1330e29105
The number of clock cycles to be written into the CLKDIV register that determines the I2C clk high phase includes the rise time. So to meet the timing requirements defined in the I2C specification which defines the minimal time SCL has to be high, the rise time has to taken into account. The same applies to the low phase with falling time. In my test on RK3288-Pink2 board, which is not an upstream board yet, if external pull-up resistor is 4.7K, rise_ns is about 700ns. So the measured high_ns is about 3900ns, which is less than 4000ns (the minimum high_ns in I2C specification for Standard-mode). To fix this bug min_low_ns should include fall time and min_high_ns should include rise time. This patch merged the patch from chromium project which can get the rise and fall times for signals from the device tree. This allows us to more accurately calculate timings. see: https://chromium-review.googlesource.com/#/c/232774/ Signed-off-by: Addy Ke <addy.ke@rock-chips.com> Reviewed-by: Doug Anderson <dianders@chromium.org> Tested-by: Doug Anderson <dianders@chromium.org> [wsa: fixed a typo in the docs] Signed-off-by: Wolfram Sang <wsa@the-dreams.de> |
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| .. | ||
| bindings | ||
| 00-INDEX | ||
| booting-without-of.txt | ||
| changesets.txt | ||
| dynamic-resolution-notes.txt | ||
| of_selftest.txt | ||
| overlay-notes.txt | ||
| todo.txt | ||
| usage-model.txt | ||