2010/11/3 Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>: > This patch modifies the MMC core code to optionally call the > set_ios() operation on the driver with the clock frequency set > to 0 (gate) after a grace period of at least 8 MCLK cycles, then > restore it (ungate) before any new request. This gives > the driver the option to shut down the MCI clock to the MMC/SD > card when the clock frequency is 0, i.e. the core has stated > that the MCI clock does not need to be generated. > > It is inspired by existing clock gating code found in the OMAP > and Atmel drivers and brings this up to the host abstraction. > Gating is performed before and after any MMC request. > > It exemplifies by implementing this for the MMCI/PL180 MMC/SD > host controller, but it should be simple to switch OMAP and > Atmel over to using this instead. > > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx> I think we have some rough consesus that: * This patch adds the desired gating functionality to the MMC subsystem. * It can be refactored to reuse parts of runtime PM in the future if some eager contributor turns up. Andrew, can you add this v8 version (not the misguided v9!) version to your patch stack? Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
