clk: intel: Add a new driver for a new clock controller IP

Hi,

This series adds clock driver for Clock Generation Unit(CGU) of Lightning Mountain(LGM) SoC.

Patch 1 adds bindings document & include file for CGU. Patch 2 adds common clock framework based clock driver for CGU.

These patches are baselined upon Linux 5.6-rc1 at below Git link:
git git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git

v7:
- Fix a mistake in comments explaining structure fields.

v6:
- Resolve Kconfig dependencies issues (Randy Dunlap)

v5:
- Address review concerns - mainly below mentioned. (Stephen Boyd)
- Improve commit message, add COMPILE_TEST in KConfig dependency.
- Remove unused header include files, drop unnecessary casts.
- Switch to using readl_poll_timeout() instead of implementing timeout routine.
- Avoid using small functions which are called just once. Inline them or remove them.
- const static --> static const
- Fix coding style/convention related review concerns.
- Use __iomem for all IO addresses variables.
- Consolidate clk_enable & clk_disable ops into a common clk_enable_disable routine to avoid redundant code.
- Remove unnecessary dev pointers for clk data structures.
- Redesign code to use new way of specifying clk_parents i.e. use clk_parent_data.fw_name instead of older parent_name strings.
- Switch from raw_spin_locks() to normal spin_locks() and realign locking.
- Drop __initconst, __init, __refdata.
- Reorder patch series - make dt-binding patch as first patch.
- Add pointer to include file in dt-bindings document.
- Remove CLK_IS_CRITICAL flag for clks for which IGNORE_UNUSED flag is enough. Add comments for clks which are marked as CRITICAL.
- Fix $id path in dt-bindings - drop bindings. (Rob Herring).
- Add Reviewed-by tag from Rob Herring. Thanks Rob.

v4:
- Add drivers/clk/x86/Kconfig file which got missed in v3 by mistake.

v3:
- Address review concerns:
Add Kconfig entry in x86 folder instead of modifying clk/Kconfig. (Andy Shevchenko) Fix coding style/convention related concerns. (Andy Shevchenko) Improve description, licensing info, rename node name correctly in dt bindings document & remove CLK_NR_CLKS from dt-bindings header file. (Stephen Boyd) Fix a build warning reported by kbuild test robot & Nathan Chancellor
- Add few new clocks & rename few existing clocks.
- Add more ops for ddiv & divider clk_ops.
- Fix few minor bugs.
- Use CLK_IS_CRITICAL flag for clocks which shall never be disabled.

v2:
- Move the driver to x86 folder.
- Remove syscon usage.
- Remove regmap based access. Use direct readl()/write() instead. Add spinlocks.
- Change all enum values to capitals.
- Rename all data structures & functions from intel_* to lgm_*.
- Remove multiple header files. Keep only one header file.
- Make probe fail when any of the clk/pll registration fails.
- Fix few bugs with clk_init_data assignement.
- Address review concerns for code quality/style/convention.

v1:
- Initial version.

Rahul Tanwar (1):
dt-bindings: clk: intel: Add bindings document & header file for CGU

rtanwar (1):
clk: intel: Add CGU clock driver for a new SoC

 .../devicetree/bindings/clock/intel,cgu-lgm.yaml   |  44 ++
 drivers/clk/Kconfig                                |   1 +
 drivers/clk/x86/Kconfig                            |   8 +
 drivers/clk/x86/Makefile                           |   1 +
 drivers/clk/x86/clk-cgu-pll.c                      | 156 +++++
 drivers/clk/x86/clk-cgu.c                          | 636 +++++++++++++++++++++
 drivers/clk/x86/clk-cgu.h                          | 335 +++++++++++
 drivers/clk/x86/clk-lgm.c                          | 492 ++++++++++++++++
 include/dt-bindings/clock/intel,lgm-clk.h          | 165 ++++++
 9 files changed, 1838 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/intel,cgu-lgm.yaml
 create mode 100644 drivers/clk/x86/Kconfig
 create mode 100644 drivers/clk/x86/clk-cgu-pll.c
 create mode 100644 drivers/clk/x86/clk-cgu.c
 create mode 100644 drivers/clk/x86/clk-cgu.h
 create mode 100644 drivers/clk/x86/clk-lgm.c
 create mode 100644 include/dt-bindings/clock/intel,lgm-clk.h

2.11.0

Clock generation unit(CGU) is a clock controller IP of Intel's Lightning Mountain(LGM) SoC. Add DT bindings include file and document for CGU clock controller driver of LGM.

---
 .../devicetree/bindings/clock/intel,cgu-lgm.yaml   |  44 ++++++
 include/dt-bindings/clock/intel,lgm-clk.h          | 165 +++++++++++++++++++++
 2 files changed, 209 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/intel,cgu-lgm.yaml
 create mode 100644 include/dt-bindings/clock/intel,lgm-clk.h

new file mode 100644
index 000000000000..6dc1414bfb7f
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/intel,cgu-lgm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Intel Lightning Mountain SoC's Clock Controller(CGU) Binding
+
+maintainers:
+  - Rahul Tanwar <[email protected]>
+
+description: |
+  Lightning Mountain(LGM) SoC's Clock Generation Unit(CGU) driver provides
+  all means to access the CGU hardware module in order to generate a series
+  of clocks for the whole system and individual peripherals.
+
+  Please refer to include/dt-bindings/clock/intel,lgm-clk.h header file, it
+  defines all available clocks as macros. These macros can be used in device
+  tree sources.
+
+properties:
+  compatible:
+    const: intel,cgu-lgm
+
+  reg:
+    maxItems: 1
+
+  '#clock-cells':
+    const: 1
+
+required:
+  - compatible
+  - reg
+  - '#clock-cells'
+
+examples:
+  - |
+    cgu: clock-controller@e0200000 {
+        compatible = "intel,cgu-lgm";
+        reg = <0xe0200000 0x33c>;
+        #clock-cells = <1>;
+    };
+
+...

2.11.0

From: rtanwar <[email protected]>

Clock Generation Unit(CGU) is a new clock controller IP of a forthcoming Intel network processor SoC named Lightning Mountain(LGM). It provides programming interfaces to control & configure all CPU & peripheral clocks. Add common clock framework based clock controller driver for CGU.

---
 drivers/clk/Kconfig           |   1 +
 drivers/clk/x86/Kconfig       |   8 +
 drivers/clk/x86/Makefile      |   1 +
 drivers/clk/x86/clk-cgu-pll.c | 156 +++++++++++
 drivers/clk/x86/clk-cgu.c     | 636 ++++++++++++++++++++++++++++++++++++++++++
 drivers/clk/x86/clk-cgu.h     | 335 ++++++++++++++++++++++
 drivers/clk/x86/clk-lgm.c     | 492 ++++++++++++++++++++++++++++++++
 7 files changed, 1629 insertions(+)
 create mode 100644 drivers/clk/x86/Kconfig
 create mode 100644 drivers/clk/x86/clk-cgu-pll.c
 create mode 100644 drivers/clk/x86/clk-cgu.c
 create mode 100644 drivers/clk/x86/clk-cgu.h
 create mode 100644 drivers/clk/x86/clk-lgm.c

index bcb257baed06..43dab257e7aa 100644
@@ -360,6 +360,7 @@ source "drivers/clk/sunxi-ng/Kconfig"
 source "drivers/clk/tegra/Kconfig"
 source "drivers/clk/ti/Kconfig"
 source "drivers/clk/uniphier/Kconfig"
+source "drivers/clk/x86/Kconfig"
 source "drivers/clk/zynqmp/Kconfig"
 
 endmenu

new file mode 100644
index 000000000000..69642e15fcc1
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config CLK_LGM_CGU
+	depends on OF && HAS_IOMEM && (X86 || COMPILE_TEST)
+	select OF_EARLY_FLATTREE
+	bool "Clock driver for Lightning Mountain(LGM) platform"
+	help
+	  Clock Generation Unit(CGU) driver for Intel Lightning Mountain(LGM)
+	  network processor SoC.

index e3ec81e2a1c2..7c774ea7ddeb 100644
@@ -3,3 +3,4 @@ obj-$(CONFIG_PMC_ATOM)		+= clk-pmc-atom.o
 obj-$(CONFIG_X86_AMD_PLATFORM_DEVICE)	+= clk-st.o
 clk-x86-lpss-objs		:= clk-lpt.o
 obj-$(CONFIG_X86_INTEL_LPSS)	+= clk-x86-lpss.o
+obj-$(CONFIG_CLK_LGM_CGU)	+= clk-cgu.o clk-cgu-pll.o clk-lgm.o

2.11.0

Hi Stephen Boyd,

After few rounds of review comments/updates from you & other reviewers, this patch series seems to be lost :-\. No further review concerns or acks from past 2 months.

I am wondering if this is due to any outstanding concerns/expectations or it is just bad luck. Since you are the clk maintainer, may i ask you to clarify what is it that i am missing. Thanks.

Regards,
Rahul