Re: [PATCH] platform/x86: peaq-wmi: Add new peaq-wmi driver

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Mon, May 08, 2017 at 02:04:41PM -0700, Darren Hart wrote:
> On Mon, May 08, 2017 at 09:56:31PM +0200, Hans de Goede wrote:
> > PEAQ is a new European OEM, I've bought one of their 2-in-1 x86
> > devices, which is actually quite a nice device. Under Windows it has
> > Dolby software for "better" sound and you can select different equalizer
> > presets using a special button.
> > 
> > This WMI interface for this button is not really nice, as it does not do
> > notifies (it really does not I tripple checked), but since I had already
> > figured out the entire WMI interface for this I decided to go the full
> > mile anyways and also implent a WMI based input driver for this using
> > input_polldev since, well, we need to poll.
> > 
> > This commit adds support for this button making it report KEY_SOUND input
> > events. KEY_SOUND is already used in various places to switch sound into
> > theatre mode and things like that so it seems appropriate here.
> > 
> > Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> 
> Thanks Hans,
> 
> A couple nits below, otherwise, looks good to me.
> 
> +Dmitry in case he cares to weigh in on input/input-polldev usage
> 
> > ---
> >  drivers/platform/x86/Kconfig    |  7 +++
> >  drivers/platform/x86/Makefile   |  1 +
> >  drivers/platform/x86/peaq-wmi.c | 94 +++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 102 insertions(+)
> >  create mode 100644 drivers/platform/x86/peaq-wmi.c
> > 
> > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> > index be2ffbd6eb6c..2bac2b2644f9 100644
> > --- a/drivers/platform/x86/Kconfig
> > +++ b/drivers/platform/x86/Kconfig
> > @@ -660,6 +660,13 @@ config MSI_WMI
> >  	 To compile this driver as a module, choose M here: the module will
> >  	 be called msi-wmi.
> >  
> > +config PEAQ_WMI
> > +	tristate "PEAQ 2-in-1 WMI hotkey driver"
> > +	depends on ACPI_WMI
> > +	depends on INPUT
> > +	help
> > +	 Say Y here if you want to support WMI-based hotkeys on PEAQ 2-in-1s.
> > +
> >  config TOPSTAR_LAPTOP
> >  	tristate "Topstar Laptop Extras"
> >  	depends on ACPI
> > diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> > index de4ffb594ba5..02487f95dd27 100644
> > --- a/drivers/platform/x86/Makefile
> > +++ b/drivers/platform/x86/Makefile
> > @@ -34,6 +34,7 @@ obj-$(CONFIG_PANASONIC_LAPTOP)	+= panasonic-laptop.o
> >  obj-$(CONFIG_INTEL_MENLOW)	+= intel_menlow.o
> >  obj-$(CONFIG_ACPI_WMI)		+= wmi.o
> >  obj-$(CONFIG_MSI_WMI)		+= msi-wmi.o
> > +obj-$(CONFIG_PEAQ_WMI)		+= peaq-wmi.o
> >  obj-$(CONFIG_SURFACE3_WMI)	+= surface3-wmi.o
> >  obj-$(CONFIG_TOPSTAR_LAPTOP)	+= topstar-laptop.o
> >  
> > diff --git a/drivers/platform/x86/peaq-wmi.c b/drivers/platform/x86/peaq-wmi.c
> > new file mode 100644
> > index 000000000000..8cd6b962ce5e
> > --- /dev/null
> > +++ b/drivers/platform/x86/peaq-wmi.c
> > @@ -0,0 +1,94 @@
> > +/*
> > + * PEAQ 2-in-1 WMI hotkey driver
> > + * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +#include <linux/acpi.h>
> > +#include <linux/input.h>
> 
> input-polldev includes input, no need for both.
> 
> > +#include <linux/input-polldev.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +
> > +#define PEAQ_DOLBY_BUTTON_GUID		"ABBC0F6F-8EA1-11D1-00A0-C90629100000"
> > +#define PEAQ_DOLBY_BUTTON_METHOD_ID	5
> > +#define PEAQ_POLL_INTERVAL_MS		250
> > +
> > +MODULE_ALIAS("wmi:"PEAQ_DOLBY_BUTTON_GUID);
> > +
> > +struct input_polled_dev *peaq_poll_dev;
> > +int peaq_ignore_events_counter;
> 
> Please make local globals static if they are needed.
> 
> Once we make WMI a bus with devices, we should be able to clean this up with
> devm.
> 
> > +
> > +/*
> > + * The Dolby button (yes really a Dolby button) causes an ACPI variable to get
> > + * set on both press and release. The WMI method checks and clears that flag.
> > + * So for a press + release we will get back One from the WMI method either once
> > + * (if polling after the release) or twice (polling between press and release).
> > + * We ignore events for 0.5s after the first event to avoid reporting 2 presses.
> > + */
> > +static void peaq_wmi_poll(struct input_polled_dev *dev)
> > +{
> > +	union acpi_object obj;
> > +	struct acpi_buffer buffer = { sizeof(obj), &obj };
> > +	acpi_status status;
> > +
> > +	status = wmi_evaluate_method(PEAQ_DOLBY_BUTTON_GUID, 1,
> > +				     PEAQ_DOLBY_BUTTON_METHOD_ID,
> > +				     NULL, &buffer);
> > +	if (ACPI_FAILURE(status))
> > +		return;
> > +
> > +	if (obj.type != ACPI_TYPE_INTEGER) {
> > +		dev_err(&peaq_poll_dev->input->dev,
> > +			"Error WMBC did not return an integer\n");
> > +		return;
> > +	}
> > +
> > +	if (peaq_ignore_events_counter && --peaq_ignore_events_counter > 0)
> > +		return;
> > +
> > +	if (obj.integer.value) {
> > +		input_event(peaq_poll_dev->input, EV_KEY, KEY_SOUND, 1);

input_sync() here as well please.

> > +		input_event(peaq_poll_dev->input, EV_KEY, KEY_SOUND, 0);
> > +		input_sync(peaq_poll_dev->input);
> > +		peaq_ignore_events_counter = 500 / peaq_poll_dev->poll_interval;
> 
> Might as well define 500 above with the interval and keep these parameters
> together, keep the units obvious, etc. e.g.
> 
> #define PEAQ_POLL_IGNORE_MS 500
> 
> Or similar
> 
> > +	}
> > +}
> > +
> > +static int __init peaq_wmi_init(void)
> > +{
> > +	if (!wmi_has_guid(PEAQ_DOLBY_BUTTON_GUID))
> > +		return -ENODEV;
> > +
> > +	peaq_poll_dev = input_allocate_polled_device();
> > +	if (!peaq_poll_dev)
> > +		return -ENOMEM;
> > +
> > +	peaq_poll_dev->poll = peaq_wmi_poll;
> > +	peaq_poll_dev->poll_interval = PEAQ_POLL_INTERVAL_MS;
> > +	peaq_poll_dev->poll_interval_max = 1000; /* 1 second */
> > +	peaq_poll_dev->input->name = "PEAQ WMI hotkeys";
> 
> Are there additional keys/buttons?
> 
> > +	peaq_poll_dev->input->phys = "wmi/input0";
> > +	peaq_poll_dev->input->id.bustype = BUS_HOST;
> > +	input_set_capability(peaq_poll_dev->input, EV_KEY, KEY_SOUND);
> > +
> > +	return input_register_polled_device(peaq_poll_dev);
> > +}
> > +
> > +static void __exit peaq_wmi_exit(void)
> > +{
> > +	if (!wmi_has_guid(PEAQ_DOLBY_BUTTON_GUID))
> > +		return;
> > +
> > +	input_unregister_polled_device(peaq_poll_dev);
> > +}
> > +
> > +module_init(peaq_wmi_init);
> > +module_exit(peaq_wmi_exit);
> > +
> > +MODULE_DESCRIPTION("PEAQ 2-in-1 WMI hotkey driver");
> > +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
> > +MODULE_LICENSE("GPL");
> > -- 
> > 2.12.2
> > 
> > 
> 
> -- 
> Darren Hart
> VMware Open Source Technology Center

-- 
Dmitry