Messages in this thread | | | Subject | Re: [PATCH v4] i2c: designware: Do not require clock when SSCN and FFCN are provided | From | Suravee Suthikulpanit <> | Date | Wed, 6 Jan 2016 23:05:14 -0600 |
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Hi,
On 01/06/2016 06:31 PM, Loc Ho wrote: > Hi All, > >>> The current driver uses input clock source frequency to calculate >>> values for [SS|FS]_[HC|LC] registers. However, when booting ACPI, we do not >>> currently have a good way to provide the frequency information. >>> Instead, we can leverage the SSCN and FFCN ACPI methods, which can be used >>> to directly provide these values. So, the clock information should >>> no longer be required during probing. >>> >>> However, since clk can be invalid, additional checks must be done where >>> we are making use of it. >>> >>> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> >>> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> >>> Tested-by: Loc Ho <lho@apm.com> >>> --- >>> >>> Note: This has been tested on AMD Seattle RevB for both DT and ACPI. >>> >>> Changes from V3 (https://lkml.org/lkml/2015/12/22/596): >>> * Add i2c_dw_plat_prepare_clk() per Andy's suggestion >>> * Add tested-by Loc Ho. >> >> The changes from V3 are big enough that I'd appreciate a new Tested-by >> tag. > > I had tested this via this mixes of test cases: > > a. NO APD driver + this patch ==> HCNT/LCNT as expected > b. with APD driver + this patch ==> HCNT/LCNT as expected > c. with APD driver + this patch + double the frequency APD driver ==> > HCNT/LCNT as expected > d. with APD driver + this patch + double the frequency APD driver + > comment out the ACPI parameter retrieve ==> HCNT/LCNT changed as > expected > > Therefore, you can add my - Tested-by: Loc Ho <lho@apm.com> > > -Loc >
Thanks Loc,
Suravee
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