Orange Pi5 kernel

// 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");