[PATCH v8 0/3] Add driver support for ESWIN eic700 SoC clock controller

dongxuyang
2025-11-13T01:37:56Z

From: Xuyang Dong <dongxuyang@eswincomputing.com>

The link [1] provides the official documentation for the EIC7700. Section 3.2
covers the clock subsystem.

[1] https://www.sifive.com/document-file/eic7700x-datasheet

Updates:
Changes in v8:
- Added clock-tree link in cover-letter.
- Updated YAML file
- Added "Acked-by: Troy Mitchell <troy.mitchell@linux.dev>" for bindings.
- Updated driver file
- Changed Kconfig symbol type from bool to tristate to build this driver as
module.
- Updated MAINTAINERS file
- Added entry "ESWIN EIC7700 CLOCK DRIVER".

- Link to v7: https://lore.kernel.org/all/20251023071658.455-1-dongxuyang@eswincomputing.com/

Changes in v7:
- Updated YAML file
- Added "Acked-by: Conor Dooley <conor.dooley@microchip.com>" for bindings.
- Updated driver file
- Added description for clk of eswin_calc_pll().
- Added macro EIC7700_MUX_TBL to manage mux clock-tree.
- Added eswin_clk_register_mux_tbl() to register mux clocks with
discontinuous parent indexes.

- Link to v6: https://lore.kernel.org/all/20251009092029.140-1-dongxuyang@eswincomputing.com/

Changes in v6:
- Removed config option patch dependency from cover letter, because the patch
was applied.
- Updated YAML file
- Added an oscillator as the clock input, named xtal24m.
- Added clocks property.
- Updated driver file
- Replaced fixed_rate_clk_xtal_24m with xtal24m.
- Dropped fixed_rate_clk_xtal_24m from driver. Because clock xtal24m was
registered by fixed-clock as oscillator.

- Link to v5: https://lore.kernel.org/all/20250923084637.1223-1-dongxuyang@eswincomputing.com/

Changes in v5:
- Removed vendor prefix patch dependency from cover letter, because the patch
was applied.
- Updated YAML file
- Placed the required after all properties.
- Removed patternProperties. Also removed compatible of eswin,pll-clock,
eswin,mux-clock, eswin,divider-clock and eswin,gate-clock as we have moved
clock tree from DTS to Linux driver.
- Removed the clock tree from DTS. Used clock-controller to manage all
clock. Removed all child nodes in clock-controller.
- Removed '#address-cells' and '#size-cells' properties, because the clock
controller did not need to define these properties.
- Removed eic7700-clocks.dtsi.
- Added dt-bindings header for clock IDs. Because used the IDs to register
clocks.
- Updated driver file
- Modified the commit for clock driver. Dropped indentation in commit.
- Removed CLK_OF_DECLARE(). Used *clk_hw_register* to register clocks. Used
devm_of_clk_add_hw_provider.
- Dropped singletons.
- Checked the value right after obtaining it.
- Removed the definitions of macro frequency in clk.h like CLK_FREQ_24M.
- Modified description of help in Kconfig.
- Added COMPILE_TEST. Added COMMON_CLK_ESWIN for clk.o. And added
"select COMMON_CLK_ESWIN" for clk-eic7700.c. Without COMMON_CLK_EIC7700,
clk.c could not be compiled.
- Used .determined_rate.
- Added macro definitions of EIC7700_DIV, EIC7700_FIXED, EIC7700_FACTOR,
EIC7700_MUX and EIC7700_PLL to manage clock tree.
- Added clk-eic7700.h to place eic7700 SoC clock registers.
- Removed refdiv_val and postdiv1_val from clk_pll_recalc_rate(). Because
these values were unused.

- Link to v4: https://lore.kernel.org/all/20250815093539.975-1-dongxuyang@eswincomputing.com/

Changes in v4:
- Updated YAML file
- Changed name from cpu-default-frequency to cpu-default-freq-hz.
- Dropped $ref of cpu-default-frequency.
- Added cpu-default-frequency for required.
- Removed cpu-default-frequency in updated file, because there was no
need to add cpu-default-frequency.
- Moved DIVIDER to DIV.
- Arranged the IDs in order.
- Dropped EIC7700_NR_CLKS.
- Removed dt-bindings eswin,eic7700-clock.h. Because IDs was not used,
and used clock device nodes.
- According to the updated driver codes, the YAML has been updated.
- Updated driver file
- Remove undocumented parameters "cpu_no_boost_1_6ghz" and
"cpu-default-frequency".
- Modified the comment and used the correct Linux coding style.
- Removed codes of voltage, because it was not the clock driver.
- Updated the formula of clock frequency calculation. Removed the logic
that only used register selection.
- Used CLK_OF_DECLARE() to register clocks. Registered pll-clock,
mux-clock, divider-clock, and gate-clock in clk-eic7700.c.
The specific implementation of clock registration was in clk.c.
- Added eic7700-clocks.dtsi.
- Moved device information to DTS. Put all clocks' node in the
eic7700-clocks.dtsi.

- Link to v3: https://lore.kernel.org/all/20250624103212.287-1-dongxuyang@eswincomputing.com/

Changes in v3:
- Update example, drop child node and add '#clock-cells' to the parent
node.
- Change parent node from sys-crg to clock-controller for this yaml.
- Drop "syscon", "simple-mfd" to clear warnings/errors by using "make
dt_binding_check". And these are not necessary.
- Add "cpu-default-frequency" definition in yaml for "undocumented ABI".
- Drop Reviewed-by, this is misunderstanding. We have not received such
an email.
- Link to v2: https://lore.kernel.org/all/20250523090747.1830-1-dongxuyang@eswincomputing.com/

Changes in v2:
- Update example, drop child node.
- Clear warnings/errors for using "make dt_binding_check".
- Change to the correct format.
- Drop some non-stanard code.
- Use dev_err_probe() in probe functions.
- Link to v1: https://lore.kernel.org/all/20250514002233.187-1-dongxuyang@eswincomputing.com/

Xuyang Dong (3):
dt-bindings: clock: eswin: Documentation for eic7700 SoC
clock: eswin: Add eic7700 clock driver
MAINTAINERS: Add entry for ESWIN EIC7700 clock driver

.../bindings/clock/eswin,eic7700-clock.yaml | 46 +
MAINTAINERS | 8 +
drivers/clk/Kconfig | 1 +
drivers/clk/Makefile | 1 +
drivers/clk/eswin/Kconfig | 15 +
drivers/clk/eswin/Makefile | 8 +
drivers/clk/eswin/clk-eic7700.c | 1033 +++++++++++++++++
drivers/clk/eswin/clk-eic7700.h | 122 ++
drivers/clk/eswin/clk.c | 481 ++++++++
drivers/clk/eswin/clk.h | 256 ++++
.../dt-bindings/clock/eswin,eic7700-clock.h | 280 +++++
11 files changed, 2251 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/eswin,eic7700-clock.yaml
create mode 100644 drivers/clk/eswin/Kconfig
create mode 100644 drivers/clk/eswin/Makefile
create mode 100644 drivers/clk/eswin/clk-eic7700.c
create mode 100644 drivers/clk/eswin/clk-eic7700.h
create mode 100644 drivers/clk/eswin/clk.c
create mode 100644 drivers/clk/eswin/clk.h
create mode 100644 include/dt-bindings/clock/eswin,eic7700-clock.h

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2.43.0