Re: [PATCH 0/8] Add TI EMIF SDRAM controller driver

From: Santosh Shilimkar
Date: Mon Mar 12 2012 - 11:58:34 EST


On Thursday 08 March 2012 09:24 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 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@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.
> - Tested the driver as a module
>
> Cc: Greg KH <greg@xxxxxxxxx>
>
> Aneesh V (7):
> misc: ddr: add LPDDR2 data from JESD209-2
> misc: emif: add register definitions for EMIF
> misc: emif: add basic infrastructure for EMIF driver
> misc: emif: handle frequency and voltage change events
> misc: emif: add interrupt and temperature handling
> misc: emif: add one-time settings
> misc: emif: add debugfs entries for emif
>
I have scanned all the patches again. Thanks a
lot for taking forward this work. Feel free to
add mine SOB for entire EMIF driver series.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>

Regards
Santosh
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