Hi, On 3/17/12, Aneesh V <aneesh@xxxxxx> 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. Do you see the devfreq? it's designed for non-cpu device frequency. It's role is similar with cpufreq. Now samsung exynos uses devfreq for DRAM bus frequency. Thank you, Kyungmin Park > > 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> > > v4: > - Converted instances of EXPORT_SYMBOL to EXPORT_SYMBOL_GPL > - Removed un-necessary "#ifndef __ASSEMBLY__' > - Minor formatting fix > > v2: > - Fixed a bug found in the implementation of errata i728 > workaround > - Fixed the value of frequency printed in debugfs > - Dropped the hwmod patch as Paul has already posted a > a hwmod series [1] that adds hwmod for EMIF > - Converted instances of __init to __init_or_module > > [1] http://thread.gmane.org/gmane.linux.ports.arm.omap/72855 > > 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 > > Documentation/misc-devices/ti-emif.txt | 58 ++ > drivers/misc/Kconfig | 12 + > drivers/misc/Makefile | 1 + > drivers/misc/emif.c | 1670 > +++++++++++++++++++++++++++++++ > drivers/misc/emif.h | 589 +++++++++++ > include/linux/platform_data/emif_plat.h | 128 +++ > include/misc/jedec_ddr.h | 175 ++++ > lib/Kconfig | 8 + > lib/Makefile | 2 + > lib/jedec_ddr_data.c | 135 +++ > 10 files changed, 2778 insertions(+), 0 deletions(-) > create mode 100644 Documentation/misc-devices/ti-emif.txt > create mode 100644 drivers/misc/emif.c > create mode 100644 drivers/misc/emif.h > create mode 100644 include/linux/platform_data/emif_plat.h > create mode 100644 include/misc/jedec_ddr.h > create mode 100644 lib/jedec_ddr_data.c > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- 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
