Hi, Marek, On Sat, Jul 30, 2011 at 1:09 AM, Marek Vasut <marek.va...@gmail.com> wrote: > On Friday, July 29, 2011 01:24:49 PM Jason Hui wrote: >> Hi, Marek, >> >> On Fri, Jul 29, 2011 at 5:32 PM, Marek Vasut <marek.va...@gmail.com> wrote: >> > Rewrite the mxc_i2c driver. >> > * This version is much closer to Linux implementation. >> > * Fixes IPG_PERCLK being incorrectly used as clock source >> > * Fixes behaviour of the driver on iMX51 >> > * Clean up coding style a bit ;-) >> >> I don't think you did the right thing by chaning IPG_PERCLK to IPG_CLK >> As I said, the IPG_CLK is for IP register clock, while IPG_PERCLK is for >> i2c function clock. >> >> if you run clock command from mx51evk, you will get: >> ... >> ipg clock : 66500000Hz >> ipg per clock : 665000000Hz >> MX51EVK U-Boot > >> >> It will give you that ipg per clock is 665M, which seems too big. It >> is due to we configure >> the pre-divider/pos-devider for perclk to zero, which leads to ipg_per >> clock to be same as pll2 clock. >> But I don't think this will have some issue. > > Yes it will, the divider will be computed to be maximum in all cases ... you > won't be able it divide 665MHz by anything from the table 40-7 in MX51RM to > achieve any reasonable frequency. > > On the contrary, 66.5MHz does give fine results.
it that, we can change the ipg_perclk to low freq, but we should not change the i2c clock to ipg_clk, this is not correct. > >> >> BTW, I have applied your patch and test on mx53evk board, it seems the >> i2c does not work correctly. > > Great. The clock used by the I2C module for this task are likely the > module_clock, which are -- like on MX51 -- 66.5MHz. What do you get when you > run > the "clock" command on MX53EVK ? I'm not in the office for the whole next week, thus, I can't give you the clock output for mx53evk, but I'm sure the ipg_perclk on mx53evk is not set at 66.5Mhz. Jason > > Thanks > >> After apply your patch: >> MX53EVK U-Boot > pmic dump 30 >> PMIC ID: 0x0000ffff [Rev: unknown] >> >> 0x00: 0001ffff 00ffffff 0039ffff 0000ffff 00ffffff 0000ffff 0000ffff >> 0000ffff 0x08: 0000ffff 0000ffff 0000ffff 0000ffff 0000ffff 0000ffff >> 0000ffff 0040ffff 0x10: 0000ffff 0000ffff 0000ffff 0000ffff 0000ffff >> 0001ffff 0000ffff 0000ffff 0x18: 0045ffff 0045ffff 0000ffff 0080ffff >> 0021ffff 0000ffff 0002ffff 0000ffff 0x20: 0004ffff 0000ffff 0021ffff >> 0000ffff 0000ffff 0000ffff 0000ffff 0000ffff 0x28: 0000ffff 0000ffff >> 0000ffff 0000ffff 0000ffff 0004ffff 0000ffff 00aeffff >> >> The old: >> MX53EVK U-Boot > pmic dump 30 >> PMIC ID: 0x000045d0 [Rev: 2.0] >> >> 0x00: 00015088 00ffffff 00395208 00000081 00fff7ff 0000401c 00000418 >> 000045d0 0x08: 00000000 00000000 00000001 00000000 00000000 00000040 >> 00000000 00400000 0x10: 00000000 00000000 00000000 00000000 00000011 >> 0001ffff 00000000 00007fff 0x18: 00454a52 00456739 0000631a 0080739c >> 0021284a 00000a0a 00024fd0 000001d8 0x20: 00049208 00000000 00218000 >> 00000000 00000000 00000000 00000000 00000000 0x28: 00000000 00000000 >> 00000000 00008000 00000000 00046046 000001c0 00aeeaee >> >> Jason > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
