Hi, Murali Nalajala a Ãcrit : > On 4/18/2011 1:02 PM, Matthieu CASTET wrote: >> Hi, >> >> Murali Nalajala a Ãcrit : >>> Add initial msm nand driver support for Qualcomm MSM platforms. >>> This driver is capable of handling both 2k and 4k page support >>> nand devices. >>> >>> This driver was originally developed by Arve HjÃnnevÃg at google. >>> Its source is available at >>> http://android.git.kernel.org/?p=kernel/msm.git under >>> android-msm-2.6.35 branch. >>> >>> CC: Dima Zavin<dima@xxxxxxxxxxx> >>> CC: Brian Swetland<swetland@xxxxxxxxxx> >>> CC: Arve HjÃnnevÃg<arve@xxxxxxxxxxx> >>> Signed-off-by: Murali Nalajala<mnalajal@xxxxxxxxxxxxxx> >>> --- >>> Changes in V2 >>> * Turn most of the pr_info() calls into pr_debug(). >>> >>> drivers/mtd/devices/Kconfig | 11 + >>> drivers/mtd/devices/Makefile | 1 + >>> drivers/mtd/devices/msm_nand.c | 1597 ++++++++++++++++++++++++++++++++++++++++ >>> drivers/mtd/devices/msm_nand.h | 77 ++ >>> 4 files changed, 1686 insertions(+), 0 deletions(-) >>> create mode 100644 drivers/mtd/devices/msm_nand.c >>> create mode 100644 drivers/mtd/devices/msm_nand.h >>> >> For the record, I am not sure it is a great idea to make nand drivers >> independent of the nand layer. >> By doing that you could change the expected behavior, and introduce bug >> difficult to debug. >> >> Why do you need that ? Nand drivers can override callbacks of nand framework. >> >> Maybe because the nand layer call the driver page per page, and you want to >> work with more than one page. But in this case you can extend nand layer. >> >> Or does your controller don't allow sending raw command ? >> And in that case all the nand logic is in the nand controller ? > > Our controller doesn't allow sending RAW commands to the flash. All > these commands are abstracted by the controller logic. Please refer the > msm_nand.h file where you will find the commands which are different > from the actual NAND device commands. Ok, but does the controller does all other check : status check, ... In the nand framework there is already controller like yours : see the denali.c as example. > > eg: To send read/write data command to the device we configure the > controller with page address & controller specific command. Then the > controller itself takes care of generating the internal h/w signals > required by the flash and it polls for the R/B signal & wait states are > internally controlled by the h/w. > So you provide your own chip->ecc.read_page chip->ecc.read_page_raw chip->ecc.read_oob chip->write_page chip->ecc.write_oob and your done. Matthieu -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
