[RESEND PATCH v2] input: pxrc: new driver for PhoenixRC Flight Controller Adapter

Marcus Folkesson
2018-01-10T13:11:57Z

This driver let you plug in your RC controller to the adapter and
use it as input device in various RC simulators.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
v2:
- Change module license to GPLv2 to match SPDX tag

Documentation/input/devices/pxrc.rst | 57 ++++++++
drivers/input/joystick/Kconfig | 9 ++
drivers/input/joystick/Makefile | 1 +
drivers/input/joystick/pxrc.c | 254 +++++++++++++++++++++++++++++++++++
4 files changed, 321 insertions(+)
create mode 100644 Documentation/input/devices/pxrc.rst
create mode 100644 drivers/input/joystick/pxrc.c

diff --git a/Documentation/input/devices/pxrc.rst b/Documentation/input/devices/pxrc.rst
new file mode 100644
index 000000000000..0ec466c58958
--- /dev/null
+++ b/Documentation/input/devices/pxrc.rst
@@ -0,0 +1,57 @@
+=======================================================
+pxrc - PhoenixRC Flight Controller Adapter
+=======================================================
+
+:Author: Marcus Folkesson <marcus.folkesson@gmail.com>
+
+This driver let you use your own RC controller plugged into the
+adapter that comes with PhoenixRC [1]_ or other compatible adapters.
+
+The adapter supports 7 analog channels and 1 digital input switch.
+
+Notes
+=====
+
+Many RC controllers is able to configure which stick goes to which channel.
+This is also configurable in most simulators, so a matching is not necessary.
+
+The driver is generating the following input event for analog channels:
+
++---------+----------------+
+| Channel | Event |
++=========+================+
+| 1 | ABS_X |
++---------+----------------+
+| 2 | ABS_Y |
++---------+----------------+
+| 3 | ABS_RX |
++---------+----------------+
+| 4 | ABS_RY |
++---------+----------------+
+| 5 | ABS_TILT_X |
++---------+----------------+
+| 6 | ABS_TILT_Y |
++---------+----------------+
+| 7 | ABS_THROTTLE |
++---------+----------------+
+
+The digital input switch is generated as an `BTN_A` event.
+
+Manual Testing
+==============
+
+To test this driver's functionality you may use `input-event` which is part of
+the `input layer utilities` suite [2]_.
+
+For example::
+
+ > modprobe pxrc
+ > input-events <devnr>
+
+To print all input events from input `devnr`.
+
+References
+==========
+
+.. [1] http://www.phoenix-sim.com/
+.. [2] https://www.kraxel.org/cgit/input/
diff --git a/drivers/input/joystick/Kconfig b/drivers/input/joystick/Kconfig
index f3c2f6ea8b44..18ab6dafff41 100644
--- a/drivers/input/joystick/Kconfig
+++ b/drivers/input/joystick/Kconfig
@@ -351,4 +351,13 @@ config JOYSTICK_PSXPAD_SPI_FF

To drive rumble motor a dedicated power supply is required.

+config JOYSTICK_PXRC
+ tristate "PhoenixRC Flight Controller Adapter"
+ depends on USB_ARCH_HAS_HCD
+ select USB
+ help
+ Say Y here if you want to use the PhoenixRC Flight Controller Adapter.
+
+ To compile this driver as a module, choose M here: the
+ module will be called pxrc.
endif
diff --git a/drivers/input/joystick/Makefile b/drivers/input/joystick/Makefile
index 67651efda2e1..dd0492ebbed7 100644
--- a/drivers/input/joystick/Makefile
+++ b/drivers/input/joystick/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_JOYSTICK_JOYDUMP) += joydump.o
obj-$(CONFIG_JOYSTICK_MAGELLAN) += magellan.o
obj-$(CONFIG_JOYSTICK_MAPLE) += maplecontrol.o
obj-$(CONFIG_JOYSTICK_PSXPAD_SPI) += psxpad-spi.o
+obj-$(CONFIG_JOYSTICK_PXRC) += pxrc.o
obj-$(CONFIG_JOYSTICK_SIDEWINDER) += sidewinder.o
obj-$(CONFIG_JOYSTICK_SPACEBALL) += spaceball.o
obj-$(CONFIG_JOYSTICK_SPACEORB) += spaceorb.o
diff --git a/drivers/input/joystick/pxrc.c b/drivers/input/joystick/pxrc.c
new file mode 100644
index 000000000000..2bec99df97e2
--- /dev/null
+++ b/drivers/input/joystick/pxrc.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Phoenix RC Flight Controller Adapter
+ *
+ * Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com>
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kref.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+#include <linux/mutex.h>
+#include <linux/input.h>
+
+#define PXRC_VENDOR_ID (0x1781)
+#define PXRC_PRODUCT_ID (0x0898)
+
+static const struct usb_device_id pxrc_table[] = {
+ { USB_DEVICE(PXRC_VENDOR_ID, PXRC_PRODUCT_ID) },
+ { }
+};
+MODULE_DEVICE_TABLE(usb, pxrc_table);
+
+struct usb_pxrc {
+ struct input_dev *input_dev;
+ struct usb_device *udev;
+ struct usb_interface *interface;
+ struct usb_anchor anchor;
+ __u8 epaddr;
+ char phys[64];
+ unsigned char *data;
+ size_t bsize;
+ struct kref kref;
+};
+
+#define to_pxrc_dev(d) container_of(d, struct usb_pxrc, kref)
+static void pxrc_delete(struct kref *kref)
+{
+ struct usb_pxrc *pxrc = to_pxrc_dev(kref);
+
+ usb_put_dev(pxrc->udev);
+}
+
+static void pxrc_usb_irq(struct urb *urb)
+{
+ struct usb_pxrc *pxrc = urb->context;
+
+ switch (urb->status) {
+ case 0:
+ /* success */
+ break;
+ case -ETIME:
+ /* this urb is timing out */
+ dev_dbg(&pxrc->interface->dev,
+ "%s - urb timed out - was the device unplugged?\n",
+ __func__);
+ return;
+ case -ECONNRESET:
+ case -ENOENT:
+ case -ESHUTDOWN:
+ case -EPIPE:
+ /* this urb is terminated, clean up */
+ dev_dbg(&pxrc->interface->dev, "%s - urb shutting down with status: %d\n",
+ __func__, urb->status);
+ return;
+ default:
+ dev_dbg(&pxrc->interface->dev, "%s - nonzero urb status received: %d\n",
+ __func__, urb->status);
+ goto exit;
+ }
+
+ if (urb->actual_length == 8) {
+ input_report_abs(pxrc->input_dev, ABS_X, pxrc->data[0]);
+ input_report_abs(pxrc->input_dev, ABS_Y, pxrc->data[2]);
+ input_report_abs(pxrc->input_dev, ABS_RX, pxrc->data[3]);
+ input_report_abs(pxrc->input_dev, ABS_RY, pxrc->data[4]);
+ input_report_abs(pxrc->input_dev, ABS_TILT_X, pxrc->data[5]);
+ input_report_abs(pxrc->input_dev, ABS_TILT_Y, pxrc->data[6]);
+ input_report_abs(pxrc->input_dev, ABS_THROTTLE, pxrc->data[7]);
+
+ input_report_key(pxrc->input_dev, BTN_A, pxrc->data[1]);
+ }
+
+exit:
+ /* Resubmit to fetch new fresh URBs */
+ usb_anchor_urb(urb, &pxrc->anchor);
+ if (usb_submit_urb(urb, GFP_ATOMIC) < 0)
+ usb_unanchor_urb(urb);
+}
+
+static int pxrc_submit_intr_urb(struct usb_pxrc *pxrc)
+{
+ struct urb *urb;
+ unsigned int pipe;
+ int err;
+
+ urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!urb)
+ return -ENOMEM;
+
+ pipe = usb_rcvintpipe(pxrc->udev, pxrc->epaddr),
+ usb_fill_int_urb(urb, pxrc->udev, pipe, pxrc->data, pxrc->bsize,
+ pxrc_usb_irq, pxrc, 1);
+ usb_anchor_urb(urb, &pxrc->anchor);
+ err = usb_submit_urb(urb, GFP_KERNEL);
+ if (err < 0)
+ usb_unanchor_urb(urb);
+
+ usb_free_urb(urb);
+ return err;
+}
+
+static int pxrc_open(struct input_dev *input)
+{
+ struct usb_pxrc *pxrc = input_get_drvdata(input);
+ int err;
+
+ err = pxrc_submit_intr_urb(pxrc);
+ if (err < 0)
+ goto error;
+
+ kref_get(&pxrc->kref);
+ return 0;
+
+error:
+ usb_kill_anchored_urbs(&pxrc->anchor);
+ return err;
+}
+
+static void pxrc_close(struct input_dev *input)
+{
+ struct usb_pxrc *pxrc = input_get_drvdata(input);
+
+ usb_kill_anchored_urbs(&pxrc->anchor);
+ kref_put(&pxrc->kref, pxrc_delete);
+}
+
+static int pxrc_input_init(struct usb_pxrc *pxrc)
+{
+ pxrc->input_dev = devm_input_allocate_device(&pxrc->interface->dev);
+ if (pxrc->input_dev == NULL) {
+ dev_err(&pxrc->interface->dev, "couldn't allocate input device\n");
+ return -ENOMEM;
+ }
+
+ pxrc->input_dev->name = "PXRC Flight Controller Adapter";
+ pxrc->input_dev->phys = pxrc->phys;
+ pxrc->input_dev->id.bustype = BUS_USB;
+ pxrc->input_dev->id.vendor = PXRC_VENDOR_ID;
+ pxrc->input_dev->id.product = PXRC_PRODUCT_ID;
+ pxrc->input_dev->id.version = 0x01;
+
+ pxrc->input_dev->open = pxrc_open;
+ pxrc->input_dev->close = pxrc_close;
+
+ pxrc->input_dev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
+ pxrc->input_dev->absbit[0] = BIT_MASK(ABS_X) |
+ BIT_MASK(ABS_Y) |
+ BIT_MASK(ABS_RY) |
+ BIT_MASK(ABS_RX) |
+ BIT_MASK(ABS_THROTTLE) |
+ BIT_MASK(ABS_TILT_X) |
+ BIT_MASK(ABS_TILT_Y);
+
+ pxrc->input_dev->keybit[BIT_WORD(BTN_JOYSTICK)] = BIT_MASK(BTN_A);
+
+ input_set_abs_params(pxrc->input_dev, ABS_X, 0, 255, 0, 0);
+ input_set_abs_params(pxrc->input_dev, ABS_Y, 0, 255, 0, 0);
+ input_set_abs_params(pxrc->input_dev, ABS_RX, 0, 255, 0, 0);
+ input_set_abs_params(pxrc->input_dev, ABS_RY, 0, 255, 0, 0);
+ input_set_abs_params(pxrc->input_dev, ABS_TILT_X, 0, 255, 0, 0);
+ input_set_abs_params(pxrc->input_dev, ABS_TILT_Y, 0, 255, 0, 0);
+ input_set_abs_params(pxrc->input_dev, ABS_THROTTLE, 0, 255, 0, 0);
+
+ input_set_drvdata(pxrc->input_dev, pxrc);
+
+ return input_register_device(pxrc->input_dev);
+}
+
+static int pxrc_probe(struct usb_interface *interface,
+ const struct usb_device_id *id)
+{
+ struct usb_pxrc *pxrc;
+ struct usb_endpoint_descriptor *epirq;
+ int retval;
+
+ pxrc = devm_kzalloc(&interface->dev, sizeof(*pxrc), GFP_KERNEL);
+
+ if (!pxrc)
+ return -ENOMEM;
+
+ kref_init(&pxrc->kref);
+ init_usb_anchor(&pxrc->anchor);
+
+ pxrc->udev = usb_get_dev(interface_to_usbdev(interface));
+ pxrc->interface = interface;
+
+ /* Set up the endpoint information */
+ /* This device only has an interrupt endpoint */
+ retval = usb_find_common_endpoints(interface->cur_altsetting,
+ NULL, NULL, &epirq, NULL);
+ if (retval) {
+ dev_err(&interface->dev,
+ "Could not find endpoint\n");
+ goto error;
+ }
+
+ pxrc->bsize = usb_endpoint_maxp(epirq);
+ pxrc->epaddr = epirq->bEndpointAddress;
+ pxrc->data = devm_kmalloc(&interface->dev, pxrc->bsize, GFP_KERNEL);
+ if (!pxrc->data) {
+ retval = -ENOMEM;
+ goto error;
+ }
+
+ usb_set_intfdata(interface, pxrc);
+ usb_make_path(pxrc->udev, pxrc->phys, sizeof(pxrc->phys));
+
+ retval = pxrc_input_init(pxrc);
+ if (retval)
+ goto error;
+
+ return 0;
+
+error:
+ /* this frees allocated memory */
+ kref_put(&pxrc->kref, pxrc_delete);
+
+ return retval;
+}
+
+static void pxrc_disconnect(struct usb_interface *interface)
+{
+ struct usb_pxrc *pxrc = usb_get_intfdata(interface);
+
+ kref_put(&pxrc->kref, pxrc_delete);
+}
+
+static struct usb_driver pxrc_driver = {
+ .name = "pxrc",
+ .probe = pxrc_probe,
+ .disconnect = pxrc_disconnect,
+ .id_table = pxrc_table,
+};
+
+module_usb_driver(pxrc_driver);
+
+MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>");
+MODULE_DESCRIPTION("PhoenixRC Flight Controller Adapter");
+MODULE_LICENSE("GPL v2");
--
2.15.1