From: maxime.ripard@free-electrons•com (Maxime Ripard)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM:MXS: Initial support for the Crystalfontz CFA-10036
Date: Thu, 21 Jun 2012 16:22:41 +0200 [thread overview]
Message-ID: <4FE32E31.2070909@free-electrons.com> (raw)
In-Reply-To: <20120621131138.GA21418@S2101-09.ap.freescale.net>
Hi Shawn,
Le 21/06/2012 15:11, Shawn Guo a ?crit :
> On Thu, Jun 21, 2012 at 10:46:52AM +0200, Maxime Ripard wrote:
>> On the MMC part though, Something odd is going on. On the first
>> patches I made against 3.4, everything was working fine. With 3.5-rc2
>> though, the MMC never replies to the first CMD52 command sent to
>> it. The pin muxing hasn't changed and has been checked, the card is
>> well detected through the card detect pin, the power enable pin is
>> correctly set to a low level, and so the SD card is correctly
>> powered. The MMC works fine with the exact same kernel on the
>> imx28-evk though.
>>
>> What seems odd to me, is that when booting the board with the 3.4
>> kernel, at boot, the mxs-mmc driver reports a SSP clock of 288MHz,
>> while on 3.5, it reports a 480MHz SSP clock. By looking at the clk
>> driver for the iMX28, there is a comment saying that the 480MHz clock
>> seems to high for SD controlers, and that it should be 288MHz
>> instead. Given that the clock part has changed quite a lot from 3.4 to
>> 3.5, I think it might be a good lead, but hardcoding the SSP clock to
>> 288MHz in the mxs-mmc driver instead of using the clk_get_rate
>> function does not resolve the problem.
>>
>> Also, this problem is seen with both DT-probing and traditionnal
>> probing.
>>
>> Do someone have an idea on what could possibly happen here ?
>>
> Can you try the change below to see if it fixes the problem?
It is indeed working now, thanks a lot :)
I've also tested it on the imx28evk, and it works as well.
You can add by Tested-by I guess :)
We have found that indeed the two registers were inverted compared to
the datasheet, but why was it still working on the iMX28-evk ?
Thanks again,
Maxime
--
Maxime Ripard, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
next prev parent reply other threads:[~2012-06-21 14:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-21 8:46 [PATCH] ARM:MXS: Initial support for the Crystalfontz CFA-10036 Maxime Ripard
2012-06-21 8:46 ` [PATCH 1/2] Early support for the Crystalfontz CFA10036 module Maxime Ripard
2012-06-21 9:47 ` Marek Vasut
2012-06-21 8:46 ` [PATCH 2/2] ARM: MXS: Add Crystalfontz CFA-10036 DTS Maxime Ripard
2012-06-21 9:49 ` Marek Vasut
2012-06-21 10:12 ` Maxime Ripard
2012-06-21 11:01 ` Marek Vasut
2012-06-21 13:29 ` Shawn Guo
2012-06-21 13:11 ` [PATCH] ARM:MXS: Initial support for the Crystalfontz CFA-10036 Shawn Guo
2012-06-21 14:22 ` Maxime Ripard [this message]
2012-06-22 2:12 ` Shawn Guo
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