diff options
Diffstat (limited to 'drivers/input/keyboard/matrix_keypad.c')
-rw-r--r-- | drivers/input/keyboard/matrix_keypad.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c new file mode 100644 index 0000000..541b981 --- /dev/null +++ b/drivers/input/keyboard/matrix_keypad.c @@ -0,0 +1,453 @@ +/* + * 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; + unsigned int row_shift; + + 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 = MATRIX_SCAN_CODE(row, col, keypad->row_shift); + 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; + unsigned int row_shift; + 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; + } + + row_shift = get_count_order(pdata->num_col_gpios); + + keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL); + keycodes = kzalloc((pdata->num_row_gpios << row_shift) * + sizeof(*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->row_shift = row_shift; + 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 = pdata->num_row_gpios << keypad->row_shift; + + 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[MATRIX_SCAN_CODE(row, col, row_shift)] = 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"); |