diff options
Diffstat (limited to 'drivers/input/keyboard/gpio_keys_polled.c')
| -rw-r--r-- | drivers/input/keyboard/gpio_keys_polled.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c new file mode 100644 index 0000000000..ba00ecfbd3 --- /dev/null +++ b/drivers/input/keyboard/gpio_keys_polled.c @@ -0,0 +1,387 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for buttons on GPIO lines not capable of generating interrupts + * + * Copyright (C) 2007-2010 Gabor Juhos <juhosg@openwrt.org> + * Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com> + * + * This file was based on: /drivers/input/misc/cobalt_btns.c + * Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> + * + * also was based on: /drivers/input/keyboard/gpio_keys.c + * Copyright 2005 Phil Blundell + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/input.h> +#include <linux/ioport.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/gpio/consumer.h> +#include <linux/gpio_keys.h> +#include <linux/property.h> + +#define DRV_NAME "gpio-keys-polled" + +struct gpio_keys_button_data { + struct gpio_desc *gpiod; + int last_state; + int count; + int threshold; +}; + +struct gpio_keys_polled_dev { + struct input_dev *input; + struct device *dev; + const struct gpio_keys_platform_data *pdata; + unsigned long rel_axis_seen[BITS_TO_LONGS(REL_CNT)]; + unsigned long abs_axis_seen[BITS_TO_LONGS(ABS_CNT)]; + struct gpio_keys_button_data data[]; +}; + +static void gpio_keys_button_event(struct input_dev *input, + const struct gpio_keys_button *button, + int state) +{ + struct gpio_keys_polled_dev *bdev = input_get_drvdata(input); + unsigned int type = button->type ?: EV_KEY; + + if (type == EV_REL) { + if (state) { + input_event(input, type, button->code, button->value); + __set_bit(button->code, bdev->rel_axis_seen); + } + } else if (type == EV_ABS) { + if (state) { + input_event(input, type, button->code, button->value); + __set_bit(button->code, bdev->abs_axis_seen); + } + } else { + input_event(input, type, button->code, state); + input_sync(input); + } +} + +static void gpio_keys_polled_check_state(struct input_dev *input, + const struct gpio_keys_button *button, + struct gpio_keys_button_data *bdata) +{ + int state; + + state = gpiod_get_value_cansleep(bdata->gpiod); + if (state < 0) { + dev_err(input->dev.parent, + "failed to get gpio state: %d\n", state); + } else { + gpio_keys_button_event(input, button, state); + + if (state != bdata->last_state) { + bdata->count = 0; + bdata->last_state = state; + } + } +} + +static void gpio_keys_polled_poll(struct input_dev *input) +{ + struct gpio_keys_polled_dev *bdev = input_get_drvdata(input); + const struct gpio_keys_platform_data *pdata = bdev->pdata; + int i; + + memset(bdev->rel_axis_seen, 0, sizeof(bdev->rel_axis_seen)); + memset(bdev->abs_axis_seen, 0, sizeof(bdev->abs_axis_seen)); + + for (i = 0; i < pdata->nbuttons; i++) { + struct gpio_keys_button_data *bdata = &bdev->data[i]; + + if (bdata->count < bdata->threshold) { + bdata->count++; + gpio_keys_button_event(input, &pdata->buttons[i], + bdata->last_state); + } else { + gpio_keys_polled_check_state(input, &pdata->buttons[i], + bdata); + } + } + + for_each_set_bit(i, input->relbit, REL_CNT) { + if (!test_bit(i, bdev->rel_axis_seen)) + input_event(input, EV_REL, i, 0); + } + + for_each_set_bit(i, input->absbit, ABS_CNT) { + if (!test_bit(i, bdev->abs_axis_seen)) + input_event(input, EV_ABS, i, 0); + } + + input_sync(input); +} + +static int gpio_keys_polled_open(struct input_dev *input) +{ + struct gpio_keys_polled_dev *bdev = input_get_drvdata(input); + const struct gpio_keys_platform_data *pdata = bdev->pdata; + + if (pdata->enable) + pdata->enable(bdev->dev); + + return 0; +} + +static void gpio_keys_polled_close(struct input_dev *input) +{ + struct gpio_keys_polled_dev *bdev = input_get_drvdata(input); + const struct gpio_keys_platform_data *pdata = bdev->pdata; + + if (pdata->disable) + pdata->disable(bdev->dev); +} + +static struct gpio_keys_platform_data * +gpio_keys_polled_get_devtree_pdata(struct device *dev) +{ + struct gpio_keys_platform_data *pdata; + struct gpio_keys_button *button; + struct fwnode_handle *child; + int nbuttons; + + nbuttons = device_get_child_node_count(dev); + if (nbuttons == 0) + return ERR_PTR(-EINVAL); + + pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * sizeof(*button), + GFP_KERNEL); + if (!pdata) + return ERR_PTR(-ENOMEM); + + button = (struct gpio_keys_button *)(pdata + 1); + + pdata->buttons = button; + pdata->nbuttons = nbuttons; + + pdata->rep = device_property_present(dev, "autorepeat"); + device_property_read_u32(dev, "poll-interval", &pdata->poll_interval); + + device_property_read_string(dev, "label", &pdata->name); + + device_for_each_child_node(dev, child) { + if (fwnode_property_read_u32(child, "linux,code", + &button->code)) { + dev_err(dev, "button without keycode\n"); + fwnode_handle_put(child); + return ERR_PTR(-EINVAL); + } + + fwnode_property_read_string(child, "label", &button->desc); + + if (fwnode_property_read_u32(child, "linux,input-type", + &button->type)) + button->type = EV_KEY; + + if (fwnode_property_read_u32(child, "linux,input-value", + (u32 *)&button->value)) + button->value = 1; + + button->wakeup = + fwnode_property_read_bool(child, "wakeup-source") || + /* legacy name */ + fwnode_property_read_bool(child, "gpio-key,wakeup"); + + if (fwnode_property_read_u32(child, "debounce-interval", + &button->debounce_interval)) + button->debounce_interval = 5; + + button++; + } + + return pdata; +} + +static void gpio_keys_polled_set_abs_params(struct input_dev *input, + const struct gpio_keys_platform_data *pdata, unsigned int code) +{ + int i, min = 0, max = 0; + + for (i = 0; i < pdata->nbuttons; i++) { + const struct gpio_keys_button *button = &pdata->buttons[i]; + + if (button->type != EV_ABS || button->code != code) + continue; + + if (button->value < min) + min = button->value; + if (button->value > max) + max = button->value; + } + + input_set_abs_params(input, code, min, max, 0, 0); +} + +static const struct of_device_id gpio_keys_polled_of_match[] = { + { .compatible = "gpio-keys-polled", }, + { }, +}; +MODULE_DEVICE_TABLE(of, gpio_keys_polled_of_match); + +static int gpio_keys_polled_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct fwnode_handle *child = NULL; + const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev); + struct gpio_keys_polled_dev *bdev; + struct input_dev *input; + int error; + int i; + + if (!pdata) { + pdata = gpio_keys_polled_get_devtree_pdata(dev); + if (IS_ERR(pdata)) + return PTR_ERR(pdata); + } + + if (!pdata->poll_interval) { + dev_err(dev, "missing poll_interval value\n"); + return -EINVAL; + } + + bdev = devm_kzalloc(dev, struct_size(bdev, data, pdata->nbuttons), + GFP_KERNEL); + if (!bdev) { + dev_err(dev, "no memory for private data\n"); + return -ENOMEM; + } + + input = devm_input_allocate_device(dev); + if (!input) { + dev_err(dev, "no memory for input device\n"); + return -ENOMEM; + } + + input_set_drvdata(input, bdev); + + input->name = pdata->name ?: pdev->name; + input->phys = DRV_NAME"/input0"; + + input->id.bustype = BUS_HOST; + input->id.vendor = 0x0001; + input->id.product = 0x0001; + input->id.version = 0x0100; + + input->open = gpio_keys_polled_open; + input->close = gpio_keys_polled_close; + + __set_bit(EV_KEY, input->evbit); + if (pdata->rep) + __set_bit(EV_REP, input->evbit); + + for (i = 0; i < pdata->nbuttons; i++) { + const struct gpio_keys_button *button = &pdata->buttons[i]; + struct gpio_keys_button_data *bdata = &bdev->data[i]; + unsigned int type = button->type ?: EV_KEY; + + if (button->wakeup) { + dev_err(dev, DRV_NAME " does not support wakeup\n"); + fwnode_handle_put(child); + return -EINVAL; + } + + if (!dev_get_platdata(dev)) { + /* No legacy static platform data */ + child = device_get_next_child_node(dev, child); + if (!child) { + dev_err(dev, "missing child device node\n"); + return -EINVAL; + } + + bdata->gpiod = devm_fwnode_gpiod_get(dev, child, + NULL, GPIOD_IN, + button->desc); + if (IS_ERR(bdata->gpiod)) { + fwnode_handle_put(child); + return dev_err_probe(dev, PTR_ERR(bdata->gpiod), + "failed to get gpio\n"); + } + } else if (gpio_is_valid(button->gpio)) { + /* + * Legacy GPIO number so request the GPIO here and + * convert it to descriptor. + */ + unsigned flags = GPIOF_IN; + + if (button->active_low) + flags |= GPIOF_ACTIVE_LOW; + + error = devm_gpio_request_one(dev, button->gpio, + flags, button->desc ? : DRV_NAME); + if (error) { + dev_err(dev, + "unable to claim gpio %u, err=%d\n", + button->gpio, error); + return error; + } + + bdata->gpiod = gpio_to_desc(button->gpio); + if (!bdata->gpiod) { + dev_err(dev, + "unable to convert gpio %u to descriptor\n", + button->gpio); + return -EINVAL; + } + } + + bdata->last_state = -1; + bdata->threshold = DIV_ROUND_UP(button->debounce_interval, + pdata->poll_interval); + + input_set_capability(input, type, button->code); + if (type == EV_ABS) + gpio_keys_polled_set_abs_params(input, pdata, + button->code); + } + + fwnode_handle_put(child); + + bdev->input = input; + bdev->dev = dev; + bdev->pdata = pdata; + + error = input_setup_polling(input, gpio_keys_polled_poll); + if (error) { + dev_err(dev, "unable to set up polling, err=%d\n", error); + return error; + } + + input_set_poll_interval(input, pdata->poll_interval); + + error = input_register_device(input); + if (error) { + dev_err(dev, "unable to register polled device, err=%d\n", + error); + return error; + } + + /* report initial state of the buttons */ + for (i = 0; i < pdata->nbuttons; i++) + gpio_keys_polled_check_state(input, &pdata->buttons[i], + &bdev->data[i]); + + input_sync(input); + + return 0; +} + +static struct platform_driver gpio_keys_polled_driver = { + .probe = gpio_keys_polled_probe, + .driver = { + .name = DRV_NAME, + .of_match_table = gpio_keys_polled_of_match, + }, +}; +module_platform_driver(gpio_keys_polled_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_DESCRIPTION("Polled GPIO Buttons driver"); +MODULE_ALIAS("platform:" DRV_NAME); |