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0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  *  GPIO driven matrix keyboard driver
0004  *
0005  *  Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com>
0006  *
0007  *  Based on corgikbd.c
0008  */
0009 
0010 #include <linux/types.h>
0011 #include <linux/delay.h>
0012 #include <linux/platform_device.h>
0013 #include <linux/input.h>
0014 #include <linux/irq.h>
0015 #include <linux/interrupt.h>
0016 #include <linux/jiffies.h>
0017 #include <linux/module.h>
0018 #include <linux/gpio.h>
0019 #include <linux/input/matrix_keypad.h>
0020 #include <linux/slab.h>
0021 #include <linux/of.h>
0022 #include <linux/of_gpio.h>
0023 #include <linux/of_platform.h>
0024 
0025 struct matrix_keypad {
0026     const struct matrix_keypad_platform_data *pdata;
0027     struct input_dev *input_dev;
0028     unsigned int row_shift;
0029 
0030     DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS);
0031 
0032     uint32_t last_key_state[MATRIX_MAX_COLS];
0033     struct delayed_work work;
0034     spinlock_t lock;
0035     bool scan_pending;
0036     bool stopped;
0037     bool gpio_all_disabled;
0038 };
0039 
0040 /*
0041  * NOTE: If drive_inactive_cols is false, then the GPIO has to be put into
0042  * HiZ when de-activated to cause minmal side effect when scanning other
0043  * columns. In that case it is configured here to be input, otherwise it is
0044  * driven with the inactive value.
0045  */
0046 static void __activate_col(const struct matrix_keypad_platform_data *pdata,
0047                int col, bool on)
0048 {
0049     bool level_on = !pdata->active_low;
0050 
0051     if (on) {
0052         gpio_direction_output(pdata->col_gpios[col], level_on);
0053     } else {
0054         gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
0055         if (!pdata->drive_inactive_cols)
0056             gpio_direction_input(pdata->col_gpios[col]);
0057     }
0058 }
0059 
0060 static void activate_col(const struct matrix_keypad_platform_data *pdata,
0061              int col, bool on)
0062 {
0063     __activate_col(pdata, col, on);
0064 
0065     if (on && pdata->col_scan_delay_us)
0066         udelay(pdata->col_scan_delay_us);
0067 }
0068 
0069 static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
0070                   bool on)
0071 {
0072     int col;
0073 
0074     for (col = 0; col < pdata->num_col_gpios; col++)
0075         __activate_col(pdata, col, on);
0076 }
0077 
0078 static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
0079              int row)
0080 {
0081     return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
0082             !pdata->active_low : pdata->active_low;
0083 }
0084 
0085 static void enable_row_irqs(struct matrix_keypad *keypad)
0086 {
0087     const struct matrix_keypad_platform_data *pdata = keypad->pdata;
0088     int i;
0089 
0090     if (pdata->clustered_irq > 0)
0091         enable_irq(pdata->clustered_irq);
0092     else {
0093         for (i = 0; i < pdata->num_row_gpios; i++)
0094             enable_irq(gpio_to_irq(pdata->row_gpios[i]));
0095     }
0096 }
0097 
0098 static void disable_row_irqs(struct matrix_keypad *keypad)
0099 {
0100     const struct matrix_keypad_platform_data *pdata = keypad->pdata;
0101     int i;
0102 
0103     if (pdata->clustered_irq > 0)
0104         disable_irq_nosync(pdata->clustered_irq);
0105     else {
0106         for (i = 0; i < pdata->num_row_gpios; i++)
0107             disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
0108     }
0109 }
0110 
0111 /*
0112  * This gets the keys from keyboard and reports it to input subsystem
0113  */
0114 static void matrix_keypad_scan(struct work_struct *work)
0115 {
0116     struct matrix_keypad *keypad =
0117         container_of(work, struct matrix_keypad, work.work);
0118     struct input_dev *input_dev = keypad->input_dev;
0119     const unsigned short *keycodes = input_dev->keycode;
0120     const struct matrix_keypad_platform_data *pdata = keypad->pdata;
0121     uint32_t new_state[MATRIX_MAX_COLS];
0122     int row, col, code;
0123 
0124     /* de-activate all columns for scanning */
0125     activate_all_cols(pdata, false);
0126 
0127     memset(new_state, 0, sizeof(new_state));
0128 
0129     /* assert each column and read the row status out */
0130     for (col = 0; col < pdata->num_col_gpios; col++) {
0131 
0132         activate_col(pdata, col, true);
0133 
0134         for (row = 0; row < pdata->num_row_gpios; row++)
0135             new_state[col] |=
0136                 row_asserted(pdata, row) ? (1 << row) : 0;
0137 
0138         activate_col(pdata, col, false);
0139     }
0140 
0141     for (col = 0; col < pdata->num_col_gpios; col++) {
0142         uint32_t bits_changed;
0143 
0144         bits_changed = keypad->last_key_state[col] ^ new_state[col];
0145         if (bits_changed == 0)
0146             continue;
0147 
0148         for (row = 0; row < pdata->num_row_gpios; row++) {
0149             if ((bits_changed & (1 << row)) == 0)
0150                 continue;
0151 
0152             code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
0153             input_event(input_dev, EV_MSC, MSC_SCAN, code);
0154             input_report_key(input_dev,
0155                      keycodes[code],
0156                      new_state[col] & (1 << row));
0157         }
0158     }
0159     input_sync(input_dev);
0160 
0161     memcpy(keypad->last_key_state, new_state, sizeof(new_state));
0162 
0163     activate_all_cols(pdata, true);
0164 
0165     /* Enable IRQs again */
0166     spin_lock_irq(&keypad->lock);
0167     keypad->scan_pending = false;
0168     enable_row_irqs(keypad);
0169     spin_unlock_irq(&keypad->lock);
0170 }
0171 
0172 static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
0173 {
0174     struct matrix_keypad *keypad = id;
0175     unsigned long flags;
0176 
0177     spin_lock_irqsave(&keypad->lock, flags);
0178 
0179     /*
0180      * See if another IRQ beaten us to it and scheduled the
0181      * scan already. In that case we should not try to
0182      * disable IRQs again.
0183      */
0184     if (unlikely(keypad->scan_pending || keypad->stopped))
0185         goto out;
0186 
0187     disable_row_irqs(keypad);
0188     keypad->scan_pending = true;
0189     schedule_delayed_work(&keypad->work,
0190         msecs_to_jiffies(keypad->pdata->debounce_ms));
0191 
0192 out:
0193     spin_unlock_irqrestore(&keypad->lock, flags);
0194     return IRQ_HANDLED;
0195 }
0196 
0197 static int matrix_keypad_start(struct input_dev *dev)
0198 {
0199     struct matrix_keypad *keypad = input_get_drvdata(dev);
0200 
0201     keypad->stopped = false;
0202     mb();
0203 
0204     /*
0205      * Schedule an immediate key scan to capture current key state;
0206      * columns will be activated and IRQs be enabled after the scan.
0207      */
0208     schedule_delayed_work(&keypad->work, 0);
0209 
0210     return 0;
0211 }
0212 
0213 static void matrix_keypad_stop(struct input_dev *dev)
0214 {
0215     struct matrix_keypad *keypad = input_get_drvdata(dev);
0216 
0217     spin_lock_irq(&keypad->lock);
0218     keypad->stopped = true;
0219     spin_unlock_irq(&keypad->lock);
0220 
0221     flush_delayed_work(&keypad->work);
0222     /*
0223      * matrix_keypad_scan() will leave IRQs enabled;
0224      * we should disable them now.
0225      */
0226     disable_row_irqs(keypad);
0227 }
0228 
0229 #ifdef CONFIG_PM_SLEEP
0230 static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad)
0231 {
0232     const struct matrix_keypad_platform_data *pdata = keypad->pdata;
0233     unsigned int gpio;
0234     int i;
0235 
0236     if (pdata->clustered_irq > 0) {
0237         if (enable_irq_wake(pdata->clustered_irq) == 0)
0238             keypad->gpio_all_disabled = true;
0239     } else {
0240 
0241         for (i = 0; i < pdata->num_row_gpios; i++) {
0242             if (!test_bit(i, keypad->disabled_gpios)) {
0243                 gpio = pdata->row_gpios[i];
0244 
0245                 if (enable_irq_wake(gpio_to_irq(gpio)) == 0)
0246                     __set_bit(i, keypad->disabled_gpios);
0247             }
0248         }
0249     }
0250 }
0251 
0252 static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad)
0253 {
0254     const struct matrix_keypad_platform_data *pdata = keypad->pdata;
0255     unsigned int gpio;
0256     int i;
0257 
0258     if (pdata->clustered_irq > 0) {
0259         if (keypad->gpio_all_disabled) {
0260             disable_irq_wake(pdata->clustered_irq);
0261             keypad->gpio_all_disabled = false;
0262         }
0263     } else {
0264         for (i = 0; i < pdata->num_row_gpios; i++) {
0265             if (test_and_clear_bit(i, keypad->disabled_gpios)) {
0266                 gpio = pdata->row_gpios[i];
0267                 disable_irq_wake(gpio_to_irq(gpio));
0268             }
0269         }
0270     }
0271 }
0272 
0273 static int matrix_keypad_suspend(struct device *dev)
0274 {
0275     struct platform_device *pdev = to_platform_device(dev);
0276     struct matrix_keypad *keypad = platform_get_drvdata(pdev);
0277 
0278     matrix_keypad_stop(keypad->input_dev);
0279 
0280     if (device_may_wakeup(&pdev->dev))
0281         matrix_keypad_enable_wakeup(keypad);
0282 
0283     return 0;
0284 }
0285 
0286 static int matrix_keypad_resume(struct device *dev)
0287 {
0288     struct platform_device *pdev = to_platform_device(dev);
0289     struct matrix_keypad *keypad = platform_get_drvdata(pdev);
0290 
0291     if (device_may_wakeup(&pdev->dev))
0292         matrix_keypad_disable_wakeup(keypad);
0293 
0294     matrix_keypad_start(keypad->input_dev);
0295 
0296     return 0;
0297 }
0298 #endif
0299 
0300 static SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops,
0301              matrix_keypad_suspend, matrix_keypad_resume);
0302 
0303 static int matrix_keypad_init_gpio(struct platform_device *pdev,
0304                    struct matrix_keypad *keypad)
0305 {
0306     const struct matrix_keypad_platform_data *pdata = keypad->pdata;
0307     int i, err;
0308 
0309     /* initialized strobe lines as outputs, activated */
0310     for (i = 0; i < pdata->num_col_gpios; i++) {
0311         err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
0312         if (err) {
0313             dev_err(&pdev->dev,
0314                 "failed to request GPIO%d for COL%d\n",
0315                 pdata->col_gpios[i], i);
0316             goto err_free_cols;
0317         }
0318 
0319         gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
0320     }
0321 
0322     for (i = 0; i < pdata->num_row_gpios; i++) {
0323         err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
0324         if (err) {
0325             dev_err(&pdev->dev,
0326                 "failed to request GPIO%d for ROW%d\n",
0327                 pdata->row_gpios[i], i);
0328             goto err_free_rows;
0329         }
0330 
0331         gpio_direction_input(pdata->row_gpios[i]);
0332     }
0333 
0334     if (pdata->clustered_irq > 0) {
0335         err = request_any_context_irq(pdata->clustered_irq,
0336                 matrix_keypad_interrupt,
0337                 pdata->clustered_irq_flags,
0338                 "matrix-keypad", keypad);
0339         if (err < 0) {
0340             dev_err(&pdev->dev,
0341                 "Unable to acquire clustered interrupt\n");
0342             goto err_free_rows;
0343         }
0344     } else {
0345         for (i = 0; i < pdata->num_row_gpios; i++) {
0346             err = request_any_context_irq(
0347                     gpio_to_irq(pdata->row_gpios[i]),
0348                     matrix_keypad_interrupt,
0349                     IRQF_TRIGGER_RISING |
0350                     IRQF_TRIGGER_FALLING,
0351                     "matrix-keypad", keypad);
0352             if (err < 0) {
0353                 dev_err(&pdev->dev,
0354                     "Unable to acquire interrupt for GPIO line %i\n",
0355                     pdata->row_gpios[i]);
0356                 goto err_free_irqs;
0357             }
0358         }
0359     }
0360 
0361     /* initialized as disabled - enabled by input->open */
0362     disable_row_irqs(keypad);
0363     return 0;
0364 
0365 err_free_irqs:
0366     while (--i >= 0)
0367         free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
0368     i = pdata->num_row_gpios;
0369 err_free_rows:
0370     while (--i >= 0)
0371         gpio_free(pdata->row_gpios[i]);
0372     i = pdata->num_col_gpios;
0373 err_free_cols:
0374     while (--i >= 0)
0375         gpio_free(pdata->col_gpios[i]);
0376 
0377     return err;
0378 }
0379 
0380 static void matrix_keypad_free_gpio(struct matrix_keypad *keypad)
0381 {
0382     const struct matrix_keypad_platform_data *pdata = keypad->pdata;
0383     int i;
0384 
0385     if (pdata->clustered_irq > 0) {
0386         free_irq(pdata->clustered_irq, keypad);
0387     } else {
0388         for (i = 0; i < pdata->num_row_gpios; i++)
0389             free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
0390     }
0391 
0392     for (i = 0; i < pdata->num_row_gpios; i++)
0393         gpio_free(pdata->row_gpios[i]);
0394 
0395     for (i = 0; i < pdata->num_col_gpios; i++)
0396         gpio_free(pdata->col_gpios[i]);
0397 }
0398 
0399 #ifdef CONFIG_OF
0400 static struct matrix_keypad_platform_data *
0401 matrix_keypad_parse_dt(struct device *dev)
0402 {
0403     struct matrix_keypad_platform_data *pdata;
0404     struct device_node *np = dev->of_node;
0405     unsigned int *gpios;
0406     int ret, i, nrow, ncol;
0407 
0408     if (!np) {
0409         dev_err(dev, "device lacks DT data\n");
0410         return ERR_PTR(-ENODEV);
0411     }
0412 
0413     pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
0414     if (!pdata) {
0415         dev_err(dev, "could not allocate memory for platform data\n");
0416         return ERR_PTR(-ENOMEM);
0417     }
0418 
0419     pdata->num_row_gpios = nrow = of_gpio_named_count(np, "row-gpios");
0420     pdata->num_col_gpios = ncol = of_gpio_named_count(np, "col-gpios");
0421     if (nrow <= 0 || ncol <= 0) {
0422         dev_err(dev, "number of keypad rows/columns not specified\n");
0423         return ERR_PTR(-EINVAL);
0424     }
0425 
0426     if (of_get_property(np, "linux,no-autorepeat", NULL))
0427         pdata->no_autorepeat = true;
0428 
0429     pdata->wakeup = of_property_read_bool(np, "wakeup-source") ||
0430             of_property_read_bool(np, "linux,wakeup"); /* legacy */
0431 
0432     if (of_get_property(np, "gpio-activelow", NULL))
0433         pdata->active_low = true;
0434 
0435     pdata->drive_inactive_cols =
0436         of_property_read_bool(np, "drive-inactive-cols");
0437 
0438     of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms);
0439     of_property_read_u32(np, "col-scan-delay-us",
0440                         &pdata->col_scan_delay_us);
0441 
0442     gpios = devm_kcalloc(dev,
0443                  pdata->num_row_gpios + pdata->num_col_gpios,
0444                  sizeof(unsigned int),
0445                  GFP_KERNEL);
0446     if (!gpios) {
0447         dev_err(dev, "could not allocate memory for gpios\n");
0448         return ERR_PTR(-ENOMEM);
0449     }
0450 
0451     for (i = 0; i < nrow; i++) {
0452         ret = of_get_named_gpio(np, "row-gpios", i);
0453         if (ret < 0)
0454             return ERR_PTR(ret);
0455         gpios[i] = ret;
0456     }
0457 
0458     for (i = 0; i < ncol; i++) {
0459         ret = of_get_named_gpio(np, "col-gpios", i);
0460         if (ret < 0)
0461             return ERR_PTR(ret);
0462         gpios[nrow + i] = ret;
0463     }
0464 
0465     pdata->row_gpios = gpios;
0466     pdata->col_gpios = &gpios[pdata->num_row_gpios];
0467 
0468     return pdata;
0469 }
0470 #else
0471 static inline struct matrix_keypad_platform_data *
0472 matrix_keypad_parse_dt(struct device *dev)
0473 {
0474     dev_err(dev, "no platform data defined\n");
0475 
0476     return ERR_PTR(-EINVAL);
0477 }
0478 #endif
0479 
0480 static int matrix_keypad_probe(struct platform_device *pdev)
0481 {
0482     const struct matrix_keypad_platform_data *pdata;
0483     struct matrix_keypad *keypad;
0484     struct input_dev *input_dev;
0485     int err;
0486 
0487     pdata = dev_get_platdata(&pdev->dev);
0488     if (!pdata) {
0489         pdata = matrix_keypad_parse_dt(&pdev->dev);
0490         if (IS_ERR(pdata))
0491             return PTR_ERR(pdata);
0492     } else if (!pdata->keymap_data) {
0493         dev_err(&pdev->dev, "no keymap data defined\n");
0494         return -EINVAL;
0495     }
0496 
0497     keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
0498     input_dev = input_allocate_device();
0499     if (!keypad || !input_dev) {
0500         err = -ENOMEM;
0501         goto err_free_mem;
0502     }
0503 
0504     keypad->input_dev = input_dev;
0505     keypad->pdata = pdata;
0506     keypad->row_shift = get_count_order(pdata->num_col_gpios);
0507     keypad->stopped = true;
0508     INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
0509     spin_lock_init(&keypad->lock);
0510 
0511     input_dev->name     = pdev->name;
0512     input_dev->id.bustype   = BUS_HOST;
0513     input_dev->dev.parent   = &pdev->dev;
0514     input_dev->open     = matrix_keypad_start;
0515     input_dev->close    = matrix_keypad_stop;
0516 
0517     err = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
0518                      pdata->num_row_gpios,
0519                      pdata->num_col_gpios,
0520                      NULL, input_dev);
0521     if (err) {
0522         dev_err(&pdev->dev, "failed to build keymap\n");
0523         goto err_free_mem;
0524     }
0525 
0526     if (!pdata->no_autorepeat)
0527         __set_bit(EV_REP, input_dev->evbit);
0528     input_set_capability(input_dev, EV_MSC, MSC_SCAN);
0529     input_set_drvdata(input_dev, keypad);
0530 
0531     err = matrix_keypad_init_gpio(pdev, keypad);
0532     if (err)
0533         goto err_free_mem;
0534 
0535     err = input_register_device(keypad->input_dev);
0536     if (err)
0537         goto err_free_gpio;
0538 
0539     device_init_wakeup(&pdev->dev, pdata->wakeup);
0540     platform_set_drvdata(pdev, keypad);
0541 
0542     return 0;
0543 
0544 err_free_gpio:
0545     matrix_keypad_free_gpio(keypad);
0546 err_free_mem:
0547     input_free_device(input_dev);
0548     kfree(keypad);
0549     return err;
0550 }
0551 
0552 static int matrix_keypad_remove(struct platform_device *pdev)
0553 {
0554     struct matrix_keypad *keypad = platform_get_drvdata(pdev);
0555 
0556     matrix_keypad_free_gpio(keypad);
0557     input_unregister_device(keypad->input_dev);
0558     kfree(keypad);
0559 
0560     return 0;
0561 }
0562 
0563 #ifdef CONFIG_OF
0564 static const struct of_device_id matrix_keypad_dt_match[] = {
0565     { .compatible = "gpio-matrix-keypad" },
0566     { }
0567 };
0568 MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match);
0569 #endif
0570 
0571 static struct platform_driver matrix_keypad_driver = {
0572     .probe      = matrix_keypad_probe,
0573     .remove     = matrix_keypad_remove,
0574     .driver     = {
0575         .name   = "matrix-keypad",
0576         .pm = &matrix_keypad_pm_ops,
0577         .of_match_table = of_match_ptr(matrix_keypad_dt_match),
0578     },
0579 };
0580 module_platform_driver(matrix_keypad_driver);
0581 
0582 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
0583 MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
0584 MODULE_LICENSE("GPL v2");
0585 MODULE_ALIAS("platform:matrix-keypad");
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