From: Hans de Goede <hdegoede@xxxxxxxxxx> [ Upstream commit 65299e8bfb24774e6340e93ae49f6626598917c8 ] Several users have been reporting that elants_i2c gives several errors during probe and that their touchscreen does not work on their Lenovo AMD based laptops with a touchscreen with a ELAN0001 ACPI hardware-id: [ 0.550596] elants_i2c i2c-ELAN0001:00: i2c-ELAN0001:00 supply vcc33 not found, using dummy regulator [ 0.551836] elants_i2c i2c-ELAN0001:00: i2c-ELAN0001:00 supply vccio not found, using dummy regulator [ 0.560932] elants_i2c i2c-ELAN0001:00: elants_i2c_send failed (77 77 77 77): -121 [ 0.562427] elants_i2c i2c-ELAN0001:00: software reset failed: -121 [ 0.595925] elants_i2c i2c-ELAN0001:00: elants_i2c_send failed (77 77 77 77): -121 [ 0.597974] elants_i2c i2c-ELAN0001:00: software reset failed: -121 [ 0.621893] elants_i2c i2c-ELAN0001:00: elants_i2c_send failed (77 77 77 77): -121 [ 0.622504] elants_i2c i2c-ELAN0001:00: software reset failed: -121 [ 0.632650] elants_i2c i2c-ELAN0001:00: elants_i2c_send failed (4d 61 69 6e): -121 [ 0.634256] elants_i2c i2c-ELAN0001:00: boot failed: -121 [ 0.699212] elants_i2c i2c-ELAN0001:00: invalid 'hello' packet: 00 00 ff ff [ 1.630506] elants_i2c i2c-ELAN0001:00: Failed to read fw id: -121 [ 1.645508] elants_i2c i2c-ELAN0001:00: unknown packet 00 00 ff ff Despite these errors, the elants_i2c driver stays bound to the device (it returns 0 from its probe method despite the errors), blocking the i2c-hid driver from binding. Manually unbinding the elants_i2c driver and binding the i2c-hid driver makes the touchscreen work. Check if the ACPI-fwnode for the touchscreen contains one of the i2c-hid compatiblity-id strings and if it has the I2C-HID spec's DSM to get the HID descriptor address, If it has both then make elants_i2c not bind, so that the i2c-hid driver can bind. This assumes that non of the (older) elan touchscreens which actually need the elants_i2c driver falsely advertise an i2c-hid compatiblity-id + DSM in their ACPI-fwnodes. If some of them actually do have this false advertising, then this change may lead to regressions. While at it also drop the unnecessary DEVICE_NAME prefixing of the "I2C check functionality error", dev_err already outputs the driver-name. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207759 Acked-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210405202756.16830-1-hdegoede@xxxxxxxxxx Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/input/touchscreen/elants_i2c.c | 44 ++++++++++++++++++++++++-- 1 file changed, 42 insertions(+), 2 deletions(-) diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c index 50c348297e38..03a482535944 100644 --- a/drivers/input/touchscreen/elants_i2c.c +++ b/drivers/input/touchscreen/elants_i2c.c @@ -38,6 +38,7 @@ #include <linux/of.h> #include <linux/gpio/consumer.h> #include <linux/regulator/consumer.h> +#include <linux/uuid.h> #include <asm/unaligned.h> /* Device, Driver information */ @@ -1224,6 +1225,40 @@ static void elants_i2c_power_off(void *_data) } } +#ifdef CONFIG_ACPI +static const struct acpi_device_id i2c_hid_ids[] = { + {"ACPI0C50", 0 }, + {"PNP0C50", 0 }, + { }, +}; + +static const guid_t i2c_hid_guid = + GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, + 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); + +static bool elants_acpi_is_hid_device(struct device *dev) +{ + acpi_handle handle = ACPI_HANDLE(dev); + union acpi_object *obj; + + if (acpi_match_device_ids(ACPI_COMPANION(dev), i2c_hid_ids)) + return false; + + obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, ACPI_TYPE_INTEGER); + if (obj) { + ACPI_FREE(obj); + return true; + } + + return false; +} +#else +static bool elants_acpi_is_hid_device(struct device *dev) +{ + return false; +} +#endif + static int elants_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -1232,9 +1267,14 @@ static int elants_i2c_probe(struct i2c_client *client, unsigned long irqflags; int error; + /* Don't bind to i2c-hid compatible devices, these are handled by the i2c-hid drv. */ + if (elants_acpi_is_hid_device(&client->dev)) { + dev_warn(&client->dev, "This device appears to be an I2C-HID device, not binding\n"); + return -ENODEV; + } + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { - dev_err(&client->dev, - "%s: i2c check functionality error\n", DEVICE_NAME); + dev_err(&client->dev, "I2C check functionality error\n"); return -ENXIO; } -- 2.30.2
