| /* |
| * 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/init.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 = pdev->dev.platform_data; |
| 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 __devexit 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; |
| |
| platform_set_drvdata(pdev, NULL); |
| |
| 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, |
| .owner = THIS_MODULE, |
| }, |
| }; |
| |
| 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); |