From: Roland Stigge <stigge-uj/7R2tJ6VmzQB+pC5nmwQ@public.gmane.org>
To: "linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Cc: gsi-ynQEQJNshbs@public.gmane.org,
agust-ynQEQJNshbs@public.gmane.org,
Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
Subject: i2c-mpc.c clock/speed
Date: Wed, 05 Mar 2014 10:29:28 +0100 [thread overview]
Message-ID: <5316EE78.2080808@antcom.de> (raw)
Hi,
in mpc_i2c_get_fdr_8xxx(), we have:
...
if (of_device_is_compatible(node, "fsl,mpc8544-i2c"))
prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2;
if (!prescaler)
prescaler = 1;
...
By restricting to "fsl,mpc8544-i2c", measured I2C speed on fsl p2020 is
only half as fast as configured (w/ prescaler = 1).
In DT (arch/powerpc/boot/dts/fsl/pq3-i2c-0.dtsi), we have "fsl-i2c"
(i.e., generic), for Freescale boards.
What would be the best solution here? Additional "compatible" strings,
e.g. "fsl,p1020-i2c" and adjusting i2c-mpc.c and DT? Or removing the
restriction to "fsl,mpc8544-i2c", i.e. calling
mpc_i2c_get_sec_cfg_8xxx() unconditionally?
Thanks in advance,
Roland.
next reply other threads:[~2014-03-05 9:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 9:29 Roland Stigge [this message]
[not found] ` <5316EE78.2080808-uj/7R2tJ6VmzQB+pC5nmwQ@public.gmane.org>
2014-03-05 17:00 ` i2c-mpc.c clock/speed Anatolij Gustschin
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