We can either map CS_PIN to GPIO in bfin SPI driver or remove CS from bfin SPI driver completely.
Which do you prefer? Sonic -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Cai, Cliff Sent: Monday, November 30, 2009 12:06 PM To: Mike Frysinger Cc: [email protected] Subject: Re: [Linux-kernel-commits] [7883]trunk/drivers/spi/bfin_sport_spi.c: bug[#5722] use the newgpio cs scheme >> If we don't use GPIO as CS, then SPORT can provide >cs-change-per-word kind of CS. >> And we can't control it.I will add the comments in the driver. > >to be frank, such CS functionality is currently (and for the >foreseeable future) completely useless. the common SPI framework does >not support toggling the cs per-word, only per-transaction. adding >support to the bus master when nothing out there wants it sounds like >bloat to me. we should only accept GPIO CS's with the SPORT/SPI >driver. Yes, the spi spec doesn't mention this scheme. I also think our spi controller should use GPIO as CS as well. Since I don't see essential difference between GPIO CS and internal CS, While there are some problems with internal CS,such as cs-change-per-word in some modes. Any thoughs? Cliff. _______________________________________________ Linux-kernel-commits mailing list [email protected] https://blackfin.uclinux.org/mailman/listinfo/linux-kernel-commits _______________________________________________ Linux-kernel-commits mailing list [email protected] https://blackfin.uclinux.org/mailman/listinfo/linux-kernel-commits
