On Fri, 21 May 2021 19:14:17 +0200 Hans de Goede hdegoede@redhat.com wrote:
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
Putting aside my general grumpiness at this stuff having to pollute accelerometer drivers (and the broken DSM implementation on the hardware!) this is a fairly clean implementation so I guess we can survive it.
Jonathan
drivers/iio/accel/bmc150-accel-core.c | 3 + drivers/iio/accel/bmc150-accel-i2c.c | 109 ++++++++++++++++++++++++++ drivers/iio/accel/bmc150-accel.h | 3 + 3 files changed, 115 insertions(+)
diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c index 0291512648b2..932007895f18 100644 --- a/drivers/iio/accel/bmc150-accel-core.c +++ b/drivers/iio/accel/bmc150-accel-core.c @@ -1803,6 +1803,9 @@ 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 diff --git a/drivers/iio/accel/bmc150-accel-i2c.c b/drivers/iio/accel/bmc150-accel-i2c.c index 1dd7b8a9a382..31256c32a33c 100644 --- a/drivers/iio/accel/bmc150-accel-i2c.c +++ b/drivers/iio/accel/bmc150-accel-i2c.c @@ -28,6 +28,107 @@ 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 (strcmp(acpi_device_hid(adev), "DUAL250E"))
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.
ouch.
*/- 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.
@@ -55,12 +156,20 @@ static void bmc150_acpi_dual_accel_probe(struct i2c_client *client) board_info.irq = acpi_dev_gpio_irq_get_by(adev, NULL, 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 diff --git a/drivers/iio/accel/bmc150-accel.h b/drivers/iio/accel/bmc150-accel.h index 5da6fd32bac5..d67d6ed6ae77 100644 --- a/drivers/iio/accel/bmc150-accel.h +++ b/drivers/iio/accel/bmc150-accel.h @@ -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;
};