diff options
| author | Chen-Yu Tsai <wens@csie.org> | 2017-12-04 06:19:12 +0100 |
|---|---|---|
| committer | Maxime Ripard <maxime.ripard@free-electrons.com> | 2017-12-07 10:09:57 +0100 |
| commit | 83fe3be4d1974f5f50c5e2039a1609f4960e8579 (patch) | |
| tree | 371fc15062d3ba4818d1e158a1060146ec4a9dcc /drivers/clk | |
| parent | clk: sunxi-ng: Support fixed post-dividers on MP style clocks (diff) | |
| download | linux-83fe3be4d1974f5f50c5e2039a1609f4960e8579.tar.xz linux-83fe3be4d1974f5f50c5e2039a1609f4960e8579.zip | |
clk: sunxi-ng: sun50i: a64: Add 2x fixed post-divider to MMC module clocks
On the A64, the MMC module clocks are fixed in the new timing mode,
i.e. they do not have a bit to select the mode. These clocks have
a 2x divider somewhere between the clock and the MMC module.
To be consistent with other SoCs supporting the new timing mode,
we model the 2x divider as a fixed post-divider on the MMC module
clocks.
This patch adds the post-dividers to the MMC clocks.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Diffstat (limited to 'drivers/clk')
| -rw-r--r-- | drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 57 |
1 files changed, 37 insertions, 20 deletions
diff --git a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c index 2bb4cabf802f..ee9c12cf3f08 100644 --- a/drivers/clk/sunxi-ng/ccu-sun50i-a64.c +++ b/drivers/clk/sunxi-ng/ccu-sun50i-a64.c @@ -400,28 +400,45 @@ static SUNXI_CCU_MP_WITH_MUX_GATE(nand_clk, "nand", mod0_default_parents, 0x080, BIT(31), /* gate */ 0); +/* + * MMC clocks are the new timing mode (see A83T & H3) variety, but without + * the mode switch. This means they have a 2x post divider between the clock + * and the MMC module. This is not documented in the manual, but is taken + * into consideration when setting the mmc module clocks in the BSP kernel. + * Without it, MMC performance is degraded. + * + * We model it here to be consistent with other SoCs supporting this mode. + * The alternative would be to add the 2x multiplier when setting the MMC + * module clock in the MMC driver, just for the A64. + */ static const char * const mmc_default_parents[] = { "osc24M", "pll-periph0-2x", "pll-periph1-2x" }; -static SUNXI_CCU_MP_WITH_MUX_GATE(mmc0_clk, "mmc0", mmc_default_parents, 0x088, - 0, 4, /* M */ - 16, 2, /* P */ - 24, 2, /* mux */ - BIT(31), /* gate */ - 0); - -static SUNXI_CCU_MP_WITH_MUX_GATE(mmc1_clk, "mmc1", mmc_default_parents, 0x08c, - 0, 4, /* M */ - 16, 2, /* P */ - 24, 2, /* mux */ - BIT(31), /* gate */ - 0); - -static SUNXI_CCU_MP_WITH_MUX_GATE(mmc2_clk, "mmc2", mmc_default_parents, 0x090, - 0, 4, /* M */ - 16, 2, /* P */ - 24, 2, /* mux */ - BIT(31), /* gate */ - 0); +static SUNXI_CCU_MP_WITH_MUX_GATE_POSTDIV(mmc0_clk, "mmc0", + mmc_default_parents, 0x088, + 0, 4, /* M */ + 16, 2, /* P */ + 24, 2, /* mux */ + BIT(31), /* gate */ + 2, /* post-div */ + 0); + +static SUNXI_CCU_MP_WITH_MUX_GATE_POSTDIV(mmc1_clk, "mmc1", + mmc_default_parents, 0x08c, + 0, 4, /* M */ + 16, 2, /* P */ + 24, 2, /* mux */ + BIT(31), /* gate */ + 2, /* post-div */ + 0); + +static SUNXI_CCU_MP_WITH_MUX_GATE_POSTDIV(mmc2_clk, "mmc2", + mmc_default_parents, 0x090, + 0, 4, /* M */ + 16, 2, /* P */ + 24, 2, /* mux */ + BIT(31), /* gate */ + 2, /* post-div */ + 0); static const char * const ts_parents[] = { "osc24M", "pll-periph0", }; static SUNXI_CCU_MP_WITH_MUX_GATE(ts_clk, "ts", ts_parents, 0x098, |