On Thu, Jan 11, 2018 at 01:07:42PM +0100, Marcus Folkesson wrote: > Hi Dmitry, > > Thank you for your review! > > On Wed, Jan 10, 2018 at 04:37:14PM -0800, Dmitry Torokhov wrote: > > Hi Marcus, > > > > On Wed, Jan 10, 2018 at 02:11:39PM +0100, Marcus Folkesson wrote: > > > 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@xxxxxxxxx> > > > --- > > > 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@xxxxxxxxx> > > > + > > > +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 | > > > ++---------+----------------+ > > > > TILT are normally reserved for stylus/pen. Do we have better event codes > > maybe? Is there a picture of the RC so I can make more sense of the > > proposed event assignment? > > > > Ok, maybe RUDDER and MISC? OK. > The driver is actually for an "adapter" [1] that you connect your RC to. > The RC is then mapping its sticks/buttons to different channels. Unlike other > joysticks, this mapping is not fixed but something you setup in your RC. > > For example, I'm using a Turnigy 9xr[2]. > > The RC is typically used with a RC Flight Simulator software (I'm using > Heli-X [3] when testing) which also map the channels to events (throttle, > rudder and so on). > > > > > +| 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@xxxxxxxxx> > > > + * > > > + */ > > > + > > > +#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); > > > > This is way to complex and I am not sure why you need to anchor URBs and > > have a separate refcounting, etc. I do not think it is even safe with > > module unloading as kref might be in flight as you run through module > > unload and devm will destroy most of the objects. > > > > Why don't you simply use usb_kill_urb() here and be done. > > input_unregister_device() that is called as part of devm unwind on > > device unbind will make sure that pxrc_close() is called. > > > > Thanks. > > > > Ok, I drop the refcounting. pxrc_delete() did more before I changed most > allocations to devm_*. > I tried to get the refcounting similiar to /drivers/usb/usb-skeleton.c. > > I have tried different approaches with the create/delete URBs. > At first I had the URB in the usb_pxrc struct that I allocated in the > probe function where I also submitted the URB. > > This worked but I found it waste to submit URBs when noone has opened the > device, so I moved the submitting to pxrc_open(). > The problem was that the same URB was submitted multiple times (gives a > warning) upon multiple calls to open(2). open() should only be called once, unless close() was called. So as long as you kill the URB in close(), you should not see warnings. > > So I removed the URB from usb_pxrc and used an anchor to still have a > reference to it for deletion. This part is heavily inspired by > drivers/bluetooth/bpa10x.c. > Maybe I should do it differently? > > I must admit that I'm not very familiar with USB drivers. I'd probably look at drivers/input/mouse/synaptics_usb.c and structured your driver similarly. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
