--- /dev/null
+/*
+ * Driver for tilt switches connected via GPIO lines
+ * not capable of generating interrupts
+ *
+ * Copyright (C) 2011 Heiko Stuebner <heiko@sntech.de>
+ *
+ * based on: drivers/input/keyboard/gpio_keys_polled.c
+ *
+ * Copyright (C) 2007-2010 Gabor Juhos <juhosg@openwrt.org>
+ * Copyright (C) 2010 Nuno Goncalves <nunojpg@gmail.com>
+ *
+ * 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/input/gpio_tilt.h>
+
+#define DRV_NAME "gpio-tilt-polled"
+
+struct gpio_tilt_polled_dev {
+ struct input_polled_dev *poll_dev;
+ struct device *dev;
+ const struct gpio_tilt_platform_data *pdata;
+
+ int last_state;
+
+ int threshold;
+ int count;
+};
+
+static void gpio_tilt_polled_poll(struct input_polled_dev *dev)
+{
+ struct gpio_tilt_polled_dev *tdev = dev->private;
+ const struct gpio_tilt_platform_data *pdata = tdev->pdata;
+ struct input_dev *input = dev->input;
+ struct gpio_tilt_state *tilt_state = NULL;
+ int state, i;
+
+ if (tdev->count < tdev->threshold) {
+ tdev->count++;
+ } else {
+ state = 0;
+ for (i = 0; i < pdata->nr_gpios; i++)
+ state |= (!!gpio_get_value(pdata->gpios[i].gpio) << i);
+
+ if (state != tdev->last_state) {
+ for (i = 0; i < pdata->nr_states; i++)
+ if (pdata->states[i].gpios == state)
+ tilt_state = &pdata->states[i];
+
+ if (tilt_state) {
+ for (i = 0; i < pdata->nr_axes; i++)
+ input_report_abs(input,
+ pdata->axes[i].axis,
+ tilt_state->axes[i]);
+
+ input_sync(input);
+ }
+
+ tdev->count = 0;
+ tdev->last_state = state;
+ }
+ }
+}
+
+static void gpio_tilt_polled_open(struct input_polled_dev *dev)
+{
+ struct gpio_tilt_polled_dev *tdev = dev->private;
+ const struct gpio_tilt_platform_data *pdata = tdev->pdata;
+
+ if (pdata->enable)
+ pdata->enable(tdev->dev);
+
+ /* report initial state of the axes */
+ tdev->last_state = -1;
+ tdev->count = tdev->threshold;
+ gpio_tilt_polled_poll(tdev->poll_dev);
+}
+
+static void gpio_tilt_polled_close(struct input_polled_dev *dev)
+{
+ struct gpio_tilt_polled_dev *tdev = dev->private;
+ const struct gpio_tilt_platform_data *pdata = tdev->pdata;
+
+ if (pdata->disable)
+ pdata->disable(tdev->dev);
+}
+
+static int gpio_tilt_polled_probe(struct platform_device *pdev)
+{
+ const struct gpio_tilt_platform_data *pdata =
+ dev_get_platdata(&pdev->dev);
+ struct device *dev = &pdev->dev;
+ struct gpio_tilt_polled_dev *tdev;
+ struct input_polled_dev *poll_dev;
+ struct input_dev *input;
+ int error, i;
+
+ if (!pdata || !pdata->poll_interval)
+ return -EINVAL;
+
+ tdev = kzalloc(sizeof(struct gpio_tilt_polled_dev), GFP_KERNEL);
+ if (!tdev) {
+ dev_err(dev, "no memory for private data\n");
+ return -ENOMEM;
+ }
+
+ error = gpio_request_array(pdata->gpios, pdata->nr_gpios);
+ if (error) {
+ dev_err(dev,
+ "Could not request tilt GPIOs: %d\n", error);
+ goto err_free_tdev;
+ }
+
+ poll_dev = input_allocate_polled_device();
+ if (!poll_dev) {
+ dev_err(dev, "no memory for polled device\n");
+ error = -ENOMEM;
+ goto err_free_gpios;
+ }
+
+ poll_dev->private = tdev;
+ poll_dev->poll = gpio_tilt_polled_poll;
+ poll_dev->poll_interval = pdata->poll_interval;
+ poll_dev->open = gpio_tilt_polled_open;
+ poll_dev->close = gpio_tilt_polled_close;
+
+ input = poll_dev->input;
+
+ input->name = pdev->name;
+ input->phys = DRV_NAME"/input0";
+ input->dev.parent = &pdev->dev;
+
+ input->id.bustype = BUS_HOST;
+ input->id.vendor = 0x0001;
+ input->id.product = 0x0001;
+ input->id.version = 0x0100;
+
+ __set_bit(EV_ABS, input->evbit);
+ for (i = 0; i < pdata->nr_axes; i++)
+ input_set_abs_params(input, pdata->axes[i].axis,
+ pdata->axes[i].min, pdata->axes[i].max,
+ pdata->axes[i].fuzz, pdata->axes[i].flat);
+
+ tdev->threshold = DIV_ROUND_UP(pdata->debounce_interval,
+ pdata->poll_interval);
+
+ tdev->poll_dev = poll_dev;
+ tdev->dev = dev;
+ tdev->pdata = pdata;
+
+ error = input_register_polled_device(poll_dev);
+ if (error) {
+ dev_err(dev, "unable to register polled device, err=%d\n",
+ error);
+ goto err_free_polldev;
+ }
+
+ platform_set_drvdata(pdev, tdev);
+
+ return 0;
+
+err_free_polldev:
+ input_free_polled_device(poll_dev);
+err_free_gpios:
+ gpio_free_array(pdata->gpios, pdata->nr_gpios);
+err_free_tdev:
+ kfree(tdev);
+
+ return error;
+}
+
+static int gpio_tilt_polled_remove(struct platform_device *pdev)
+{
+ struct gpio_tilt_polled_dev *tdev = platform_get_drvdata(pdev);
+ const struct gpio_tilt_platform_data *pdata = tdev->pdata;
+
+ input_unregister_polled_device(tdev->poll_dev);
+ input_free_polled_device(tdev->poll_dev);
+
+ gpio_free_array(pdata->gpios, pdata->nr_gpios);
+
+ kfree(tdev);
+
+ return 0;
+}
+
+static struct platform_driver gpio_tilt_polled_driver = {
+ .probe = gpio_tilt_polled_probe,
+ .remove = gpio_tilt_polled_remove,
+ .driver = {
+ .name = DRV_NAME,
+ },
+};
+
+module_platform_driver(gpio_tilt_polled_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
+MODULE_DESCRIPTION("Polled GPIO tilt driver");
+MODULE_ALIAS("platform:" DRV_NAME);
Code Review / kvmfornfv.git / blobdiff