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authorHans de Goede <hdegoede@redhat.com>2021-05-23 20:01:01 +0300
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2021-06-09 22:53:15 +0300
commitaddab6febc42ed94e4eee1abbe486150e4f8b9e9 (patch)
tree48c2dacf1baa4e9dbc7a67586aed91e603924682 /drivers/iio/accel/bmc150-accel-i2c.c
parent35157f443b6f4537b03ea1752bd96fbb28ec7a4f (diff)
downloadlinux-addab6febc42ed94e4eee1abbe486150e4f8b9e9.tar.xz
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: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: https://lore.kernel.org/r/20210523170103.176958-8-hdegoede@redhat.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio/accel/bmc150-accel-i2c.c')
-rw-r--r--drivers/iio/accel/bmc150-accel-i2c.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/drivers/iio/accel/bmc150-accel-i2c.c b/drivers/iio/accel/bmc150-accel-i2c.c
index ab0cda8ff8fa..d34dddb850d9 100644
--- a/drivers/iio/accel/bmc150-accel-i2c.c
+++ b/drivers/iio/accel/bmc150-accel-i2c.c
@@ -29,6 +29,108 @@ 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
* with index 1.
@@ -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