i2c: designware: add a new bit check for IC_CON control
On some AMD platforms, based on the new designware datasheet, BIOS sets the BIT(11) within the IC_CON register to advertise the "bus clear feature capability". AMD/Designware datasheet says: Bit(11) BUS_CLEAR_FEATURE_CTRL. Read-write,Volatile. Reset: 0. Description: In Master mode: - 1'b1: Bus Clear Feature is enabled. - 1'b0: Bus Clear Feature is Disabled. In Slave mode, this register bit is not applicable. On AMD platform designs: 1. BIOS programs the BUS_CLEAR_FEATURE_CTRL and enables the detection of SCL/SDA stuck low. 2. Whenever the stuck low is detected, the SMU FW shall do the bus recovery procedure. Currently, the way in which the "master_cfg" is built in the driver, it overrides the BUS_CLEAR_FEATURE_CTRL advertised by BIOS and the SMU FW cannot initiate the bus recovery if the stuck low is detected. Hence add a check in i2c_dw_probe_master() that if the BIOS advertises the bus clear feature, let driver not ignore it and adapt accordingly. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
Please register or sign in to comment