b1258105 - spi: intel: Add protected and locked attributes

Wed, 09 Oct 2024 06:22:44 +0000

spi: intel: Add protected and locked attributesThe manufacturing access to the PCH/SoC SPI device is traditionallyperformed via userspace driver accessing registers via /dev/mem but dueto security concerns /dev/mem access is being much restricted, hence thereason for utilizing dedicated Intel PCH/SoC SPI controller driver,which is already implemented in the Linux kernel.Intel PCH/SoC SPI controller protects the flash storage via twomechanisms one is the via region protection registers and second viaBIOS lock. The BIOS locks only the BIOS regions usually 0 and/or 6.The device always boots with BIOS lock set, but during manufacturing theBIOS lock has to be lifted in order to enable the write access. This canbe done by passing "writeable=1" in the command line when the driver isloaded. This "locked" state is exposed through new sysfs attributes(intel_spi_locked, intel_spi_bios_locked).Second, also the region protection status is exposed via sysfs attribute(intel_spi_protected) as the manufacturing will need the both files inorder to validate that the device is properly sealed.Includes code written by Tamar Mashiah.Signed-off-by: Alexander Usyskin Co-developed-by: Tomas Winkler Signed-off-by: Tomas Winkler Reviewed-by: Andy Shevchenko Signed-off-by: Mika Westerberg Link: https://patch.msgid.link/20241009062244.2436793-1-mika.westerberg@linux.intel.comSigned-off-by: Mark Brown List of files: /linux-6.15/Documentation/ABI/testing/sysfs-driver-spi-intel

Changes in sysfs-driver-spi-intel

b1258105 - spi: intel: Add protected and locked attributes