[PATCH v3 02/16] clk: sunxi-ng: h3: h5: Add minimal rate for video PLL
From: Jernej Skrabec <hidden>
Date: 2018-03-01 22:11:25
Also in:
dri-devel, linux-arm-kernel, linux-clk, lkml
Subsystem:
arm/allwinner sunxi soc support, common clk framework, the rest · Maintainers:
Chen-Yu Tsai, Jernej Skrabec, Samuel Holland, Michael Turquette, Stephen Boyd, Linus Torvalds
Although user manuals for H3 and H5 SoCs state that minimal rate supported by video PLL is around 30 MHz, it seems that in reality minimal rate is around 192 MHz. Experiments showed that any rate below 96 MHz doesn't produce any video output at all. Even at this frequency, stable output depends on right factors. For example, when N = 4 and M = 1, output is stable and when N = 8 and M = 2, it's not. BSP clock driver suggest that minimum stable frequency is 192 MHz. That would also be in line with A64 SoC, which has similar periphery. Set minimal video PLL rate for H3/H5 to 192 MHz. Signed-off-by: Jernej Skrabec <redacted> --- drivers/clk/sunxi-ng/ccu-sun8i-h3.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-h3.c b/drivers/clk/sunxi-ng/ccu-sun8i-h3.c
index 29bc0566b776..b9f39078c0b2 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-h3.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-h3.c@@ -69,17 +69,18 @@ static SUNXI_CCU_NM_WITH_SDM_GATE_LOCK(pll_audio_base_clk, "pll-audio-base", BIT(28), /* lock */ CLK_SET_RATE_UNGATE); -static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_video_clk, "pll-video", - "osc24M", 0x0010, - 8, 7, /* N */ - 0, 4, /* M */ - BIT(24), /* frac enable */ - BIT(25), /* frac select */ - 270000000, /* frac rate 0 */ - 297000000, /* frac rate 1 */ - BIT(31), /* gate */ - BIT(28), /* lock */ - CLK_SET_RATE_UNGATE); +static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK_MIN(pll_video_clk, "pll-video", + "osc24M", 0x0010, + 192000000, /* Minimum rate */ + 8, 7, /* N */ + 0, 4, /* M */ + BIT(24), /* frac enable */ + BIT(25), /* frac select */ + 270000000, /* frac rate 0 */ + 297000000, /* frac rate 1 */ + BIT(31), /* gate */ + BIT(28), /* lock */ + CLK_SET_RATE_UNGATE); static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_ve_clk, "pll-ve", "osc24M", 0x0018,
--
2.16.2