--- /dev/null
+/*
+ * GPIO driven matrix keyboard driver
+ *
+ * Copyright (c) 2008 Marek Vasut <marek.vasut@gmail.com>
+ *
+ * Based on corgikbd.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/input/matrix_keypad.h>
+
+struct matrix_keypad {
+ const struct matrix_keypad_platform_data *pdata;
+ struct input_dev *input_dev;
+ unsigned short *keycodes;
+
+ uint32_t last_key_state[MATRIX_MAX_COLS];
+ struct delayed_work work;
+ bool scan_pending;
+ bool stopped;
+ spinlock_t lock;
+};
+
+/*
+ * NOTE: normally the GPIO has to be put into HiZ when de-activated to cause
+ * minmal side effect when scanning other columns, here it is configured to
+ * be input, and it should work on most platforms.
+ */
+static void __activate_col(const struct matrix_keypad_platform_data *pdata,
+ int col, bool on)
+{
+ bool level_on = !pdata->active_low;
+
+ if (on) {
+ gpio_direction_output(pdata->col_gpios[col], level_on);
+ } else {
+ gpio_set_value_cansleep(pdata->col_gpios[col], !level_on);
+ gpio_direction_input(pdata->col_gpios[col]);
+ }
+}
+
+static void activate_col(const struct matrix_keypad_platform_data *pdata,
+ int col, bool on)
+{
+ __activate_col(pdata, col, on);
+
+ if (on && pdata->col_scan_delay_us)
+ udelay(pdata->col_scan_delay_us);
+}
+
+static void activate_all_cols(const struct matrix_keypad_platform_data *pdata,
+ bool on)
+{
+ int col;
+
+ for (col = 0; col < pdata->num_col_gpios; col++)
+ __activate_col(pdata, col, on);
+}
+
+static bool row_asserted(const struct matrix_keypad_platform_data *pdata,
+ int row)
+{
+ return gpio_get_value_cansleep(pdata->row_gpios[row]) ?
+ !pdata->active_low : pdata->active_low;
+}
+
+static void enable_row_irqs(struct matrix_keypad *keypad)
+{
+ const struct matrix_keypad_platform_data *pdata = keypad->pdata;
+ int i;
+
+ for (i = 0; i < pdata->num_row_gpios; i++)
+ enable_irq(gpio_to_irq(pdata->row_gpios[i]));
+}
+
+static void disable_row_irqs(struct matrix_keypad *keypad)
+{
+ const struct matrix_keypad_platform_data *pdata = keypad->pdata;
+ int i;
+
+ for (i = 0; i < pdata->num_row_gpios; i++)
+ disable_irq_nosync(gpio_to_irq(pdata->row_gpios[i]));
+}
+
+/*
+ * This gets the keys from keyboard and reports it to input subsystem
+ */
+static void matrix_keypad_scan(struct work_struct *work)
+{
+ struct matrix_keypad *keypad =
+ container_of(work, struct matrix_keypad, work.work);
+ struct input_dev *input_dev = keypad->input_dev;
+ const struct matrix_keypad_platform_data *pdata = keypad->pdata;
+ uint32_t new_state[MATRIX_MAX_COLS];
+ int row, col, code;
+
+ /* de-activate all columns for scanning */
+ activate_all_cols(pdata, false);
+
+ memset(new_state, 0, sizeof(new_state));
+
+ /* assert each column and read the row status out */
+ for (col = 0; col < pdata->num_col_gpios; col++) {
+
+ activate_col(pdata, col, true);
+
+ for (row = 0; row < pdata->num_row_gpios; row++)
+ new_state[col] |=
+ row_asserted(pdata, row) ? (1 << row) : 0;
+
+ activate_col(pdata, col, false);
+ }
+
+ for (col = 0; col < pdata->num_col_gpios; col++) {
+ uint32_t bits_changed;
+
+ bits_changed = keypad->last_key_state[col] ^ new_state[col];
+ if (bits_changed == 0)
+ continue;
+
+ for (row = 0; row < pdata->num_row_gpios; row++) {
+ if ((bits_changed & (1 << row)) == 0)
+ continue;
+
+ code = (row << 4) + col;
+ input_event(input_dev, EV_MSC, MSC_SCAN, code);
+ input_report_key(input_dev,
+ keypad->keycodes[code],
+ new_state[col] & (1 << row));
+ }
+ }
+ input_sync(input_dev);
+
+ memcpy(keypad->last_key_state, new_state, sizeof(new_state));
+
+ activate_all_cols(pdata, true);
+
+ /* Enable IRQs again */
+ spin_lock_irq(&keypad->lock);
+ keypad->scan_pending = false;
+ enable_row_irqs(keypad);
+ spin_unlock_irq(&keypad->lock);
+}
+
+static irqreturn_t matrix_keypad_interrupt(int irq, void *id)
+{
+ struct matrix_keypad *keypad = id;
+ unsigned long flags;
+
+ spin_lock_irqsave(&keypad->lock, flags);
+
+ /*
+ * See if another IRQ beaten us to it and scheduled the
+ * scan already. In that case we should not try to
+ * disable IRQs again.
+ */
+ if (unlikely(keypad->scan_pending || keypad->stopped))
+ goto out;
+
+ disable_row_irqs(keypad);
+ keypad->scan_pending = true;
+ schedule_delayed_work(&keypad->work,
+ msecs_to_jiffies(keypad->pdata->debounce_ms));
+
+out:
+ spin_unlock_irqrestore(&keypad->lock, flags);
+ return IRQ_HANDLED;
+}
+
+static int matrix_keypad_start(struct input_dev *dev)
+{
+ struct matrix_keypad *keypad = input_get_drvdata(dev);
+
+ keypad->stopped = false;
+ mb();
+
+ /*
+ * Schedule an immediate key scan to capture current key state;
+ * columns will be activated and IRQs be enabled after the scan.
+ */
+ schedule_delayed_work(&keypad->work, 0);
+
+ return 0;
+}
+
+static void matrix_keypad_stop(struct input_dev *dev)
+{
+ struct matrix_keypad *keypad = input_get_drvdata(dev);
+
+ keypad->stopped = true;
+ mb();
+ flush_work(&keypad->work.work);
+ /*
+ * matrix_keypad_scan() will leave IRQs enabled;
+ * we should disable them now.
+ */
+ disable_row_irqs(keypad);
+}
+
+#ifdef CONFIG_PM
+static int matrix_keypad_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct matrix_keypad *keypad = platform_get_drvdata(pdev);
+ const struct matrix_keypad_platform_data *pdata = keypad->pdata;
+ int i;
+
+ matrix_keypad_stop(keypad->input_dev);
+
+ if (device_may_wakeup(&pdev->dev))
+ for (i = 0; i < pdata->num_row_gpios; i++)
+ enable_irq_wake(gpio_to_irq(pdata->row_gpios[i]));
+
+ return 0;
+}
+
+static int matrix_keypad_resume(struct platform_device *pdev)
+{
+ struct matrix_keypad *keypad = platform_get_drvdata(pdev);
+ const struct matrix_keypad_platform_data *pdata = keypad->pdata;
+ int i;
+
+ if (device_may_wakeup(&pdev->dev))
+ for (i = 0; i < pdata->num_row_gpios; i++)
+ disable_irq_wake(gpio_to_irq(pdata->row_gpios[i]));
+
+ matrix_keypad_start(keypad->input_dev);
+
+ return 0;
+}
+#else
+#define matrix_keypad_suspend NULL
+#define matrix_keypad_resume NULL
+#endif
+
+static int __devinit init_matrix_gpio(struct platform_device *pdev,
+ struct matrix_keypad *keypad)
+{
+ const struct matrix_keypad_platform_data *pdata = keypad->pdata;
+ int i, err = -EINVAL;
+
+ /* initialized strobe lines as outputs, activated */
+ for (i = 0; i < pdata->num_col_gpios; i++) {
+ err = gpio_request(pdata->col_gpios[i], "matrix_kbd_col");
+ if (err) {
+ dev_err(&pdev->dev,
+ "failed to request GPIO%d for COL%d\n",
+ pdata->col_gpios[i], i);
+ goto err_free_cols;
+ }
+
+ gpio_direction_output(pdata->col_gpios[i], !pdata->active_low);
+ }
+
+ for (i = 0; i < pdata->num_row_gpios; i++) {
+ err = gpio_request(pdata->row_gpios[i], "matrix_kbd_row");
+ if (err) {
+ dev_err(&pdev->dev,
+ "failed to request GPIO%d for ROW%d\n",
+ pdata->row_gpios[i], i);
+ goto err_free_rows;
+ }
+
+ gpio_direction_input(pdata->row_gpios[i]);
+ }
+
+ for (i = 0; i < pdata->num_row_gpios; i++) {
+ err = request_irq(gpio_to_irq(pdata->row_gpios[i]),
+ matrix_keypad_interrupt,
+ IRQF_DISABLED |
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ "matrix-keypad", keypad);
+ if (err) {
+ dev_err(&pdev->dev,
+ "Unable to acquire interrupt for GPIO line %i\n",
+ pdata->row_gpios[i]);
+ goto err_free_irqs;
+ }
+ }
+
+ /* initialized as disabled - enabled by input->open */
+ disable_row_irqs(keypad);
+ return 0;
+
+err_free_irqs:
+ while (--i >= 0)
+ free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
+ i = pdata->num_row_gpios;
+err_free_rows:
+ while (--i >= 0)
+ gpio_free(pdata->row_gpios[i]);
+ i = pdata->num_col_gpios;
+err_free_cols:
+ while (--i >= 0)
+ gpio_free(pdata->col_gpios[i]);
+
+ return err;
+}
+
+static int __devinit matrix_keypad_probe(struct platform_device *pdev)
+{
+ const struct matrix_keypad_platform_data *pdata;
+ const struct matrix_keymap_data *keymap_data;
+ struct matrix_keypad *keypad;
+ struct input_dev *input_dev;
+ unsigned short *keycodes;
+ int i;
+ int err;
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata) {
+ dev_err(&pdev->dev, "no platform data defined\n");
+ return -EINVAL;
+ }
+
+ keymap_data = pdata->keymap_data;
+ if (!keymap_data) {
+ dev_err(&pdev->dev, "no keymap data defined\n");
+ return -EINVAL;
+ }
+
+ if (!keymap_data->max_keymap_size) {
+ dev_err(&pdev->dev, "invalid keymap data supplied\n");
+ return -EINVAL;
+ }
+
+ keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL);
+ keycodes = kzalloc(keymap_data->max_keymap_size *
+ sizeof(keypad->keycodes),
+ GFP_KERNEL);
+ input_dev = input_allocate_device();
+ if (!keypad || !keycodes || !input_dev) {
+ err = -ENOMEM;
+ goto err_free_mem;
+ }
+
+ keypad->input_dev = input_dev;
+ keypad->pdata = pdata;
+ keypad->keycodes = keycodes;
+ keypad->stopped = true;
+ INIT_DELAYED_WORK(&keypad->work, matrix_keypad_scan);
+ spin_lock_init(&keypad->lock);
+
+ input_dev->name = pdev->name;
+ input_dev->id.bustype = BUS_HOST;
+ input_dev->dev.parent = &pdev->dev;
+ input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
+ input_dev->open = matrix_keypad_start;
+ input_dev->close = matrix_keypad_stop;
+
+ input_dev->keycode = keycodes;
+ input_dev->keycodesize = sizeof(*keycodes);
+ input_dev->keycodemax = keymap_data->max_keymap_size;
+
+ for (i = 0; i < keymap_data->keymap_size; i++) {
+ unsigned int key = keymap_data->keymap[i];
+ unsigned int row = KEY_ROW(key);
+ unsigned int col = KEY_COL(key);
+ unsigned short code = KEY_VAL(key);
+
+ keycodes[(row << 4) + col] = code;
+ __set_bit(code, input_dev->keybit);
+ }
+ __clear_bit(KEY_RESERVED, input_dev->keybit);
+
+ input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+ input_set_drvdata(input_dev, keypad);
+
+ err = init_matrix_gpio(pdev, keypad);
+ if (err)
+ goto err_free_mem;
+
+ err = input_register_device(keypad->input_dev);
+ if (err)
+ goto err_free_mem;
+
+ device_init_wakeup(&pdev->dev, pdata->wakeup);
+ platform_set_drvdata(pdev, keypad);
+
+ return 0;
+
+err_free_mem:
+ input_free_device(input_dev);
+ kfree(keycodes);
+ kfree(keypad);
+ return err;
+}
+
+static int __devexit matrix_keypad_remove(struct platform_device *pdev)
+{
+ struct matrix_keypad *keypad = platform_get_drvdata(pdev);
+ const struct matrix_keypad_platform_data *pdata = keypad->pdata;
+ int i;
+
+ device_init_wakeup(&pdev->dev, 0);
+
+ for (i = 0; i < pdata->num_row_gpios; i++) {
+ free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad);
+ gpio_free(pdata->row_gpios[i]);
+ }
+
+ for (i = 0; i < pdata->num_col_gpios; i++)
+ gpio_free(pdata->col_gpios[i]);
+
+ input_unregister_device(keypad->input_dev);
+ platform_set_drvdata(pdev, NULL);
+ kfree(keypad->keycodes);
+ kfree(keypad);
+
+ return 0;
+}
+
+static struct platform_driver matrix_keypad_driver = {
+ .probe = matrix_keypad_probe,
+ .remove = __devexit_p(matrix_keypad_remove),
+ .suspend = matrix_keypad_suspend,
+ .resume = matrix_keypad_resume,
+ .driver = {
+ .name = "matrix-keypad",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init matrix_keypad_init(void)
+{
+ return platform_driver_register(&matrix_keypad_driver);
+}
+
+static void __exit matrix_keypad_exit(void)
+{
+ platform_driver_unregister(&matrix_keypad_driver);
+}
+
+module_init(matrix_keypad_init);
+module_exit(matrix_keypad_exit);
+
+MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
+MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:matrix-keypad");
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