--- /dev/null
+/*
+ * 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
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/input-polldev.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 {
+ int last_state;
+ int count;
+ int threshold;
+ int can_sleep;
+};
+
+struct gpio_keys_polled_dev {
+ struct input_polled_dev *poll_dev;
+ struct device *dev;
+ const struct gpio_keys_platform_data *pdata;
+ struct gpio_keys_button_data data[0];
+};
+
+static void gpio_keys_polled_check_state(struct input_dev *input,
+ struct gpio_keys_button *button,
+ struct gpio_keys_button_data *bdata)
+{
+ int state;
+
+ if (bdata->can_sleep)
+ state = !!gpiod_get_value_cansleep(button->gpiod);
+ else
+ state = !!gpiod_get_value(button->gpiod);
+
+ if (state != bdata->last_state) {
+ unsigned int type = button->type ?: EV_KEY;
+
+ input_event(input, type, button->code, state);
+ input_sync(input);
+ bdata->count = 0;
+ bdata->last_state = state;
+ }
+}
+
+static void gpio_keys_polled_poll(struct input_polled_dev *dev)
+{
+ struct gpio_keys_polled_dev *bdev = dev->private;
+ const struct gpio_keys_platform_data *pdata = bdev->pdata;
+ struct input_dev *input = dev->input;
+ int i;
+
+ for (i = 0; i < pdata->nbuttons; i++) {
+ struct gpio_keys_button_data *bdata = &bdev->data[i];
+
+ if (bdata->count < bdata->threshold)
+ bdata->count++;
+ else
+ gpio_keys_polled_check_state(input, &pdata->buttons[i],
+ bdata);
+ }
+}
+
+static void gpio_keys_polled_open(struct input_polled_dev *dev)
+{
+ struct gpio_keys_polled_dev *bdev = dev->private;
+ const struct gpio_keys_platform_data *pdata = bdev->pdata;
+
+ if (pdata->enable)
+ pdata->enable(bdev->dev);
+}
+
+static void gpio_keys_polled_close(struct input_polled_dev *dev)
+{
+ struct gpio_keys_polled_dev *bdev = dev->private;
+ 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 error;
+ int nbuttons;
+
+ nbuttons = device_get_child_node_count(dev);
+ if (nbuttons == 0)
+ return NULL;
+
+ pdata = devm_kzalloc(dev, sizeof(*pdata) + nbuttons * sizeof(*button),
+ GFP_KERNEL);
+ if (!pdata)
+ return ERR_PTR(-ENOMEM);
+
+ pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
+
+ pdata->rep = device_property_present(dev, "autorepeat");
+ device_property_read_u32(dev, "poll-interval", &pdata->poll_interval);
+
+ device_for_each_child_node(dev, child) {
+ struct gpio_desc *desc;
+
+ desc = devm_get_gpiod_from_child(dev, NULL, child);
+ if (IS_ERR(desc)) {
+ error = PTR_ERR(desc);
+ if (error != -EPROBE_DEFER)
+ dev_err(dev,
+ "Failed to get gpio flags, error: %d\n",
+ error);
+ fwnode_handle_put(child);
+ return ERR_PTR(error);
+ }
+
+ button = &pdata->buttons[pdata->nbuttons++];
+ button->gpiod = desc;
+
+ if (fwnode_property_read_u32(child, "linux,code", &button->code)) {
+ dev_err(dev, "Button without keycode: %d\n",
+ pdata->nbuttons - 1);
+ 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;
+
+ button->wakeup = fwnode_property_present(child, "gpio-key,wakeup");
+
+ if (fwnode_property_read_u32(child, "debounce-interval",
+ &button->debounce_interval))
+ button->debounce_interval = 5;
+ }
+
+ if (pdata->nbuttons == 0)
+ return ERR_PTR(-EINVAL);
+
+ return pdata;
+}
+
+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;
+ const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
+ struct gpio_keys_polled_dev *bdev;
+ struct input_polled_dev *poll_dev;
+ struct input_dev *input;
+ size_t size;
+ int error;
+ int i;
+
+ if (!pdata) {
+ pdata = gpio_keys_polled_get_devtree_pdata(dev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ if (!pdata) {
+ dev_err(dev, "missing platform data\n");
+ return -EINVAL;
+ }
+ }
+
+ if (!pdata->poll_interval) {
+ dev_err(dev, "missing poll_interval value\n");
+ return -EINVAL;
+ }
+
+ size = sizeof(struct gpio_keys_polled_dev) +
+ pdata->nbuttons * sizeof(struct gpio_keys_button_data);
+ bdev = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+ if (!bdev) {
+ dev_err(dev, "no memory for private data\n");
+ return -ENOMEM;
+ }
+
+ poll_dev = devm_input_allocate_polled_device(&pdev->dev);
+ if (!poll_dev) {
+ dev_err(dev, "no memory for polled device\n");
+ return -ENOMEM;
+ }
+
+ poll_dev->private = bdev;
+ poll_dev->poll = gpio_keys_polled_poll;
+ poll_dev->poll_interval = pdata->poll_interval;
+ poll_dev->open = gpio_keys_polled_open;
+ poll_dev->close = gpio_keys_polled_close;
+
+ input = poll_dev->input;
+
+ input->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;
+
+ __set_bit(EV_KEY, input->evbit);
+ if (pdata->rep)
+ __set_bit(EV_REP, input->evbit);
+
+ for (i = 0; i < pdata->nbuttons; i++) {
+ 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");
+ return -EINVAL;
+ }
+
+ /*
+ * Legacy GPIO number so request the GPIO here and
+ * convert it to descriptor.
+ */
+ if (!button->gpiod && gpio_is_valid(button->gpio)) {
+ unsigned flags = 0;
+
+ if (button->active_low)
+ flags |= GPIOF_ACTIVE_LOW;
+
+ error = devm_gpio_request_one(&pdev->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;
+ }
+
+ button->gpiod = gpio_to_desc(button->gpio);
+ }
+
+ if (IS_ERR(button->gpiod))
+ return PTR_ERR(button->gpiod);
+
+ bdata->can_sleep = gpiod_cansleep(button->gpiod);
+ bdata->last_state = -1;
+ bdata->threshold = DIV_ROUND_UP(button->debounce_interval,
+ pdata->poll_interval);
+
+ input_set_capability(input, type, button->code);
+ }
+
+ bdev->poll_dev = poll_dev;
+ bdev->dev = dev;
+ bdev->pdata = pdata;
+ platform_set_drvdata(pdev, bdev);
+
+ error = input_register_polled_device(poll_dev);
+ 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]);
+
+ 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);
Code Review / kvmfornfv.git / blobdiff