On Sat, Jan 27, 2018 at 3:32 PM, Pali Rohár <pali.rohar@xxxxxxxxx> wrote: > Dell platform team told us that some (DMI whitelisted) Dell Latitude > machines have ST microelectronics accelerometer at i2c address 0x29. > > Presence of that ST microelectronics accelerometer is verified by existence > of SMO88xx ACPI device which represent that accelerometer. Unfortunately > ACPI device does not specify i2c address. > > This patch registers lis3lv02d device for selected Dell Latitude machines > at i2c address 0x29 after detection. And for Dell Vostro V131 machine at > i2c address 0x1d which was manually detected. > > Finally commit a7ae81952cda ("i2c: i801: Allow ACPI SystemIO OpRegion to > conflict with PCI BAR") allowed to use i2c-i801 driver on Dell machines so > lis3lv02d correctly initialize accelerometer. > > Tested on Dell Latitude E6440. > +static acpi_status check_acpi_smo88xx_device(acpi_handle obj_handle, > + u32 nesting_level, > + void *context, > + void **return_value) > +{ > + struct acpi_device_info *info; > + acpi_status status; > + char *hid; > + > + status = acpi_get_object_info(obj_handle, &info); > + if (!ACPI_SUCCESS(status) || !(info->valid & ACPI_VALID_HID)) > + return AE_OK; > + > + hid = info->hardware_id.string; > + if (!hid) > + return AE_OK; > + > + if (strlen(hid) < 7) > + return AE_OK; > + > + if (memcmp(hid, "SMO88", 5) != 0) > + return AE_OK; > + > + *((bool *)return_value) = true; > + return AE_CTRL_TERMINATE; > +} > + > +static bool is_dell_system_with_lis3lv02d(void) > +{ > + /* > + * Check that ACPI device SMO88xx exists and is enabled. That ACPI > + * device represent our ST microelectronics lis3lv02d accelerometer but > + * unfortunately without any other information (like i2c address). > + */ Isn't it simple return acpi_dev_present("SMO88", NULL, -1); call? > + found = false; > + status = acpi_get_devices(NULL, check_acpi_smo88xx_device, NULL, > + (void **)&found); > + if (!ACPI_SUCCESS(status) || !found) > + return false; > + > + return true; > +} -- With Best Regards, Andy Shevchenko