[RESEND,v5,5/5] input: joystick: Add ADC attached joystick driver.

Message ID	20200417202859.35427-5-contact@artur-rojek.eu (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=UPod=6B=vger.kernel.org=linux-iio-owner@kernel.org> sender: contact@artur-rojek.eu) by relay2-d.mail.gandi.net (Postfix) with ESMTPSA id 4020840007; Fri, 17 Apr 2020 20:20:31 +0000 (UTC) From: Artur Rojek <contact@artur-rojek.eu> To: Dmitry Torokhov <dmitry.torokhov@gmail.com>, Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Jonathan Cameron <jic23@kernel.org>, Paul Cercueil <paul@crapouillou.net> Cc: Heiko Stuebner <heiko@sntech.de>, linux-input@vger.kernel.org, devicetree@vger.kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Artur Rojek <contact@artur-rojek.eu> Subject: [RESEND PATCH v5 5/5] input: joystick: Add ADC attached joystick driver. Date: Fri, 17 Apr 2020 22:28:59 +0200 Message-Id: <20200417202859.35427-5-contact@artur-rojek.eu> In-Reply-To: <20200417202859.35427-1-contact@artur-rojek.eu> References: <20200417202859.35427-1-contact@artur-rojek.eu> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-iio-owner@vger.kernel.org Precedence: bulk
Series	[RESEND,v5,1/5] IIO: Ingenic JZ47xx: Add xlate cb to retrieve correct channel idx \| expand [RESEND,v5,1/5] IIO: Ingenic JZ47xx: Add xlate cb to retrieve correct channel idx [RESEND,v5,2/5] dt-bindings: iio/adc: Add touchscreen idx for JZ47xx SoC ADC [RESEND,v5,3/5] IIO: Ingenic JZ47xx: Add touchscreen mode. [RESEND,v5,4/5] dt-bindings: input: Add docs for ADC driven joystick. [RESEND,v5,5/5] input: joystick: Add ADC attached joystick driver.

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");

[RESEND,v5,5/5] input: joystick: Add ADC attached joystick driver.

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