order(pdata->num_col_gpios); 339 340 keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL); 341 keycodes = kzalloc((pdata->num_row_gpios << row_shift) * 342 sizeof(*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->row_shift = row_shift; 354 keypad->stopped = true; 355 INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan); 356 spin_lock_init(&keypad->lock); 357 358 input_dev->name = pdev->name; 359 input_dev->id.bustype = BUS_HOST; 360 input_dev->dev.parent = &pdev->dev; 361 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP); 362 input_dev->open = matrix_keypad_start; 363 input_dev->close = matrix_keypad_stop; 364 365 input_dev->keycode = keycodes; 366 input_dev->keycodesize = sizeof(*keycodes); 367 input_dev->keycodemax = pdata->num_row_gpios << row_shift; 368 369 matrix_keypad_build_keymap(keymap_data, row_shift, 370 input_dev->keycode, input_dev->keybit); 371 372 input_set_capability(input_dev, EV_MSC, MSC_SCAN); 373 input_set_drvdata(input_dev, keypad); 374 375 err = init_matrix_gpio(pdev, keypad); 376 if (err) 377 goto err_free_mem; 378 379 err = input_register_device(keypad->input_dev); 380 if (err) 381 goto err_free_mem; 382 383 device_init_wakeup(&pdev->dev, pdata->wakeup); 384 platform_set_drvdata(pdev, keypad); 385 386 return 0; 387 388 err_free_mem: 389 input_free_device(input_dev); 390 kfree(keycodes); 391 kfree(keypad); 392 return err; 393 } 394 395 static int __devexit matrix_keypad_remove(struct platform_device *pdev) 396 { 397 struct matrix_keypad *keypad = platform_get_drvdata(pdev); 398 const struct matrix_keypad_platform_data *pdata = keypad->pdata; 399 int i; 400 401 device_init_wakeup(&pdev->dev, 0); 402 403 for (i = 0; i < pdata->num_row_gpios; i++) { 404 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad); 405 gpio_free(pdata->row_gpios[i]); 406 } 407 408 for (i = 0; i < pdata->num_col_gpios; i++) 409 gpio_free(pdata->col_gpios[i]); 410 411 input_unregister_device(keypad->input_dev); 412 platform_set_drvdata(pdev, NULL); 413 kfree(keypad->keycodes); 414 kfree(keypad); 415 416 return 0; 417 } 418 419 static struct platform_driver matrix_keypad_driver = { 420 .probe = matrix_keypad_probe, 421 .remove = __devexit_p(matrix_keypad_remove), 422 .driver = { 423 .name = "matrix-keypad", 424 .owner = THIS_MODULE, 425 #ifdef CONFIG_PM 426 .pm = &matrix_keypad_pm_ops, 427 #endif 428 }, 429 }; 430 431 static int __init matrix_keypad_init(void) 432 { 433 return platform_driver_register(&matrix_keypad_driver); 434 } 435 436 static void __exit matrix_keypad_exit(void) 437 { 438 platform_driver_unregister(&matrix_keypad_driver); 439 } 440 441 module_init(matrix_keypad_init); 442 module_exit(matrix_keypad_exit); 443 444 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>"); 445 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver"); 446 MODULE_LICENSE("GPL v2"); 447 MODULE_ALIAS("platform:matrix-keypad"); 448