Hi Przemyslaw,
Thanks for the documents suggested by you. Now I understand better the
SDHCI controller implementations. The U-boot version I'm using the
downloaded from
https://github.com/hardkernel/u-boot/commits/odroid-v2010.12. From where
I can download the version you're fixing?
Thank you very much for your collaboration.
Humberto
On 10/01/2015 07:24 AM, Przemyslaw Marczak wrote:
Hello Humberto,
On 09/28/2015 03:27 PM, Humberto López León wrote:
Hi Przemyslaw,
With the information you gave me I managed to implement an important
part of SDHCI controller. Currently the driver detects the SD card
correctly but I have a problem with writing operations. With the help of
linux command dd I found that the driver reads correctly but fails when
trying to write. I studied implementations of SDHCI controller in the
Linux kernel and the U-boot, but there are things I do not understand.
You have a document that explains how works the SDHCI controller ?
Please register at Jedec.org, and get this:
https://www.jedec.org/standards-documents/results/JESD84-B451
for eMMC 4.51, there are also older versions.
For SD card:
https://www.sdcard.org/downloads/pls/index.html
Try to find: SDCardStandardv1.9.pdf on the internet :)
I've also been working on the implementation of DWMMC controller to
manage the eMMC in ODROID-X2 (Exynos4412). Currently this driver detects
the eMMC card but fails to calculate the capacity of the card. The read
and write operations are not yet implemented.
You have a document that explains how works the DWMMC controller?
Thank you for your help!!
Humberto
Which U-Boot version do you use? There was an issue in the mainline
with device-tree, which results in eMMC/SD card detection issue.
I think, that in few days my patches with fixes can be merged.
On 08/27/2015 02:47 AM, Przemyslaw Marczak wrote:
Hi Humberto,
On 08/26/2015 07:24 PM, Humberto López León wrote:
Hi Przemyslaw,
On 08/26/2015 10:12 AM, Przemyslaw Marczak wrote:
Hi Humberto,
On 08/26/2015 03:40 PM, Humberto López León wrote:
Hi community,
thank you all for answering my questions.
On 08/26/2015 02:53 AM, Przemyslaw Marczak wrote:
Hi,
On 08/26/2015 08:23 AM, Jaehoon Chung wrote:
On 08/26/2015 11:26 AM, Simon Glass wrote:
+Samsung people
Hi,
On 25 August 2015 at 13:10, Humberto López León
<humbe...@uclv.cu>
wrote:
Hi Simon,
I'm working on implementing a driver for SD/MMC cards in the
framework
GenodeOS. I think you could help me with your experience in this
type of
implementation in the u-boot.
The hardware platform on which the driver will work is a
ODROID-x2
(exynos4412). I use the DWMMC contoller, but I'm not sure if
this
is the
right controller to handle SD/MMC cards in Exynos4412 SoC. The
SDHCI
controller is most appropriate?
If you're using exynos4412 board, you can choose sdhci or dwmmc
controller for eMMC, not SD/SDIO.
And in my experiment, dwmmc controller is more appropriate than
sdhci.(ex, performance)
It depends which mmc channel is used. In Exynos4412, there are 5
channels, but some channel configurations shares GPIO pins:
- MMC0 - sdhci
- MMC1 - sdhci, or MMC0 8-bit
- MMC2 - sdhci - Odroid SD card, 4-bit mode
- MMC3 - sdhci - or MMC2 8-bit
- MMC4 - dwmmc, uses MMC0 pins for 4-bit, and MMC0-1 for 8-bit mode
Odroid is using MMC2(sdhci) and MMC0/4(sdhci or dwmmc).
So for eMMC cards you can use the dwmmc, and as Jaehoon wrote it is
recommended for the better performance, but for SD card you must
use
sdhci controller.
This information is valuable to me, but now I would help if you
tell me
where I can find the code of SDHCI controller for the SD card of
Exynos4412 in U-boat 2015.04-rc2 for a implementationtation
reference. I
was reviewing the file exynos_dw_mmc.c as reference of DWMMC
driver,
but now I have no idea what the file where the SDHCI driver for the
exynos4412 is implemented.
Thank you very much for your collaboration.
Please check those files:
- drivers/mmc/s5p_sdhci.c
- drivers/mmc/sdhci.c
But, isn't the kernel a better reference for you?
Thanks for your time to answer my questions. I have reviewed the
implementation of SDHCI controller in the Linux kernel for Odroid
(https://github.com/hardkernel/linux/blob/odroid-3.0.y/), but have not
been able to identify the specific implementation that is used for
handling of SD cards in exynos4412.
You know in what file this controller is implemented? I think the
file
should be drivers/mmc/host/sdhci-s3c.c
(https://github.com/hardkernel/linux/blob/odroid-3.0.y/drivers/mmc/host/sdhci-s3c.c)
but I'm not sure.
What do you think?
Thanks again.
Humberto
Yes, this is the right file. Also remember about the pinmux setting
for sd/mmc.
In U-Boot: arch/arm/mach-exynos/pinmux.c
In kernel: drivers/pinctrl/pinctrl-exynos.c
Best regards,
Best regards,
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