eSDHC controller driver on MPC8308rdb

Maria Johansen m.johansen at no.parkairsystems.com
Tue Oct 19 18:26:52 EST 2010



>-----Original Message-----
>From: Tonyliu [mailto:Bo.Liu at windriver.com] 
><snip>
>> Could this be a problem related the eSDHC controller (or the driver), 
>> or is it the memory card? (a 4GB SanDisk Extreme SDHC card, which unfortunately is the only card I have available at the moment.) I will keep digging into drivers/mmc/host/sdhci.c in search of a solution, and any tips to how I should proceed would be greatly appreciated!
>>   
>Hi,
>Try the patch in attatchment. By default, on some e300 platforms such as mpc8308_rdb, the entry "clock-frequency" of section sdchi in DTB is not fixed by u-boot, so has to >caculate the input clock for sdhci controller explicitly in driver.
>
>Tony

Thanks, the missing clock-frequency was part of my problem. The rest was solved by adding some more quirks to the esdhc-driver (SDHCI_QUIRK_FORCE_1_BIT_DATA and SDHCI_QUIRK_RESET_AFTER_REQUEST). Why it is necessary to force 1-bit data transfers I am a bit unsure about, since the mpc8308 reference manual clearly states that 4-bit transfers are supported.

Thanks for your help :)

--
Maria






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