This change adds the use of devfreq based clock scaling to MMC. This applicable for eMMC and SDCard. For some workloads, such as video playback, it isn't necessary for these cards to run at high speed. Running at lower frequency, in such cases can still meet the deadlines for data transfers. Scaling down the clock frequency dynamically has power savings not only because the bus is running at lower frequency but also has an advantage of scaling down the system core voltage, if supported. Provide an ondemand clock scaling support similar to the cpufreq ondemand governor having two thresholds, up_threshold and down_threshold to decide whether to increase the frequency or scale it down respectively as per load. Ram Prakash Gupta (6): mmc: core: Parse clk scaling dt entries mmc: core: Add core scaling support in driver mmc: core: Initialize clk scaling for mmc and SDCard mmc: core: Add debugfs entries for scaling support mmc: sdhci-msm: Add capability in platfrom host dt-bindings: mmc: sdhci-msm: Add clk scaling dt parameters .../devicetree/bindings/mmc/sdhci-msm.txt | 19 + drivers/mmc/core/block.c | 19 +- drivers/mmc/core/core.c | 777 +++++++++++++++++++++ drivers/mmc/core/core.h | 17 + drivers/mmc/core/debugfs.c | 90 +++ drivers/mmc/core/host.c | 226 ++++++ drivers/mmc/core/mmc.c | 246 ++++++- drivers/mmc/core/queue.c | 2 + drivers/mmc/core/sd.c | 84 ++- drivers/mmc/host/sdhci-msm.c | 2 + include/linux/mmc/card.h | 7 + include/linux/mmc/host.h | 66 ++ 12 files changed, 1550 insertions(+), 5 deletions(-) -- 1.9.1
