Hi,
On 10/20/20 2:15 AM, Mark Pearson wrote:
> Use input device event support for notifying userspace of palm sensor
> state changes
>
> Signed-off-by: Mark Pearson <markpearson@xxxxxxxxxx>
> ---
> drivers/platform/x86/thinkpad_acpi.c | 99 +++++++++++++++++++++++++++-
> 1 file changed, 97 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
> index eae3579f106f..5ddf2775fb06 100644
> --- a/drivers/platform/x86/thinkpad_acpi.c
> +++ b/drivers/platform/x86/thinkpad_acpi.c
> @@ -4013,6 +4013,7 @@ static bool hotkey_notify_usrevent(const u32 hkey,
> }
>
> static void thermal_dump_all_sensors(void);
> +static void proxsensor_refresh(void);
>
> static bool hotkey_notify_6xxx(const u32 hkey,
> bool *send_acpi_ev,
> @@ -4079,8 +4080,8 @@ static bool hotkey_notify_6xxx(const u32 hkey,
>
> case TP_HKEY_EV_PALM_DETECTED:
> case TP_HKEY_EV_PALM_UNDETECTED:
> - /* palm detected hovering the keyboard, forward to user-space
> - * via netlink for consumption */
> + /* palm detected - pass on to event handler */
> + proxsensor_refresh();
> return true;
>
> default:
> @@ -9918,6 +9919,96 @@ static struct ibm_struct dytc_driver_data = {
> .exit = dytc_exit,
> };
>
> +/*************************************************************************
> + * Proximity sensor subdriver
> + */
> +
> +#define PALMSENSOR_PRESENT_BIT 0 /* Determine if psensor present */
> +#define PALMSENSOR_ON_BIT 1 /* psensor status */
> +
> +struct input_dev *tpacpi_sw_dev;
> +bool has_palmsensor;
> +bool palmsensor_state;
There is no need to make palmsensor_state global, see below.
> +
> +static int palmsensor_get(bool *present, bool *state)
> +{
> + acpi_handle psensor_handle;
> + int output;
> +
> + if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "GPSS", &psensor_handle)))
> + return -ENODEV;
> + if (!acpi_evalf(psensor_handle, &output, NULL, "d"))
> + return -EIO;
> +
> + *present = output & BIT(PALMSENSOR_PRESENT_BIT) ? true : false;
> + *state = output & BIT(PALMSENSOR_ON_BIT) ? true : false;
> + return 0;
> +}
> +
> +static void proxsensor_refresh(void)
> +{
> + bool new_state;
> + int err;
> +
> + if (has_palmsensor) {
> + err = palmsensor_get(&has_palmsensor, &new_state);
> + if (err)
> + return;
> + if (new_state != palmsensor_state) {
> + input_report_switch(tpacpi_sw_dev, SW_PALMREST_PROXIMITY, new_state);
> + input_sync(tpacpi_sw_dev);
> + palmsensor_state = new_state;
> + }
There is no need for the whole new_state / orig_state dance here, the input subsys
will only send events to userspace if anything has actually changed, so you can just
write the following here:
err = palmsensor_get(&has_palmsensor, &new_state);
if (err)
return;
input_report_switch(tpacpi_sw_dev, SW_PALMREST_PROXIMITY, new_state);
input_sync(tpacpi_sw_dev);
> + }
> +}
> +
> +static int tpacpi_proxsensor_init(struct ibm_init_struct *iibm)
> +{
> + int palm_err;
> +
> + palm_err = palmsensor_get(&has_palmsensor, &palmsensor_state);
> + /* If support isn't available (ENODEV) then don't return an error */
> + if (palm_err == -ENODEV)
> + return 0;
If you return 1 here, then this new-module will not be added
to the tpacpi_all_drivers list (which is good since it is non functional)
and then tpacpi_proxsensor_exit will also be skipped.
> + /* For all other errors we can flag the failure */
> + if (palm_err)
> + return palm_err;
> +
> + if (has_palmsensor) {
> + tpacpi_sw_dev = input_allocate_device();
> + if (!tpacpi_sw_dev)
> + return -ENOMEM;
> + tpacpi_sw_dev->name = "Thinkpad proximity switches";
> + tpacpi_sw_dev->phys = TPACPI_DRVR_NAME "/input1";
> + tpacpi_sw_dev->id.bustype = BUS_HOST;
> + tpacpi_sw_dev->id.vendor = thinkpad_id.vendor;
> + tpacpi_sw_dev->id.product = TPACPI_HKEY_INPUT_PRODUCT;
> + tpacpi_sw_dev->id.version = TPACPI_HKEY_INPUT_VERSION;
> + tpacpi_sw_dev->dev.parent = &tpacpi_pdev->dev;
> +
> + if (has_palmsensor) {
> + input_set_capability(tpacpi_sw_dev, EV_SW, SW_PALMREST_PROXIMITY);
> + input_report_switch(tpacpi_sw_dev, SW_PALMREST_PROXIMITY, palmsensor_state);
> + }
> + palm_err = input_register_device(tpacpi_sw_dev);
> + if (palm_err) {
> + input_free_device(tpacpi_sw_dev);
Maybe do "tpacpi_sw_dev = NULL" here to avoid leaving a dangling global pointer around ?
> + return palm_err;
> + }
return 0 here
> + }
> + return 0;
And return 1 here, as discussed above.
This will ...
> +}
> +
> +static void proxsensor_exit(void)
> +{
> + input_unregister_device(tpacpi_sw_dev);
Avoid a NULL pointer deref here when there is no palmrest sensor.
> + input_free_device(tpacpi_sw_dev);
The line needs to be deleted, input_free_device() is only for freeing
devices before they are registered (so in case of some error)
input_unregister_device() already does a put on the device, so also
calling input_free_device() here messes up the ref counting.
> +}
> +
> +static struct ibm_struct proxsensor_driver_data = {
> + .name = "proximity-sensor",
> + .exit = proxsensor_exit,
> +};
> /****************************************************************************
> ****************************************************************************
> *
> @@ -10411,6 +10502,10 @@ static struct ibm_init_struct ibms_init[] __initdata = {
> .init = tpacpi_dytc_init,
> .data = &dytc_driver_data,
> },
> + {
> + .init = tpacpi_proxsensor_init,
> + .data = &proxsensor_driver_data,
> + },
> };
>
> static int __init set_ibm_param(const char *val, const struct kernel_param *kp)
>
Otherwise this looks good to me.
Regards,
Hans
