1 files changed, 391 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 000000000..c3937d2fc
--- /dev/null
+++ b/drivers/input/keyboard/gpio_keys_polled.c
@@ -0,0 +1,391 @@
+// 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)) {
+				error = PTR_ERR(bdata->gpiod);
+				if (error != -EPROBE_DEFER)
+					dev_err(dev,
+						"failed to get gpio: %d\n",
+						error);
+				fwnode_handle_put(child);
+				return error;
+			}
+		} 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);