From: chin.yew.tan@intel.com
To: jarkko.nikula@linux.intel.com, andriy.shevchenko@linux.intel.com,
mika.westerberg@linux.intel.com
Cc: linux-i2c@vger.kernel.org
Subject: [PATCH] Set sda-hold-time based on ACPI *CNT value
Date: Fri, 10 Feb 2017 19:15:35 +0800 [thread overview]
Message-ID: <1486725336-19405-1-git-send-email-chin.yew.tan@intel.com> (raw)
From: Tan Chin Yew <chin.yew.tan@intel.com>
For I2c to operate correctly under all speed mode, sda-hold-time need to
be perfectly tuned. However, sda-hold-time is precalculated according to
circuit parameter which make it platform-specific.
In order to get accurate sda-hold-time for all platforms, pretuned
sda-hold-time for particular platform is stored in ACPI table and driver
to load the sda holding time from ACPI table.
This patch read the I2c sda-hold-time from ACPI table and assigned the
suitable hold time based on the i2c clock frequency.
Tested on Intel Apollo Lake.
Tan Chin Yew (1):
i2c: designware: Get selected speed mode sda-hold-time via ACPI
drivers/i2c/busses/i2c-designware-platdrv.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
--
1.9.1
next reply other threads:[~2017-02-10 11:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-10 11:15 chin.yew.tan [this message]
-- strict thread matches above, loose matches on Subject: below --
2017-02-10 11:28 [PATCH] Set sda-hold-time based on ACPI *CNT value chin.yew.tan
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