On Aug 10, 2011, at 1:16 PM, Wolfgang Grandegger wrote: > On 08/10/2011 07:01 PM, Kumar Gala wrote: >> >> On Aug 10, 2011, at 11:27 AM, Robin Holt wrote: >> >>> I added a simple clock source for the p1010rdb so the flexcan driver >>> could determine a clock frequency. The p1010 flexcan device only has >>> an oscillator of system bus frequency divided by 2. >>> >>> Signed-off-by: Robin Holt <h...@sgi.com> >>> Acked-by: Marc Kleine-Budde <m...@pengutronix.de>, >>> Acked-by: Wolfgang Grandegger <w...@grandegger.com>, >>> Cc: U Bhaskar-B22300 <b22...@freescale.com> >>> Cc: socketcan-c...@lists.berlios.de, >>> Cc: net...@vger.kernel.org, >>> Cc: PPC list <linuxppc-dev@lists.ozlabs.org> >>> Cc: Kumar Gala <ga...@kernel.crashing.org> >>> --- >>> arch/powerpc/platforms/85xx/Kconfig | 2 + >>> arch/powerpc/platforms/85xx/Makefile | 2 + >>> arch/powerpc/platforms/85xx/clock.c | 52 >>> ++++++++++++++++++++++++++++++++ >>> arch/powerpc/platforms/85xx/p1010rdb.c | 8 +++++ >>> 4 files changed, 64 insertions(+), 0 deletions(-) >>> create mode 100644 arch/powerpc/platforms/85xx/clock.c >> >> I dont understand how mpc85xx_clk_functions() ends up being associated with >> the frequency the flexcan is running at. > > The function mpc85xx_clk_get_rate() returns "fsl_get_sys_freq() / 2" for > Flexcan devices. > >> This either seems to global or I'm missing something. > > This patch extends the existing Flexcan platform driver for ARM for the > PowerPC using the device tree. Due to the nice integration of the device > tree (of-platform) into the platform driver and devices, the difference > are quite small (see patches 1..3). Apart from the endianess issue, only > the clock needs to be handled in a common way. As ARM already uses the > clk interface, we found it straight-forward to implement it for the > P1010, or more general for the 85xx, as well, instead of using an > additional helper function.
I see, that. What concerns me is there are numerous clocks / frequencies that exist inside a MPC85xx/P1010 SOC. The code I'm seeing does NOT seem to do anything to relate this clock JUST to the flexcan. >> I still think the clk / freq info should be in the device tree and handled >> in the driver and NOT arch/powerpc platform code. > > If I understand you correctly, you want the boot-loader to provide the > relevant information by fixing up the device tree, which then can be > handled arch-independently by the driver, right? Yes, that is part of what I want. - k _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev