On Thu, Feb 16, 2012 at 04:21:11PM +0530, Santosh Shilimkar wrote: > Andrew, Greg, > > On Saturday 04 February 2012 05:46 PM, Aneesh V wrote: > > Add a driver for the EMIF SDRAM controller used in TI SoCs > > > > EMIF is an SDRAM controller that supports, based on its revision, > > one or more of LPDDR2/DDR2/DDR3 protocols.This driver adds support > > for LPDDR2. > > > > The driver supports the following features: > > - Calculates the DDR AC timing parameters to be set in EMIF > > registers using data from the device data-sheets and based > > on the DDR frequency. If data from data-sheets is not available > > default timing values from the JEDEC spec are used. These > > will be safe, but not necessarily optimal > > - API for changing timings during DVFS or at boot-up > > - Temperature alert configuration and handling of temperature > > alerts, if any for LPDDR2 devices > > * temperature alert is based on periodic polling of MR4 mode > > register in DDR devices automatically performed by hardware > > * timings are de-rated and brought back to nominal when > > temperature raises and falls respectively > > - Cache of calculated register values to avoid re-calculating > > them > > > > The driver will need some minor updates when it is eventually > > integrated with DVFS. This can not be done now as DVFS support > > is not available yet in mainline. > > > > Discussions with Santosh Shilimkar <santosh.shilimkar@xxxxxx> > > were immensely helpful in shaping up the interfaces. Vibhore Vardhan > > <vvardhan@xxxxxxxxx> did the initial code snippet for thermal > > handling. > > > > Testing: > > - The driver is tested on OMAP4430 SDP. > > - The driver in a slightly adapted form is also tested on OMAP5. > > - Since mainline kernel doesn't have DVFS support yet, > > testing was done using a test module. > > - Temperature alert handling was tested with simulated interrupts > > and faked temperature values as testing all cases in real-life > > scenarios is difficult. > > > [...] > > > arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 110 ++ > > drivers/misc/Kconfig | 20 + > > drivers/misc/Makefile | 2 + > > drivers/misc/emif.c | 1522 ++++++++++++++++++++++++++++ > > drivers/misc/emif_regs.h | 461 +++++++++ > > drivers/misc/jedec_ddr_data.c | 141 +++ > > include/linux/emif.h | 257 +++++ > > include/linux/jedec_ddr.h | 174 ++++ > > Any suggestion on where this driver can reside. It's a memory > controller driver which supports standard DDR functionality > as per JDEC specs including thermal alert. On top of > that it does support DVFS using the TI PRCM IP block. I don't know what any of those TLA words mean, so I really can't suggest where this code should go. But just from this diffstat, it looks like you are creating a new user/kernel interface, without documenting it anywhere, which isn't ok. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
