Hi Elaine, Am Mittwoch, 3. April 2019, 11:42:24 CEST schrieb Elaine Zhang: > From: Finley Xiao <[email protected]> > > From Rockchips fractional divider usage, some clocks can be generated > by fractional divider, but the input clock frequency of fractional > divider should be less than a specified value. > > Signed-off-by: Finley Xiao <[email protected]> > Signed-off-by: Elaine Zhang <[email protected]>
can you tell me where these maximum input values come from? I talked to Christoph from Theobroma (Cc'ed) last week and he mentioned that they're using the fractional divider with a higher input frequency to create a very specific frequency [some details are gone from my memory though] they can't get otherwise. So I really don't want to break their working setup by introducing barriers that are not strictly necessary. @Christoph: can you describe the bits from your fractional setup that I've forgotten please? Thanks Heiko > diff --git a/drivers/clk/rockchip/clk-px30.c b/drivers/clk/rockchip/clk-px30.c > index 601a77f1af78..ccabce35580b 100644 > --- a/drivers/clk/rockchip/clk-px30.c > +++ b/drivers/clk/rockchip/clk-px30.c > @@ -21,6 +21,7 @@ > #include "clk.h" > > #define PX30_GRF_SOC_STATUS0 0x480 > +#define PX30_FRAC_MAX_PRATE 600000000 > diff --git a/drivers/clk/rockchip/clk-rk3368.c > b/drivers/clk/rockchip/clk-rk3368.c > index 7c4d242f19c1..67c2da5e7d61 100644 > --- a/drivers/clk/rockchip/clk-rk3368.c > +++ b/drivers/clk/rockchip/clk-rk3368.c > @@ -20,6 +20,9 @@ > #include "clk.h" > > #define RK3368_GRF_SOC_STATUS0 0x480 > +#define RK3368_I2S_FRAC_MAX_PRATE 600000000 > +#define RK3368_UART_FRAC_MAX_PRATE 600000000 > +#define RK3368_SPDIF_FRAC_MAX_PRATE 600000000 > diff --git a/drivers/clk/rockchip/clk-rk3399.c > b/drivers/clk/rockchip/clk-rk3399.c > index 5a628148f3f0..1d81382bd3e0 100644 > --- a/drivers/clk/rockchip/clk-rk3399.c > +++ b/drivers/clk/rockchip/clk-rk3399.c > @@ -21,6 +21,12 @@ > #include <dt-bindings/clock/rk3399-cru.h> > #include "clk.h" > > +#define RK3399_I2S_FRAC_MAX_PRATE 600000000 > +#define RK3399_UART_FRAC_MAX_PRATE 600000000 > +#define RK3399_SPDIF_FRAC_MAX_PRATE 600000000 > +#define RK3399_VOP_FRAC_MAX_PRATE 600000000 > +#define RK3399_WIFI_FRAC_MAX_PRATE 600000000 > +
