Messages in this thread | | | Date | Tue, 3 Apr 2012 10:11:12 -0700 | From | Chris Wright <> | Subject | Re: [PATCH-v3] Support M95040 SPI EEPROM |
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* Wolfram Sang (w.sang@pengutronix.de) wrote: > On Tue, Apr 03, 2012 at 09:53:20AM -0700, Chris Wright wrote: > > * Ivo Sieben (meltedpianoman@gmail.com) wrote: > > > + instr = AT25_READ; > > > + if (at25->chip.flags & EE_INSTR_BIT3_IS_ADDR) > > > + if (offset >= (1U << (at25->addrlen * 8))) > > > + instr |= AT25_INSTR_BIT3; > > > + *cp++ = instr; > > <snip> > > > + /* > > > + * Certain EEPROMS have a size that is larger than the number of address > > > + * bytes would allow (e.g. like M95040 from ST that has 512 Byte size > > > + * but uses only one address byte (A0 to A7) for addressing.) For > > > + * the extra address bit (A8, A16 or A24) bit 3 of the instruction byte > > > + * is used. This instruction bit is normally defined as don't care for > > > + * other AT25 like chips. > > > + */ > > > +#define EE_INSTR_BIT3_IS_ADDR 0x0010 > > > > Is there some guarantee that this chip flag will always have this > > meaning? > > ? This is a driver flag.
Sorry, I don't see it set anywhere, so unclear on where it comes from. I thought it was from a generic spi probe.
thanks, -chris
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