Messages in this thread Patch in this message | | | From | Martin Blumenstingl <> | Subject | [PATCH 4/4] clk: meson: meson8b: Make the CCF use the glitch-free VPU mux | Date | Tue, 14 Apr 2020 22:00:17 +0200 |
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The "vpu_0" or "vpu_1" clock trees should not be updated while the clock is running. Enforce this by setting CLK_SET_RATE_GATE on the "vpu_0" and "vpu_1" gates. This makes the CCF switch to the "vpu_1" tree when "vpu_0" is currently active and vice versa, which is exactly what the vendor driver does when updating the frequency of the VPU clock.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> --- drivers/clk/meson/meson8b.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c index ed4b70c2d4bd..427392678fec 100644 --- a/drivers/clk/meson/meson8b.c +++ b/drivers/clk/meson/meson8b.c @@ -2063,7 +2063,7 @@ static struct clk_regmap meson8b_vpu_0 = { &meson8b_vpu_0_div.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT, }, }; @@ -2134,10 +2134,18 @@ static struct clk_regmap meson8b_vpu_1 = { &meson8b_vpu_1_div.hw }, .num_parents = 1, - .flags = CLK_SET_RATE_PARENT, + .flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT, }, }; +/* + * The VPU clock has two two identical clock trees (vpu_0 and vpu_1) + * muxed by a glitch-free switch on Meson8b and Meson8m2. The CCF can + * actually manage this glitch-free mux because it does top-to-bottom + * updates the each clock tree and switches to the "inactive" one when + * CLK_SET_RATE_GATE is set. + * Meson8 only has vpu_0 and no glitch-free mux. + */ static struct clk_regmap meson8b_vpu = { .data = &(struct clk_regmap_mux_data){ .offset = HHI_VPU_CLK_CNTL, @@ -2152,7 +2160,7 @@ static struct clk_regmap meson8b_vpu = { &meson8b_vpu_1.hw, }, .num_parents = 2, - .flags = CLK_SET_RATE_NO_REPARENT, + .flags = CLK_SET_RATE_PARENT, }, }; -- 2.26.0
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