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 --- 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. + */ + 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; };