Messages in this thread | | | Date | Thu, 15 Dec 2005 13:28:47 +0000 | From | Russell King <> | Subject | Re: [patch 1/5] [RFC] Add MMC password protection (lock/unlock) support |
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On Wed, Dec 14, 2005 at 09:30:49AM -0400, Anderson Briglia wrote: > @@ -69,12 +70,16 @@ struct mmc_card { > #define mmc_card_bad(c) ((c)->state & MMC_STATE_BAD) > #define mmc_card_sd(c) ((c)->state & MMC_STATE_SDCARD) > #define mmc_card_readonly(c) ((c)->state & MMC_STATE_READONLY) > +#define mmc_card_locked(c) ((c)->state & MMC_STATE_LOCKED) > + > +#define mmc_card_lockable(c) ((c)->csd.cmdclass & CCC_LOCK_CARD)
Looking at some of the MMC specs, this is not sufficient to tell whether the card supports the lock/unlock commands - eg, the Sandisk cards have a CCC value of 0x1ff but do not appear to support CMD42.
It would appear that there are different definitions for command classes 6 to 8:
command group: A B 6 write write-protection write protection 7 read write-protection lock card 8 erase write-protection app. specific
What the interpretation of whether A or B applies is unclear. Type A cards have CSD structure 1 and MMC protocol version code 1. Type B cards have CSD structure 2 and MMC protocol version code 3.
It would appear that the "CSD structure" field describes the version of the CSD structure itself, and in part determines the validity of the MMC protocol version field (maybe defining the mapping of version codes to MMC spec versions). Sandisk implies that CSD structure 1 has version codes 0=v1.0-v1.2, 1=v1.4.
CSD structure 2 we have less idea about the interpretation of the MMC protocol version codes, except that 3 may mean MMC spec v3.1.
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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