Re: [PATCH] platform: hp_accel: add a i8042 filter to remove HPQ6000 data from kb bus stream

From: Darren Hart
Date: Wed Oct 29 2014 - 21:41:08 EST


On Wed, Oct 29, 2014 at 09:16:22PM +0200, Giedrius Statkevicius wrote:
> Add a i8042 filter to hp_accel to remove accelerometer's data with acpi
> id HPQ6000 from keyboard bus stream. The codes sent by accelerometer are
> e0 25, e0 26, e0 27 and e0 28. The relevant information is already
> passed through /dev/freefall so no need to send these undocumented weird
> signals through the keyboard bus. Also, unclogs `dmesg` because atkbd
> complained about weird scan codes, saves processing power and disk
> space.
>
> Signed-off-by: Giedrius StatkeviÄius <giedriuswork@xxxxxxxxx>
> ---
> First of all, any Tested-Bys are very welcome by people who also have a
> accelerometer with acpi id HPQ6000. If it happens with HPQ6007 too we
> can easily modify this to install the filter when HPQ6007 is detected.
> For the time being the filter is only installed when HPQ6000 is
> detected.
>
> Now moving to what was changed since the RFC. I reworked the filter
> function to hopefully make it more clear what it is doing. Since the
> codes sent by the accelerometer are extended then we need to filter all
> of 0xe0's and then send one 0xe0 back when the actual key isn't in the
> range of 0x25-0x28. Also, I've removed the check for errors for
> i8042_install_filter() because it's unnecessary to check if it failed.
> If multiple HPQ6000's are in the system then no issue occurs even if
> multiple i8042_install_filter() are issued because this is handled by
> i8042 and it's smart enough not to install the same filter two or more
> times.
>
> drivers/platform/x86/hp_accel.c | 45 ++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/hp_accel.c b/drivers/platform/x86/hp_accel.c
> index 13e14ec..a751621 100644
> --- a/drivers/platform/x86/hp_accel.c
> +++ b/drivers/platform/x86/hp_accel.c
> @@ -38,6 +38,8 @@
> #include <linux/atomic.h>
> #include <linux/acpi.h>
> #include "../../misc/lis3lv02d/lis3lv02d.h"
> +#include <linux/i8042.h>
> +#include <linux/serio.h>

Please include before the relative path includes.

Otherwise, I'm happy with this - but I'd like a serio / i8042 person to weigh
in.... Dmitry?

>
> #define DRIVER_NAME "hp_accel"
> #define ACPI_MDPS_CLASS "accelerometer"
> @@ -73,6 +75,13 @@ static inline void delayed_sysfs_set(struct led_classdev *led_cdev,
>
> /* HP-specific accelerometer driver ------------------------------------ */
>
> +/* e0 25, e0 26, e0 27, e0 28 are scan codes that the accelerometer with acpi id
> + * HPQ6000 sends through the keyboard bus */
> +#define ACCEL_1 0x25
> +#define ACCEL_2 0x26
> +#define ACCEL_3 0x27
> +#define ACCEL_4 0x28
> +
> /* For automatic insertion of the module */
> static const struct acpi_device_id lis3lv02d_device_ids[] = {
> {"HPQ0004", 0}, /* HP Mobile Data Protection System PNP */
> @@ -82,7 +91,6 @@ static const struct acpi_device_id lis3lv02d_device_ids[] = {
> };
> MODULE_DEVICE_TABLE(acpi, lis3lv02d_device_ids);
>
> -
> /**
> * lis3lv02d_acpi_init - ACPI _INI method: initialize the device.
> * @lis3: pointer to the device struct
> @@ -294,6 +302,35 @@ static void lis3lv02d_enum_resources(struct acpi_device *device)
> printk(KERN_DEBUG DRIVER_NAME ": Error getting resources\n");
> }
>
> +static bool hp_accel_i8042_filter(unsigned char data, unsigned char str,
> + struct serio *port)
> +{
> + static bool extended;
> +
> + if (str & I8042_STR_AUXDATA)
> + return false;
> +
> + if (data == 0xe0) {
> + extended = true;
> + return true;
> + } else if (unlikely(extended)) {
> + extended = false;
> +
> + switch (data) {
> + case ACCEL_1:
> + case ACCEL_2:
> + case ACCEL_3:
> + case ACCEL_4:
> + return true;
> + default:
> + serio_interrupt(port, 0xe0, 0);
> + return false;
> + }
> + }
> +
> + return false;
> +}
> +
> static int lis3lv02d_add(struct acpi_device *device)
> {
> int ret;
> @@ -326,6 +363,11 @@ static int lis3lv02d_add(struct acpi_device *device)
> if (ret)
> return ret;
>
> + /* filter to remove HPQ6000 accelerometer data
> + * from keyboard bus stream */
> + if (strstr(dev_name(&device->dev), "HPQ6000"))
> + i8042_install_filter(hp_accel_i8042_filter);
> +
> INIT_WORK(&hpled_led.work, delayed_set_status_worker);
> ret = led_classdev_register(NULL, &hpled_led.led_classdev);
> if (ret) {
> @@ -343,6 +385,7 @@ static int lis3lv02d_remove(struct acpi_device *device)
> if (!device)
> return -EINVAL;
>
> + i8042_remove_filter(hp_accel_i8042_filter);
> lis3lv02d_joystick_disable(&lis3_dev);
> lis3lv02d_poweroff(&lis3_dev);
>
> --
> 2.1.2
>
>

--
Darren Hart
Intel Open Source Technology Center
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/