Commit addab6fe authored by Hans de Goede's avatar Hans de Goede Committed by Jonathan Cameron

iio: accel: bmc150: Add support for DUAL250E ACPI DSM for setting the hinge angle

Some 360 degree hinges (yoga) style 2-in-1 devices use 2 bmc150 accels
to allow the OS to determine the angle between the display and the base
of the device, so that the OS can determine if the 2-in-1 is in laptop
or in tablet-mode.

On Windows both accelerometers are read (polled) by a special service
and this service calls the DSM (Device Specific Method), which in turn
translates the angles to one of laptop/tablet/tent/stand mode and then
notifies the EC about the new mode and the EC then enables or disables
the builtin keyboard and touchpad based in the mode.

When the 2-in-1 is powered-on or resumed folded in tablet mode the
EC senses this independent of the DSM by using a HALL effect sensor
which senses that the keyboard has been folded away behind the display.

At power-on or resume the EC disables the keyboard based on this and
the only way to get the keyboard to work after this is to call the
DSM to re-enable it.

Call the DSM on probe() and resume() to fix the keyboard not working
when powered-on / resumed in tablet-mode.

This patch was developed and tested on a Lenovo Yoga 300-IBR.
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210523170103.176958-8-hdegoede@redhat.comSigned-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 35157f44
......@@ -1798,6 +1798,9 @@ static int bmc150_accel_resume(struct device *dev)
bmc150_accel_fifo_set_mode(data);
mutex_unlock(&data->mutex);
if (data->resume_callback)
data->resume_callback(dev);
return 0;
}
#endif
......
......@@ -28,6 +28,108 @@ static const struct acpi_device_id bmc150_acpi_dual_accel_ids[] = {
{ }
};
/*
* The DUAL250E ACPI device for 360° hinges type 2-in-1s with 1 accelerometer
* in the display and 1 in the hinge has an ACPI-method (DSM) to tell the
* ACPI code about the angle between the 2 halves. This will make the ACPI
* code enable/disable the keyboard and touchpad. We need to call this to avoid
* the keyboard being disabled when the 2-in-1 is turned-on or resumed while
* fully folded into tablet mode (which gets detected with a HALL-sensor).
* If we don't call this then the keyboard won't work even when the 2-in-1 is
* changed to be used in laptop mode after the power-on / resume.
*
* This DSM takes 2 angles, selected by setting aux0 to 0 or 1, these presumably
* define the angle between the gravity vector measured by the accelerometer in
* the display (aux0=0) resp. the base (aux0=1) and some reference vector.
* The 2 angles get subtracted from each other so the reference vector does
* not matter and we can simply leave the second angle at 0.
*/
#define BMC150_DSM_GUID "7681541e-8827-4239-8d9d-36be7fe12542"
#define DUAL250E_SET_ANGLE_FN_INDEX 3
struct dual250e_set_angle_args {
u32 aux0;
u32 ang0;
u32 rawx;
u32 rawy;
u32 rawz;
} __packed;
static bool bmc150_acpi_set_angle_dsm(struct i2c_client *client, u32 aux0, u32 ang0)
{
struct acpi_device *adev = ACPI_COMPANION(&client->dev);
struct dual250e_set_angle_args args = {
.aux0 = aux0,
.ang0 = ang0,
};
union acpi_object args_obj, *obj;
guid_t guid;
if (!acpi_dev_hid_uid_match(adev, "DUAL250E", NULL))
return false;
guid_parse(BMC150_DSM_GUID, &guid);
if (!acpi_check_dsm(adev->handle, &guid, 0, BIT(DUAL250E_SET_ANGLE_FN_INDEX)))
return false;
/*
* Note this triggers the following warning:
* "ACPI Warning: \_SB.PCI0.I2C2.ACC1._DSM: Argument #4 type mismatch -
* Found [Buffer], ACPI requires [Package]"
* This is unavoidable since the _DSM implementation expects a "naked"
* buffer, so wrapping it in a package will _not_ work.
*/
args_obj.type = ACPI_TYPE_BUFFER;
args_obj.buffer.length = sizeof(args);
args_obj.buffer.pointer = (u8 *)&args;
obj = acpi_evaluate_dsm(adev->handle, &guid, 0, DUAL250E_SET_ANGLE_FN_INDEX, &args_obj);
if (!obj) {
dev_err(&client->dev, "Failed to call DSM to enable keyboard and touchpad\n");
return false;
}
ACPI_FREE(obj);
return true;
}
static bool bmc150_acpi_enable_keyboard(struct i2c_client *client)
{
/*
* The EC must see a change for it to re-enable the kbd, so first
* set the angle to 270° (tent/stand mode) and then change it to
* 90° (laptop mode).
*/
if (!bmc150_acpi_set_angle_dsm(client, 0, 270))
return false;
/* The EC needs some time to notice the angle being changed */
msleep(100);
return bmc150_acpi_set_angle_dsm(client, 0, 90);
}
static void bmc150_acpi_resume_work(struct work_struct *work)
{
struct bmc150_accel_data *data =
container_of(work, struct bmc150_accel_data, resume_work.work);
bmc150_acpi_enable_keyboard(data->second_device);
}
static void bmc150_acpi_resume_handler(struct device *dev)
{
struct bmc150_accel_data *data = iio_priv(dev_get_drvdata(dev));
/*
* Delay the bmc150_acpi_enable_keyboard() call till after the system
* resume has completed, otherwise it will not work.
*/
schedule_delayed_work(&data->resume_work, msecs_to_jiffies(1000));
}
/*
* Some acpi_devices describe 2 accelerometers in a single ACPI device,
* try instantiating a second i2c_client for an I2cSerialBusV2 ACPI resource
......@@ -56,12 +158,20 @@ static void bmc150_acpi_dual_accel_probe(struct i2c_client *client)
board_info.irq = acpi_dev_gpio_irq_get(adev, 1);
data->second_device = i2c_acpi_new_device(&client->dev, 1, &board_info);
if (!IS_ERR(data->second_device) && bmc150_acpi_enable_keyboard(data->second_device)) {
INIT_DELAYED_WORK(&data->resume_work, bmc150_acpi_resume_work);
data->resume_callback = bmc150_acpi_resume_handler;
}
}
static void bmc150_acpi_dual_accel_remove(struct i2c_client *client)
{
struct bmc150_accel_data *data = iio_priv(i2c_get_clientdata(client));
if (data->resume_callback)
cancel_delayed_work_sync(&data->resume_work);
i2c_unregister_device(data->second_device);
}
#else
......
......@@ -6,6 +6,7 @@
#include <linux/iio/iio.h>
#include <linux/mutex.h>
#include <linux/regulator/consumer.h>
#include <linux/workqueue.h>
struct regmap;
struct i2c_client;
......@@ -62,6 +63,8 @@ struct bmc150_accel_data {
int64_t timestamp, old_timestamp; /* Only used in hw fifo mode. */
const struct bmc150_accel_chip_info *chip_info;
struct i2c_client *second_device;
void (*resume_callback)(struct device *dev);
struct delayed_work resume_work;
struct iio_mount_matrix orientation;
};
......
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