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Diffstat (limited to 'doc/driver-model/UDM-twserial.txt')
| -rw-r--r-- | doc/driver-model/UDM-twserial.txt | 47 |
1 files changed, 0 insertions, 47 deletions
diff --git a/doc/driver-model/UDM-twserial.txt b/doc/driver-model/UDM-twserial.txt deleted file mode 100644 index 5f2c5a3..0000000 --- a/doc/driver-model/UDM-twserial.txt +++ /dev/null @@ -1,47 +0,0 @@ -================================== -TWserial device subsystem analysis -================================== - -Tomas Hlavacek<tmshlvck@gmail.com> -2012-03-21 - -I) Overview ------------ - -U-Boot currently implements one common API for TWSerial devices. The interface -is defined in include/tws.h and comprises of functions: - - int tws_read(uchar *buffer, int len); - int tws_write(uchar *buffer, int len); - -The functions are implemented by a proper device driver in drivers/twserial -directory and the driver to be compiled in is selected in a Makefile. There is -only one driver present now. - -The driver depends on ad-hoc code in board specific data, namely functions: - - void tws_ce(unsigned bit); - void tws_wr(unsigned bit); - void tws_clk(unsigned bit); - void tws_data(unsigned bit); - unsigned tws_data_read(void); - void tws_data_config_output(unsigned output); - -implemented in include/configs/inka4x0.h . - -II) Approach ------------- - - U-Boot TWserial drivers exports two simple functions and therefore the conversion - of the driver and creating a core for it is not needed. It should be consolidated - with include/configs/inka4x0.h and taken to the misc/ dir. - - -III) Analysis of in-tree drivers --------------------------------- - - drivers/twserial/soft_tws.c - --------------------------- - The driver is the only TWserial driver. The ad-hoc part in - include/configs/inka4x0.h and the core soft_tws driver should be consolidated - to one compact driver and moved to misc/ . |