Re: [PATCH v4] i2c: designware: Do not require clock when SSCN and FFCN are provided

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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@xxxxxxxxxxxxxxx>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
Tested-by: Loc Ho <lho@xxxxxxx>
---

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@xxxxxxx>

-Loc


Thanks Loc,

Suravee
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux IBM ACPI]     [Linux Power Management]     [Linux Kernel]     [Linux Laptop]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux