MPC82xx ADS SCC ports initialisation
Laurent Pinchart
laurent.pinchart at technotrade.biz
Wed Jul 11 00:19:51 EST 2007
Hi everybody,
while checking the availability of MPC8260 support in ARCH=powerpc, I ran
across a possible issue in SCC ports initialisation for the MPC82xx ADS
boards.
init_scc1_uart_ioports and init_scc4_uart_ioports in
arch/powerpc/platforms/mpc82xx/mpx82xx_ads.c use the following code to
configure the SCC clocks:
clrbits32(&immap->im_cpmux.cmx_scr, (0x00000007 << (4 - data->clk_tx)));
clrbits32(&immap->im_cpmux.cmx_scr, (0x00000038 << (4 - data->clk_rx)));
setbits32(&immap->im_cpmux.cmx_scr,
((data->clk_tx - 1) << (4 - data->clk_tx)));
setbits32(&immap->im_cpmux.cmx_scr,
((data->clk_rx - 1) << (4 - data->clk_rx)));
The shift right-hand operand doesn't seem to be correct. Could anyone confirm
this ? If my assumption is right, could anyone tell me if the MPC82xx
processors are actually supported by the powerpc architecture, or if the
MPC82xx ADS code is just a non-functional work in progress.
I also noticed that U-Boot doesn't have flatten device tree support for the
MPC82xx family. There seem to be still a lot of work to do to support the
MPC82xx in the powerpc tree, and the effort is much bigger than just porting
a board from ppc to powerpc.
Laurent Pinchart
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