[v2,0/6] Add support for Mobileye EyeQ5 clock controller

Message

Théo Lebrun Dec. 27, 2023, 4:23 p.m. UTC

Hi,

We replace fixed clocks as declared in the initial platform support
series [1] by read-only clocks exposed by the clock driver implemented
here. Write-ability is supported by the hardware but not implemented,
it could be added later-on if the need appears.

We expose ten PLLs that derive directly from the main crystal. Also, a
divider clock is exposed as a child clock of one of the PLLs.

The platform devicetree has many more clock nodes but those are
fixed-factors that are not hardware controllable; we therefore do not
deal with them.

This is V2. Full changelog below. Major changes are:

 - Switch to a platform driver.
 - Switch to declaring PLLs as fixed-factor.
 - Point to the parent clk using the fw_name field in clk_parent_data.
 - The above two points means we add support in fixed-factor to (1) allow
   fixed accuracy rather than parent accuracy and (2) add new register
   prototypes to point to the parent clk using fw_name.

[1]: https://lore.kernel.org/lkml/[e-mail]/

Have a nice day,
Théo Lebrun

Signed-off-by: Théo Lebrun <[e-mail]>
---
Changes in v2:
- Drop [PATCH 1/5] that was taken by Stephen for clk-next.
- Add accuracy support to fixed-factor that is enabled with a flag.
  Register prototypes were added to exploit this feature.
- Add fw_name support to fixed-factor. This allows pointing to parent
  clocks using the value in `clock-names` in the DT. Register
  prototypes were added for that.
- Bindings were modified to be less dumb: a binding was added for OLB
  and the clock-controller is a child property of it. Removed the
  possibility of pointing to OLB using a phandle. $nodename is the
  generic `clock-controller` and not custom `clocks`. Fix dt-bindings
  examples.
- Fix commit message for the driver patch. Add details, remove useless
  fluff.
- Squash both driver commits together.
- Declare a platform_driver instead of using CLK_OF_DECLARE_DRIVER. This
  also means using `dev_*` for logging, removing `pr_fmt`. We add a
  pointer to device in the private structure.
- Use fixed-factor instead of fixed-rate for PLLs. We don't grab a
  reference to the parent clk, instead using newly added fixed-factor
  register prototypes and fwname.
- NULL is not an error when registering PLLs anymore.
- Now checking the return value of of_clk_add_hw_provider for errors.
- Fix includes.
- Remove defensive conditional at start of eq5c_pll_parse_registers.
- Rename clk_hw_to_ospi_priv to clk_to_priv to avoid confusion: it is
  not part of the clk_hw_* family of symbols.
- Fix negative returns in eq5c_ospi_div_set_rate. It was a typo
  highlighted by Stephen Boyd.
- Declare eq5c_ospi_div_ops as static.
- In devicetree, move the OLB node prior to the UARTs, as platform
  device probe scheduling is dependent on devicetree ordering. This is
  required to declare the driver as a platform driver, else it
  CLK_OF_DECLARE_DRIVER is required.
- In device, create a core0-timer-clk fixed clock to feed to the GIC
  timer. It requires a clock earlier than platform bus type init.
- Link to v1: https://lore.kernel.org/r/[e-mail]

---
Théo Lebrun (6):
      clk: fixed-factor: add optional accuracy support
      clk: fixed-factor: add fwname-based constructor functions
      dt-bindings: soc: mobileye: add EyeQ5 OLB system controller
      dt-bindings: clock: mobileye,eyeq5-clk: add bindings
      clk: eyeq5: add platform driver
      MIPS: mobileye: eyeq5: use OLB clocks controller

 .../bindings/clock/mobileye,eyeq5-clk.yaml         |  50 +++
 .../bindings/soc/mobileye/mobileye,eyeq5-olb.yaml  |  48 +++
 MAINTAINERS                                        |   4 +
 .../{eyeq5-fixed-clocks.dtsi => eyeq5-clocks.dtsi} |  54 ++--
 arch/mips/boot/dts/mobileye/eyeq5.dtsi             |  23 +-
 drivers/clk/Kconfig                                |  11 +
 drivers/clk/Makefile                               |   1 +
 drivers/clk/clk-eyeq5.c                            | 348 +++++++++++++++++++++
 drivers/clk/clk-fixed-factor.c                     |  94 +++++-
 include/dt-bindings/clock/mobileye,eyeq5-clk.h     |  22 ++
 include/linux/clk-provider.h                       |  26 +-
 11 files changed, 621 insertions(+), 60 deletions(-)
---
base-commit: daf471f1ce94536da77948fac81d5c85ae12dbfa
change-id: 20231023-mbly-clk-87ce5c241f08

Best regards,