[PATCH 0/3] - clk: meson8b: add the (read-only) video clock trees

[Martin Blumenstingl]

This is the Meson8b variant of Neil's series from [0] called "- clk:
meson: Add video clocks path".
GXBB and newer use a -- vid_pll divider IP block which doesn't exist on
the 32-bit SoCs. Instead the 32-bit SoCs use three simple dividers,
a few muxes and some fixed dividers.

I used Neil's GXBB patches as initial reference, together with Amlogic's
3.10 kernel sources (drivers/amlogic/display/vout/enc_clk_config.c): [1]

With Jianxin's help I was able to get the clock tree into a state where
the code is now able to recalculate the frequencies of the video clocks.
I am using the clock measurer as "expected" values, together with the
data from enc_clk_config.c where all the dividers are documented. My
test protocol on Meson8b and Meson8m2 is attached below.

One note for all brave people who look at enc_clk_config.c from
Amlogic's 3.10 kernel: some frequencies seem to be doubled there.
VMODE_1080P is defined with hpll_clk_out = 2970, but it's only using
the following PLL parameters: M = 61, N = 1, FRAC = 3584. At first I
though that there's a pre-multiplier like on GXBB, but after digging
deeper into the code I don't believe that pre-multiplier exists. The
reason for this is for example VMODE_1080P_30HZ which uses
hpll_clk_out = 1485 with the same PLL parameters as 2970 MHz. However,
since the current code can recalculate the frequencies correctly I will
leave it to a future patch to solve this "frequency doubling" - more
work is needed anyways for actually changing the PLL's frequency (as
there are many bits in HHI_VID_PLL_CNTL2, HHI_VID_PLL_CNTL3,
HHI_VID_PLL_CNTL4 and HHI_VID_PLL_CNTL5 which the Amlogic 3.10 kernel
is changing together with the M/N/FRAC values.


[0] https://patchwork.kernel.org/cover/10670657/
[1] https://github.com/endlessm/linux-meson/blob/cd4096c3ff4eb5b8a8a5581bb46508601c5470dc/drivers/amlogic/display/vout/enc_clk_config.c


1080P / Meson8b Odroid-C1
- u-boot:
-- odroidc#video dev open 1080P
-- mode = 8 vic = 16
-- set HDMI vic: 16
-- mode is: 8
-- viu chan = 1
-- config HPLL
-- config HPLL done
-- reconfig packet setting done
- clkmsr:
-- vid_pll 148497596 +/-4807Hz
-- encp 148497596 +/-4807Hz
-- encl 0 +/-3125Hz
-- hdmi_ch0_tmds 148500000 +/-4807Hz
-- hdmi_tx_pixel 148497596 +/-4807Hz
- clk:
-- hdmi_pll_dco 0 0 0 1485000000 0 0 50000
-- vid_pll 0 0 0 148500000 0 0 50000
-- cts_encp 0 0 0 148500000 0 0 50000
-- cts_encl 0 0 0 148500000 0 0 50000
-- hdmi_tx_pixel 0 0 0 148500000 0 0 50000

720P / Meson8b Odroid-C1
- u-boot:
-- odroidc#video dev open 720P
-- mode = 6 vic = 4
-- set HDMI vic: 4
-- mode is: 6
-- viu chan = 1
-- config HPLL
-- config HPLL done
-- reconfig packet setting done
- clkmsr:
-- vid_pll 148497596 +/-4807Hz
-- encp 148497596 +/-4807Hz
-- encl 0 +/-3125Hz
-- hdmi_ch0_tmds 74250000 +/-3125Hz
-- hdmi_tx_pixel 74248438 +/-3125Hz
- clk:
-- hdmi_pll_dco 0 0 0 1485000000 0 0 50000
-- vid_pll 0 0 0 148500000 0 0 50000
-- cts_encp 0 0 0 148500000 0 0 50000
-- cts_encl 0 0 0 148500000 0 0 50000
-- hdmi_tx_pixel 0 0 0 74250000 0 0 50000

480P / Meson8b Odroid-C1
- u-boot:
-- odroidc#video dev open 480P
-- mode = 2 vic = 3
-- set HDMI vic: 3
-- mode is: 2
-- viu chan = 1
-- config HPLL
-- config HPLL done
-- reconfig packet setting done
- clkmsr:
-- vid_pll 215996528 +/-6944Hz
-- encp 53998438 +/-3125Hz
-- encl 0 +/-3125Hz
-- hdmi_ch0_tmds 26998438 +/-3125Hz
-- hdmi_tx_pixel 27000000 +/-3125Hz
- clk:
-- hdmi_pll_dco 0 0 0 1080000000 0 0 50000
-- vid_pll 0 0 0 216000000 0 0 50000
-- cts_encp 0 0 0 54000000 0 0 50000
-- cts_encl 0 0 0 54000000 0 0 50000
-- hdmi_tx_pixel 0 0 0 27000000 0 0 50000


4K2K30HZ / Meson8m2 M8S
- u-boot:
-- m8m2_n200_v1#video dev open 4K2K30HZ
-- mode = 13 vic = 68
-- set HDMI vic: 68
-- config HPLL
-- config HPLL done
-- reconfig packet setting done
- clkmsr:
-- vid_pll 297000000 +/-10416Hz
-- encp 296989583 +/-10416Hz
-- encl 296989583 +/-10416Hz
-- hdmi_ch0_tmds 296984375 +/-10416Hz
-- hdmi_tx_pixel 296979167 +/-10416Hz
-- hdmi_sys 23998438 +/-3125Hz
- clk:
-- hdmi_pll_dco 0 0 0 1485000000 0 0 50000
-- vid_pll 0 0 0 297000000 0 0 50000
-- cts_encp 0 0 0 297000000 0 0 50000
-- cts_encl 0 0 0 297000000 0 0 50000
-- hdmi_tx_pixel 0 0 0 297000000 0 0 50000
-- hdmi_sys 0 0 0 24000000 0 0 50000

1080P / Meson8m2 M8S
- u-boot:
-- m8m2_n200_v1#video dev open 1080P
-- mode = 8 vic = 16
-- set HDMI vic: 16
-- config HPLL
-- config HPLL done
-- reconfig packet setting done
- clkmsr:
-- vid_pll 148500000 +/-4807Hz
-- encp 148500000 +/-4807Hz
-- encl 148497596 +/-4807Hz
-- hdmi_ch0_tmds 148497596 +/-4807Hz
-- hdmi_tx_pixel 148497596 +/-4807Hz
-- hdmi_sys 24000000 +/-3125Hz
- clk:
-- hdmi_pll_dco 0 0 0 1485000000 0 0 50000
-- vid_pll 0 0 0 148500000 0 0 50000
-- cts_encp 0 0 0 148500000 0 0 50000
-- cts_encl 0 0 0 148500000 0 0 50000
-- hdmi_tx_pixel 0 0 0 148500000 0 0 50000
-- hdmi_sys 0 0 0 24000000 0 0 50000

720P / Meson8m2 M8S
- u-boot:
-- m8m2_n200_v1#video dev open 720P
-- mode = 6 vic = 4
-- set HDMI vic: 4
-- config HPLL
-- config HPLL done
-- reconfig packet setting done
- clkmsr:
-- vid_pll 148500000 +/-4807Hz
-- encp 148500000 +/-4807Hz
-- encl 148497596 +/-4807Hz
-- hdmi_ch0_tmds 74248438 +/-3125Hz
-- hdmi_tx_pixel 74248438 +/-3125Hz
-- hdmi_sys 24000000 +/-3125Hz
- clk:
-- hdmi_pll_dco 0 0 0 1485000000 0 0 50000
-- vid_pll 0 0 0 148500000 0 0 50000
-- cts_encp 0 0 0 148500000 0 0 50000
-- cts_encl 0 0 0 148500000 0 0 50000
-- hdmi_tx_pixel 0 0 0 74250000 0 0 50000
-- hdmi_sys 0 0 0 24000000 0 0 50000

480P / Meson8m2 M8S
- u-boot:
-- m8m2_n200_v1#video dev open 480P
-- mode = 2 vic = 3
-- set HDMI vic: 3
-- config HPLL
-- config HPLL done
-- reconfig packet setting done
- - clkmsr:
-- vid_pll 215996528 +/-6944Hz
-- encp 54000000 +/-3125Hz
-- encl 53998438 +/-3125Hz
-- hdmi_ch0_tmds 27000000 +/-3125Hz
-- hdmi_tx_pixel 27000000 +/-3125Hz
-- hdmi_sys 24000000 +/-3125Hz
- - clk:
-- hdmi_pll_dco 0 0 0 1080000000 0 0 50000
-- vid_pll 0 0 0 216000000 0 0 50000
-- cts_encp 0 0 0 54000000 0 0 50000
-- cts_encl 0 0 0 54000000 0 0 50000
-- hdmi_tx_pixel 0 0 0 27000000 0 0 50000
-- hdmi_sys 0 0 0 24000000 0 0 50000


Martin Blumenstingl (3):
  - clk: meson: meson8b: fix the offset of -- vid_pll_dco's N value
  - clk: meson: meson8b: add the fractional divider for -- vid_pll_dco
  - clk: meson: meson8b: add the read-only video clock trees

 drivers/clk/meson/meson8b.c | 746 +++++++++++++++++++++++++++++++++++-
 drivers/clk/meson/meson8b.h |  54 ++-
 2 files changed, 789 insertions(+), 11 deletions(-)

-- 
2.19.2