Re: [PATCH v2 5/5] input: joystick: Add ADC attached joystick driver.

Paul Cercueil
2020-02-10T22:45:41Z

Hi Jonathan, Rob,

The DT check does succeed here, as long as patch [2/5] is applied. I
believe Rob's automated test does not apply all patches and that's why
it fails here, as the DTS example includes a file that is added in
patch 2/5.

-Paul

Le dim., févr. 2, 2020 at 14:58, Jonathan Cameron
<jic23@jic23.retrosnub.co.uk> a écrit :
> On Sun, 26 Jan 2020 17:12:36 +0100
> Artur Rojek <contact@artur-rojek.eu> wrote:
>
>> Add a driver for joystick devices connected to ADC controllers
>> supporting the Industrial I/O subsystem.
>>
>> Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
>> Tested-by: Paul Cercueil <paul@crapouillou.net>
>> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
>
> This also looks good to me. Just that dt patch to tidy up.
>
> Thanks,
>
> Jonathan
>
>> ---
>>
>> Changes:
>>
>> v2: - sanity check supported channel format on probe,
>> - rename adc_joystick_disable to a more sensible
>> adc_joystick_cleanup,
>> - enforce correct axis order by checking the `reg` property of
>> child nodes
>>
>> drivers/input/joystick/Kconfig | 10 ++
>> drivers/input/joystick/Makefile | 1 +
>> drivers/input/joystick/adc-joystick.c | 245
>> ++++++++++++++++++++++++++
>> 3 files changed, 256 insertions(+)
>> create mode 100644 drivers/input/joystick/adc-joystick.c
>>
>> diff --git a/drivers/input/joystick/Kconfig
>> b/drivers/input/joystick/Kconfig
>> index 940b744639c7..efbc20ec5099 100644
>> --- a/drivers/input/joystick/Kconfig
>> +++ b/drivers/input/joystick/Kconfig
>> @@ -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
>> diff --git a/drivers/input/joystick/Makefile
>> b/drivers/input/joystick/Makefile
>> index 8656023f6ef5..58232b3057d3 100644
>> --- a/drivers/input/joystick/Makefile
>> +++ b/drivers/input/joystick/Makefile
>> @@ -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
>> diff --git a/drivers/input/joystick/adc-joystick.c
>> b/drivers/input/joystick/adc-joystick.c
>> new file mode 100644
>> index 000000000000..9cb9896da26e
>> --- /dev/null
>> +++ b/drivers/input/joystick/adc-joystick.c
>> @@ -0,0 +1,245 @@
>> +// 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/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/property.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, i;
>> + bool sign;
>> +
>> + bytes = joy->chans[0].channel->scan_type.storagebits >> 3;
>> +
>> + for (i = 0; i < joy->num_chans; ++i) {
>> + 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)[i];
>> + break;
>> + case 2:
>> + val = ((const u16 *)data)[i];
>> + if (endianness == IIO_BE)
>> + val = be16_to_cpu(val);
>> + else if (endianness == IIO_LE)
>> + val = le16_to_cpu(val);
>> + 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);
>> + int ret;
>> +
>> + ret = iio_channel_start_all_cb(joy->buffer);
>> + if (ret)
>> + dev_err(dev->dev.parent, "Unable to start callback buffer");
>> +
>> + 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, ret, i;
>> +
>> + num_axes = device_get_child_node_count(dev);
>> + if (!num_axes) {
>> + dev_err(dev, "Unable to find child nodes");
>> + return -EINVAL;
>> + }
>> +
>> + if (num_axes != joy->num_chans) {
>> + dev_err(dev, "Got %d child nodes for %d channels",
>> + 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) {
>> + ret = fwnode_property_read_u32(child, "reg", &i);
>> + if (ret || i >= num_axes) {
>> + dev_err(dev, "reg invalid or missing");
>> + goto err;
>> + }
>> +
>> + if (fwnode_property_read_u32(child, "linux,code",
>> + &axes[i].code)) {
>> + dev_err(dev, "linux,code invalid or missing");
>> + goto err;
>> + }
>> +
>> + if (fwnode_property_read_u32_array(child, "abs-range",
>> + axes[i].range, 2)) {
>> + dev_err(dev, "abs-range invalid or missing");
>> + goto err;
>> + }
>> +
>> + 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_handle_put(child);
>> + return -EINVAL;
>> +}
>> +
>> +static int adc_joystick_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct adc_joystick *joy;
>> + struct input_dev *input;
>> + int bits, ret, 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)) {
>> + ret = PTR_ERR(joy->chans);
>> + if (ret != -EPROBE_DEFER)
>> + dev_err(dev, "Unable to get IIO channels");
>> + return ret;
>> + }
>> +
>> + /* Count how many channels we got. NULL terminated. */
>> + while (joy->chans[joy->num_chans].indio_dev)
>> + joy->num_chans++;
>> +
>> + bits = joy->chans[0].channel->scan_type.storagebits;
>> + if (!bits || (bits >> 3) > 2) {
>> + dev_err(dev, "Unsupported channel storage size");
>> + return -EINVAL;
>> + }
>> + for (i = 1; i < joy->num_chans; ++i)
>> + if (joy->chans[i].channel->scan_type.storagebits != bits) {
>> + dev_err(dev, "Channels must have equal storage size");
>> + return -EINVAL;
>> + }
>> +
>> + input = devm_input_allocate_device(dev);
>> + if (!input) {
>> + dev_err(dev, "Unable to allocate input device");
>> + return -ENOMEM;
>> + }
>> +
>> + joy->input = input;
>> + input->name = pdev->name;
>> + input->id.bustype = BUS_HOST;
>> + input->open = adc_joystick_open;
>> + input->close = adc_joystick_close;
>> +
>> + ret = adc_joystick_set_axes(dev, joy);
>> + if (ret)
>> + return ret;
>> +
>> + input_set_drvdata(input, joy);
>> + ret = input_register_device(input);
>> + if (ret) {
>> + dev_err(dev, "Unable to register input device: %d", ret);
>> + return ret;
>> + }
>> +
>> + 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");
>> + return PTR_ERR(joy->buffer);
>> + }
>> +
>> + ret = devm_add_action_or_reset(dev, adc_joystick_cleanup,
>> joy->buffer);
>> + if (ret)
>> + dev_err(dev, "Unable to add action");
>> +
>> + return ret;
>> +}
>> +
>> +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 = of_match_ptr(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");
>