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

Greg KH gregkh at linuxfoundation.org
Wed May 2 01:16:23 EDT 2012


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.

thanks,

greg k-h



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