| Message ID | 20210917065436.145629-4-chanho61.park@samsung.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | introduce exynosauto v9 ufs driver | expand |
Hi Chanho, 21. 9. 17. 오후 3:54에 Chanho Park 이(가) 쓴 글: > To support 167MHz PCLK, we need to adjust the maximum value. > > Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com> > Signed-off-by: Chanho Park <chanho61.park@samsung.com> > --- > drivers/scsi/ufs/ufs-exynos.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/ufs/ufs-exynos.h b/drivers/scsi/ufs/ufs-exynos.h > index dadf4fd10dd8..0a31f77a5f48 100644 > --- a/drivers/scsi/ufs/ufs-exynos.h > +++ b/drivers/scsi/ufs/ufs-exynos.h > @@ -99,7 +99,7 @@ struct exynos_ufs; > #define PA_HIBERN8TIME_VAL 0x20 > > #define PCLK_AVAIL_MIN 70000000 > -#define PCLK_AVAIL_MAX 133000000 > +#define PCLK_AVAIL_MAX 167000000 > I'm not sure but doesn't the maximum clock frequency depend on a given machine? Is it true for all machines using different SoC? Thanks, Inki Dae > struct exynos_ufs_uic_attr { > /* TX Attributes */ >
> > #define PCLK_AVAIL_MIN 70000000 > > -#define PCLK_AVAIL_MAX 133000000 > > +#define PCLK_AVAIL_MAX 167000000 > > > > I'm not sure but doesn't the maximum clock frequency depend on a given > machine? Is it true for all machines using different SoC? Regarding pclk(sclk_unipro)of the ufs, it can be defined by mux(MUX_CLK_FSYS2_UFS_EMBD). It can be either 167MHz or 160MHz. And it can be defined by OSCCLK(26MHz) as well. The value was up to 133Mhz in case of exynos7 but can be extended up to 167MHz for later SoCs, AFAIK. Best Regards, Chanho Park
21. 9. 27. 오후 3:46에 Chanho Park 이(가) 쓴 글: >>> #define PCLK_AVAIL_MIN 70000000 >>> -#define PCLK_AVAIL_MAX 133000000 >>> +#define PCLK_AVAIL_MAX 167000000 >>> >> >> I'm not sure but doesn't the maximum clock frequency depend on a given >> machine? Is it true for all machines using different SoC? > > Regarding pclk(sclk_unipro)of the ufs, it can be defined by mux(MUX_CLK_FSYS2_UFS_EMBD). > It can be either 167MHz or 160MHz. And it can be defined by OSCCLK(26MHz) as well. The value was up to 133Mhz in case of exynos7 but can be extended up to 167MHz for later SoCs, AFAIK. Oscillator clock frequency could be different according to machine. And what if UFS driver is enabled for other machine using Exynos7? Is it true to use a fixed 167MHz frequency for these machines? I think you could get a proper pclk frequency from device tree specific to machine. Thanks, Inki Dae > > Best Regards, > Chanho Park > >
> >>> #define PCLK_AVAIL_MIN 70000000 > >>> -#define PCLK_AVAIL_MAX 133000000 > >>> +#define PCLK_AVAIL_MAX 167000000 > >>> > >> > >> I'm not sure but doesn't the maximum clock frequency depend on a > >> given machine? Is it true for all machines using different SoC? > > > > Regarding pclk(sclk_unipro)of the ufs, it can be defined by > mux(MUX_CLK_FSYS2_UFS_EMBD). > > It can be either 167MHz or 160MHz. And it can be defined by OSCCLK(26MHz) > as well. The value was up to 133Mhz in case of exynos7 but can be extended > up to 167MHz for later SoCs, AFAIK. > > Oscillator clock frequency could be different according to machine. And > what if UFS driver is enabled for other machine using Exynos7? Is it true > to use a fixed 167MHz frequency for these machines? > I think you could get a proper pclk frequency from device tree specific to > machine. The actual pclk value will be get by CCF's clk_get_rate. PCLK_AVAIL_MAX represents the available maximum value of UFS's pclk to find an optimal value of unipro clock. I just extend the maximum pclk rate from 133MHz to 167MHz. The divider will be calculated according to the actual pclk value :) [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/scsi/ufs/ufs-exynos.c?h=v5.15-rc3#n287 Best Regards, Chanho Park
21. 9. 27. 오후 8:08에 Chanho Park 이(가) 쓴 글: >>>>> #define PCLK_AVAIL_MIN 70000000 >>>>> -#define PCLK_AVAIL_MAX 133000000 >>>>> +#define PCLK_AVAIL_MAX 167000000 >>>>> >>>> >>>> I'm not sure but doesn't the maximum clock frequency depend on a >>>> given machine? Is it true for all machines using different SoC? >>> >>> Regarding pclk(sclk_unipro)of the ufs, it can be defined by >> mux(MUX_CLK_FSYS2_UFS_EMBD). >>> It can be either 167MHz or 160MHz. And it can be defined by OSCCLK(26MHz) >> as well. The value was up to 133Mhz in case of exynos7 but can be extended >> up to 167MHz for later SoCs, AFAIK. >> >> Oscillator clock frequency could be different according to machine. And >> what if UFS driver is enabled for other machine using Exynos7? Is it true >> to use a fixed 167MHz frequency for these machines? >> I think you could get a proper pclk frequency from device tree specific to >> machine. > > The actual pclk value will be get by CCF's clk_get_rate. PCLK_AVAIL_MAX represents the available maximum value of UFS's pclk to find an optimal value of unipro clock. I just extend the maximum pclk rate from 133MHz to 167MHz. The divider will be calculated according to the actual pclk value :) > > [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/scsi/ufs/ufs-exynos.c?h=v5.15-rc3#n287 > Thanks for the link. I thought only PCLK_AVAIL_MAX is valid but it means available maximum clock so clock frequency between the min and max would be allowed as well. :) Reviewed-by : Inki Dae <inki.dae@samsung.com> Thanks, Inki Dae > Best Regards, > Chanho Park > >
diff --git a/drivers/scsi/ufs/ufs-exynos.h b/drivers/scsi/ufs/ufs-exynos.h index dadf4fd10dd8..0a31f77a5f48 100644 --- a/drivers/scsi/ufs/ufs-exynos.h +++ b/drivers/scsi/ufs/ufs-exynos.h @@ -99,7 +99,7 @@ struct exynos_ufs; #define PA_HIBERN8TIME_VAL 0x20 #define PCLK_AVAIL_MIN 70000000 -#define PCLK_AVAIL_MAX 133000000 +#define PCLK_AVAIL_MAX 167000000 struct exynos_ufs_uic_attr { /* TX Attributes */