Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Vignesh R | 522 | 90.62% | 1 | 33.33% |
Dmitry Torokhov | 52 | 9.03% | 1 | 33.33% |
Thomas Gleixner | 2 | 0.35% | 1 | 33.33% |
Total | 576 | 3 |
// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/ * * A generic driver to read multiple gpio lines and translate the * encoded numeric value into an input event. */ #include <linux/device.h> #include <linux/gpio/consumer.h> #include <linux/input.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> struct gpio_decoder { struct gpio_descs *input_gpios; struct device *dev; u32 axis; u32 last_stable; }; static int gpio_decoder_get_gpios_state(struct gpio_decoder *decoder) { struct gpio_descs *gpios = decoder->input_gpios; unsigned int ret = 0; int i, val; for (i = 0; i < gpios->ndescs; i++) { val = gpiod_get_value_cansleep(gpios->desc[i]); if (val < 0) { dev_err(decoder->dev, "Error reading gpio %d: %d\n", desc_to_gpio(gpios->desc[i]), val); return val; } val = !!val; ret = (ret << 1) | val; } return ret; } static void gpio_decoder_poll_gpios(struct input_dev *input) { struct gpio_decoder *decoder = input_get_drvdata(input); int state; state = gpio_decoder_get_gpios_state(decoder); if (state >= 0 && state != decoder->last_stable) { input_report_abs(input, decoder->axis, state); input_sync(input); decoder->last_stable = state; } } static int gpio_decoder_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct gpio_decoder *decoder; struct input_dev *input; u32 max; int err; decoder = devm_kzalloc(dev, sizeof(*decoder), GFP_KERNEL); if (!decoder) return -ENOMEM; decoder->dev = dev; device_property_read_u32(dev, "linux,axis", &decoder->axis); decoder->input_gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN); if (IS_ERR(decoder->input_gpios)) { dev_err(dev, "unable to acquire input gpios\n"); return PTR_ERR(decoder->input_gpios); } if (decoder->input_gpios->ndescs < 2) { dev_err(dev, "not enough gpios found\n"); return -EINVAL; } if (device_property_read_u32(dev, "decoder-max-value", &max)) max = (1U << decoder->input_gpios->ndescs) - 1; input = devm_input_allocate_device(dev); if (!input) return -ENOMEM; input_set_drvdata(input, decoder); input->name = pdev->name; input->id.bustype = BUS_HOST; input_set_abs_params(input, decoder->axis, 0, max, 0, 0); err = input_setup_polling(input, gpio_decoder_poll_gpios); if (err) { dev_err(dev, "failed to set up polling\n"); return err; } err = input_register_device(input); if (err) { dev_err(dev, "failed to register input device\n"); return err; } return 0; } #ifdef CONFIG_OF static const struct of_device_id gpio_decoder_of_match[] = { { .compatible = "gpio-decoder", }, { }, }; MODULE_DEVICE_TABLE(of, gpio_decoder_of_match); #endif static struct platform_driver gpio_decoder_driver = { .probe = gpio_decoder_probe, .driver = { .name = "gpio-decoder", .of_match_table = of_match_ptr(gpio_decoder_of_match), } }; module_platform_driver(gpio_decoder_driver); MODULE_DESCRIPTION("GPIO decoder input driver"); MODULE_AUTHOR("Vignesh R <vigneshr@ti.com>"); MODULE_LICENSE("GPL v2");
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