^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * This program is free software; you can redistribute it and/or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * modify it under the terms of the GNU General Public License as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * published by the Free Software Foundation version 2.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * This program is distributed "as is" WITHOUT ANY WARRANTY of any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * kind, whether express or implied; without even the implied warranty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * GNU General Public License for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * A generic driver to read multiple gpio lines and translate the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * encoded numeric value into an input event.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/gpio/consumer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/input.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/of.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/platform_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) struct gpio_decoder {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) struct gpio_descs *input_gpios;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) struct device *dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) u32 axis;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) u32 last_stable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) static int gpio_decoder_get_gpios_state(struct gpio_decoder *decoder)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) struct gpio_descs *gpios = decoder->input_gpios;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) unsigned int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) int i, val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) for (i = 0; i < gpios->ndescs; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) val = gpiod_get_value_cansleep(gpios->desc[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) if (val < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) dev_err(decoder->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) "Error reading gpio %d: %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) desc_to_gpio(gpios->desc[i]), val);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) return val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) val = !!val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) ret = (ret << 1) | val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) static void gpio_decoder_poll_gpios(struct input_dev *input)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) struct gpio_decoder *decoder = input_get_drvdata(input);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) int state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) state = gpio_decoder_get_gpios_state(decoder);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) if (state >= 0 && state != decoder->last_stable) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) input_report_abs(input, decoder->axis, state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) input_sync(input);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) decoder->last_stable = state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) static int gpio_decoder_probe(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) struct device *dev = &pdev->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) struct gpio_decoder *decoder;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) struct input_dev *input;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) u32 max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) decoder = devm_kzalloc(dev, sizeof(*decoder), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) if (!decoder)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) decoder->dev = dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) device_property_read_u32(dev, "linux,axis", &decoder->axis);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) decoder->input_gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) if (IS_ERR(decoder->input_gpios)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) dev_err(dev, "unable to acquire input gpios\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) return PTR_ERR(decoder->input_gpios);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) if (decoder->input_gpios->ndescs < 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) dev_err(dev, "not enough gpios found\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) if (device_property_read_u32(dev, "decoder-max-value", &max))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) max = (1U << decoder->input_gpios->ndescs) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) input = devm_input_allocate_device(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) if (!input)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) input_set_drvdata(input, decoder);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) input->name = pdev->name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) input->id.bustype = BUS_HOST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) input_set_abs_params(input, decoder->axis, 0, max, 0, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) err = input_setup_polling(input, gpio_decoder_poll_gpios);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) dev_err(dev, "failed to set up polling\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) err = input_register_device(input);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) dev_err(dev, "failed to register input device\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) #ifdef CONFIG_OF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) static const struct of_device_id gpio_decoder_of_match[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) { .compatible = "gpio-decoder", },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) { },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) MODULE_DEVICE_TABLE(of, gpio_decoder_of_match);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) static struct platform_driver gpio_decoder_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) .probe = gpio_decoder_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) .name = "gpio-decoder",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) .of_match_table = of_match_ptr(gpio_decoder_of_match),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) module_platform_driver(gpio_decoder_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) MODULE_DESCRIPTION("GPIO decoder input driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) MODULE_AUTHOR("Vignesh R <vigneshr@ti.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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