Hi Jacopo, On Wed, Oct 4, 2017 at 5:40 PM, Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> wrote: > The system clock described by extal_clk is reported to have a frequency > of 13.333 Mhz and is correctly described by gr-peach device tree. > > However, when enabling a RIIC device the following error is reported by > drivers/i2c/busses/i2c-riic.c > > "invalid parent clk (33332500). Must be 33325000Hz" > > As RIIC devices have a clock source obtained by dividing by 12 the > system clock, the resulting value is not accepted by the driver > (which clearly states not to support any frequency except the reported > 33325000Hz one). > > Hence, reduce the system clock accuracy to a value which makes > frequencies obtained through division accepted by RIIC driver. > > Please note that other r7s72100 boards, such as Genmai, report the same > "reduced accuracy" frequency, even if their external clock sources are > effectively 13.333Mhz as gr-peach one. > > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> There's no need to do this, Chris already proposed a fix, cfr. "[PATCH v2] i2c: riic: remove fixed clock restriction" (https://www.spinics.net/lists/linux-renesas-soc/msg18573.html). Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds