Input: joystick - add ADC attached joystick driver. (2c2b364f) · Commits · 戴 / test

drivers/input/joystick/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,16 @@ config JOYSTICK_A3D
		To compile this driver as a module, choose M here: the
		module will be called a3d.

		config JOYSTICK_ADC
		tristate "Simple joystick connected over ADC"
		depends on IIO
		select IIO_BUFFER_CB
		help
		Say Y here if you have a simple joystick connected over ADC.

		To compile this driver as a module, choose M here: the
		module will be called adc-joystick.

		config JOYSTICK_ADI
		tristate "Logitech ADI digital joysticks and gamepads"
		select GAMEPORT

drivers/input/joystick/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -6,6 +6,7 @@
		# Each configuration option enables a list of files.

		obj-$(CONFIG_JOYSTICK_A3D) += a3d.o
		obj-$(CONFIG_JOYSTICK_ADC) += adc-joystick.o
		obj-$(CONFIG_JOYSTICK_ADI) += adi.o
		obj-$(CONFIG_JOYSTICK_AMIGA) += amijoy.o
		obj-$(CONFIG_JOYSTICK_AS5011) += as5011.o

drivers/input/joystick/adc-joystick.c

0 → 100644

+264 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		/*
		* Input driver for joysticks connected over ADC.
		* Copyright (c) 2019-2020 Artur Rojek <contact@artur-rojek.eu>
		*/
		#include <linux/ctype.h>
		#include <linux/input.h>
		#include <linux/iio/iio.h>
		#include <linux/iio/consumer.h>
		#include <linux/module.h>
		#include <linux/platform_device.h>
		#include <linux/property.h>

		#include <asm/unaligned.h>

		struct adc_joystick_axis {
		u32 code;
		s32 range[2];
		s32 fuzz;
		s32 flat;
		};

		struct adc_joystick {
		struct input_dev *input;
		struct iio_cb_buffer *buffer;
		struct adc_joystick_axis *axes;
		struct iio_channel *chans;
		int num_chans;
		};

		static int adc_joystick_handle(const void data, void private)
		{
		struct adc_joystick *joy = private;
		enum iio_endian endianness;
		int bytes, msb, val, idx, i;
		const u16 *data_u16;
		bool sign;

		bytes = joy->chans[0].channel->scan_type.storagebits >> 3;

		for (i = 0; i < joy->num_chans; ++i) {
		idx = joy->chans[i].channel->scan_index;
		endianness = joy->chans[i].channel->scan_type.endianness;
		msb = joy->chans[i].channel->scan_type.realbits - 1;
		sign = tolower(joy->chans[i].channel->scan_type.sign) == 's';

		switch (bytes) {
		case 1:
		val = ((const u8 *)data)[idx];
		break;
		case 2:
		data_u16 = (const u16 *)data + idx;

		/*
		* Data is aligned to the sample size by IIO core.
		* Call `get_unaligned_xe16` to hide type casting.
		*/
		if (endianness == IIO_BE)
		val = get_unaligned_be16(data_u16);
		else if (endianness == IIO_LE)
		val = get_unaligned_le16(data_u16);
		else /* IIO_CPU */
		val = *data_u16;
		break;
		default:
		return -EINVAL;
		}

		val >>= joy->chans[i].channel->scan_type.shift;
		if (sign)
		val = sign_extend32(val, msb);
		else
		val &= GENMASK(msb, 0);
		input_report_abs(joy->input, joy->axes[i].code, val);
		}

		input_sync(joy->input);

		return 0;
		}

		static int adc_joystick_open(struct input_dev *dev)
		{
		struct adc_joystick *joy = input_get_drvdata(dev);
		struct device *devp = &dev->dev;
		int ret;

		ret = iio_channel_start_all_cb(joy->buffer);
		if (ret)
		dev_err(devp, "Unable to start callback buffer: %d\n", ret);

		return ret;
		}

		static void adc_joystick_close(struct input_dev *dev)
		{
		struct adc_joystick *joy = input_get_drvdata(dev);

		iio_channel_stop_all_cb(joy->buffer);
		}

		static void adc_joystick_cleanup(void *data)
		{
		iio_channel_release_all_cb(data);
		}

		static int adc_joystick_set_axes(struct device dev, struct adc_joystick joy)
		{
		struct adc_joystick_axis *axes;
		struct fwnode_handle *child;
		int num_axes, error, i;

		num_axes = device_get_child_node_count(dev);
		if (!num_axes) {
		dev_err(dev, "Unable to find child nodes\n");
		return -EINVAL;
		}

		if (num_axes != joy->num_chans) {
		dev_err(dev, "Got %d child nodes for %d channels\n",
		num_axes, joy->num_chans);
		return -EINVAL;
		}

		axes = devm_kmalloc_array(dev, num_axes, sizeof(*axes), GFP_KERNEL);
		if (!axes)
		return -ENOMEM;

		device_for_each_child_node(dev, child) {
		error = fwnode_property_read_u32(child, "reg", &i);
		if (error) {
		dev_err(dev, "reg invalid or missing\n");
		goto err_fwnode_put;
		}

		if (i >= num_axes) {
		error = -EINVAL;
		dev_err(dev, "No matching axis for reg %d\n", i);
		goto err_fwnode_put;
		}

		error = fwnode_property_read_u32(child, "linux,code",
		&axes[i].code);
		if (error) {
		dev_err(dev, "linux,code invalid or missing\n");
		goto err_fwnode_put;
		}

		error = fwnode_property_read_u32_array(child, "abs-range",
		axes[i].range, 2);
		if (error) {
		dev_err(dev, "abs-range invalid or missing\n");
		goto err_fwnode_put;
		}

		fwnode_property_read_u32(child, "abs-fuzz", &axes[i].fuzz);
		fwnode_property_read_u32(child, "abs-flat", &axes[i].flat);

		input_set_abs_params(joy->input, axes[i].code,
		axes[i].range[0], axes[i].range[1],
		axes[i].fuzz, axes[i].flat);
		input_set_capability(joy->input, EV_ABS, axes[i].code);
		}

		joy->axes = axes;

		return 0;

		err_fwnode_put:
		fwnode_handle_put(child);
		return error;
		}

		static int adc_joystick_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		struct adc_joystick *joy;
		struct input_dev *input;
		int error;
		int bits;
		int i;

		joy = devm_kzalloc(dev, sizeof(*joy), GFP_KERNEL);
		if (!joy)
		return -ENOMEM;

		joy->chans = devm_iio_channel_get_all(dev);
		if (IS_ERR(joy->chans)) {
		error = PTR_ERR(joy->chans);
		if (error != -EPROBE_DEFER)
		dev_err(dev, "Unable to get IIO channels");
		return error;
		}

		/* Count how many channels we got. NULL terminated. */
		for (i = 0; joy->chans[i].indio_dev; i++) {
		bits = joy->chans[i].channel->scan_type.storagebits;
		if (!bits \|\| bits > 16) {
		dev_err(dev, "Unsupported channel storage size\n");
		return -EINVAL;
		}
		if (bits != joy->chans[0].channel->scan_type.storagebits) {
		dev_err(dev, "Channels must have equal storage size\n");
		return -EINVAL;
		}
		}
		joy->num_chans = i;

		input = devm_input_allocate_device(dev);
		if (!input) {
		dev_err(dev, "Unable to allocate input device\n");
		return -ENOMEM;
		}

		joy->input = input;
		input->name = pdev->name;
		input->id.bustype = BUS_HOST;
		input->open = adc_joystick_open;
		input->close = adc_joystick_close;

		error = adc_joystick_set_axes(dev, joy);
		if (error)
		return error;

		input_set_drvdata(input, joy);
		error = input_register_device(input);
		if (error) {
		dev_err(dev, "Unable to register input device\n");
		return error;
		}

		joy->buffer = iio_channel_get_all_cb(dev, adc_joystick_handle, joy);
		if (IS_ERR(joy->buffer)) {
		dev_err(dev, "Unable to allocate callback buffer\n");
		return PTR_ERR(joy->buffer);
		}

		error = devm_add_action_or_reset(dev, adc_joystick_cleanup, joy->buffer);
		if (error) {
		dev_err(dev, "Unable to add action\n");
		return error;
		}

		return 0;
		}

		static const struct of_device_id adc_joystick_of_match[] = {
		{ .compatible = "adc-joystick", },
		{ }
		};
		MODULE_DEVICE_TABLE(of, adc_joystick_of_match);

		static struct platform_driver adc_joystick_driver = {
		.driver = {
		.name = "adc-joystick",
		.of_match_table = adc_joystick_of_match,
		},
		.probe = adc_joystick_probe,
		};
		module_platform_driver(adc_joystick_driver);

		MODULE_DESCRIPTION("Input driver for joysticks connected over ADC");
		MODULE_AUTHOR("Artur Rojek <contact@artur-rojek.eu>");
		MODULE_LICENSE("GPL");

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