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

Shilimkar, Santosh santosh.shilimkar at ti.com
Thu May 3 02:15:37 EDT 2012


On Wed, May 2, 2012 at 11:33 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
> 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.
>
Thanks !!

Regards
Santosh



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