[PATCH v5 0/7] Add TI EMIF SDRAM controller driver

Greg KH gregkh at linuxfoundation.org
Wed May 2 14:03:22 EDT 2012


On Wed, May 02, 2012 at 12:20:24PM +0530, Santosh Shilimkar wrote:
> Greg,
> 
> On Wednesday 02 May 2012 10:46 AM, Greg KH wrote:
> > On Fri, Apr 27, 2012 at 05:54:02PM +0530, Santosh Shilimkar wrote:
> >> Add a driver for the EMIF SDRAM controller used in Texas Instrument 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 Dynamic Voltage and Frequency Scaling (DVFS).
> >> This can not be done now as DVFS support is not available in
> >> the mainline yet.
> >>
> >> Discussions with Santosh Shilimkar <santosh.shilimkar at ti.com>
> >> were immensely helpful in shaping up the interfaces. Vibhore Vardhan
> >> <vvardhan at gmail.com> 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.
> >> - Tested the driver as a module
> >>
> >> Cc: Greg KH <greg at kroah.com>
> > 
> > This all looks good to me now, thanks for reworking this.
> > 
> > So, do you want me to take this through my "driver" tree to get to Linus
> > for 3.5, or do you want it to go through somewhere else?
> > 
> > If somewhere else, that's fine with me, consider this an:
> > 	Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> > 
> > If you want me to take it, just let me know, whichever you prefer is
> > fine with me.
> > 
> Can you take this one through your 3.5 driver tree please ?
> Thanks for help.

Ok, all now applied.

greg k-h



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