diff options
Diffstat (limited to 'kernel/drivers/input/keyboard/matrix_keypad.c')
-rw-r--r-- | kernel/drivers/input/keyboard/matrix_keypad.c | 577 |
1 files changed, 577 insertions, 0 deletions
diff --git a/kernel/drivers/input/keyboard/matrix_keypad.c b/kernel/drivers/input/keyboard/matrix_keypad.c new file mode 100644 index 000000000..b370a59cb --- /dev/null +++ b/kernel/drivers/input/keyboard/matrix_keypad.c @@ -0,0 +1,577 @@ +/* + * 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/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> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/of_gpio.h> +#include <linux/of_platform.h> + +struct matrix_keypad { + const struct matrix_keypad_platform_data *pdata; + struct input_dev *input_dev; + unsigned int row_shift; + + DECLARE_BITMAP(disabled_gpios, MATRIX_MAX_ROWS); + + uint32_t last_key_state[MATRIX_MAX_COLS]; + struct delayed_work work; + spinlock_t lock; + bool scan_pending; + bool stopped; + bool gpio_all_disabled; +}; + +/* + * 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; + + if (pdata->clustered_irq > 0) + enable_irq(pdata->clustered_irq); + else { + 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; + + if (pdata->clustered_irq > 0) + disable_irq_nosync(pdata->clustered_irq); + else { + 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 unsigned short *keycodes = input_dev->keycode; + 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, + 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_SLEEP +static void matrix_keypad_enable_wakeup(struct matrix_keypad *keypad) +{ + const struct matrix_keypad_platform_data *pdata = keypad->pdata; + unsigned int gpio; + int i; + + if (pdata->clustered_irq > 0) { + if (enable_irq_wake(pdata->clustered_irq) == 0) + keypad->gpio_all_disabled = true; + } else { + + for (i = 0; i < pdata->num_row_gpios; i++) { + if (!test_bit(i, keypad->disabled_gpios)) { + gpio = pdata->row_gpios[i]; + + if (enable_irq_wake(gpio_to_irq(gpio)) == 0) + __set_bit(i, keypad->disabled_gpios); + } + } + } +} + +static void matrix_keypad_disable_wakeup(struct matrix_keypad *keypad) +{ + const struct matrix_keypad_platform_data *pdata = keypad->pdata; + unsigned int gpio; + int i; + + if (pdata->clustered_irq > 0) { + if (keypad->gpio_all_disabled) { + disable_irq_wake(pdata->clustered_irq); + keypad->gpio_all_disabled = false; + } + } else { + for (i = 0; i < pdata->num_row_gpios; i++) { + if (test_and_clear_bit(i, keypad->disabled_gpios)) { + gpio = pdata->row_gpios[i]; + disable_irq_wake(gpio_to_irq(gpio)); + } + } + } +} + +static int matrix_keypad_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct matrix_keypad *keypad = platform_get_drvdata(pdev); + + matrix_keypad_stop(keypad->input_dev); + + if (device_may_wakeup(&pdev->dev)) + matrix_keypad_enable_wakeup(keypad); + + return 0; +} + +static int matrix_keypad_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct matrix_keypad *keypad = platform_get_drvdata(pdev); + + if (device_may_wakeup(&pdev->dev)) + matrix_keypad_disable_wakeup(keypad); + + matrix_keypad_start(keypad->input_dev); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(matrix_keypad_pm_ops, + matrix_keypad_suspend, matrix_keypad_resume); + +static int matrix_keypad_init_gpio(struct platform_device *pdev, + struct matrix_keypad *keypad) +{ + const struct matrix_keypad_platform_data *pdata = keypad->pdata; + int i, err; + + /* 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]); + } + + if (pdata->clustered_irq > 0) { + err = request_any_context_irq(pdata->clustered_irq, + matrix_keypad_interrupt, + pdata->clustered_irq_flags, + "matrix-keypad", keypad); + if (err < 0) { + dev_err(&pdev->dev, + "Unable to acquire clustered interrupt\n"); + goto err_free_rows; + } + } else { + for (i = 0; i < pdata->num_row_gpios; i++) { + err = request_any_context_irq( + gpio_to_irq(pdata->row_gpios[i]), + matrix_keypad_interrupt, + IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING, + "matrix-keypad", keypad); + if (err < 0) { + 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 void matrix_keypad_free_gpio(struct matrix_keypad *keypad) +{ + const struct matrix_keypad_platform_data *pdata = keypad->pdata; + int i; + + if (pdata->clustered_irq > 0) { + free_irq(pdata->clustered_irq, keypad); + } else { + for (i = 0; i < pdata->num_row_gpios; i++) + free_irq(gpio_to_irq(pdata->row_gpios[i]), keypad); + } + + for (i = 0; i < pdata->num_row_gpios; i++) + gpio_free(pdata->row_gpios[i]); + + for (i = 0; i < pdata->num_col_gpios; i++) + gpio_free(pdata->col_gpios[i]); +} + +#ifdef CONFIG_OF +static struct matrix_keypad_platform_data * +matrix_keypad_parse_dt(struct device *dev) +{ + struct matrix_keypad_platform_data *pdata; + struct device_node *np = dev->of_node; + unsigned int *gpios; + int i, nrow, ncol; + + if (!np) { + dev_err(dev, "device lacks DT data\n"); + return ERR_PTR(-ENODEV); + } + + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) { + dev_err(dev, "could not allocate memory for platform data\n"); + return ERR_PTR(-ENOMEM); + } + + pdata->num_row_gpios = nrow = of_gpio_named_count(np, "row-gpios"); + pdata->num_col_gpios = ncol = of_gpio_named_count(np, "col-gpios"); + if (nrow <= 0 || ncol <= 0) { + dev_err(dev, "number of keypad rows/columns not specified\n"); + return ERR_PTR(-EINVAL); + } + + if (of_get_property(np, "linux,no-autorepeat", NULL)) + pdata->no_autorepeat = true; + if (of_get_property(np, "linux,wakeup", NULL)) + pdata->wakeup = true; + if (of_get_property(np, "gpio-activelow", NULL)) + pdata->active_low = true; + + of_property_read_u32(np, "debounce-delay-ms", &pdata->debounce_ms); + of_property_read_u32(np, "col-scan-delay-us", + &pdata->col_scan_delay_us); + + gpios = devm_kzalloc(dev, + sizeof(unsigned int) * + (pdata->num_row_gpios + pdata->num_col_gpios), + GFP_KERNEL); + if (!gpios) { + dev_err(dev, "could not allocate memory for gpios\n"); + return ERR_PTR(-ENOMEM); + } + + for (i = 0; i < pdata->num_row_gpios; i++) + gpios[i] = of_get_named_gpio(np, "row-gpios", i); + + for (i = 0; i < pdata->num_col_gpios; i++) + gpios[pdata->num_row_gpios + i] = + of_get_named_gpio(np, "col-gpios", i); + + pdata->row_gpios = gpios; + pdata->col_gpios = &gpios[pdata->num_row_gpios]; + + return pdata; +} +#else +static inline struct matrix_keypad_platform_data * +matrix_keypad_parse_dt(struct device *dev) +{ + dev_err(dev, "no platform data defined\n"); + + return ERR_PTR(-EINVAL); +} +#endif + +static int matrix_keypad_probe(struct platform_device *pdev) +{ + const struct matrix_keypad_platform_data *pdata; + struct matrix_keypad *keypad; + struct input_dev *input_dev; + int err; + + pdata = dev_get_platdata(&pdev->dev); + if (!pdata) { + pdata = matrix_keypad_parse_dt(&pdev->dev); + if (IS_ERR(pdata)) { + dev_err(&pdev->dev, "no platform data defined\n"); + return PTR_ERR(pdata); + } + } else if (!pdata->keymap_data) { + dev_err(&pdev->dev, "no keymap data defined\n"); + return -EINVAL; + } + + keypad = kzalloc(sizeof(struct matrix_keypad), GFP_KERNEL); + input_dev = input_allocate_device(); + if (!keypad || !input_dev) { + err = -ENOMEM; + goto err_free_mem; + } + + keypad->input_dev = input_dev; + keypad->pdata = pdata; + keypad->row_shift = get_count_order(pdata->num_col_gpios); + 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->open = matrix_keypad_start; + input_dev->close = matrix_keypad_stop; + + err = matrix_keypad_build_keymap(pdata->keymap_data, NULL, + pdata->num_row_gpios, + pdata->num_col_gpios, + NULL, input_dev); + if (err) { + dev_err(&pdev->dev, "failed to build keymap\n"); + goto err_free_mem; + } + + if (!pdata->no_autorepeat) + __set_bit(EV_REP, input_dev->evbit); + input_set_capability(input_dev, EV_MSC, MSC_SCAN); + input_set_drvdata(input_dev, keypad); + + err = matrix_keypad_init_gpio(pdev, keypad); + if (err) + goto err_free_mem; + + err = input_register_device(keypad->input_dev); + if (err) + goto err_free_gpio; + + device_init_wakeup(&pdev->dev, pdata->wakeup); + platform_set_drvdata(pdev, keypad); + + return 0; + +err_free_gpio: + matrix_keypad_free_gpio(keypad); +err_free_mem: + input_free_device(input_dev); + kfree(keypad); + return err; +} + +static int matrix_keypad_remove(struct platform_device *pdev) +{ + struct matrix_keypad *keypad = platform_get_drvdata(pdev); + + device_init_wakeup(&pdev->dev, 0); + + matrix_keypad_free_gpio(keypad); + input_unregister_device(keypad->input_dev); + kfree(keypad); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id matrix_keypad_dt_match[] = { + { .compatible = "gpio-matrix-keypad" }, + { } +}; +MODULE_DEVICE_TABLE(of, matrix_keypad_dt_match); +#endif + +static struct platform_driver matrix_keypad_driver = { + .probe = matrix_keypad_probe, + .remove = matrix_keypad_remove, + .driver = { + .name = "matrix-keypad", + .pm = &matrix_keypad_pm_ops, + .of_match_table = of_match_ptr(matrix_keypad_dt_match), + }, +}; +module_platform_driver(matrix_keypad_driver); + +MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>"); +MODULE_DESCRIPTION("GPIO Driven Matrix Keypad Driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:matrix-keypad"); |