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path: root/src/soc/intel/skylake/i2c.c
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2016-07-01skylake: Generate ACPI timing values for I2C devicesDuncan Laurie
Have the Skylake SOC generate ACPI timing values for the enabled I2C controllers instead of passing it in the DSDT with static timings. The timing values are generated from the controller clock speed and are more accurate than the hardcoded values that were in the ASL which were originally copied from Broadwell where the controller is running at a different clock speed... Additionally it is now possible for a board to override the values using devicetree.cb. If zero is passed in for SCL HCNT or LCNT then the kernel will generate its own timing using the same forumla, but if the SDA hold time value is zero the kernel will NOT generate a correct value and the SDA hold time may be incorrect. This was tested on the Chell platform to ensure all the I2C devices on the board are still operational with these new timing values. Change-Id: I4feb3df9e083592792f8fadd7105e081a984a906 Signed-off-by: Duncan Laurie <dlaurie@chromium.org> Reviewed-on: https://review.coreboot.org/15291 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2016-06-09skylake: Support common LPSS I2C driverDuncan Laurie
Support the common Intel LPSS I2C driver for the 6 I2C bus controllers that are present on the Skylake-LP PCH with a 120 mHz clock. The required lpss_i2c_base_address() method is implemented separately for verstage/romstage and ramstage environments. This provides methods to convert to and from "struct device" and the I2C controller bus number for that device. These are used to provide support for the "I2C Bus Operations" that are present in the coreboot devicetree. To support the I2C controller before ramstage an early init function is provided to do minimal initializaiton of the PCI device and assign a temporary base address for use before memory. The final base address is assigned during device enumeration and used during ramstage. Because it is usually not necessary to enable I2C controllers before ramstage a config register for the devicetree is provided to perform early initialization of this controller. In addition the bus speed can be set in the devicetree and that speed will be applied when the device is initialized. If not provided the default speed is set to I2C_SPEED_FAST. This was tested with the google/chell mainboard by reading and writing from the trackpad and codec devices during both verstage and ramstage. Change-Id: Ia0270adfaf2843a3be4e00c732c85401a3401ef5 Signed-off-by: Duncan Laurie <dlaurie@chromium.org> Reviewed-on: https://review.coreboot.org/15105 Reviewed-by: Aaron Durbin <adurbin@chromium.org> Tested-by: build bot (Jenkins)
2016-05-31skylake: Add I2C devicesDuncan Laurie
Add the I2C devices to skylake with the scan_bus handler for SMBUS devices so that I2C-based devices can be declared in devicetree.cb and get initialized properly during ramstage. This does not yet provide the I2C driver, but it allows for devices that are declared in devicetree.cb to provide ACPI tables to the OS. Change-Id: I9dfe4a06a8b0bc549a2b0e2d7c033c895188ba30 Signed-off-by: Duncan Laurie <dlaurie@chromium.org> Reviewed-on: https://review.coreboot.org/14992 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@chromium.org>