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* [PATCH 0/3] clk: meson: add support for PCIE PLL
@ 2019-03-07 14:14 Neil Armstrong
  2019-03-07 14:14 ` [PATCH 1/3] clk: meson-pll: add reduced specific clk_ops for G12A PCIe PLL Neil Armstrong
                   ` (3 more replies)
  0 siblings, 4 replies; 9+ messages in thread
From: Neil Armstrong @ 2019-03-07 14:14 UTC (permalink / raw)
  To: jbrunet
  Cc: Neil Armstrong, linux-clk, linux-amlogic, linux-arm-kernel, linux-kernel

The Amlogic G12A SoCs embeds a dedicated PLL to feed the USB3+PCIE
Combo PHY. This PLL needs a very specific and strict register sequence
in order to correcly enable it and deliver the 100MHz reference clock
to the Analog PHY.

After lot of trials and errors, and since this PLL will ever feed 100MHz
with a static configuration, it is simpler to setup a dedicated ops
structure with a custom _enable() op applying the init register sequence.

The rate calculation ops are kept in order to keep the nominal read
ops as-in, but set_rate is removed.

With this setup, the PLL can be enabled and disable safely and always have
the recommended PLL setup to feed the USB3+PCIE Combo PHY.

Neil Armstrong (3):
  clk: meson-pll: add reduced specific clk_ops for G12A PCIe PLL
  dt-bindings: clk: g12a-clkc: add PCIE PLL clock ID
  clk: meson-g12a: add PCIE PLL clocks

 drivers/clk/meson/clk-pll.c           |  26 ++++++
 drivers/clk/meson/clk-pll.h           |   1 +
 drivers/clk/meson/g12a.c              | 118 ++++++++++++++++++++++++++
 drivers/clk/meson/g12a.h              |   5 +-
 include/dt-bindings/clock/g12a-clkc.h |   1 +
 5 files changed, 150 insertions(+), 1 deletion(-)

-- 
2.20.1


^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2019-03-27 23:47 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-07 14:14 [PATCH 0/3] clk: meson: add support for PCIE PLL Neil Armstrong
2019-03-07 14:14 ` [PATCH 1/3] clk: meson-pll: add reduced specific clk_ops for G12A PCIe PLL Neil Armstrong
2019-03-07 14:14 ` [PATCH 2/3] dt-bindings: clk: g12a-clkc: add PCIE PLL clock ID Neil Armstrong
2019-03-27 23:47   ` Rob Herring
2019-03-07 14:14 ` [PATCH 3/3] clk: meson-g12a: add PCIE PLL clocks Neil Armstrong
2019-03-19  9:55   ` Jerome Brunet
2019-03-19  9:58     ` Neil Armstrong
2019-03-19 10:01 ` [PATCH 0/3] clk: meson: add support for PCIE PLL Jerome Brunet
2019-03-19 20:23   ` Neil Armstrong

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