From 3bfd5c5baf66e975b0f365a0cda8d75bf2953ebe Mon Sep 17 00:00:00 2001 From: Heiko Stübner Date: Tue, 29 Nov 2011 11:04:09 -0800 Subject: Input: add generic GPIO-tilt driver There exist tilt switches that simply report their tilt-state via some gpios. The number and orientation of their axes can vary depending on the switch used and the build of the device. Also two or more one-axis switches could be combined to provide multi-dimensional orientation. One example of a device using such a switch is the family of Qisda ebook readers, where the switch provides information about the landscape / portrait orientation of the device. The example in Documentation/input/gpio-tilt.txt documents exactly this one-axis device. Signed-off-by: Heiko Stuebner Signed-off-by: Dmitry Torokhov --- drivers/input/misc/Kconfig | 14 +++ drivers/input/misc/Makefile | 1 + drivers/input/misc/gpio_tilt_polled.c | 213 ++++++++++++++++++++++++++++++++++ 3 files changed, 228 insertions(+) create mode 100644 drivers/input/misc/gpio_tilt_polled.c (limited to 'drivers') diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig index 22d875fde53a..e53b443d1e33 100644 --- a/drivers/input/misc/Kconfig +++ b/drivers/input/misc/Kconfig @@ -179,6 +179,20 @@ config INPUT_APANEL To compile this driver as a module, choose M here: the module will be called apanel. +config INPUT_GPIO_TILT_POLLED + tristate "Polled GPIO tilt switch" + depends on GENERIC_GPIO + select INPUT_POLLDEV + help + This driver implements support for tilt switches connected + to GPIO pins that are not capable of generating interrupts. + + The list of gpios to use and the mapping of their states + to specific angles is done via platform data. + + To compile this driver as a module, choose M here: the + module will be called gpio_tilt_polled. + config INPUT_IXP4XX_BEEPER tristate "IXP4XX Beeper support" depends on ARCH_IXP4XX diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile index a244fc6a781c..90070c1a4ad3 100644 --- a/drivers/input/misc/Makefile +++ b/drivers/input/misc/Makefile @@ -23,6 +23,7 @@ obj-$(CONFIG_INPUT_CMA3000_I2C) += cma3000_d0x_i2c.o obj-$(CONFIG_INPUT_COBALT_BTNS) += cobalt_btns.o obj-$(CONFIG_INPUT_DM355EVM) += dm355evm_keys.o obj-$(CONFIG_HP_SDC_RTC) += hp_sdc_rtc.o +obj-$(CONFIG_INPUT_GPIO_TILT_POLLED) += gpio_tilt_polled.o obj-$(CONFIG_INPUT_IXP4XX_BEEPER) += ixp4xx-beeper.o obj-$(CONFIG_INPUT_KEYSPAN_REMOTE) += keyspan_remote.o obj-$(CONFIG_INPUT_KXTJ9) += kxtj9.o diff --git a/drivers/input/misc/gpio_tilt_polled.c b/drivers/input/misc/gpio_tilt_polled.c new file mode 100644 index 000000000000..277a0574c199 --- /dev/null +++ b/drivers/input/misc/gpio_tilt_polled.c @@ -0,0 +1,213 @@ +/* + * Driver for tilt switches connected via GPIO lines + * not capable of generating interrupts + * + * Copyright (C) 2011 Heiko Stuebner + * + * based on: drivers/input/keyboard/gpio_keys_polled.c + * + * Copyright (C) 2007-2010 Gabor Juhos + * Copyright (C) 2010 Nuno Goncalves + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 __devinit 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 = __devexit_p(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 "); +MODULE_DESCRIPTION("Polled GPIO tilt driver"); +MODULE_ALIAS("platform:" DRV_NAME); -- cgit v1.2.3-59-g8ed1b