Hi, On Thu, Jul 20, 2017 at 11:44:43AM +0800, Chen-Yu Tsai wrote: > Starting with the A83T SoC, Allwinner introduced a new timing mode for > its MMC clocks. The new mode changes how the MMC controller sample and > output clocks are delayed to match chip and board specifics. There are > two controls for this, one on the CCU side controlling how the clocks > behave, and one in the MMC controller controlling what inputs to take > and how to route them. > > In the old mode, the MMC clock had 2 child clocks providing the output > and sample clocks, which could be delayed by a number of clock cycles > measured from the MMC clock's parent. > > With the new mode, the 2 delay clocks are no longer active. Instead, > the delays and associated controls are moved into the MMC controller. > The output of the MMC clock is also halved. > > The difference in how things are wired between the modes means that the > clock controls and the MMC controls must match. To achieve this in a > clear, explicit way, we introduce two functions for the MMC driver to > use: one queries the hardware for the current mode set, and the other > allows the MMC driver to request a mode. > > Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx> > --- > drivers/clk/sunxi-ng/Makefile | 1 + > drivers/clk/sunxi-ng/ccu_common.h | 5 +++ > drivers/clk/sunxi-ng/ccu_mmc_timing.c | 73 +++++++++++++++++++++++++++++++++++ > include/linux/clk/sunxi-ng.h | 35 +++++++++++++++++ > 4 files changed, 114 insertions(+) > create mode 100644 drivers/clk/sunxi-ng/ccu_mmc_timing.c > create mode 100644 include/linux/clk/sunxi-ng.h > > diff --git a/drivers/clk/sunxi-ng/Makefile b/drivers/clk/sunxi-ng/Makefile > index 0c45fa50283d..45a5910379a5 100644 > --- a/drivers/clk/sunxi-ng/Makefile > +++ b/drivers/clk/sunxi-ng/Makefile > @@ -1,5 +1,6 @@ > # Common objects > lib-$(CONFIG_SUNXI_CCU) += ccu_common.o > +lib-$(CONFIG_SUNXI_CCU) += ccu_mmc_timing.o > lib-$(CONFIG_SUNXI_CCU) += ccu_reset.o > > # Base clock types > diff --git a/drivers/clk/sunxi-ng/ccu_common.h b/drivers/clk/sunxi-ng/ccu_common.h > index d6fdd7a789aa..1e2761c53f06 100644 > --- a/drivers/clk/sunxi-ng/ccu_common.h > +++ b/drivers/clk/sunxi-ng/ccu_common.h > @@ -23,6 +23,11 @@ > #define CCU_FEATURE_FIXED_POSTDIV BIT(3) > #define CCU_FEATURE_ALL_PREDIV BIT(4) > #define CCU_FEATURE_LOCK_REG BIT(5) > +#define CCU_FEATURE_MMC_TIMING_SWITCH BIT(6) > +#define CCU_FEATURE_MMC_ALWAYS_NEW BIT(7) Didn't we agree on removing that flag? Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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