[v2,5/5] input: joystick: Add ADC attached joystick driver.
diff mbox series

Message ID 20200126161236.63631-5-contact@artur-rojek.eu
State Superseded
Headers show
Series
  • [v2,1/5] IIO: Ingenic JZ47xx: Add xlate cb to retrieve correct channel idx
Related show

Commit Message

Artur Rojek Jan. 26, 2020, 4:12 p.m. UTC
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>
---

 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

Comments

Jonathan Cameron Feb. 2, 2020, 2:58 p.m. UTC | #1
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");
Paul Cercueil Feb. 10, 2020, 10:45 p.m. UTC | #2
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");
>
Heiko Stuebner Feb. 29, 2020, 9:18 p.m. UTC | #3
Am Sonntag, 26. Januar 2020, 17:12:36 CET schrieb Artur Rojek:
> 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>

On a rk3326-based Odroid Go Advance
Tested-by: Heiko Stuebner <heiko@sntech.de>

would be cool to get this merged ;-)

Thanks
Heiko

Patch
diff mbox series

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");