1 // SPDX-License-Identifier: GPL-2.0-only
3 * GPIO driven matrix keyboard driver
5 * Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com>
10 #include <linux/types.h>
11 #include <linux/delay.h>
12 #include <linux/gpio/consumer.h>
13 #include <linux/platform_device.h>
14 #include <linux/input.h>
15 #include <linux/irq.h>
16 #include <linux/interrupt.h>
17 #include <linux/jiffies.h>
18 #include <linux/module.h>
19 #include <linux/gpio.h>
20 #include <linux/input/matrix_keypad.h>
21 #include <linux/slab.h>
23 #include <linux/of_gpio.h>
24 #include <linux/of_platform.h>
26 struct matrix_keypad {
27 const struct matrix_keypad_platform_data *pdata;
28 struct input_dev *input_dev;
29 unsigned int row_shift;
31 DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
33 uint32_t last_key_state[MATRIX_MAX_COLS];
34 struct delayed_work work;
38 bool gpio_all_disabled;
42 * NOTE: If drive_inactive_cols is false, then the GPIO has to be put into
43 * HiZ when de-activated to cause minmal side effect when scanning other
44 * columns. In that case it is configured here to be input, otherwise it is
45 * driven with the inactive value.
47 static void __activate_col(const struct matrix_keypad_platform_data *pdata,
50 bool level_on = !pdata->active_low;
53 gpio_direction_output(pdata->col_gpios[col], level_on);
55 gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
56 if (!pdata->drive_inactive_cols)
57 gpio_direction_input(pdata->col_gpios[col]);
61 static void activate_col(const struct matrix_keypad_platform_data *pdata,
64 __activate_col(pdata, col, on);
66 if (on && pdata->col_scan_delay_us)
67 udelay(pdata->col_scan_delay_us);
70 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
75 for (col = 0; col < pdata->num_col_gpios; col++)
76 __activate_col(pdata, col, on);
79 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
82 return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
83 !pdata->active_low : pdata->active_low;
86 static void enable_row_irqs(struct matrix_keypad *keypad)
88 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
91 if (pdata->clustered_irq > 0)
92 enable_irq(pdata->clustered_irq);
94 for (i = 0; i < pdata->num_row_gpios; i++)
95 enable_irq(gpio_to_irq(pdata->row_gpios[i]));
99 static void disable_row_irqs(struct matrix_keypad *keypad)
101 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
104 if (pdata->clustered_irq > 0)
105 disable_irq_nosync(pdata->clustered_irq);
107 for (i = 0; i < pdata->num_row_gpios; i++)
108 disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
113 * This gets the keys from keyboard and reports it to input subsystem
115 static void matrix_keypad_scan(struct work_struct *work)
117 struct matrix_keypad *keypad =
118 container_of(work, struct matrix_keypad, work.work);
119 struct input_dev *input_dev = keypad->input_dev;
120 const unsigned short *keycodes = input_dev->keycode;
121 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
122 uint32_t new_state[MATRIX_MAX_COLS];
125 /* de-activate all columns for scanning */
126 activate_all_cols(pdata, false);
128 memset(new_state, 0, sizeof(new_state));
130 for (row = 0; row < pdata->num_row_gpios; row++)
131 gpio_direction_input(pdata->row_gpios[row]);
133 /* assert each column and read the row status out */
134 for (col = 0; col < pdata->num_col_gpios; col++) {
136 activate_col(pdata, col, true);
138 for (row = 0; row < pdata->num_row_gpios; row++)
140 row_asserted(pdata, row) ? (1 << row) : 0;
142 activate_col(pdata, col, false);
145 for (col = 0; col < pdata->num_col_gpios; col++) {
146 uint32_t bits_changed;
148 bits_changed = keypad->last_key_state[col] ^ new_state[col];
149 if (bits_changed == 0)
152 for (row = 0; row < pdata->num_row_gpios; row++) {
153 if ((bits_changed & (1 << row)) == 0)
156 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
157 input_event(input_dev, EV_MSC, MSC_SCAN, code);
158 input_report_key(input_dev,
160 new_state[col] & (1 << row));
163 input_sync(input_dev);
165 memcpy(keypad->last_key_state, new_state, sizeof(new_state));
167 activate_all_cols(pdata, true);
169 /* Enable IRQs again */
170 spin_lock_irq(&keypad->lock);
171 keypad->scan_pending = false;
172 enable_row_irqs(keypad);
173 spin_unlock_irq(&keypad->lock);
176 static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
178 struct matrix_keypad *keypad = id;
181 spin_lock_irqsave(&keypad->lock, flags);
184 * See if another IRQ beaten us to it and scheduled the
185 * scan already. In that case we should not try to
186 * disable IRQs again.
188 if (unlikely(keypad->scan_pending || keypad->stopped))
191 disable_row_irqs(keypad);
192 keypad->scan_pending = true;
193 schedule_delayed_work(&keypad->work,
194 msecs_to_jiffies(keypad->pdata->debounce_ms));
197 spin_unlock_irqrestore(&keypad->lock, flags);
201 static int matrix_keypad_start(struct input_dev *dev)
203 struct matrix_keypad *keypad = input_get_drvdata(dev);
205 keypad->stopped = false;
209 * Schedule an immediate key scan to capture current key state;
210 * columns will be activated and IRQs be enabled after the scan.
212 schedule_delayed_work(&keypad->work, 0);
217 static void matrix_keypad_stop(struct input_dev *dev)
219 struct matrix_keypad *keypad = input_get_drvdata(dev);
221 spin_lock_irq(&keypad->lock);
222 keypad->stopped = true;
223 spin_unlock_irq(&keypad->lock);
225 flush_delayed_work(&keypad->work);
227 * matrix_keypad_scan() will leave IRQs enabled;
228 * we should disable them now.
230 disable_row_irqs(keypad);
233 static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
235 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
239 if (pdata->clustered_irq > 0) {
240 if (enable_irq_wake(pdata->clustered_irq) == 0)
241 keypad->gpio_all_disabled = true;
244 for (i = 0; i < pdata->num_row_gpios; i++) {
245 if (!test_bit(i, keypad->disabled_gpios)) {
246 gpio = pdata->row_gpios[i];
248 if (enable_irq_wake(gpio_to_irq(gpio)) == 0)
249 __set_bit(i, keypad->disabled_gpios);
255 static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
257 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
261 if (pdata->clustered_irq > 0) {
262 if (keypad->gpio_all_disabled) {
263 disable_irq_wake(pdata->clustered_irq);
264 keypad->gpio_all_disabled = false;
267 for (i = 0; i < pdata->num_row_gpios; i++) {
268 if (test_and_clear_bit(i, keypad->disabled_gpios)) {
269 gpio = pdata->row_gpios[i];
270 disable_irq_wake(gpio_to_irq(gpio));
276 static int matrix_keypad_suspend(struct device *dev)
278 struct platform_device *pdev = to_platform_device(dev);
279 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
281 matrix_keypad_stop(keypad->input_dev);
283 if (device_may_wakeup(&pdev->dev))
284 matrix_keypad_enable_wakeup(keypad);
289 static int matrix_keypad_resume(struct device *dev)
291 struct platform_device *pdev = to_platform_device(dev);
292 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
294 if (device_may_wakeup(&pdev->dev))
295 matrix_keypad_disable_wakeup(keypad);
297 matrix_keypad_start(keypad->input_dev);
302 static DEFINE_SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
303 matrix_keypad_suspend, matrix_keypad_resume);
305 static int matrix_keypad_init_gpio(struct platform_device *pdev,
306 struct matrix_keypad *keypad)
308 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
311 /* initialized strobe lines as outputs, activated */
312 for (i = 0; i < pdata->num_col_gpios; i++) {
313 err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
316 "failed to request GPIO%d for COL%d\n",
317 pdata->col_gpios[i], i);
321 gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
324 for (i = 0; i < pdata->num_row_gpios; i++) {
325 err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
328 "failed to request GPIO%d for ROW%d\n",
329 pdata->row_gpios[i], i);
333 gpio_direction_input(pdata->row_gpios[i]);
336 if (pdata->clustered_irq > 0) {
337 err = request_any_context_irq(pdata->clustered_irq,
338 matrix_keypad_interrupt,
339 pdata->clustered_irq_flags,
340 "matrix-keypad", keypad);
343 "Unable to acquire clustered interrupt\n");
347 for (i = 0; i < pdata->num_row_gpios; i++) {
348 err = request_any_context_irq(
349 gpio_to_irq(pdata->row_gpios[i]),
350 matrix_keypad_interrupt,
351 IRQF_TRIGGER_RISING |
352 IRQF_TRIGGER_FALLING,
353 "matrix-keypad", keypad);
356 "Unable to acquire interrupt for GPIO line %i\n",
357 pdata->row_gpios[i]);
363 /* initialized as disabled - enabled by input->open */
364 disable_row_irqs(keypad);
369 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
370 i = pdata->num_row_gpios;
373 gpio_free(pdata->row_gpios[i]);
374 i = pdata->num_col_gpios;
377 gpio_free(pdata->col_gpios[i]);
382 static void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
384 const struct matrix_keypad_platform_data *pdata = keypad->pdata;
387 if (pdata->clustered_irq > 0) {
388 free_irq(pdata->clustered_irq, keypad);
390 for (i = 0; i < pdata->num_row_gpios; i++)
391 free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
394 for (i = 0; i < pdata->num_row_gpios; i++)
395 gpio_free(pdata->row_gpios[i]);
397 for (i = 0; i < pdata->num_col_gpios; i++)
398 gpio_free(pdata->col_gpios[i]);
402 static struct matrix_keypad_platform_data *
403 matrix_keypad_parse_dt(struct device *dev)
405 struct matrix_keypad_platform_data *pdata;
406 struct device_node *np = dev->of_node;
408 int ret, i, nrow, ncol;
411 dev_err(dev, "device lacks DT data\n");
412 return ERR_PTR(-ENODEV);
415 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
417 dev_err(dev, "could not allocate memory for platform data\n");
418 return ERR_PTR(-ENOMEM);
421 pdata->num_row_gpios = nrow = gpiod_count(dev, "row");
422 pdata->num_col_gpios = ncol = gpiod_count(dev, "col");
423 if (nrow < 0 || ncol < 0) {
424 dev_err(dev, "number of keypad rows/columns not specified\n");
425 return ERR_PTR(-EINVAL);
428 pdata->no_autorepeat = of_property_read_bool(np, "linux,no-autorepeat");
430 pdata->wakeup = of_property_read_bool(np, "wakeup-source") ||
431 of_property_read_bool(np, "linux,wakeup"); /* legacy */
433 pdata->active_low = of_property_read_bool(np, "gpio-activelow");
435 pdata->drive_inactive_cols =
436 of_property_read_bool(np, "drive-inactive-cols");
438 of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
439 of_property_read_u32(np, "col-scan-delay-us",
440 &pdata->col_scan_delay_us);
442 gpios = devm_kcalloc(dev,
443 pdata->num_row_gpios + pdata->num_col_gpios,
444 sizeof(unsigned int),
447 dev_err(dev, "could not allocate memory for gpios\n");
448 return ERR_PTR(-ENOMEM);
451 for (i = 0; i < nrow; i++) {
452 ret = of_get_named_gpio(np, "row-gpios", i);
458 for (i = 0; i < ncol; i++) {
459 ret = of_get_named_gpio(np, "col-gpios", i);
462 gpios[nrow + i] = ret;
465 pdata->row_gpios = gpios;
466 pdata->col_gpios = &gpios[pdata->num_row_gpios];
471 static inline struct matrix_keypad_platform_data *
472 matrix_keypad_parse_dt(struct device *dev)
474 dev_err(dev, "no platform data defined\n");
476 return ERR_PTR(-EINVAL);
480 static int matrix_keypad_probe(struct platform_device *pdev)
482 const struct matrix_keypad_platform_data *pdata;
483 struct matrix_keypad *keypad;
484 struct input_dev *input_dev;
487 pdata = dev_get_platdata(&pdev->dev);
489 pdata = matrix_keypad_parse_dt(&pdev->dev);
491 return PTR_ERR(pdata);
492 } else if (!pdata->keymap_data) {
493 dev_err(&pdev->dev, "no keymap data defined\n");
497 keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
498 input_dev = input_allocate_device();
499 if (!keypad || !input_dev) {
504 keypad->input_dev = input_dev;
505 keypad->pdata = pdata;
506 keypad->row_shift = get_count_order(pdata->num_col_gpios);
507 keypad->stopped = true;
508 INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
509 spin_lock_init(&keypad->lock);
511 input_dev->name = pdev->name;
512 input_dev->id.bustype = BUS_HOST;
513 input_dev->dev.parent = &pdev->dev;
514 input_dev->open = matrix_keypad_start;
515 input_dev->close = matrix_keypad_stop;
517 err = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
518 pdata->num_row_gpios,
519 pdata->num_col_gpios,
522 dev_err(&pdev->dev, "failed to build keymap\n");
526 if (!pdata->no_autorepeat)
527 __set_bit(EV_REP, input_dev->evbit);
528 input_set_capability(input_dev, EV_MSC, MSC_SCAN);
529 input_set_drvdata(input_dev, keypad);
531 err = matrix_keypad_init_gpio(pdev, keypad);
535 err = input_register_device(keypad->input_dev);
539 device_init_wakeup(&pdev->dev, pdata->wakeup);
540 platform_set_drvdata(pdev, keypad);
545 matrix_keypad_free_gpio(keypad);
547 input_free_device(input_dev);
552 static void matrix_keypad_remove(struct platform_device *pdev)
554 struct matrix_keypad *keypad = platform_get_drvdata(pdev);
556 matrix_keypad_free_gpio(keypad);
557 input_unregister_device(keypad->input_dev);
562 static const struct of_device_id matrix_keypad_dt_match[] = {
563 { .compatible = "gpio-matrix-keypad" },
566 MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
569 static struct platform_driver matrix_keypad_driver = {
570 .probe = matrix_keypad_probe,
571 .remove_new = matrix_keypad_remove,
573 .name = "matrix-keypad",
574 .pm = pm_sleep_ptr(&matrix_keypad_pm_ops),
575 .of_match_table = of_match_ptr(matrix_keypad_dt_match),
578 module_platform_driver(matrix_keypad_driver);
580 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
581 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
582 MODULE_LICENSE("GPL v2");
583 MODULE_ALIAS("platform:matrix-keypad");