linux/drivers/i2c
Mika Westerberg defc0b2fb5 i2c: designware: make HCNT/LCNT values configurable
The DesignWare I2C controller has high count (HCNT) and low count (LCNT)
registers for each of the I2C speed modes (standard and fast). These
registers are programmed based on the input clock speed in the driver.

The current code calculates these values based on the input clock speed and
tries hard to meet the I2C bus timing requirements. This could result
non-optimal values with regarding to the bus speed. For example on Intel
BayTrail we get bus speed of 315.41kHz which is ~20% slower than we would
expect (400kHz) in fast mode (even though the timing requirements are met).

This patch makes it possible for the platform code to pass more optimal
HCNT/LCNT values to the core driver if they are known beforehand. If these
are not set we use the calculated and more conservative values.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Shinya Kuribayashi <skuribay@pobox.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-28 11:11:10 +02:00
..
algos Linux 3.6-rc7 2012-10-08 12:46:32 +02:00
busses i2c: designware: make HCNT/LCNT values configurable 2013-08-28 11:11:10 +02:00
muxes i2c: move OF helpers into the core 2013-08-23 10:22:20 +02:00
i2c-boardinfo.c i2c: Update the FSF address 2012-03-26 21:47:19 +02:00
i2c-core.c i2c: move ACPI helpers into the core 2013-08-23 10:22:29 +02:00
i2c-core.h i2c: Update the FSF address 2012-03-26 21:47:19 +02:00
i2c-dev.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
i2c-mux.c i2c: move OF helpers into the core 2013-08-23 10:22:20 +02:00
i2c-smbus.c i2c: use dev_get_platdata() 2013-08-19 19:46:30 +02:00
i2c-stub.c i2c-stub: Move to drivers/i2c 2012-10-28 21:37:00 +01:00
Kconfig drivers/i2c: remove !S390 dependency, add missing GENERIC_HARDIRQS dependencies 2013-03-11 09:59:02 +01:00
Makefile i2c-stub: Move to drivers/i2c 2012-10-28 21:37:00 +01:00