kernel-fxtec-pro1x/drivers/i2c
Jarkko Nikula 5853b22d96 i2c: core: Add function for finding the bus speed from ACPI, take 2
ACPI 5 specification doesn't have property for the I2C bus speed but
I2cSerialBus resource descriptor which define each controller-slave
connection define the maximum speed supported by that connection.

Thus finding the maximum safe speed for the bus is to walk through all
I2cSerialBus resources that are associated to I2C controller and use the
speed of slowest connection.

Add function i2c_acpi_find_bus_speed() to the i2c-core that adapter
drivers can call prior registering itself to core.

This implies two-step walk through the I2cSerialBus resources: call to
i2c_acpi_find_bus_speed() does the first scan and finds the safe bus
speed that adapter drivers can set up. Adapter driver registration does
the second scan when i2c-core creates the I2C slaves by calling the
i2c_acpi_register_devices(). In that way the bus speed is set in case
slave device probe gets called during registration and does communication.

Previous version commit 55d38d060e ("i2c: core: Add function for finding
the bus speed from ACPI") got reverted due merge conflicts from
commit 525e6fabea ("i2c / ACPI: add support for ACPI reconfigure
notifications").

This version is a bit bigger than previous version but is still sharing
the lowest and complicated part of I2cSerialBus lookup routines with the
existing code.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-26 00:42:10 +02:00
..
algos i2c: algo-bit: declare i2c_bit_quirk_no_clk_stretch as static 2016-05-11 17:16:30 +02:00
busses i2c: designware: Enable high speed mode 2016-08-26 00:42:07 +02:00
muxes i2c: mux: demux-pinctrl: properly roll back when adding adapter fails 2016-08-15 00:55:07 +02:00
i2c-boardinfo.c i2c: remove __init from i2c_register_board_info() 2016-06-19 14:13:50 +02:00
i2c-core.c i2c: core: Add function for finding the bus speed from ACPI, take 2 2016-08-26 00:42:10 +02:00
i2c-core.h i2c: remove FSF address 2014-11-07 18:35:33 +01:00
i2c-dev.c i2c-dev: don't get i2c adapter via i2c_dev 2016-07-08 10:29:31 +09:00
i2c-mux.c i2c: add i2c_trylock_bus wrapper, use it 2016-08-25 18:02:14 +02:00
i2c-slave-eeprom.c i2c: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
i2c-smbus.c i2c: i2c-smbus: fix i2c_handle_smbus_host_notify documentation 2016-07-18 20:09:54 +02:00
i2c-stub.c i2c: i2c-stub: sort includes 2016-02-20 23:33:39 +01:00
Kconfig i2c: Update the description of I2C_SMBUS 2016-07-18 20:11:08 +02:00
Makefile i2c: slave-eeprom: add eeprom simulator driver 2014-12-11 22:25:54 +01:00