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 >>> humberto@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...)
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,